using Minesweeper.Cli;
using Minesweeper.Core;

namespace Minesweeper.Core.Tests;

public class CommandLineTests
{
    [Fact]
    public void TryParse_WithoutArguments_UsesBeginnerDefaults()
    {
        Assert.True(CommandLine.TryParse([], out var options, out var error));

        Assert.Empty(error);
        Assert.Equal(GameDifficulty.Beginner, options.Difficulty);
        Assert.Null(options.Seed);
        Assert.False(options.UseKeys);
        Assert.False(options.ShowHelp);
    }

    [Theory]
    [InlineData("-d", "expert", GameDifficulty.Expert)]
    [InlineData("--difficulty", "EXPERT", GameDifficulty.Expert)]
    [InlineData("-d", "hard", GameDifficulty.Expert)]
    [InlineData("-d", "3", GameDifficulty.Expert)]
    [InlineData("-d", "e", GameDifficulty.Expert)]
    [InlineData("-d", "beginner", GameDifficulty.Beginner)]
    [InlineData("-d", "easy", GameDifficulty.Beginner)]
    [InlineData("-d", "1", GameDifficulty.Beginner)]
    [InlineData("-d", "intermediate", GameDifficulty.Intermediate)]
    [InlineData("-d", "medium", GameDifficulty.Intermediate)]
    [InlineData("-d", "2", GameDifficulty.Intermediate)]
    public void TryParse_DifficultySwitch(string flag, string value, GameDifficulty expected)
    {
        Assert.True(CommandLine.TryParse([flag, value], out var options, out _));

        Assert.Equal(expected, options.Difficulty);
    }

    [Theory]
    [InlineData(new[] { "-b" }, GameDifficulty.Beginner)]
    [InlineData(new[] { "-i" }, GameDifficulty.Intermediate)]
    [InlineData(new[] { "-e" }, GameDifficulty.Expert)]
    public void TryParse_DifficultyShorthands(string[] args, GameDifficulty expected)
    {
        Assert.True(CommandLine.TryParse(args, out var options, out _));

        Assert.Equal(expected, options.Difficulty);
    }

    [Fact]
    public void TryParse_CombinesOptions()
    {
        Assert.True(CommandLine.TryParse(["-e", "--seed", "42", "-k"], out var options, out _));

        Assert.Equal(GameDifficulty.Expert, options.Difficulty);
        Assert.Equal(42, options.Seed);
        Assert.True(options.UseKeys);
    }

    [Theory]
    [InlineData("0")]
    [InlineData("-7")]
    [InlineData("999999999")]
    public void TryParse_AcceptsAnyIntegerSeed(string seed)
    {
        Assert.True(CommandLine.TryParse(["--seed", seed], out var options, out _));

        Assert.Equal(int.Parse(seed), options.Seed);
    }

    [Fact]
    public void TryParse_Help()
    {
        Assert.True(CommandLine.TryParse(["--help"], out var options, out _));
        Assert.True(options.ShowHelp);
        Assert.True(CommandLine.TryParse(["-h"], out options, out _));
        Assert.True(options.ShowHelp);
    }

    [Fact]
    public void TryParse_Keys()
    {
        Assert.True(CommandLine.TryParse(["--keys"], out var options, out _));
        Assert.True(options.UseKeys);
        Assert.True(CommandLine.TryParse(["-k"], out options, out _));
        Assert.True(options.UseKeys);
    }

    [Theory]
    [InlineData("--difficulty")]
    [InlineData("-d")]
    public void TryParse_DifficultyWithoutValue_Fails(string flag)
    {
        Assert.False(CommandLine.TryParse([flag], out var options, out var error));

        Assert.Null(options);
        Assert.Contains("difficulty", error);
    }

    [Theory]
    [InlineData("impossible")]
    [InlineData("")]
    public void TryParse_UnknownDifficulty_Fails(string value)
    {
        Assert.False(CommandLine.TryParse(["-d", value], out var options, out var error));

        Assert.Null(options);
        Assert.Contains("difficulty", error);
    }

    [Theory]
    [InlineData("--seed")]
    [InlineData("--seed", "abc")]
    [InlineData("--seed", "1.5")]
    public void TryParse_BadSeed_Fails(params string[] args)
    {
        Assert.False(CommandLine.TryParse(args, out var options, out var error));

        Assert.Null(options);
        Assert.Contains("seed", error);
    }

    [Fact]
    public void TryParse_UnknownOption_FailsAndNamesIt()
    {
        Assert.False(CommandLine.TryParse(["--turbo"], out var options, out var error));

        Assert.Null(options);
        Assert.Contains("--turbo", error);
    }

    [Fact]
    public void Usage_MentionsEveryOption()
    {
        Assert.Contains("--difficulty", CommandLine.Usage);
        Assert.Contains("--seed", CommandLine.Usage);
        Assert.Contains("--keys", CommandLine.Usage);
        Assert.Contains("--help", CommandLine.Usage);
    }

    [Fact]
    public void HelpText_ListsEveryCommandVerb()
    {
        foreach (var verb in new[] { "reveal", "flag", "chord", "go", "difficulty", "new", "help", "quit" })
        {
            Assert.Contains(verb, GameSession.HelpText);
        }
    }
}