import { isEmpty } from './helpers'

/**
 * Trims the build tree to only show the first path
 * Removes alternate build paths to keep the UI clean
 */
export function trimBuilds(builds: Builds): void {
  if (!builds?.tree?.children) return

  // Keep only the first child (primary build path)
  builds.tree.children.splice(1, builds.tree.children.length - 1)

  // Also trim grandchildren to first path only
  if (builds.tree.children[0]?.children) {
    builds.tree.children[0].children.splice(1, builds.tree.children[0].children.length - 1)
  }
}

/**
 * Removes late game items that appear in the core build tree
 * Prevents duplicate items from being shown
 */
export function trimLateGameItems(builds: Builds): void {
  if (!builds?.tree || isEmpty(builds.lateGame)) return

  const coreItemIds = new Set<number>()

  // Collect all item IDs from the tree
  function collectItemIds(tree: ItemTree): void {
    if (tree.data !== undefined) {
      coreItemIds.add(tree.data)
    }
    for (const child of tree.children || []) {
      collectItemIds(child)
    }
  }

  collectItemIds(builds.tree)

  // Remove late game items that appear in core
  builds.lateGame = builds.lateGame.filter(item => !coreItemIds.has(item.data))
}

/**
 * Gets the index of the build with the highest pickrate
 */
export function getHighestPickrateBuildIndex(runes: Array<{ pickrate: number }>): number {
  if (runes.length === 0) return 0

  return runes.reduce(
    (maxIdx, rune, idx, arr) => (rune.pickrate > arr[maxIdx].pickrate ? idx : maxIdx),
    0
  )
}

/**
 * Gets the first core item for each build variant
 */
export function getFirstCoreItems(runes: unknown[], builds: Builds): number[] {
  return runes.map(() => {
    const tree = builds?.tree
    return tree?.children?.[0]?.data ?? tree?.data ?? 0
  })
}