using DramaLing.Api.Models.DTOs;
using DramaLing.Api.Services;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using System.Security.Claims;

namespace DramaLing.Api.Controllers;

[Route("api/[controller]")]
[Authorize]
public class ImageGenerationController : BaseController
{
    private readonly IImageGenerationOrchestrator _orchestrator;

    public ImageGenerationController(
        IImageGenerationOrchestrator orchestrator,
        ILogger<ImageGenerationController> logger) : base(logger)
    {
        _orchestrator = orchestrator ?? throw new ArgumentNullException(nameof(orchestrator));
    }

    /// <summary>
    /// 為指定詞卡生成例句圖片
    /// </summary>
    /// <param name="flashcardId">詞卡 ID</param>
    /// <param name="request">生成請求參數</param>
    /// <returns>生成請求結果</returns>
    [HttpPost("flashcards/{flashcardId}/generate")]
    public async Task<IActionResult> GenerateImage(
        Guid flashcardId,
        [FromBody] GenerationRequest request)
    {
        try
        {
            var userId = GetCurrentUserId();
            request.UserId = userId;

            _logger.LogInformation("Starting image generation for flashcard {FlashcardId} by user {UserId}",
                flashcardId, userId);

            var result = await _orchestrator.StartGenerationAsync(flashcardId, request);

            return SuccessResponse(result);
        }
        catch (ArgumentException ex)
        {
            _logger.LogWarning(ex, "Invalid request for flashcard {FlashcardId}", flashcardId);
            return ErrorResponse("INVALID_REQUEST", ex.Message, null, 400);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to start image generation for flashcard {FlashcardId}", flashcardId);
            return ErrorResponse("GENERATION_FAILED", "Failed to start generation");
        }
    }

    /// <summary>
    /// 獲取圖片生成狀態
    /// </summary>
    /// <param name="requestId">生成請求 ID</param>
    /// <returns>生成狀態詳情</returns>
    [HttpGet("requests/{requestId}/status")]
    public async Task<IActionResult> GetGenerationStatus(Guid requestId)
    {
        try
        {
            var userId = GetCurrentUserId();
            _logger.LogInformation("Getting generation status for request {RequestId} by user {UserId}",
                requestId, userId);

            var status = await _orchestrator.GetGenerationStatusAsync(requestId);

            return SuccessResponse(status);
        }
        catch (ArgumentException ex)
        {
            _logger.LogWarning(ex, "Generation request {RequestId} not found", requestId);
            return ErrorResponse("NOT_FOUND", ex.Message, null, 404);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to get status for request {RequestId}", requestId);
            return ErrorResponse("STATUS_ERROR", "Failed to get status");
        }
    }

    /// <summary>
    /// 取消圖片生成請求
    /// </summary>
    /// <param name="requestId">生成請求 ID</param>
    /// <returns>取消結果</returns>
    [HttpPost("requests/{requestId}/cancel")]
    public async Task<IActionResult> CancelGeneration(Guid requestId)
    {
        try
        {
            var userId = GetCurrentUserId();
            _logger.LogInformation("Cancelling generation request {RequestId} by user {UserId}",
                requestId, userId);

            var cancelled = await _orchestrator.CancelGenerationAsync(requestId);

            if (cancelled)
            {
                return SuccessResponse(new { message = "Generation cancelled successfully" });
            }
            else
            {
                return ErrorResponse("CANCEL_FAILED", "Cannot cancel this request", null, 400);
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to cancel generation request {RequestId}", requestId);
            return ErrorResponse("CANCEL_ERROR", "Failed to cancel generation");
        }
    }

    /// <summary>
    /// 獲取用戶的圖片生成歷史
    /// </summary>
    /// <param name="page">頁碼</param>
    /// <param name="pageSize">每頁數量</param>
    /// <returns>生成歷史列表</returns>
    [HttpGet("history")]
    public async Task<IActionResult> GetGenerationHistory(
        [FromQuery] int page = 1,
        [FromQuery] int pageSize = 20)
    {
        try
        {
            var userId = GetCurrentUserId();

            // TODO: 實現分頁查詢邏輯
            // 暫時返回空列表
            var history = new
            {
                requests = new List<object>(),
                pagination = new
                {
                    currentPage = page,
                    pageSize = pageSize,
                    totalCount = 0,
                    totalPages = 0
                }
            };

            return SuccessResponse(history);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to get generation history for user");
            return ErrorResponse("HISTORY_ERROR", "Failed to get history");
        }
    }

    private Guid GetCurrentUserId()
    {
        var userIdClaim = User.FindFirst(ClaimTypes.NameIdentifier)?.Value
                          ?? User.FindFirst("sub")?.Value;

        if (string.IsNullOrEmpty(userIdClaim))
        {
            throw new UnauthorizedAccessException("User ID not found in token");
        }

        if (!Guid.TryParse(userIdClaim, out var userId))
        {
            throw new UnauthorizedAccessException("Invalid user ID format in token");
        }

        return userId;
    }
}