using Microsoft.AspNetCore.Identity;
using RpgRoller.Contracts;
using RpgRoller.Domain;
using RpgRoller.Services;

namespace RpgRoller.Tests;

public sealed class GameServiceTests
{
    [Fact]
    public void Register_ValidatesRequiredFieldsAndDuplicates()
    {
        var service = CreateService();

        var invalidUsername = service.Register(new RegisterRequest("", "Password123", "Display"));
        var invalidDisplay = service.Register(new RegisterRequest("user", "Password123", ""));
        var invalidPassword = service.Register(new RegisterRequest("user", "short", "Display"));
        var valid = service.Register(new RegisterRequest("user", "Password123", "Display"));
        var duplicate = service.Register(new RegisterRequest("user", "Password123", "Display 2"));

        Assert.False(invalidUsername.Succeeded);
        Assert.False(invalidDisplay.Succeeded);
        Assert.False(invalidPassword.Succeeded);
        Assert.True(valid.Succeeded);
        Assert.False(duplicate.Succeeded);
    }

    [Fact]
    public void Login_ValidatesCredentialsAndSessionLookup()
    {
        var service = CreateService();
        service.Register(new RegisterRequest("user", "Password123", "Display"));

        var invalidUser = service.Login(new LoginRequest("missing", "Password123"));
        var invalidPassword = service.Login(new LoginRequest("user", "bad-password"));
        var valid = service.Login(new LoginRequest("user", "Password123"));

        Assert.False(invalidUser.Succeeded);
        Assert.False(invalidPassword.Succeeded);
        Assert.True(valid.Succeeded);

        var sessionUser = service.GetUserBySession(valid.Value.SessionToken);
        Assert.NotNull(sessionUser);

        service.Logout(valid.Value.SessionToken);
        Assert.Null(service.GetUserBySession(valid.Value.SessionToken));
    }

    [Fact]
    public void CampaignAndCharacterOperations_CheckUnauthorizedAndNotFoundCases()
    {
        var service = CreateService();

        var unauthorizedCampaign = service.CreateCampaign("missing", new CreateCampaignRequest("Name", "d6"));
        Assert.False(unauthorizedCampaign.Succeeded);

        service.Register(new RegisterRequest("gm", "Password123", "GM"));
        var gmSession = GetValue(service.Login(new LoginRequest("gm", "Password123"))).SessionToken;
        var campaign = GetValue(service.CreateCampaign(gmSession, new CreateCampaignRequest("Name", "d6")));

        var invalidRuleset = service.CreateCampaign(gmSession, new CreateCampaignRequest("Name 2", "unknown"));
        Assert.False(invalidRuleset.Succeeded);

        var noCampaignCharacter = service.CreateCharacter(gmSession, new CreateCharacterRequest("Hero", Guid.NewGuid()));
        Assert.False(noCampaignCharacter.Succeeded);

        var character = GetValue(service.CreateCharacter(gmSession, new CreateCharacterRequest("Hero", campaign.Id)));

        var missingCharacterActivate = service.ActivateCharacter(gmSession, Guid.NewGuid());
        Assert.False(missingCharacterActivate.Succeeded);

        var activateSuccess = service.ActivateCharacter(gmSession, character.Id);
        Assert.True(activateSuccess.Succeeded);

        var currentCharacters = service.GetCurrentCampaignCharacters(gmSession);
        Assert.True(currentCharacters.Succeeded);
        Assert.Single(GetValue(currentCharacters));

        var missingCampaignGet = service.GetCampaign(gmSession, Guid.NewGuid());
        Assert.False(missingCampaignGet.Succeeded);
    }

    [Fact]
    public void CharacterSkillAndRollOperations_CheckAuthorizationAndValidationBranches()
    {
        var service = CreateService(3, 4, 5, 6);
        service.Register(new RegisterRequest("gm", "Password123", "GM"));
        service.Register(new RegisterRequest("owner", "Password123", "Owner"));
        service.Register(new RegisterRequest("other", "Password123", "Other"));

        var gmSession = GetValue(service.Login(new LoginRequest("gm", "Password123"))).SessionToken;
        var ownerSession = GetValue(service.Login(new LoginRequest("owner", "Password123"))).SessionToken;
        var otherSession = GetValue(service.Login(new LoginRequest("other", "Password123"))).SessionToken;

        var campaign = GetValue(service.CreateCampaign(gmSession, new CreateCampaignRequest("Main", "dnd5e")));
        var character = GetValue(service.CreateCharacter(ownerSession, new CreateCharacterRequest("Owner Char", campaign.Id)));

        var noPermissionUpdate = service.UpdateCharacter(otherSession, character.Id, new UpdateCharacterRequest("Renamed", campaign.Id));
        Assert.False(noPermissionUpdate.Succeeded);

        var invalidCharacterName = service.UpdateCharacter(ownerSession, character.Id, new UpdateCharacterRequest("", campaign.Id));
        Assert.False(invalidCharacterName.Succeeded);

        var missingTargetCampaign = service.UpdateCharacter(ownerSession, character.Id, new UpdateCharacterRequest("Renamed", Guid.NewGuid()));
        Assert.False(missingTargetCampaign.Succeeded);

        var noSkillName = service.CreateSkill(ownerSession, character.Id, new CreateSkillRequest("", "1d20"));
        Assert.False(noSkillName.Succeeded);

        var invalidExpression = service.CreateSkill(ownerSession, character.Id, new CreateSkillRequest("Skill", "5D+4"));
        Assert.False(invalidExpression.Succeeded);

        var skill = GetValue(service.CreateSkill(ownerSession, character.Id, new CreateSkillRequest("Skill", "1d20+2")));

        var missingSkillUpdate = service.UpdateSkill(ownerSession, Guid.NewGuid(), new UpdateSkillRequest("X", "1d20"));
        Assert.False(missingSkillUpdate.Succeeded);

        var forbiddenSkillUpdate = service.UpdateSkill(otherSession, skill.Id, new UpdateSkillRequest("X", "1d20"));
        Assert.False(forbiddenSkillUpdate.Succeeded);

        var gmSkillUpdate = service.UpdateSkill(gmSession, skill.Id, new UpdateSkillRequest("GM Edit", "2d6+1"));
        Assert.True(gmSkillUpdate.Succeeded);

        var missingRoll = service.RollSkill(ownerSession, Guid.NewGuid(), new RollSkillRequest("public"));
        Assert.False(missingRoll.Succeeded);

        var invalidVisibility = service.RollSkill(ownerSession, skill.Id, new RollSkillRequest("hidden"));
        Assert.False(invalidVisibility.Succeeded);

        var forbiddenRoll = service.RollSkill(otherSession, skill.Id, new RollSkillRequest("public"));
        Assert.False(forbiddenRoll.Succeeded);

        var privateRoll = service.RollSkill(ownerSession, skill.Id, new RollSkillRequest("private"));
        var publicRoll = service.RollSkill(ownerSession, skill.Id, new RollSkillRequest("public"));
        Assert.True(privateRoll.Succeeded);
        Assert.True(publicRoll.Succeeded);

        var ownerLog = service.GetCampaignLog(ownerSession, campaign.Id);
        var gmLog = service.GetCampaignLog(gmSession, campaign.Id);
        var outsiderLog = service.GetCampaignLog(otherSession, campaign.Id);

        Assert.Equal(2, GetValue(ownerLog).Count);
        Assert.Equal(2, GetValue(gmLog).Count);
        Assert.False(outsiderLog.Succeeded);

        var version = service.GetCampaignVersion(ownerSession, campaign.Id);
        var missingVersion = service.GetCampaignVersion(ownerSession, Guid.NewGuid());
        Assert.True(version.Succeeded);
        Assert.False(missingVersion.Succeeded);
    }

    [Fact]
    public void CurrentCampaignCharacters_ReturnsNoActiveCharacterWhenUnset()
    {
        var service = CreateService();
        service.Register(new RegisterRequest("user", "Password123", "User"));
        var sessionToken = GetValue(service.Login(new LoginRequest("user", "Password123"))).SessionToken;

        var result = service.GetCurrentCampaignCharacters(sessionToken);
        Assert.False(result.Succeeded);
    }

    [Fact]
    public void GetCampaigns_ReturnsOwnedAndParticipatingCampaigns()
    {
        var service = CreateService();
        service.Register(new RegisterRequest("gm", "Password123", "GM"));
        service.Register(new RegisterRequest("player", "Password123", "Player"));
        var gmSession = GetValue(service.Login(new LoginRequest("gm", "Password123"))).SessionToken;
        var playerSession = GetValue(service.Login(new LoginRequest("player", "Password123"))).SessionToken;

        var gmCampaign = GetValue(service.CreateCampaign(gmSession, new CreateCampaignRequest("Owned", "d6")));
        _ = GetValue(service.CreateCampaign(gmSession, new CreateCampaignRequest("Owned 2", "d6")));
        _ = service.CreateCharacter(playerSession, new CreateCharacterRequest("Joiner", gmCampaign.Id));

        var playerCampaigns = service.GetCampaigns(playerSession);
        Assert.True(playerCampaigns.Succeeded);
        var campaigns = GetValue(playerCampaigns);
        Assert.Single(campaigns);
        Assert.Equal(gmCampaign.Id, campaigns[0].Id);
    }

    [Fact]
    public void DiceRules_CoversParsingAndMappingBranches()
    {
        Assert.Equal(RulesetKind.D6, DiceRules.TryParseRulesetId("d6"));
        Assert.Equal(RulesetKind.Dnd5e, DiceRules.TryParseRulesetId("dnd5e"));
        Assert.Null(DiceRules.TryParseRulesetId("unknown"));

        var d6 = DiceRules.ParseExpression(RulesetKind.D6, "5D+4");
        var dnd = DiceRules.ParseExpression(RulesetKind.Dnd5e, "2d12+2");
        var badFormat = DiceRules.ParseExpression(RulesetKind.Dnd5e, "abc");
        var tooManyDice = DiceRules.ParseExpression(RulesetKind.D6, "51D+1");
        var tooManySides = DiceRules.ParseExpression(RulesetKind.Dnd5e, "1d1001");
        var tooLargeModifier = DiceRules.ParseExpression(RulesetKind.Dnd5e, "1d20+1001");

        Assert.True(d6.Succeeded);
        Assert.True(dnd.Succeeded);
        Assert.False(badFormat.Succeeded);
        Assert.False(tooManyDice.Succeeded);
        Assert.False(tooManySides.Succeeded);
        Assert.False(tooLargeModifier.Succeeded);

        Assert.Equal("d6", DiceRules.ToRulesetId(RulesetKind.D6));
        Assert.Equal("dnd5e", DiceRules.ToRulesetId(RulesetKind.Dnd5e));
        Assert.Throws<ArgumentOutOfRangeException>(() => DiceRules.ToRulesetId((RulesetKind)99));
    }

    [Fact]
    public void RandomDiceRoller_ProducesValueWithinRange()
    {
        var roller = new RandomDiceRoller();
        for (var i = 0; i < 64; i += 1)
        {
            var value = roller.Roll(12);
            Assert.InRange(value, 1, 12);
        }
    }

    private static GameService CreateService(params int[] rollValues)
    {
        return new GameService(new PasswordHasher<UserAccount>(), new FixedDiceRoller(rollValues));
    }

    private static T GetValue<T>(ServiceResult<T> result)
    {
        Assert.True(result.Succeeded);
        Assert.NotNull(result.Value);
        return result.Value!;
    }

    private sealed class FixedDiceRoller : IDiceRoller
    {
        private readonly Queue<int> m_Values;

        public FixedDiceRoller(IEnumerable<int> values)
        {
            m_Values = new Queue<int>(values);
        }

        public int Roll(int sides)
        {
            var next = m_Values.Count > 0 ? m_Values.Dequeue() : 1;
            return Math.Clamp(next, 1, sides);
        }
    }
}