using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using MotoresArgentinosV2.Infrastructure.Data;
using MotoresArgentinosV2.Core.Entities;
using MotoresArgentinosV2.Core.Interfaces;

using Microsoft.AspNetCore.Authorization;

using MotoresArgentinosV2.Core.DTOs;

namespace MotoresArgentinosV2.API.Controllers;

[Authorize(Roles = "Admin")]
[ApiController]
[Route("api/[controller]")]
public class AdminController : ControllerBase
{
    private readonly MotoresV2DbContext _context;
    private readonly IAdSyncService _syncService;
    private readonly INotificationService _notificationService;

    public AdminController(MotoresV2DbContext context, IAdSyncService syncService, INotificationService notificationService)
    {
        _context = context;
        _syncService = syncService;
        _notificationService = notificationService;
    }

    // --- MODERACIÓN ---

    // GESTIÓN GLOBAL DE AVISOS (Buscador Admin)
    [HttpGet("ads")]
    public async Task<IActionResult> GetAllAds(
        [FromQuery] string? q = null,
        [FromQuery] int? statusId = null,
        [FromQuery] int page = 1)
    {
        const int pageSize = 20;
        var query = _context.Ads
            .Include(a => a.Brand)
            .Include(a => a.User)
            .Include(a => a.Photos) // Para mostrar la miniatura
            .AsNoTracking() // Optimización de lectura
            .AsQueryable();

        // Filtro por Texto (Marca, Modelo, Email Usuario, Nombre Usuario)
        if (!string.IsNullOrEmpty(q))
        {
            query = query.Where(a =>
                a.VersionName!.Contains(q) ||
                a.Brand.Name.Contains(q) ||
                a.User.Email.Contains(q) ||
                a.User.UserName.Contains(q)
            );
        }

        // Filtro por Estado
        if (statusId.HasValue)
        {
            query = query.Where(a => a.StatusID == statusId.Value);
        }

        var total = await query.CountAsync();

        var ads = await query
            .OrderByDescending(a => a.CreatedAt)
            .Skip((page - 1) * pageSize)
            .Take(pageSize)
            .Select(a => new
            {
                a.AdID,
                BrandName = a.Brand != null ? a.Brand.Name : null,
                VersionName = a.VersionName,
                StatusID = a.StatusID,

                CreatedAt = a.CreatedAt,
                PublishedAt = a.PublishedAt,
                ExpiresAt = a.ExpiresAt,
                DeletedAt = a.DeletedAt,
                Views = a.ViewsCounter,
                LegacyID = a.LegacyAdID,

                // Datos de la transacción APROBADA más reciente
                PaidAmount = _context.Transactions
                    .Where(t => t.AdID == a.AdID && t.Status == "APPROVED")
                    .OrderByDescending(t => t.CreatedAt)
                    .Select(t => (decimal?)t.Amount) // Cast a nullable para detectar si no hubo pago
                    .FirstOrDefault(),

                PaidDate = _context.Transactions
                    .Where(t => t.AdID == a.AdID && t.Status == "APPROVED")
                    .OrderByDescending(t => t.CreatedAt)
                    .Select(t => (DateTime?)t.CreatedAt)
                    .FirstOrDefault(),

                UserEmail = a.User.Email,
                UserName = a.User.UserName,
                Thumbnail = a.Photos.Where(p => p.IsCover).Select(p => p.FilePath).FirstOrDefault()
                            ?? a.Photos.Select(p => p.FilePath).FirstOrDefault()
            })
            .ToListAsync();

        return Ok(new { ads, total, page, pageSize });
    }

    [HttpGet("ads/pending")]
    public async Task<IActionResult> GetPendingAds()
    {
        var ads = await _context.Ads
            .Include(a => a.User)
            .Include(a => a.Photos)
            .Where(a => a.StatusID == (int)AdStatusEnum.ModerationPending)
            .OrderByDescending(a => a.CreatedAt)
            .Select(a => new
            {
                a.AdID,
                VersionName = a.Brand != null ? $"{a.Brand.Name} {a.VersionName}" : a.VersionName,
                a.Price,
                a.Currency,
                a.CreatedAt,
                UserID = a.UserID,
                UserName = a.User.UserName,
                Email = a.User.Email,
                Thumbnail = a.Photos.Where(p => p.IsCover).Select(p => p.FilePath).FirstOrDefault() ?? a.Photos.Select(p => p.FilePath).FirstOrDefault()
            })
            .ToListAsync();

        return Ok(ads);
    }

    [HttpPost("ads/{id}/approve")]
    public async Task<IActionResult> ApproveAd(int id)
    {
        var ad = await _context.Ads.Include(a => a.User).Include(a => a.Brand).FirstOrDefaultAsync(a => a.AdID == id);
        if (ad == null) return NotFound();

        ad.StatusID = (int)AdStatusEnum.Active;
        ad.PublishedAt = DateTime.UtcNow;
        ad.ExpiresAt = DateTime.UtcNow.AddDays(30);

        await _context.SaveChangesAsync();

        // Audit Log
        var adminId = int.Parse(User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value ?? "0");
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "AD_APPROVED",
            Entity = "Ad",
            EntityID = id,
            UserID = adminId,
            Details = $"Aviso '{ad.Brand?.Name} {ad.VersionName}' aprobado por administrador."
        });
        await _context.SaveChangesAsync();

        // Sincronizar a Legacy
        try
        {
            await _syncService.SyncAdToLegacyAsync(id);
            var adTitle = $"{ad.Brand?.Name} {ad.VersionName}";
            await _notificationService.SendAdStatusChangedEmailAsync(ad.User?.Email ?? string.Empty, adTitle, "APROBADO");
        }
        catch (Exception)
        {
            // Logueamos pero no bloqueamos la aprobación en V2
        }

        return Ok(new { message = "Aviso aprobado y publicado." });
    }

    [HttpPost("ads/{id}/reject")]
    public async Task<IActionResult> RejectAd(int id, [FromBody] string reason)
    {
        var ad = await _context.Ads.Include(a => a.User).Include(a => a.Brand).FirstOrDefaultAsync(a => a.AdID == id);
        if (ad == null) return NotFound();

        ad.StatusID = (int)AdStatusEnum.Rejected;

        await _context.SaveChangesAsync();

        // Audit Log
        var adminId = int.Parse(User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value ?? "0");
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "AD_REJECTED",
            Entity = "Ad",
            EntityID = id,
            UserID = adminId,
            Details = $"Aviso '{ad.Brand?.Name} {ad.VersionName}' rechazado. Motivo: {reason}"
        });
        await _context.SaveChangesAsync();

        // Notificar rechazo
        var adTitle = $"{ad.Brand?.Name} {ad.VersionName}";
        await _notificationService.SendAdStatusChangedEmailAsync(ad.User?.Email ?? string.Empty, adTitle, "RECHAZADO", reason);

        return Ok(new { message = "Aviso rechazado." });
    }

    // --- TRANSACCIONES ---

    [HttpGet("transactions")]
    public async Task<IActionResult> GetTransactions(
        [FromQuery] string? status = null,
        [FromQuery] string? userSearch = null,
        [FromQuery] DateTime? fromDate = null,
        [FromQuery] DateTime? toDate = null,
        [FromQuery] int page = 1)
    {
        const int pageSize = 20;

        var query = from t in _context.Transactions
                    join a in _context.Ads on t.AdID equals a.AdID into adGroup
                    from ad in adGroup.DefaultIfEmpty() // Left Join con Ads
                    join u in _context.Users on ad.UserID equals u.UserID into userGroup
                    from user in userGroup.DefaultIfEmpty() // Left Join con Users
                    select new { t, ad, user };

        // 1. Filtro por Estado
        if (!string.IsNullOrEmpty(status))
        {
            query = query.Where(x => x.t.Status == status);
        }

        // 2. Filtro por Usuario (Búsqueda)
        if (!string.IsNullOrEmpty(userSearch))
        {
            // Solo buscamos si el usuario existe (no es nulo)
            query = query.Where(x =>
                x.user != null &&
                (x.user.Email.Contains(userSearch) || x.user.UserName.Contains(userSearch))
            );
        }

        // 3. Filtro por Fechas
        if (fromDate.HasValue)
        {
            query = query.Where(x => x.t.CreatedAt >= fromDate.Value);
        }

        if (toDate.HasValue)
        {
            var toDateEndOfDay = toDate.Value.Date.AddHours(23).AddMinutes(59).AddSeconds(59);
            query = query.Where(x => x.t.CreatedAt <= toDateEndOfDay);
        }

        // 4. Paginación y Ejecución
        var total = await query.CountAsync();

        var txs = await query
            .OrderByDescending(x => x.t.CreatedAt)
            .Skip((page - 1) * pageSize)
            .Take(pageSize)
            .Select(x => new
            {
                x.t.TransactionID,
                x.t.OperationCode,
                x.t.Amount,
                x.t.Status,
                x.t.CreatedAt,
                x.t.UpdatedAt,
                AdID = x.t.AdID,

                // LÓGICA DE PRIORIDAD: Snapshot > Relación Viva > Default
                UserID = (x.ad != null) ? x.ad.UserID : 0,

                UserName = !string.IsNullOrEmpty(x.t.SnapshotUserName)
                           ? x.t.SnapshotUserName
                           : ((x.user != null) ? x.user.UserName : "ELIMINADO"),

                UserEmail = !string.IsNullOrEmpty(x.t.SnapshotUserEmail)
                            ? x.t.SnapshotUserEmail
                            : ((x.user != null) ? x.user.Email : "-"),

                AdTitle = !string.IsNullOrEmpty(x.t.SnapshotAdTitle)
                          ? x.t.SnapshotAdTitle
                          : ((x.ad != null && x.ad.Brand != null) ? $"{x.ad.Brand.Name} {x.ad.VersionName}" : "Vehículo Desconocido/Eliminado")
            })
            .ToListAsync();

        return Ok(new { transactions = txs, total, page, pageSize });
    }

    // --- USUARIOS ---
    [HttpGet("users")]
    public async Task<IActionResult> GetUsers([FromQuery] string? q = null, [FromQuery] int page = 1)
    {
        const int pageSize = 20;
        var query = _context.Users.AsQueryable();

        if (!string.IsNullOrEmpty(q))
        {
            query = query.Where(u => (u.Email ?? "").Contains(q) ||
                                     (u.UserName ?? "").Contains(q) ||
                                     (u.FirstName ?? "").Contains(q) ||
                                     (u.LastName ?? "").Contains(q));
        }

        var total = await query.CountAsync();
        var users = await query
            .OrderByDescending(u => u.CreatedAt)
            .Skip((page - 1) * pageSize)
            .Take(pageSize)
            .Select(u => new
            {
                u.UserID,
                u.UserName,
                u.Email,
                u.FirstName,
                u.LastName,
                u.UserType,
                u.MigrationStatus,
                u.IsBlocked,
                u.CreatedAt
            })
            .ToListAsync();

        return Ok(new { users, total, page, pageSize });
    }

    [HttpGet("users/{id}")]
    public async Task<IActionResult> GetUserDetail(int id)
    {
        var user = await _context.Users
            .Where(u => u.UserID == id)
            .Select(u => new UserDetailDto
            {
                UserID = u.UserID,
                UserName = u.UserName,
                Email = u.Email,
                FirstName = u.FirstName,
                LastName = u.LastName,
                PhoneNumber = u.PhoneNumber,
                UserType = u.UserType,
                IsBlocked = u.IsBlocked,
                MigrationStatus = u.MigrationStatus,
                IsEmailVerified = u.IsEmailVerified,
                CreatedAt = u.CreatedAt
            })
            .FirstOrDefaultAsync();

        if (user == null) return NotFound();
        return Ok(user);
    }

    [HttpPut("users/{id}")]
    public async Task<IActionResult> UpdateUser(int id, [FromBody] UserUpdateDto dto)
    {
        var user = await _context.Users.FindAsync(id);
        if (user == null) return NotFound();

        user.UserName = dto.UserName;
        user.FirstName = dto.FirstName;
        user.LastName = dto.LastName;
        user.PhoneNumber = dto.PhoneNumber;
        user.UserType = dto.UserType;

        await _context.SaveChangesAsync();

        // Audit Log
        var adminId = int.Parse(User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value ?? "0");
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "USER_UPDATED",
            Entity = "User",
            EntityID = id,
            UserID = adminId,
            Details = $"Usuario '{user.UserName}' actualizado por administrador."
        });
        await _context.SaveChangesAsync();

        return Ok(new { message = "Usuario actualizado correctamente." });
    }

    [HttpGet("stats")]
    public async Task<IActionResult> GetStats()
    {
        var stats = new
        {
            // 1. Usamos AuditLogs para contar TODAS las creaciones históricas,
            // incluso si el aviso ya fue borrado físicamente de la tabla Ads.
            TotalAds = await _context.AuditLogs.CountAsync(l => l.Action == "AD_CREATED"),

            // 2. Avisos actualmente activos (Status = 4)
            ActiveAds = await _context.Ads.CountAsync(a => a.StatusID == (int)AdStatusEnum.Active),

            // 3. Pendientes de moderación (Status = 3)
            PendingAds = await _context.Ads.CountAsync(a => a.StatusID == (int)AdStatusEnum.ModerationPending),

            // 4. Total de Usuarios
            TotalUsers = await _context.Users.CountAsync(),

            // 5. Mensajes NO LEÍDOS (IsRead = false)
            UnreadMessages = await _context.ChatMessages.CountAsync(m => !m.IsRead)
        };
        return Ok(stats);
    }

    [HttpGet("audit")]
    public async Task<IActionResult> GetAuditLogs(
        [FromQuery] string? actionType = null,
        [FromQuery] string? entity = null,
        [FromQuery] int? userId = null,
        [FromQuery] DateTime? fromDate = null,
        [FromQuery] DateTime? toDate = null,
        [FromQuery] int page = 1)
    {
        const int pageSize = 50;
        var query = _context.AuditLogs.AsQueryable();

        if (!string.IsNullOrEmpty(actionType))
            query = query.Where(l => l.Action == actionType);

        if (!string.IsNullOrEmpty(entity))
            query = query.Where(l => l.Entity == entity);

        if (userId.HasValue)
            query = query.Where(l => l.UserID == userId.Value);

        if (fromDate.HasValue)
            query = query.Where(l => l.CreatedAt >= fromDate.Value);

        if (toDate.HasValue)
            query = query.Where(l => l.CreatedAt <= toDate.Value);

        var total = await query.CountAsync();
        var logs = await query
            .OrderByDescending(l => l.CreatedAt)
            .Skip((page - 1) * pageSize)
            .Take(pageSize)
            .Select(l => new
            {
                l.AuditLogID,
                l.Action,
                l.Entity,
                l.EntityID,
                l.UserID,
                l.Details,
                l.CreatedAt,
                UserName = l.UserID == 0 ? "Sistema" : _context.Users.Where(u => u.UserID == l.UserID).Select(u => u.UserName).FirstOrDefault() ?? "Desconocido"
            })
            .ToListAsync();

        return Ok(new { logs, total, page, pageSize });
    }

    // BÚSQUEDA DE USUARIOS PARA ASIGNAR AVISO
    [HttpGet("users/search")]
    public async Task<IActionResult> SearchUsers([FromQuery] string q)
    {
        if (string.IsNullOrEmpty(q)) return Ok(new List<object>());

        var users = await _context.Users
            .Where(u => (u.Email ?? "").Contains(q) || (u.UserName ?? "").Contains(q) || (u.FirstName ?? "").Contains(q) || (u.LastName ?? "").Contains(q))
            .Take(10)
            .Select(u => new { u.UserID, u.UserName, u.Email, u.FirstName, u.LastName, u.PhoneNumber, u.IsBlocked })
            .ToListAsync();

        return Ok(users);
    }

    // GESTIÓN DE BLOQUEO
    [HttpPost("users/{id}/toggle-block")]
    public async Task<IActionResult> ToggleBlockUser(int id)
    {
        var user = await _context.Users.FindAsync(id);
        if (user == null) return NotFound();

        // Evitar autobloqueo
        var currentAdminId = int.Parse(User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value ?? "0");
        if (user.UserID == currentAdminId) return BadRequest("No puedes bloquearte a ti mismo.");

        user.IsBlocked = !user.IsBlocked;

        // 📝 AUDITORÍA
        _context.AuditLogs.Add(new AuditLog
        {
            Action = user.IsBlocked ? "USER_BLOCKED" : "USER_UNBLOCKED",
            Entity = "User",
            EntityID = user.UserID,
            UserID = currentAdminId,
            Details = $"Usuario '{user.UserName}' {(user.IsBlocked ? "bloqueado" : "desbloqueado")} por administrador."
        });

        await _context.SaveChangesAsync();

        return Ok(new { message = user.IsBlocked ? "Usuario bloqueado" : "Usuario desbloqueado", isBlocked = user.IsBlocked });
    }

    // REPUBLICAR AVISO VENCIDO
    [HttpPost("ads/{id}/republish")]
    public async Task<IActionResult> RepublishAd(int id)
    {
        var ad = await _context.Ads.Include(a => a.Brand).FirstOrDefaultAsync(a => a.AdID == id);
        if (ad == null) return NotFound();

        // Verificación de seguridad: solo se pueden republicar avisos vencidos.
        if (ad.StatusID != (int)AdStatusEnum.Expired)
        {
            return BadRequest("Solo se pueden republicar avisos que se encuentren vencidos.");
        }

        // Actualizamos el estado y las fechas para un nuevo ciclo de 30 días.
        ad.StatusID = (int)AdStatusEnum.Active;
        ad.PublishedAt = DateTime.UtcNow; // La nueva fecha de publicación es ahora.
        ad.ExpiresAt = DateTime.UtcNow.AddDays(30);
        ad.ExpirationWarningSent = false; // Reseteamos la advertencia de expiración.

        // Audit Log
        var adminId = int.Parse(User.FindFirst(System.Security.Claims.ClaimTypes.NameIdentifier)?.Value ?? "0");
        _context.AuditLogs.Add(new AuditLog
        {
            Action = "AD_REPUBLISHED_BY_ADMIN",
            Entity = "Ad",
            EntityID = id,
            UserID = adminId,
            Details = $"Aviso ID {id} ('{ad.Brand?.Name} {ad.VersionName}') republicado por administrador."
        });

        await _context.SaveChangesAsync();

        // Aquí podrías agregar una sincronización con el sistema legacy si fuera necesario.
        // await _syncService.SyncAdToLegacyAsync(id);

        return Ok(new { message = "Aviso republicado y activado por 30 días." });
    }
}