using Deal.Api.Endpoints.RequestModels;
using Deal.Api.Events;
using Deal.Api.Extensions;
using Deal.Api.Services;
using Deal.Modules.Cards.Application.Abstractions;
using Deal.Modules.Cards.Application.Dtos;
using Deal.Modules.Cards.Application.Models;
using Deal.Modules.Kanban.Application.Models;
using Deal.Modules.Kanban.Application.Services;
using Deal.Modules.Pipeline.Application.Models;
using Deal.Modules.Pipeline.Application.Services;
using Deal.Modules.Tenants.Application.Models;

namespace Deal.Api.Endpoints;

/// <summary>
/// Эндпоинты карточек и поиска
/// </summary>
public static class CardsEndpoints
{
    // Префикс группы карточек.
    private const string CardsGroupPrefix = "/api/cards";

    // Префикс группы поиска (единственный эндпоинт группы — /api/search).
    private const string ApiGroupPrefix = "/api";

    // Путь поиска (GET).
    private const string SearchPath = "/search";

    private const string OpenApiTag = "dashboard";

    private const string CardNotFoundDetail = "Карточка не найдена";

    // 400 GET /cards: containerId не существует.
    private const string UnknownColumnDetail = "Неизвестный контейнер";

    private const string UserActor = "user";

    private const string ReclassifiedEventType = "cards_reclassified";

    // Контекст ручного перехода карточки: пользователь, обучение ML по цели переноса.
    private static readonly TransitionContext UserMoveContext = new() { Actor = UserActor, Learn = true };

    /// <summary>
    /// Регистрирует группы /api/cards и /api
    /// </summary>
    /// <param name="app">Построитель маршрутов приложения.</param>
    /// <returns>Построитель маршрутов для цепочки вызовов.</returns>
    public static IEndpointRouteBuilder MapCardsEndpoints(this IEndpointRouteBuilder app)
    {
        var leads = app.MapGroup(CardsGroupPrefix).WithTags(OpenApiTag);

        // Статические сегменты ДО /cards/{cardId}: ASP.NET Core отдаёт приоритет литералам, порядок регистрации
        // сохранён для читаемости.
        leads.MapGet("", ListCardsAsync);
        leads.MapGet("/counts", CountsAsync);
        leads.MapPost("/mark-all-seen", MarkAllSeenAsync);
        leads.MapPost("/mark-col-seen", MarkColSeenAsync);
        leads.MapPost("/clear-col", ClearColAsync);
        leads.MapPost("/reclassify", ReclassifyAsync);
        leads.MapGet("/{cardId}", GetCardAsync);
        leads.MapPost("/{cardId}/reclassify", ReclassifyOneAsync);
        leads.MapPost("/{cardId}/move", MoveAsync);
        leads.MapPost("/{cardId}/trash", TrashAsync);
        leads.MapPost("/{cardId}/restore", RestoreAsync);
        leads.MapDelete("/{cardId}", DeleteAsync);
        leads.MapPost("/{cardId}/comments", AddCommentAsync);

        app.MapGroup(ApiGroupPrefix).WithTags(OpenApiTag).MapGet(SearchPath, SearchAsync);

        return app;
    }

    // GET /api/cards?containerId=: карточки контейнера (или все карточки дашборда); 400 «Неизвестный контейнер».
    // Параметр col принят как алиас containerId (совместимость со старым фронтом).
    private static async Task<IResult> ListCardsAsync(
        string? containerId,
        string? col,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        string? target = string.IsNullOrEmpty(containerId) ? col : containerId;
        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        if (!string.IsNullOrEmpty(target) && !await IsKnownContainerAsync(target, context, ct))
        {
            return EndpointResults.BadRequest(UnknownColumnDetail);
        }

        IReadOnlyList<CardDto> cards = await cardsService.ListCardsAsync(target, ct);
        return Results.Ok(new { items = cards });
    }

    private static async Task<IResult> CountsAsync(HttpContext context, CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        CardCountsDto counts = await cardsService.CountsAsync(ct);

        var wire = new Dictionary<string, object> { ["new"] = counts.New };
        foreach ((string col, CardColumnCountDto column) in counts.Columns)
        {
            wire[col] = column;
        }

        wire["learning"] = counts.Learning;
        wire["ml"] = counts.Ml;
        wire["ai"] = counts.Ai;
        return Results.Ok(wire);
    }

    private static async Task<IResult> GetCardAsync(
        string cardId,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        CardDto card = await cardsService.GetCardAsync(cardId, ct);
        return Results.Ok(card);
    }

    private static async Task<IResult> MarkAllSeenAsync(HttpContext context, CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        await cardsService.MarkSeenAsync(cardId: null, col: null, ct);
        return Results.Ok(new { ok = true });
    }

    private static async Task<IResult> MarkColSeenAsync(
        MarkColBody body,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        if (body.Col is null)
        {
            return EndpointResults.BadRequest(UnknownColumnDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        await cardsService.MarkSeenAsync(cardId: null, col: body.Col, ct);
        return Results.Ok(new { ok = true });
    }

    private static async Task<IResult> MoveAsync(
        string cardId,
        MoveBody body,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        ICardMover mover = context.RequestServices.GetRequiredService<ICardMover>();
        CardMoveResultDto outcome = await mover.MoveAsync(cardId, body.To ?? string.Empty, UserMoveContext, ct);
        if (outcome.Error is not null)
        {
            return EndpointResults.BadRequest(outcome.Error);
        }

        await AuditAppender.AppendTenantAsync(context, AuditEvents.CardMoved, new { cardId, to = body.To }, ct);

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        CardDto unified = await cardsService.GetCardAsync(cardId, ct);
        return Results.Ok(unified);
    }

    private static async Task<IResult> TrashAsync(
        string cardId,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        await cardsService.TrashCardAsync(cardId, ct);

        await AuditAppender.AppendTenantAsync(context, AuditEvents.CardTrashed, new { cardId }, ct);
        return Results.Ok(new { ok = true });
    }

    private static async Task<IResult> RestoreAsync(
        string cardId,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        string col = await cardsService.RestoreCardAsync(cardId, ct);

        await AuditAppender.AppendTenantAsync(context, AuditEvents.CardRestored, new { cardId, col }, ct);
        return Results.Ok(new { ok = true, col });
    }

    private static async Task<IResult> DeleteAsync(
        string cardId,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        bool deleted = await cardsService.DeleteForeverAsync(cardId, ct);
        if (!deleted)
        {
            return EndpointResults.NotFound(CardNotFoundDetail);
        }

        await AuditAppender.AppendTenantAsync(context, AuditEvents.CardDeleted, new { cardId }, ct);
        return Results.Ok(new { ok = true });
    }

    private static async Task<IResult> ClearColAsync(
        ClearColBody body,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        ClearColResultDto result = await cardsService.ClearColAsync(body.Col ?? string.Empty, ct);
        return result.Error is not null
            ? EndpointResults.BadRequest(result.Error)
            : Results.Ok(new { ok = true, cleared = result.Cleared });
    }

    private static async Task<IResult> AddCommentAsync(
        string cardId,
        CommentBody body,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        AddCommentResultDto result = await cardsService.AddCommentAsync(cardId, body.Text ?? string.Empty, ct);
        if (result.Error is not null)
        {
            return EndpointResults.BadRequest(result.Error);
        }

        if (result.Comments is null)
        {
            return EndpointResults.NotFound(CardNotFoundDetail);
        }

        await AuditAppender.AppendTenantAsync(context, AuditEvents.CardCommentAdded, new { cardId }, ct);
        return Results.Ok(new { comments = result.Comments });
    }

    // POST /api/cards/reclassify: переклассификация «Неразобранного» (все карточки либо ids).
    // Тело ids опционально (фронт шлёт запрос без тела — все карточки inbox). Проход синхронный; при занятом
    // проходе ответ {started:false, busy:true}. Поля started/busy/attempted сохранены ради совместимости,
    // добавлены reclassified/moved/kept/trashed/skipped/usedAi/reason. Аудит — card_reclassified; после
    // успешного прохода (reclassified &gt; 0) публикуется SSE cards_reclassified {reclassified,moved}.
    // body: Тело запроса (ids — опционально).
    // context: Контекст запроса.
    // ct: Токен отмены.
    private static async Task<IResult> ReclassifyAsync(
        ReclassifyBody? body,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardReclassifier reclassifier = context.RequestServices.GetRequiredService<CardReclassifier>();
        SseBroker broker = context.RequestServices.GetRequiredService<SseBroker>();
        Guid tenantId = context.GetCurrentUser()!.TenantId;
        // Синхронный IProgress: события прогресса уходят в SSE в порядке прохода, до финального события.
        var progress = new InlineProgress<ReclassifyProgressDto>(value => broker.Publish(
            tenantId,
            ReclassifiedEventType,
            new
            {
                progress = true,
                done = value.Done,
                total = value.Total,
                moved = value.Moved,
                kept = value.Kept,
                trashed = value.Trashed,
                skipped = value.Skipped,
            }));
        ReclassifyResultDto result = await reclassifier.ReclassifyInboxAsync(body?.Ids, ct, progress);
        await AppendReclassifyAuditAsync(context, result, ct);
        PublishReclassified(context, result);
        return Results.Ok(ToReclassifyWire(result));
    }

    // POST /api/cards/{cardId}/reclassify: переклассификация одной карточки; 404 «Карточка не найдена».
    // cardId: Id карточки (c_...).
    // context: Контекст запроса.
    // ct: Токен отмены.
    private static async Task<IResult> ReclassifyOneAsync(
        string cardId,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        CardDto card = await cardsService.GetCardAsync(cardId, ct);

        CardReclassifier reclassifier = context.RequestServices.GetRequiredService<CardReclassifier>();
        ReclassifyResultDto result = await reclassifier.ReclassifyCardAsync(card, ct);
        await AppendReclassifyAuditAsync(context, result, ct);
        PublishReclassified(context, result);
        return Results.Ok(ToReclassifyWire(result));
    }

    // Wire-форма итога переклассификации (camelCase; сохранены started/busy/attempted).
    // result: Итог прохода.
    // Возвращает: Объект ответа эндпоинта.
    private static object ToReclassifyWire(ReclassifyResultDto result) => new
    {
        started = result.Started,
        busy = result.Busy,
        attempted = result.Attempted,
        reclassified = result.Reclassified,
        moved = result.Moved,
        kept = result.Kept,
        trashed = result.Trashed,
        skipped = result.Skipped,
        usedAi = result.UsedAi,
        reason = result.Reason,
    };

    private static void PublishReclassified(HttpContext context, ReclassifyResultDto result)
    {
        if (!result.Started || result.Reclassified == 0)
        {
            return;
        }

        SseBroker broker = context.RequestServices.GetRequiredService<SseBroker>();
        broker.Publish(
            context.GetCurrentUser()!.TenantId,
            ReclassifiedEventType,
            new { reclassified = result.Reclassified, moved = result.Moved, progress = false });
    }

    // Аудит переклассификации: пишется только когда проход реально что-то изменил.
    // context: Контекст запроса.
    // result: Итог прохода.
    // ct: Токен отмены.
    private static Task AppendReclassifyAuditAsync(
        HttpContext context,
        ReclassifyResultDto result,
        CancellationToken ct)
    {
        if (result.Reclassified == 0)
        {
            return Task.CompletedTask;
        }

        return AuditAppender.AppendTenantAsync(
            context,
            AuditEvents.CardReclassified,
            new { attempted = result.Attempted, reclassified = result.Reclassified, moved = result.Moved, trashed = result.Trashed },
            ct);
    }

    private static async Task<IResult> SearchAsync(
        string? q,
        HttpContext context,
        CancellationToken ct)
    {
        if (!context.HasUser())
        {
            return EndpointResults.Unauthorized(AuthHelpers.UnauthorizedDetail);
        }

        CardsService cardsService = context.RequestServices.GetRequiredService<CardsService>();
        IReadOnlyList<CardDto> leads = await cardsService.SearchCardsAsync(q, ct);

        // messages всегда []: фронт их не читает.
        return Results.Ok(new { cards = leads, messages = Array.Empty<object>() });
    }

    // ── Внутреннее ─────────────────────────────────────────────────────────

    // Существует ли контейнер с таким id (служебная зона/стадия/доска).
    // col: Значение query-параметра containerId (непустое).
    // context: Контекст запроса (для резолва ContainersService).
    // ct: Токен отмены.
    // Возвращает: True — контейнер допустим для фильтра.
    private static async Task<bool> IsKnownContainerAsync(
        string col,
        HttpContext context,
        CancellationToken ct)
    {
        ContainersService containers = context.RequestServices.GetRequiredService<ContainersService>();
        return await containers.GetAsync(col, ct) is not null;
    }
}