//! The `pkh new` interactive wizard.
//!
//! [`run`] is the single entry point: on an interactive terminal it asks the
//! questions of the spec's "Proposed UX" transcript, fills a
//! [`NewCli`] with the answers (explicit flags are never re-asked), and
//! reuses [`options::resolve`] as the single source of truth for defaults,
//! detection and validation — so the non-interactive and interactive paths
//! cannot drift apart. Without a terminal (or with `--defaults`) it goes
//! straight through [`options::resolve`], whose error lists every missing
//! answer.
//!
//! After the summary screen is confirmed, the wizard offers the two
//! verification builds of the spec ([`offer_verification`]); a failed
//! verification never undoes the scaffold.
//!
//! The prompt calls live in `run_wizard` and `offer_verification` only;
//! everything else in this module is pure and unit-tested.

use std::error::Error;
use std::io::IsTerminal;
use std::path::PathBuf;

use indicatif::MultiProgress;

use crate::new::detect::{self, Detection};
use crate::new::git;
use crate::new::licenses;
use crate::new::options::{self, NewCli, NewOptions, SourceDir, SourceFormat, TemplateId};
use crate::new::origin::GitOrigin;
use crate::new::templates::{self, ProbeResult, ScaffoldOutcome};
use crate::ui::prompt;

/// Answer of the "where is the source code?" question: fresh skeleton.
const SOURCE_SKELETON: &str = "Create a new project skeleton here";
/// Answer of the "where is the source code?" question: this directory.
const SOURCE_HERE: &str = "Package the sources in this directory";
/// Answer of the "where is the source code?" question: another directory.
const SOURCE_PATH: &str = "Package the sources in another directory…";

/// The "everything else" entry of the license menu.
const LICENSE_OTHER: &str = "Other (enter a SPDX identifier)";

/// Labels of the interactive `select` questions. `prompt::select` renders
/// `> <label><answer>` verbatim — unlike [`prompt::text`], it appends no
/// formatting of its own — so each label carries its own separator:
/// field-style prompts end with `": "`, question-style ones with `"? "`.
const LANGUAGE_LABEL: &str = "Which language/build system is your program using? ";
const SOURCE_LABEL: &str = "Where is the source code? ";
const LICENSE_LABEL: &str = "License: ";
const DIST_LABEL: &str = "Target distribution: ";
const SERIES_LABEL: &str = "Target series: ";
const ORIG_LABEL: &str = "Where should the orig tarball come from? ";

/// All select labels, so the separator test can check them in one place.
#[cfg(test)]
const SELECT_LABELS: [&str; 6] = [
    LANGUAGE_LABEL,
    SOURCE_LABEL,
    LICENSE_LABEL,
    DIST_LABEL,
    SERIES_LABEL,
    ORIG_LABEL,
];

/// Run the `pkh new` flow: the wizard on an interactive terminal, plain
/// [`options::resolve`] otherwise (and with `--defaults`).
pub async fn run(cli: NewCli) -> Result<NewOptions, Box<dyn Error>> {
    if cli.defaults || !is_interactive() {
        return Ok(options::resolve(cli).await?);
    }
    run_wizard(cli).await
}

/// Whether both ends of the terminal are interactive; the wizard and the
/// verification offers only run when this holds (the prompts' non-TTY
/// fallbacks would otherwise silently take defaults).
fn is_interactive() -> bool {
    std::io::stdin().is_terminal() && std::io::stdout().is_terminal()
}

/// The wizard question flow (spec "Proposed UX"), in order:
/// package name, language/build system, source location, upstream version
/// (with the checkout-tag offer when the version names an existing tag),
/// the orig-tarball origin (quilt + existing project only), Debian
/// revision, one-line description, homepage, license, command name,
/// maintainer, target distribution, target series, metapackage Depends
/// (`empty` template only), git init — then the summary screen and the
/// final `Generate?` confirmation. Every question with an explicit flag
/// answer is skipped (flag > detected/probe > default merge order).
async fn run_wizard(mut cli: NewCli) -> Result<NewOptions, Box<dyn Error>> {
    let cwd = std::env::current_dir()?;
    let mut detect_dir = cli.source.clone().unwrap_or_else(|| cwd.clone());
    let (detection, mut probe) = detect_and_probe(&detect_dir);
    // Whether the flags imply a fresh skeleton (name given, no --source).
    let implied_skeleton = cli.source.is_none() && cli.name.is_some();
    // Whether the language question is skipped by a confident detection
    // (only when packaging the detected directory, never for a skeleton).
    let detection_decides = matches!(detection, Detection::Single(_)) && !implied_skeleton;

    // 1. Package name: the detected project name, else the sanitized
    //    basename of the current directory.
    if cli.name.is_none() {
        let default = default_package_name(&cwd, probe.as_ref());
        let answer = ask_text("Package name", &default, options::validate_source_name)?;
        cli.name = Some(answer);
    }

    // 2. Language / build system. An explicit `--lang` wins over any
    //    detection (flag > detected/probe > default): it is never
    //    overwritten and the question is never re-asked — the detection is
    //    only logged for information.
    match language_choice(cli.lang.as_deref(), &detection, detection_decides) {
        LanguageChoice::Flag => match &detection {
            Detection::Single(id) => log::info!(
                "Detected: {} project in {}; --lang takes precedence",
                id.display_name(),
                detect_dir.display()
            ),
            Detection::Ambiguous(candidates) => log::info!(
                "Several build systems found in {} ({}); --lang takes \
                 precedence",
                detect_dir.display(),
                candidates
                    .iter()
                    .map(|id| id.as_str())
                    .collect::<Vec<_>>()
                    .join(", ")
            ),
            Detection::Empty => {}
        },
        LanguageChoice::Detected(id) => {
            log::info!(
                "Detected: {} project in {}",
                id.display_name(),
                detect_dir.display()
            );
            cli.lang = Some(id.as_str().to_string());
        }
        LanguageChoice::Ask(preselected) => {
            let menu = language_menu(&[]);
            let default = preselected
                .unwrap_or(TemplateId::EMPTY)
                .display_name()
                .to_string();
            let id = select_template(&menu, &default)?;
            cli.lang = Some(id.as_str().to_string());
        }
        LanguageChoice::Ambiguous(candidates) => {
            log::info!(
                "Several build systems found in {} ({}): candidates listed \
                 first, the highest-precedence one preselected",
                detect_dir.display(),
                candidates
                    .iter()
                    .map(|id| id.as_str())
                    .collect::<Vec<_>>()
                    .join(", ")
            );
            let menu = language_menu(&candidates);
            let id = select_template(&menu, &menu[0])?;
            cli.lang = Some(id.as_str().to_string());
        }
    }
    let template = TemplateId::parse(cli.lang.as_deref().unwrap_or_default())?;

    // The rust toolchain pin of the packaged project does not travel into
    // the chroot build: surface it now so a too-old pin is not a surprise
    // when `pkh deb` compiles with the distribution's rustc.
    let toolchain_pin = if template == TemplateId::RUST {
        probe.as_ref().and_then(|p| p.toolchain_pin.clone())
    } else {
        None
    };
    if let Some(pin) = &toolchain_pin {
        log::info!(
            "Project pins rust {pin} via rust-toolchain.toml; the chroot \
             build uses the distribution's rustc and ignores the pin — \
             adjust or remove it if the code needs newer compiler features"
        );
    }

    // 3. Source location. Skipped (with the inline notice) when a confident
    //    detection already decided to package the current directory; a
    //    --source flag skips it too.
    if cli.source.is_none() && !detection_decides {
        let options = vec![
            SOURCE_SKELETON.to_string(),
            SOURCE_HERE.to_string(),
            SOURCE_PATH.to_string(),
        ];
        let default = if implied_skeleton {
            SOURCE_SKELETON
        } else {
            SOURCE_HERE
        };
        let answer = select_from(SOURCE_LABEL, &options, default, |answer| {
            options.contains(&answer.to_string())
        })?;
        if answer == SOURCE_HERE {
            cli.source = Some(cwd.clone());
        } else if answer == SOURCE_PATH {
            let validator = |path: &str| validate_directory_answer(path);
            let path = prompt::text("Source directory", "", Some(&validator))?;
            cli.source = Some(PathBuf::from(path));
        }
        // SOURCE_SKELETON: cli.source stays unset (the name decides).
    } else if cli.source.is_none() {
        cli.source = Some(cwd.clone());
    }

    // The source format this run will produce: explicit flags win, then the
    // mode (skeleton → native, existing project → quilt). The wizard
    // surfaces it in the summary; `options::resolve` re-derives it the same
    // way for the non-interactive path.
    let source_format = match (cli.native, cli.quilt) {
        (true, true) => {
            return Err("--native and --quilt are mutually exclusive".into());
        }
        (true, false) => SourceFormat::Native,
        (false, true) => SourceFormat::Quilt,
        (false, false) => {
            if cli.source.is_none() {
                SourceFormat::Native
            } else {
                SourceFormat::Quilt
            }
        }
    };

    // Git origin of the packaged directory: drives the version default, the
    // checkout-tag offer and the orig-tarball question. Purely local.
    let packaged_dir = cli.source.clone();
    let mut origin = packaged_dir.as_deref().and_then(GitOrigin::detect);

    // The probe data read above describes `detect_dir` — the cwd unless
    // `--source` pointed somewhere. When the source-location answer just
    // redirected the wizard to another directory, re-run the detection +
    // probe there (the same code path as the initial pass) so every
    // following probe-derived default — upstream version, description,
    // homepage, license, command, the pkg-config hint — describes the
    // project actually being packaged. The detected directory itself is
    // never re-probed (the data is already fresh and the scan is not free),
    // and explicit flags keep winning throughout: the probe only ever feeds
    // the defaults of questions without a flag answer.
    if let Some(chosen) = packaged_dir.as_deref()
        && !same_directory(chosen, &detect_dir)
    {
        let (_, refreshed) = detect_and_probe(chosen);
        probe = refreshed;
        // The license sniff and the pkg-config hint read the same directory
        // the probe data now comes from.
        detect_dir = chosen.to_path_buf();
    }

    // 4. Upstream version: probed project version, then the tag HEAD sits
    //    on, then `<lasttag>+git<YYYYMMDD>.<hash>`, then 0.1.0. A raw probe
    //    that fails `validate_upstream_version` (e.g. `1.0-2` or `v1.0`) is
    //    not offered as the default — the same validator `resolve` applies
    //    decides, so Enter can never accept it and crash late.
    if cli.upstream_version.is_none() {
        let default = probe
            .as_ref()
            .and_then(|p| p.version.clone())
            .or_else(|| origin.as_ref().and_then(GitOrigin::head_tag_version))
            .or_else(|| origin.as_ref().and_then(GitOrigin::git_version))
            .unwrap_or_else(|| "0.1.0".to_string());
        let revision = cli.revision.unwrap_or(1);
        let validate = move |version: &str| options::validate_upstream_version(version, revision);
        let answer = ask_text("Upstream version", &default, validate)?;
        cli.upstream_version = Some(answer.clone());

        // The typed version names an existing tag HEAD is not on: offer to
        // check the release out (the packaging then matches the version).
        if let Some(origin_state) = &origin
            && let Some(tag) = origin_state.tag_for_version(&answer)
            && Some(tag) != origin_state.head_tag.as_deref()
        {
            let question = format!(
                "Version {answer} matches tag {tag}, but HEAD is not that \
                 tag. Check out {tag} now?"
            );
            if prompt::confirm(&question, false)? {
                let dir = packaged_dir.as_deref().expect("origin implies a directory");
                crate::new::origin::checkout_tag(dir, tag)?;
                log::info!(
                    "Checked out {tag} (detached HEAD — expected when \
                     packaging a release)"
                );
                // HEAD moved: the release/git-archive choices below must
                // reflect the checkout.
                origin = GitOrigin::detect(dir);
            }
            // Declined (or non-TTY): keep the current tree and the typed
            // version.
        }
    }

    // 4b. Orig-tarball origin (quilt + existing project only): one select
    //     question, options pre-ordered by what the detection found. The
    //     release download is explicit network consent; a skeleton quilt
    //     tree has no upstream history and is only ever snapshotted.
    if source_format == SourceFormat::Quilt && packaged_dir.is_some() {
        let choices = orig_origin_choices(origin.as_ref());
        let labels: Vec<String> = choices.iter().map(|(label, _)| label.clone()).collect();
        let head_tagged = origin
            .as_ref()
            .and_then(|o| o.head_tag.as_deref())
            .is_some();
        let default = if head_tagged {
            labels[0].clone()
        } else {
            "Snapshot this working tree".to_string()
        };
        let answer = select_from(ORIG_LABEL, &labels, &default, |answer| {
            labels.contains(&answer.to_string())
        })?;
        let chosen = choices
            .iter()
            .find(|(label, _)| label == &answer)
            .map(|(_, value)| *value)
            .expect("answer comes from the choice list");
        cli.orig_from = Some(chosen.to_string());
        if chosen == "path" {
            let validator = |path: &str| options::validate_orig_path(path);
            let path = prompt::text("Tarball path or URL", "", Some(&validator))?;
            cli.orig_path = Some(path);
        }
    }

    // 5. Debian revision.
    if cli.revision.is_none() {
        let answer = ask_text("Debian revision", "1", validate_revision_answer)?;
        cli.revision = answer.parse::<u32>().ok();
    }

    // 6. One-line description (required: an empty answer re-asks).
    if cli.description.is_none() {
        let default = probe
            .as_ref()
            .and_then(|p| p.description.clone())
            .unwrap_or_default();
        let validate = required_answer("the description");
        let answer = ask_text("One-line description", &default, validate)?;
        cli.description = Some(answer);
    }

    // 7. Homepage (blank skips; a probed default must still be a valid URL).
    if cli.homepage.is_none() {
        let default = probe
            .as_ref()
            .and_then(|p| p.homepage.clone())
            .unwrap_or_default();
        let validate = |url: &str| {
            if url.is_empty() {
                Ok(())
            } else {
                options::validate_homepage(url)
            }
        };
        let answer = ask_text("Homepage (blank to skip)", &default, validate)?;
        if !answer.is_empty() {
            cli.homepage = Some(answer);
        }
    }

    // 8. License: curated SPDX menu plus a free-text entry. The default
    //    comes from the project metadata (Cargo.toml / pyproject.toml), then
    //    from sniffing the LICENSE/COPYING file.
    if cli.license.is_none() {
        let detected = probe
            .as_ref()
            .and_then(|p| p.license.clone())
            .or_else(|| detect::sniff_license(&detect_dir));
        let (default, custom_default) = license_question_default(detected.as_deref());
        let options = license_menu();
        let answer = select_from(LICENSE_LABEL, &options, &default, |answer| {
            options.contains(&answer.to_string())
        })?;
        if answer == LICENSE_OTHER {
            let validate = required_answer("the license identifier");
            let license = ask_text("License (SPDX identifier)", &custom_default, validate)?;
            cli.license = Some(license);
        } else {
            cli.license = Some(answer);
        }
    }

    // 9. Command name (skipped for the empty template, where nothing is
    //    installed). Typed answers and the offered default go through the
    //    same `validate_command` bar as `resolve` applies (which also
    //    requires a non-empty answer), so an unusable probe is withheld and
    //    invalid input re-asks here instead of failing late in `resolve`.
    if cli.command.is_none() && template != TemplateId::EMPTY {
        let default = probe
            .as_ref()
            .and_then(|p| p.command.clone())
            .unwrap_or_else(|| cli.name.clone().unwrap_or_default());
        let command = ask_text("Command name", &default, options::validate_command)?;
        cli.command = Some(command);
    }

    // 10. Maintainer, defaulting to the DEBEMAIL/git-config identity. The
    //     git-derived default goes through `parse_maintainer` like typed
    //     input: an empty git user.email yields a `Name <>` default that is
    //     ignored (the question is asked without one) instead of accepted
    //     verbatim and only failing late in `resolve`. An empty answer
    //     re-asks.
    if cli.maintainer.is_none() {
        let candidate = crate::changelog::get_maintainer_info()
            .map(|(name, email)| format!("{name} <{email}>"))
            .unwrap_or_default();
        let default = if options::parse_maintainer(&candidate).is_ok() {
            candidate
        } else {
            String::new()
        };
        if default.is_empty() {
            log::warn!(
                "Could not determine a maintainer default (no DEBFULLNAME/\
                 DEBEMAIL and no git user config): answer as 'Name <email>'"
            );
        }
        let validate = |answer: &str| options::parse_maintainer(answer).map(|_| ());
        cli.maintainer = Some(ask_text("Maintainer", &default, validate)?);
    }

    // 11. Target distribution. The menu derives from the distro data pkh
    //     ships (sorted); ubuntu is moved to the front when present so it
    //     stays the menu's first entry and fallback default as it has always
    //     been — prompt::select positions on a default value, not an index.
    if cli.dist.is_none() {
        let vendor = crate::build::env::current_vendor().to_lowercase();
        let mut options = crate::distro_info::supported_dists();
        if let Some(pos) = options.iter().position(|d| d == "ubuntu")
            && pos > 0
        {
            let ubuntu = options.remove(pos);
            options.insert(0, ubuntu);
        }
        let default = if options.contains(&vendor) {
            vendor
        } else {
            "ubuntu".to_string()
        };
        let answer = select_from(DIST_LABEL, &options, &default, |answer| {
            options.contains(&answer.to_string())
        })?;
        cli.dist = Some(answer);
    }
    let dist = cli
        .dist
        .clone()
        .unwrap_or_else(|| crate::build::env::current_vendor().to_lowercase());

    // 12. Target series: the development series first, preselected.
    if cli.series.is_none() {
        match crate::distro_info::get_ordered_series_name(&dist).await {
            Ok(series) if !series.is_empty() => {
                let answer = prompt::select(SERIES_LABEL, &series, &series[0])?;
                cli.series = Some(answer);
            }
            _ => {
                log::warn!(
                    "Could not fetch the series list for '{dist}'; \
                     defaulting to its development series"
                );
            }
        }
    }

    // 13. Metapackage Depends (empty template only).
    if template == TemplateId::EMPTY && cli.depends.is_empty() {
        let validate = |answer: &str| options::validate_depends(answer).map(|_| ());
        let answer = ask_text(
            "Depends (metapackage, comma-separated, blank for an empty base)",
            "",
            validate,
        )?;
        if !answer.trim().is_empty() {
            cli.depends = vec![answer];
        }
    }

    // 14. Git init — asked only when a git init would actually happen
    //     (outside any repository, without `--no-git`). Inside an existing
    //     git work tree there is nothing to initialize: the question is
    //     skipped, the run assumes No and the scaffold logs its usual skip
    //     (the .gitignore files are written regardless). The probe looks at
    //     the packaged directory — or, for a skeleton, at the directory it
    //     would be created in.
    let probe_dir = cli.source.clone().unwrap_or_else(|| cwd.clone());
    let inside_repo = cli.git && git::inside_work_tree(&probe_dir);
    if git_init_answer(!cli.git, inside_repo).is_some() {
        // `--no-git` already declined, or there is nothing to initialize.
        cli.git = false;
    } else {
        cli.git = prompt::confirm("Initialize a git repository?", cli.git)?;
    }

    // Resolve through the same pipeline as the non-interactive path: one
    // source of truth for defaults and validation.
    let mut opts = options::resolve(cli).await?;

    // The meson/cmake opt-in question of the spec's template table: does the
    // build resolve libraries through pkg-config? The project files prefill
    // the default (dependency() / pkg_check_modules calls found).
    if matches!(template, TemplateId::MESON | TemplateId::CMAKE)
        && prompt::confirm(
            "Does the build resolve libraries through pkg-config (add it to Build-Depends)?",
            pkg_config_hint(&detect_dir, template),
        )?
    {
        opts.pkg_config = true;
    }

    // Wizard-only extras (default off).
    if template != TemplateId::EMPTY
        && prompt::confirm(
            "Add an autopkgtest smoke test (debian/tests/control)?",
            false,
        )?
    {
        opts.autopkgtest = true;
    }
    if let Some(watch) = watch_template(opts.homepage.as_deref())
        && prompt::confirm("Add a debian/watch release watcher?", false)?
    {
        opts.watch = Some(watch);
    }

    // Summary screen + final confirmation: Ctrl+C or 'n' abort with
    // nothing written (generation is all-or-nothing later anyway).
    println!("{}", summary_text(&opts, toolchain_pin.as_deref()));
    if !prompt::confirm("Generate?", true)? {
        return Err("Aborted: nothing was written to disk.".into());
    }

    Ok(opts)
}

/// The post-scaffold verification offers (spec "Verification" steps 2–3),
/// interactive only and skipped with `--no-verify`: the source build
/// (`pkh build`, offered yes) and the binary build (`pkh deb`, offered no —
/// it needs network + build deps). A failed verification build never undoes
/// the scaffold: the error is printed together with the manual next steps.
///
/// When the scaffold's vendoring step failed (`outcome`), a prominent notice
/// states that the tree will not build until the dependencies are vendored —
/// printed with or without a TTY — and the build offer is reworded with its
/// default flipped to *no*.
pub async fn offer_verification(
    opts: &NewOptions,
    outcome: &ScaffoldOutcome,
    multi: &MultiProgress,
    no_verify: bool,
) {
    let tree = opts.target_dir(&std::env::current_dir().unwrap_or_default());
    let display = crate::ui::display_path(&tree);
    let display = if display.is_empty() {
        ".".to_string()
    } else {
        display
    };

    if outcome.vendoring_failed {
        // Set apart from the surrounding success output by blank lines: a
        // single warning between two success lines is easy to miss.
        println!();
        log::warn!(
            "The Cargo dependencies could NOT be vendored: this package will \
             not build until the vendoring is completed by hand:\n\
             \x20 1. `cd {display} && cargo vendor`\n\
             \x20 2. add the printed source replacement to .cargo/config.toml, \
             plus `[net] offline = true`"
        );
        println!();
    }

    if no_verify || !is_interactive() {
        return;
    }

    let build_offer = if outcome.vendoring_failed {
        "Verify with `pkh build` now? (it will fail until dependencies are vendored)"
    } else {
        "Verify with `pkh build` now?"
    };
    let verify_source = match prompt::confirm(build_offer, !outcome.vendoring_failed) {
        Ok(answer) => answer,
        Err(_) => return,
    };
    if !verify_source {
        return;
    }

    let ui = Some(std::sync::Arc::new(crate::ui::deb::DebUi::new(multi)));
    if let Err(e) = crate::build::build_source_package(
        Some(&tree),
        crate::build::SourceBuildOptions::default(),
        ui,
    ) {
        log::error!("Verification source build failed: {e}");
        log::info!(
            "The scaffolded tree is intact. Inspect it, then retry with \
             `cd {display} && pkh build`."
        );
        log::info!(
            "Hint: failures here usually come from a missing build dependency \
             or build file, not from the scaffold itself; check debian/control \
             and the template's build file."
        );
        return;
    }

    let verify_deb = match prompt::confirm(
        "Verify with `pkh deb` now? (needs network + build deps)",
        false,
    ) {
        Ok(answer) => answer,
        Err(_) => return,
    };
    if !verify_deb {
        return;
    }

    let ui = Some(std::sync::Arc::new(crate::ui::deb::DebUi::new(multi)));
    if let Err(e) = crate::deb::build_binary_package(
        None,
        Some(&opts.series),
        None,
        Some(&tree),
        false,
        None,
        None,
        None,
        None,
        ui,
        None,
    )
    .await
    {
        log::error!("Verification binary build failed: {e}");
        log::info!(
            "The scaffolded tree is intact. Once the build dependencies are \
             available, retry with `cd {display} && pkh deb`."
        );
        log::info!(
            "Hint: when a build dependency is missing from the {} archive, \
             `pkh deb --inject <package>` makes it available in the build \
             environment (e.g. a PEP 517 backend like python3-poetry-core).",
            opts.series
        );
    }
}

/// Detection + template probe of one candidate directory: the probe data
/// exists only for a confidently detected single-template project. The one
/// code path for both wizard passes — the initial sweep of the detected
/// directory and the re-probe when the source-location answer redirects the
/// wizard elsewhere.
fn detect_and_probe(dir: &std::path::Path) -> (Detection, Option<ProbeResult>) {
    let detection = detect::detect(dir);
    let probe = match &detection {
        Detection::Single(id) => templates::get(*id).and_then(|t| t.probe(dir)),
        _ => None,
    };
    (detection, probe)
}

/// Whether two paths name the same directory: lexical equality first, then
/// (for spellings like `.` next to the absolute cwd) the canonicalized
/// forms. A path that cannot be canonicalized only ever equals itself.
fn same_directory(a: &std::path::Path, b: &std::path::Path) -> bool {
    if a == b {
        return true;
    }
    match (a.canonicalize(), b.canonicalize()) {
        (Ok(a), Ok(b)) => a == b,
        _ => false,
    }
}

/// The preselected default of the pkg-config opt-in question: whether the
/// project's build file hints at pkg-config usage (`dependency(` in
/// meson.build, `pkg_check_modules` / `find_package(PkgConfig` in
/// CMakeLists.txt).
fn pkg_config_hint(dir: &std::path::Path, template: TemplateId) -> bool {
    let (file, needles): (&str, &[&str]) = match template {
        TemplateId::MESON => ("meson.build", &["dependency("]),
        TemplateId::CMAKE => (
            "CMakeLists.txt",
            &[
                "pkg_check_modules",
                "find_package(pkgconfig",
                "find_package(pkg_config",
            ],
        ),
        _ => return false,
    };
    std::fs::read_to_string(dir.join(file))
        .map(|content| {
            let lower = content.to_ascii_lowercase();
            needles.iter().any(|needle| lower.contains(needle))
        })
        .unwrap_or(false)
}

/// The default package name: the detected project's name, else the
/// sanitized basename of the current directory.
fn default_package_name(cwd: &std::path::Path, probe: Option<&ProbeResult>) -> String {
    probe
        .and_then(|p| p.name.as_deref())
        .and_then(options::sanitize_name)
        .or_else(|| {
            cwd.file_name()
                .and_then(std::ffi::OsStr::to_str)
                .and_then(options::sanitize_name)
        })
        .unwrap_or_default()
}

/// The language menu: detected candidates first (in their detection order),
/// then every other template in registry order.
fn language_menu(candidates: &[TemplateId]) -> Vec<String> {
    candidates
        .iter()
        .copied()
        .chain(
            TemplateId::all()
                .iter()
                .copied()
                .filter(|id| !candidates.contains(id)),
        )
        .map(|id| id.display_name().to_string())
        .collect()
}

/// What the language step does with the detection result: how an explicit
/// `--lang` flag combines with it (flag > detected/probe > default).
#[derive(Debug, PartialEq, Eq)]
enum LanguageChoice {
    /// An explicit `--lang` wins: it is kept as-is, the question is never
    /// re-asked and the detection stays informational.
    Flag,
    /// No flag, confident detection, packaging the detected directory: the
    /// detection decides.
    Detected(TemplateId),
    /// Ask the question, preselecting the detected ecosystem (a skeleton
    /// was asked for); `None` when nothing was detected.
    Ask(Option<TemplateId>),
    /// Ask the question with the ambiguous candidates listed first (the
    /// highest-precedence one preselected).
    Ambiguous(Vec<TemplateId>),
}

/// The language step's decision for one wizard run. With the flag absent
/// this mirrors the historical behavior exactly; the flag always wins.
fn language_choice(
    flag: Option<&str>,
    detection: &Detection,
    detection_decides: bool,
) -> LanguageChoice {
    if flag.is_some() {
        return LanguageChoice::Flag;
    }
    match detection {
        Detection::Single(id) if detection_decides => LanguageChoice::Detected(*id),
        Detection::Single(id) => LanguageChoice::Ask(Some(*id)),
        Detection::Ambiguous(candidates) => LanguageChoice::Ambiguous(candidates.clone()),
        Detection::Empty => LanguageChoice::Ask(None),
    }
}

/// The license menu: the `menu` labels of the bundled license table
/// (`data/licenses.yml`) plus the free-text entry.
fn license_menu() -> Vec<String> {
    licenses::entries()
        .iter()
        .map(|entry| entry.menu.clone())
        .chain(std::iter::once(LICENSE_OTHER.to_string()))
        .collect()
}

/// The defaults of the license question for a probed SPDX identifier: the
/// matching curated entry (case-insensitive over the menu labels) is
/// preselected; anything else preselects the free-text entry prefilled with
/// the probe. Without a probe the curated list defaults to MIT (the first
/// menu entry of the bundled table).
fn license_question_default(probe_license: Option<&str>) -> (String, String) {
    match probe_license {
        Some(license) => {
            match licenses::entries()
                .iter()
                .find(|entry| entry.menu.eq_ignore_ascii_case(license))
            {
                Some(known) => (known.menu.clone(), String::new()),
                None => (LICENSE_OTHER.to_string(), license.to_string()),
            }
        }
        None => ("MIT".to_string(), String::new()),
    }
}

/// Ask the language question until a known template label (or CLI
/// identifier) is answered — the selector allows typing arbitrary text.
fn select_template(options: &[String], default: &str) -> Result<TemplateId, Box<dyn Error>> {
    loop {
        let answer = prompt::select(LANGUAGE_LABEL, options, default)?;
        match TemplateId::from_label(&answer) {
            Some(id) => return Ok(id),
            None => log::warn!(
                "'{answer}' is not a known template; pick one from the list \
                 (Tab completes its name)"
            ),
        }
    }
}

/// Ask a `select` question until `accept` holds for the answer (the
/// selector allows typing arbitrary text, which callers may need to reject).
fn select_from(
    label: &str,
    options: &[String],
    default: &str,
    accept: impl Fn(&str) -> bool,
) -> Result<String, Box<dyn Error>> {
    loop {
        let answer = prompt::select(label, options, default)?;
        if accept(&answer) {
            return Ok(answer);
        }
        log::warn!("'{answer}' is not one of the offered answers; pick from the list");
    }
}

/// The default a question is offered with: a probed default must clear the
/// same `validate` bar as typed input, so an unusable probe (e.g. an
/// upstream version like `1.0-2` carrying a Debian revision) is withheld —
/// the question is asked without a default instead of offering one that
/// Enter would accept verbatim.
fn offered_default<'a>(default: &'a str, validate: &prompt::Validator) -> &'a str {
    if default.is_empty() || validate(default).is_ok() {
        default
    } else {
        ""
    }
}

/// One round of [`ask_text`]: an empty answer takes the (pre-validated)
/// `default`, and whatever answer is finally proposed — typed or the
/// default — must pass `validate`. `Err` carries the validation error so the
/// caller re-asks with it.
fn accept_answer(
    answer: &str,
    default: &str,
    validate: &prompt::Validator,
) -> Result<String, String> {
    let answer = if answer.is_empty() { default } else { answer };
    validate(answer).map(|_| answer.to_string())
}

/// One free-text question implementing the spec's "Enter accepts the
/// default": an empty answer falls back to the default (`Esc` keeps its
/// prompt-level meaning of restoring it). Both the typed answer and the
/// default go through `validate`: a probed default that fails validation is
/// never offered ([`offered_default`]), and an empty answer without a valid
/// default is treated like any other invalid answer (re-ask with the
/// validation error) — probe data can never bypass validation and only blow
/// up later in [`options::resolve`].
fn ask_text(
    label: &str,
    default: &str,
    validate: impl Fn(&str) -> Result<(), String> + 'static,
) -> Result<String, Box<dyn Error>> {
    // The offered default must clear the same bar as typed input: an
    // unusable probe is withheld and the question is asked without one.
    let default = offered_default(default, &validate);
    // Enter/Esc (and the non-TTY fallback) return the default without
    // validation, so pre-decide what an empty answer yields: the default
    // itself (it passed the bar above), or the rejection it shares with any
    // invalid answer when no valid default exists. Computed here because
    // `validate` moves into the prompt wrapper below.
    let empty_answer = accept_answer("", default, &validate);
    let accept_empty = move |answer: &str| {
        if answer.is_empty() {
            Ok(())
        } else {
            validate(answer)
        }
    };
    loop {
        let answer = prompt::text(label, default, Some(&accept_empty))?;
        // Typed non-empty answers were already validated by the prompt; only
        // an empty one resolves to the default, pre-decided above.
        let answer = if answer.is_empty() {
            empty_answer.clone()
        } else {
            Ok(answer)
        };
        match answer {
            Ok(answer) => return Ok(answer),
            Err(error) => log::warn!("{error}"),
        }
    }
}

/// A validator requiring a non-empty answer.
fn required_answer(what: &str) -> impl Fn(&str) -> Result<(), String> + '_ {
    move |answer: &str| {
        if answer.trim().is_empty() {
            Err(format!("{what} must not be empty"))
        } else {
            Ok(())
        }
    }
}

/// Validator of the source-directory answer: an existing directory.
fn validate_directory_answer(path: &str) -> Result<(), String> {
    if path.trim().is_empty() {
        return Err("a directory path is required".to_string());
    }
    if std::path::Path::new(path).is_dir() {
        Ok(())
    } else {
        Err(format!("'{path}' is not a directory"))
    }
}

/// Validator of the Debian revision answer: a positive integer.
fn validate_revision_answer(answer: &str) -> Result<(), String> {
    match answer.parse::<u32>() {
        Ok(0) => Err("the Debian revision must be at least 1".to_string()),
        Ok(_) => Ok(()),
        Err(_) => Err(format!(
            "'{answer}' is not a valid Debian revision: expected a positive integer"
        )),
    }
}

/// The choices of the orig-tarball-origin question for a quilt packaging of
/// an existing directory: `(menu label, --orig-from value)` pairs,
/// pre-ordered by what the git origin detection found — the release
/// download and `git archive` only exist when HEAD sits exactly on a tag,
/// the release download additionally needs a recognized forge. The working
/// tree snapshot is always available (and is the implicit default when HEAD
/// is not on a tag).
fn orig_origin_choices(origin: Option<&GitOrigin>) -> Vec<(String, &'static str)> {
    let mut choices: Vec<(String, &'static str)> = Vec::new();
    if let Some(origin) = origin
        && let Some(tag) = &origin.head_tag
    {
        if let Some(forge) = &origin.forge {
            choices.push((
                format!(
                    "Download the upstream release tarball from {} ({tag})",
                    forge.host()
                ),
                "release",
            ));
        }
        choices.push((
            format!("Create it from the git tag ({tag}, git archive)"),
            "git",
        ));
    }
    choices.push(("Use a tarball I provide".to_string(), "path"));
    choices.push(("Snapshot this working tree".to_string(), "snapshot"));
    choices
}

/// The git-init answer when the question must not be asked: `Some(false)`
/// both for `--no-git` (already declined) and inside an existing git work
/// tree (nothing to initialize — the scaffold logs the skip and writes the
/// `.gitignore` files anyway). `None` asks the wizard question, i.e.
/// whenever a git init would actually happen (fresh skeleton or packaged
/// directory outside any repository).
fn git_init_answer(no_git: bool, inside_repo: bool) -> Option<bool> {
    (no_git || inside_repo).then_some(false)
}

/// A `debian/watch` template for GitHub/GitLab-hosted projects; `None` when
/// the homepage is not one of those hosts (the wizard skips the question).
pub fn watch_template(homepage: Option<&str>) -> Option<String> {
    let homepage = homepage?;
    let (scheme, path) = homepage.split_once("://")?;
    if scheme != "https" && scheme != "http" {
        return None;
    }
    let (host, repo_path) = path.split_once('/')?;
    let host = host.to_ascii_lowercase();
    if host != "github.com" && host != "gitlab.com" {
        return None;
    }
    let mut segments = repo_path.trim_end_matches('/').split('/');
    let owner = segments.next()?.trim_end_matches(".git");
    let repo = segments.next()?.trim_end_matches(".git");
    if owner.is_empty() || repo.is_empty() {
        return None;
    }
    Some(format!(
        "version=4\nhttps://{host}/{owner}/{repo}/releases .*/v?@ANY_VERSION@\\.tar\\.gz\n"
    ))
}

/// The pre-flight summary screen shown before the final `Generate?`
/// confirmation (spec transcript): identity line, template/license/maintainer
/// line, the generated-file overview and — for a metapackage — the Depends
/// payload, for a skeleton — the upstream files that will be created, and
/// for rust — the probed toolchain pin (when any; the chroot build ignores
/// it) plus a warning when dependencies cannot be vendored on this host.
pub fn summary_text(opts: &NewOptions, toolchain_pin: Option<&str>) -> String {
    let template = templates::get(opts.template);
    let mut lines = Vec::new();

    lines.push("────────────────────────────────────────────".to_string());
    lines.push(format!(
        "  {} {} · builds for {}/{}",
        opts.name,
        opts.full_version(),
        opts.dist,
        opts.series
    ));
    lines.push(format!(
        "  {} · {} · {} <{}>",
        opts.template.display_name(),
        opts.license.spdx(),
        opts.maintainer.0,
        opts.maintainer.1
    ));

    if let Some(template) = template {
        lines.push(format!(
            "  debian/control    Source + 1 binary (Architecture: {})",
            template.architecture(opts)
        ));
        if opts.template == TemplateId::EMPTY {
            // The Depends list is the payload of the metapackage flavor.
            if !opts.depends.is_empty() {
                lines.push(format!("  Depends           {}", opts.depends.join(", ")));
            }
        } else if opts.template == TemplateId::RUST {
            // Nothing is vendored yet at this point: only announce that the
            // generation will attempt it.
            lines.push(
                "  debian/rules      cargo build --release --offline (vendored at generation)"
                    .to_string(),
            );
            // A pinned rust-toolchain.toml does not reach the chroot build:
            // flagged here so a too-old pin is no surprise later.
            if let Some(pin) = toolchain_pin {
                lines.push(format!(
                    "  rust-toolchain    {pin} (ignored by the chroot build)"
                ));
            }
        } else {
            lines.push(format!("  debian/rules      {}", template.rules_dh_line()));
        }
    }
    lines.push(format!(
        "  debian/source/format {}",
        opts.source_format.deb_string()
    ));
    if let Some(orig) = &opts.orig {
        lines.push(format!("  orig tarball        {}", orig.label()));
    }
    let distribution = if opts.release {
        opts.series.as_str()
    } else {
        crate::distro_info::UNRELEASED
    };
    lines.push(format!(
        "  debian/changelog  {} {distribution}, Initial release",
        opts.full_version()
    ));
    lines.push(format!(
        "  debian/copyright  {} (DEP-5)",
        opts.license.spdx()
    ));
    if opts.autopkgtest {
        lines.push("  debian/tests      autopkgtest smoke test".to_string());
    }
    if opts.watch.is_some() {
        lines.push("  debian/watch      release watcher".to_string());
    }
    if matches!(opts.source_dir, SourceDir::Skeleton)
        && let Some(template) = template
    {
        let names: Vec<String> = template
            .skeleton(opts)
            .iter()
            .map(|file| file.path.clone())
            .collect();
        if !names.is_empty() {
            lines.push(format!("  + {} (new skeleton)", names.join(", ")));
        }
    }
    if opts.template == TemplateId::RUST && templates::find_on_path("cargo").is_none() {
        lines.push(
            "  ! cargo not found on PATH: dependencies cannot be vendored at \
             scaffold time; the package will not build until you run \
             `cargo vendor`"
                .to_string(),
        );
    }

    lines.join("\n")
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::new::options::License;
    use crate::new::options::TemplateId as Tid;

    fn opts(template: Tid) -> NewOptions {
        NewOptions {
            name: "mytool".into(),
            template,
            source_dir: options::SourceDir::Skeleton,
            upstream_version: "0.1.0".into(),
            revision: 1,
            summary: "A tool that does one thing well".into(),
            long_description: "A tool that does one thing well".into(),
            homepage: None,
            license: License::Mit,
            command: "mytool".into(),
            maintainer: ("Jane Doe".into(), "jane@example.com".into()),
            dist: "ubuntu".into(),
            series: "resolute".into(),
            release: false,
            depends: Vec::new(),
            source_format: options::SourceFormat::Native,
            orig: None,
            git: true,
            autopkgtest: false,
            pkg_config: false,
            watch: None,
        }
    }

    #[test]
    fn default_package_name_prefers_probe_then_basename() {
        let probe = ProbeResult {
            name: Some("My_Tool".to_string()),
            ..Default::default()
        };
        let cwd = std::path::Path::new("/home/user/projects");
        assert_eq!(
            default_package_name(cwd, Some(&probe)),
            "my-tool".to_string()
        );

        // No probe: the directory basename, sanitized.
        assert_eq!(
            default_package_name(std::path::Path::new("/tmp/My Tool"), None),
            "my-tool".to_string()
        );

        // Nothing sane anywhere: empty (the validator forces an answer).
        assert_eq!(default_package_name(std::path::Path::new("/"), None), "");
    }

    #[test]
    fn language_menu_lists_candidates_first() {
        let menu = language_menu(&[Tid::MAKEFILE, Tid::RUST]);
        assert_eq!(menu[0], "Generic (Makefile)");
        assert_eq!(menu[1], "Rust (Cargo.toml)");
        // The remaining seven follow in registry order, no duplicates.
        assert_eq!(menu.len(), Tid::all().len());
        let unique: std::collections::HashSet<&String> = menu.iter().collect();
        assert_eq!(unique.len(), menu.len());
    }

    /// An explicit `--lang` wins over any detection (the flag outranks the
    /// detection and the defaults): the flag is kept and the question is
    /// never re-asked, whatever the detection found (regression: a
    /// confident detection used to overwrite the flag and an ambiguous one
    /// re-asked the question).
    #[test]
    fn language_choice_flag_wins_over_detection() {
        let detections = [
            Detection::Single(Tid::RUST),
            Detection::Ambiguous(vec![Tid::RUST, Tid::PYTHON]),
            Detection::Empty,
        ];
        for detection in &detections {
            for decides in [false, true] {
                assert_eq!(
                    language_choice(Some("python"), detection, decides),
                    LanguageChoice::Flag,
                    "detection {detection:?}, decides {decides}"
                );
            }
        }
    }

    /// Without the flag the detection behaves exactly as before: it decides
    /// for a confident detection (packaging the detected directory), asks
    /// with a preselection for a skeleton run, lists the candidates first
    /// when ambiguous, and falls back to the plain menu otherwise.
    #[test]
    fn language_choice_without_flag_follows_detection() {
        assert_eq!(
            language_choice(None, &Detection::Single(Tid::RUST), true),
            LanguageChoice::Detected(Tid::RUST)
        );
        // Skeleton run: ask, preselecting the detected ecosystem.
        assert_eq!(
            language_choice(None, &Detection::Single(Tid::RUST), false),
            LanguageChoice::Ask(Some(Tid::RUST))
        );
        assert_eq!(
            language_choice(
                None,
                &Detection::Ambiguous(vec![Tid::GO, Tid::PYTHON]),
                true
            ),
            LanguageChoice::Ambiguous(vec![Tid::GO, Tid::PYTHON])
        );
        // Nothing detected: plain menu, the empty template preselected.
        assert_eq!(
            language_choice(None, &Detection::Empty, false),
            LanguageChoice::Ask(None)
        );
    }

    #[test]
    fn license_menu_and_defaults() {
        let menu = license_menu();
        assert_eq!(menu.len(), licenses::entries().len() + 1);
        assert_eq!(menu[0], "MIT");
        assert_eq!(menu.last().unwrap(), LICENSE_OTHER);

        // No probe: MIT preselected, no custom prefill.
        assert_eq!(
            license_question_default(None),
            ("MIT".to_string(), String::new())
        );
        // Curated probe: matched case-insensitively.
        assert_eq!(
            license_question_default(Some("apache-2.0")),
            ("Apache-2.0".to_string(), String::new())
        );
        // Unusual probe: free-text entry prefilled.
        assert_eq!(
            license_question_default(Some("Zlib")),
            (LICENSE_OTHER.to_string(), "Zlib".to_string())
        );
    }

    #[test]
    fn watch_template_hosts() {
        assert_eq!(
            watch_template(Some("https://github.com/foo/bar")),
            Some(
                "version=4\nhttps://github.com/foo/bar/releases .*/v?@ANY_VERSION@\\.tar\\.gz\n"
                    .to_string()
            )
        );
        assert_eq!(
            watch_template(Some("https://gitlab.com/foo/bar/")),
            Some(
                "version=4\nhttps://gitlab.com/foo/bar/releases .*/v?@ANY_VERSION@\\.tar\\.gz\n"
                    .to_string()
            )
        );
        // .git suffixes and deeper paths are handled.
        assert_eq!(
            watch_template(Some("https://github.com/foo/bar.git/tree")),
            Some(
                "version=4\nhttps://github.com/foo/bar/releases .*/v?@ANY_VERSION@\\.tar\\.gz\n"
                    .to_string()
            )
        );
        // Other hosts, no homepage, or no repo path: skipped.
        assert!(watch_template(Some("https://example.com/foo/bar")).is_none());
        assert!(watch_template(Some("https://github.com/foo")).is_none());
        assert!(watch_template(None).is_none());
    }

    /// The orig-origin choices are pre-ordered by what the detection found:
    /// release download only with a forge, git archive only on a tag,
    /// tarball/snapshot always; snapshot last (the off-tag default).
    #[test]
    fn orig_origin_choices_preorder_by_detection() {
        use crate::new::origin::Forge;
        let tagged_forge = GitOrigin {
            forge: Some(Forge::parse("https://github.com/foo/bar").unwrap()),
            head_tag: Some("v1.4.0".into()),
            ..Default::default()
        };
        let choices = orig_origin_choices(Some(&tagged_forge));
        assert_eq!(choices.len(), 4);
        assert_eq!(choices[0].1, "release");
        assert!(choices[0].0.contains("github.com"));
        assert!(choices[0].0.contains("v1.4.0"));
        assert_eq!(choices[1].1, "git");
        assert!(choices[1].0.contains("git archive"));
        assert_eq!(choices[2].1, "path");
        assert_eq!(choices[3].1, "snapshot");

        // Tag without a recognized forge: no download option.
        let tagged = GitOrigin {
            head_tag: Some("1.0.0".into()),
            ..Default::default()
        };
        let choices = orig_origin_choices(Some(&tagged));
        assert_eq!(choices.len(), 3);
        assert_eq!(choices[0].1, "git");
        assert_eq!(choices[1].1, "path");
        assert_eq!(choices[2].1, "snapshot");

        // Off a tag (or not even a repo): tarball + snapshot only.
        let off_tag = GitOrigin {
            last_tag: Some("v1.0.0".into()),
            ..Default::default()
        };
        let choices = orig_origin_choices(Some(&off_tag));
        assert_eq!(choices.len(), 2);
        assert_eq!(choices[0].1, "path");
        assert_eq!(choices[1].1, "snapshot");
        assert_eq!(orig_origin_choices(None).len(), 2);
    }

    /// The summary surfaces the derived source format and, for quilt, the
    /// planned orig origin.
    #[test]
    fn summary_screen_shows_format_and_orig_origin() {
        // Native skeleton: the format row, no orig row.
        let text = summary_text(&opts(Tid::SHELL), None);
        assert!(text.contains("debian/source/format 3.0 (native)"), "{text}");
        assert!(!text.contains("orig tarball"), "{text}");

        // Quilt over an existing project: both rows.
        let mut quilt = opts(Tid::SHELL);
        quilt.source_dir = options::SourceDir::Here;
        quilt.source_format = options::SourceFormat::Quilt;
        quilt.orig = Some(options::OrigOrigin::GitArchive {
            tag: "v1.4.0".to_string(),
        });
        let text = summary_text(&quilt, None);
        assert!(text.contains("debian/source/format 3.0 (quilt)"), "{text}");
        assert!(
            text.contains("orig tarball        git archive (v1.4.0)"),
            "{text}"
        );

        // The release-download label of the origin matrix.
        let mut release = quilt.clone();
        release.orig = Some(options::OrigOrigin::Release {
            tag: "v0.14.0".to_string(),
            forge: crate::new::origin::Forge::parse("https://gitlab.com/foo/bar").unwrap(),
        });
        let text = summary_text(&release, None);
        assert!(
            text.contains("orig tarball        release download (v0.14.0)"),
            "{text}"
        );
    }

    #[test]
    fn summary_screen_skeleton() {
        let text = summary_text(&opts(Tid::MAKEFILE), None);
        assert!(
            text.contains("mytool 0.1.0-1 · builds for ubuntu/resolute"),
            "{text}"
        );
        assert!(
            text.contains("Generic (Makefile) · MIT · Jane Doe <jane@example.com>"),
            "{text}"
        );
        assert!(
            text.contains("debian/control    Source + 1 binary (Architecture: any)"),
            "{text}"
        );
        assert!(text.contains("debian/rules      dh $@"), "{text}");
        assert!(
            text.contains("debian/changelog  0.1.0-1 UNRELEASED, Initial release"),
            "{text}"
        );
        assert!(text.contains("debian/copyright  MIT (DEP-5)"), "{text}");
        assert!(
            text.contains("+ hello.c, Makefile (new skeleton)"),
            "{text}"
        );
        // No extra files unless asked for.
        assert!(!text.contains("debian/tests"));
        assert!(!text.contains("debian/watch"));
    }

    #[test]
    fn summary_screen_metapackage_shows_depends() {
        let mut o = opts(Tid::EMPTY);
        o.depends = vec!["hello".to_string(), "hello-data (>= 1.0)".to_string()];
        o.source_dir = options::SourceDir::Here;
        let text = summary_text(&o, None);
        assert!(text.contains("Architecture: all"), "{text}");
        assert!(
            text.contains("Depends           hello, hello-data (>= 1.0)"),
            "{text}"
        );
        // Build info is replaced by the Depends payload; no skeleton line.
        assert!(!text.contains("debian/rules"), "{text}");
        assert!(!text.contains("(new skeleton)"), "{text}");
    }

    #[test]
    fn summary_screen_release_and_extras() {
        let mut o = opts(Tid::SHELL);
        o.release = true;
        o.autopkgtest = true;
        o.watch = Some("version=4\n".to_string());
        let text = summary_text(&o, None);
        assert!(text.contains("0.1.0-1 resolute, Initial release"), "{text}");
        assert!(
            text.contains("debian/tests      autopkgtest smoke test"),
            "{text}"
        );
        assert!(text.contains("debian/watch      release watcher"), "{text}");
    }

    /// The rust summary only announces the vendoring attempt of the
    /// generation, it must not assert an outcome that has not been tried
    /// yet (regression: it claimed "(vendored)" before generating).
    #[test]
    fn summary_screen_rust_does_not_presume_vendoring() {
        let text = summary_text(&opts(Tid::RUST), None);
        assert!(
            text.contains("cargo build --release --offline (vendored at generation)"),
            "{text}"
        );
        assert!(!text.contains("(vendored)"), "{text}");
    }

    /// A probed rust toolchain pin surfaces in the summary as its own row
    /// (rust template only), flagged as ignored by the chroot build.
    #[test]
    fn summary_screen_shows_the_toolchain_pin() {
        let text = summary_text(&opts(Tid::RUST), Some("1.98.0"));
        assert!(
            text.contains("rust-toolchain    1.98.0 (ignored by the chroot build)"),
            "{text}"
        );

        // No pin, no row.
        assert!(!summary_text(&opts(Tid::RUST), None).contains("rust-toolchain"));
        // A pin under a template other than rust is not shown either (the
        // pin only matters for a cargo build).
        assert!(!summary_text(&opts(Tid::GO), Some("1.98.0")).contains("rust-toolchain"));
    }

    /// The git-init question is only asked when a git init would actually
    /// happen: inside an existing work tree it is skipped with the assumed
    /// No (with or without `--no-git`), and `--no-git` has already answered
    /// it on its own.
    #[test]
    fn git_init_question_decision() {
        assert_eq!(git_init_answer(false, true), Some(false));
        assert_eq!(git_init_answer(true, true), Some(false));
        assert_eq!(git_init_answer(true, false), Some(false));
        // Outside any repository without --no-git: the wizard asks.
        assert_eq!(git_init_answer(false, false), None);
    }

    #[test]
    fn answer_validators() {
        assert!(validate_revision_answer("1").is_ok());
        assert!(validate_revision_answer("0").is_err());
        assert!(validate_revision_answer("x").is_err());

        assert!(validate_directory_answer("/tmp").is_ok());
        assert!(validate_directory_answer("").is_err());
        assert!(validate_directory_answer("/definitely/not/here").is_err());

        assert!(required_answer("x")("").is_err());
        assert!(required_answer("x")("ok").is_ok());
    }

    /// A probed upstream-version default must clear the same
    /// [`options::validate_upstream_version`] bar that `resolve` applies: a
    /// raw probe carrying a Debian revision or a `v` prefix fails it, so the
    /// wizard withholds it instead of offering it for blind Enter-acceptance
    /// and crashing late in `resolve` (regression).
    #[test]
    fn probed_version_defaults_fail_upstream_validation() {
        assert!(options::validate_upstream_version("1.0-2", 1).is_err());
        assert!(options::validate_upstream_version("v1.0", 1).is_err());
        assert!(options::validate_upstream_version("1.0.0", 1).is_ok());

        let validate = |version: &str| options::validate_upstream_version(version, 1);
        // Invalid probes are not offered as the default...
        assert_eq!(offered_default("1.0-2", &validate), "");
        assert_eq!(offered_default("v1.0", &validate), "");
        // ...clean probes keep theirs, and no default stays none.
        assert_eq!(offered_default("1.0.0", &validate), "1.0.0");
        assert_eq!(offered_default("", &validate), "");
    }

    /// [`accept_answer`] routes typed answers and Enter-taken defaults
    /// through the same validation: valid typed input accepted verbatim,
    /// invalid typed input rejected (re-ask), an empty answer taking a valid
    /// default, and an empty answer with an invalid or missing default
    /// rejected like any other invalid answer.
    #[test]
    fn accept_answer_validates_typed_answers_and_defaults() {
        let validate = |answer: &str| {
            if answer == "ok" {
                Ok(())
            } else {
                Err(format!("not ok: {answer}"))
            }
        };

        assert_eq!(accept_answer("ok", "ok", &validate), Ok("ok".to_string()));
        assert!(accept_answer("bad", "ok", &validate).is_err());

        // An empty answer takes the default, which must itself validate: an
        // invalid (or missing) default is rejected, not taken.
        assert_eq!(accept_answer("", "ok", &validate), Ok("ok".to_string()));
        assert!(accept_answer("", "bad", &validate).is_err());
        assert!(accept_answer("", "", &validate).is_err());

        // The upstream-version scenario end to end: Enter on an invalid
        // probed default (offered as none) fails instead of taking it
        // verbatim, while a valid default is taken.
        let version = |v: &str| options::validate_upstream_version(v, 1);
        assert!(accept_answer("", "1.0-2", &version).is_err());
        assert_eq!(
            accept_answer("", "1.0.0", &version),
            Ok("1.0.0".to_string())
        );
    }

    /// The git-derived maintainer default goes through
    /// [`options::parse_maintainer`] before it is offered: an empty git
    /// email yields a `Name <>` default that parses to an error and is
    /// ignored, instead of being accepted verbatim and only failing late in
    /// `resolve` (regression).
    #[test]
    fn maintainer_default_validated_by_parse_maintainer() {
        assert!(
            options::parse_maintainer("Jane Doe <jane@example.com>").is_ok(),
            "a well-formed identity is offered as the default"
        );
        // Empty git user.email (or DEBEMAIL): `Name <>` must not parse.
        assert!(options::parse_maintainer("Jane Doe <>").is_err());
        // An empty git user.name: `<>` (or `<email>`) must not parse either.
        assert!(options::parse_maintainer(" <jane@example.com>").is_err());
    }

    #[test]
    fn select_labels_carry_their_own_separator() {
        // prompt::select renders `> <label><answer>` verbatim; a label
        // without a trailing separator glues the answer to the prompt
        // (regression: the wizard once rendered "> LicenseMIT").
        for label in SELECT_LABELS {
            assert!(
                label.ends_with(": ") || label.ends_with("? "),
                "select label {label:?} lacks a trailing separator"
            );
        }
    }

    /// The probe helper is the same code path for the initial pass and the
    /// re-probe: pointed at directory A it reports A's project, pointed at
    /// directory B it reports B's. So when the source-location answer
    /// redirects the wizard from the detected directory to another one, the
    /// refreshed defaults (upstream version, description, homepage, license)
    /// describe the project actually being packaged — regression: they used
    /// to keep coming from the original directory.
    #[test]
    fn detect_and_probe_reports_the_directory_it_is_given() {
        use tempfile::tempdir;

        let manifest = |name: &str, version: &str, license: &str| {
            format!(
                "[package]\nname = \"{name}\"\nversion = \"{version}\"\n\
                 edition = \"2021\"\ndescription = \"{name} does {name} \
                 things\"\nhomepage = \"https://{name}.example.com\"\n\
                 license = \"{license}\"\n"
            )
        };
        let dir_a = tempdir().unwrap();
        std::fs::write(
            dir_a.path().join("Cargo.toml"),
            manifest("alpha", "0.1.0", "MIT"),
        )
        .unwrap();
        let dir_b = tempdir().unwrap();
        std::fs::write(
            dir_b.path().join("Cargo.toml"),
            manifest("beta", "2.9.9", "GPL-3.0+"),
        )
        .unwrap();

        // The initial pass over dir A.
        let (detection_a, probe_a) = detect_and_probe(dir_a.path());
        assert_eq!(detection_a, Detection::Single(Tid::RUST));
        let probe_a = probe_a.expect("dir A is a rust project");
        assert_eq!(probe_a.name.as_deref(), Some("alpha"));
        assert_eq!(probe_a.version.as_deref(), Some("0.1.0"));
        assert_eq!(probe_a.license.as_deref(), Some("MIT"));

        // The user chose dir B instead: the refreshed probe comes from B,
        // never from A.
        let (detection_b, probe_b) = detect_and_probe(dir_b.path());
        assert_eq!(detection_b, Detection::Single(Tid::RUST));
        let probe_b = probe_b.expect("dir B is a rust project");
        assert_eq!(probe_b.name.as_deref(), Some("beta"));
        assert_eq!(probe_b.version.as_deref(), Some("2.9.9"));
        assert_eq!(
            probe_b.description.as_deref(),
            Some("beta does beta things")
        );
        assert_eq!(
            probe_b.homepage.as_deref(),
            Some("https://beta.example.com")
        );
        assert_eq!(probe_b.license.as_deref(), Some("GPL-3.0+"));

        // A directory without project markers probes to nothing (the
        // questions fall back to their plain defaults).
        let dir_c = tempdir().unwrap();
        let (detection_c, probe_c) = detect_and_probe(dir_c.path());
        assert_eq!(detection_c, Detection::Empty);
        assert!(probe_c.is_none());
    }

    /// The re-probe skip predicate: the detected/cwd directory never
    /// re-probes — lexically identical paths and spellings of the same
    /// directory (`.`, a trailing slash) all compare equal, different
    /// directories and non-existent paths do not.
    #[test]
    fn same_directory_compares_spellings_of_one_directory() {
        use tempfile::tempdir;

        let dir = tempdir().unwrap();
        let other = tempdir().unwrap();
        assert!(same_directory(dir.path(), dir.path()));

        // `.` names the current directory.
        assert!(same_directory(
            std::path::Path::new("."),
            &std::env::current_dir().unwrap()
        ));

        assert!(!same_directory(dir.path(), other.path()));
        // A path that cannot be canonicalized only ever equals itself.
        assert!(!same_directory(dir.path(), &dir.path().join("missing")));
    }
}