/*
 * Command-line option parsing
 */
#include "vriscv.h"

#define OPTION_SEPARATOR "-"

uint64_t memory_size = 512 * 1024 * 1024;
char* file_path;
bool gdbstub = false;
bool trace = false;

static void print_usage();
static void print_help();
static void print_version();

static int parse_long_option(char* str, char* argq);

void parse_options(int argc, char** argv)
{
	for(int i = 1; i < argc; i++)
	{
		// Start option parsing for argument 'i'
		if(argv[i][0] != *OPTION_SEPARATOR) continue;

		// Check for long options
		if(argv[i][1] == *OPTION_SEPARATOR)
		{
			i += parse_long_option(argv[i] + 2, argv[i + 1]);
			continue;
		}

		// Parse short options
		int k = 1;
		while(argv[i][k])
		{
			switch(argv[i][k])
			{
				case 'h':
				case '?':
				{
					print_help();
					exit(0);
				}
				case 'v':
				{
					print_version();
					exit(0);
				}
				case 'm':
				{
					// First try to convert next chars into int (ex. -m512)
					char* end;
					memory_size = strtol(&argv[i][k + 1], &end, 10);
					if(*end != '\0' || end == &argv[i][k + 1])
					{
						if(argv[i][k + 1])
						{
							fprintf(stderr, "Error: Option -m needs an argument, but you used -m in a group of options without an integer next to it\n");
							exit(EXIT_FAILURE);
						}

						// Try to parse next arg as integer
						if(argc <= i + 1)
						{
							fprintf(stderr, "Error: Option " OPTION_SEPARATOR "m needs an argument\n");
							exit(EXIT_FAILURE);
						}

						memory_size = strtol(argv[i + 1], &end, 10);
						if(*end != '\0')
						{
							fprintf(stderr, "Error: Invalid argument '%s' for option " OPTION_SEPARATOR "m\n", argv[i + 1]);
							exit(EXIT_FAILURE);
						}
						else
						{
							i++;
							k = strlen(argv[i]) - 1;
						}
					}
					else k += (end - &argv[i][k + 1]);

					if(memory_size <= 0)
					{
						fprintf(stderr, "Error: Memory size needs to be > 0\n");
						exit(EXIT_FAILURE);
					}

					if(memory_size > 4096)
					{
						fprintf(stderr, "Error: Cannot address more than 4 GiB of memory on 32-bits !\n");
						exit(EXIT_FAILURE);
					}
					memory_size *= 1024 * 1024;

					break;
				}
				case 's':
				{
					gdbstub = true;
					break;
				}
				case 't':
				{
					trace = true;
					break;
				}
				default:
				{
					fprintf(stderr, "Error: Unknown short option -%c\n", argv[i][k]);
					exit(EXIT_FAILURE);
				}
			}
			k++;
		}
	}

	if(argc <= 1)
	{
		print_usage();
		exit(EXIT_FAILURE);
	}
	else file_path = argv[argc - 1];
}

static int parse_long_option(char* str, char* argq)
{
	if(strcmp(str, "help") == 0)
	{
		print_help();
		exit(0);
	}
	else if(strcmp(str, "version") == 0)
	{
		print_version();
		exit(0);
	}
	else if(strcmp(str, "memory") == 0)
	{
		if(argq == NULL)
		{
			fprintf(stderr, "Error: No argument given for option " OPTION_SEPARATOR "-memory\n");
			exit(EXIT_FAILURE);
		}

		// Convert argument to integer
		char* end;
		memory_size = strtol(argq, &end, 10);
		if(*end != '\0')
		{
			fprintf(stderr, "Error: Invalid argument '%s' for option " OPTION_SEPARATOR "-memory\n", argq);
			exit(EXIT_FAILURE);
		}

		if(memory_size > 4096)
		{
			fprintf(stderr, "Error: Cannot address more than 4 GiB of memory on 32-bits !\n");
			exit(EXIT_FAILURE);
		}
		memory_size *= 1024 * 1024;

		return 1;
	}
	else if(strcmp(str, "gdb-stub") == 0)
	{
		gdbstub = true;
		return 0;
	}
	else if(strcmp(str, "trace") == 0)
	{
		trace = true;
		return 0;
	}
	else
	{
		fprintf(stderr, "Error: Unknown long option " OPTION_SEPARATOR OPTION_SEPARATOR "%s\n", str);
		exit(EXIT_FAILURE);
	}
}

static void print_usage()
{
	printf("Usage: %s [options] <elf-file>\n", CURRENT_NAME);
}

static void print_help()
{
	print_usage();

	printf("Options:\n");
	printf("  " OPTION_SEPARATOR "h, " OPTION_SEPARATOR "?, --help\t\tPrint this help message\n");
	printf("  " OPTION_SEPARATOR "v, --version\t\t\tPrint version information\n");
	printf("  " OPTION_SEPARATOR "m, --memory\t\t\tSet the simulated memory size, in MiB (max 4096)\n");
	printf("  " OPTION_SEPARATOR "t, --trace\t\t\tTrace executed instructions in stdout\n");
	printf("  " OPTION_SEPARATOR "s, --gdb-stub\t\tLaunch a gdb stub server (remote gdb debugging)\n");
}

static void print_version()
{
	printf("%s (%s) version %s\n", CURRENT_NAME, NAME, VERSION);
}