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

namespace DramaLing.Api.Controllers;

[ApiController]
public abstract class BaseController : ControllerBase
{
    protected readonly ILogger _logger;
    protected readonly IAuthService? _authService;

    protected BaseController(ILogger logger, IAuthService? authService = null)
    {
        _logger = logger;
        _authService = authService;
    }

    /// <summary>
    /// 統一的成功響應格式
    /// </summary>
    protected IActionResult SuccessResponse<T>(T data, string? message = null)
    {
        return Ok(new ApiResponse<T>
        {
            Success = true,
            Data = data,
            Message = message,
            Timestamp = DateTime.UtcNow
        });
    }

    /// <summary>
    /// 統一的錯誤響應格式
    /// </summary>
    protected IActionResult ErrorResponse(string code, string message, object? details = null, int statusCode = 500)
    {
        var response = new ApiErrorResponse
        {
            Success = false,
            Error = new ApiError
            {
                Code = code,
                Message = message,
                Details = details,
                Suggestions = GetSuggestionsForError(code)
            },
            RequestId = Guid.NewGuid().ToString(),
            Timestamp = DateTime.UtcNow
        };

        return StatusCode(statusCode, response);
    }

    /// <summary>
    /// 獲取當前用戶ID（統一處理認證）
    /// </summary>
    protected async Task<Guid> GetCurrentUserIdAsync()
    {
        if (_authService != null)
        {
            // 使用AuthService進行JWT解析（適用於已實現認證的Controller）
            var userId = await _authService.GetUserIdFromTokenAsync(Request.Headers.Authorization);
            if (userId.HasValue)
                return userId.Value;
        }

        // Fallback: 從Claims直接解析
        var userIdString = User.FindFirst(ClaimTypes.NameIdentifier)?.Value ??
                          User.FindFirst("sub")?.Value;

        if (Guid.TryParse(userIdString, out var parsedUserId))
            return parsedUserId;

        throw new UnauthorizedAccessException("Invalid or missing user authentication");
    }

    /// <summary>
    /// 檢查是否為測試環境
    /// </summary>
    protected bool IsTestEnvironment()
    {
        var environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
        return environment == "Development" || environment == "Testing";
    }

    /// <summary>
    /// 統一的模型驗證錯誤處理
    /// </summary>
    protected IActionResult HandleModelStateErrors()
    {
        var errors = ModelState
            .Where(x => x.Value?.Errors.Count > 0)
            .ToDictionary(
                kvp => kvp.Key,
                kvp => kvp.Value?.Errors.Select(e => e.ErrorMessage).ToArray() ?? Array.Empty<string>()
            );

        return ErrorResponse("VALIDATION_ERROR", "輸入資料驗證失敗", errors, 400);
    }

    /// <summary>
    /// 根據錯誤代碼獲取建議
    /// </summary>
    private List<string> GetSuggestionsForError(string errorCode)
    {
        return errorCode switch
        {
            "VALIDATION_ERROR" => new List<string> { "請檢查輸入格式", "確保所有必填欄位已填寫" },
            "INVALID_INPUT" => new List<string> { "請檢查輸入格式", "確保文本長度在限制內" },
            "RATE_LIMIT_EXCEEDED" => new List<string> { "升級到Premium帳戶以獲得無限使用", "明天重新嘗試" },
            "AI_SERVICE_ERROR" => new List<string> { "請稍後重試", "如果問題持續，請聯繫客服" },
            "UNAUTHORIZED" => new List<string> { "請檢查登入狀態", "確認Token是否有效" },
            "NOT_FOUND" => new List<string> { "請檢查資源ID是否正確", "確認資源是否存在" },
            _ => new List<string> { "請稍後重試", "如果問題持續，請聯繫客服" }
        };
    }
}

/// <summary>
/// 統一API響應格式
/// </summary>
public class ApiResponse<T>
{
    public bool Success { get; set; } = true;
    public T? Data { get; set; }
    public string? Message { get; set; }
    public DateTime Timestamp { get; set; } = DateTime.UtcNow;
}

/// <summary>
/// 分頁響應格式
/// </summary>
public class PagedApiResponse<T> : ApiResponse<List<T>>
{
    public PaginationMetadata Pagination { get; set; } = new();
}

/// <summary>
/// 分頁元數據
/// </summary>
public class PaginationMetadata
{
    public int CurrentPage { get; set; }
    public int PageSize { get; set; }
    public int TotalCount { get; set; }
    public int TotalPages { get; set; }
    public bool HasNext { get; set; }
    public bool HasPrevious { get; set; }
}