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

namespace DramaLing.Api.Controllers;

[Route("api/ai")]
[Authorize]
public class AIController : BaseController
{
    private readonly IAnalysisService _analysisService;

    public AIController(
        IAnalysisService analysisService,
        ILogger<AIController> logger) : base(logger)
    {
        _analysisService = analysisService;
    }

    /// <summary>
    /// 智能分析英文句子
    /// </summary>
    /// <param name="request">分析請求</param>
    /// <returns>分析結果</returns>
    [HttpPost("analyze-sentence")]
    public async Task<IActionResult> AnalyzeSentence(
        [FromBody] SentenceAnalysisRequest request)
    {
        var requestId = Guid.NewGuid().ToString();
        var stopwatch = Stopwatch.StartNew();

        try
        {
            _logger.LogInformation("Processing sentence analysis request {RequestId}", requestId);

            // Input validation
            if (!ModelState.IsValid)
            {
                return HandleModelStateErrors();
            }

            // 使用帶快取的分析服務
            var options = request.Options ?? new AnalysisOptions();
            var analysisData = await _analysisService.AnalyzeSentenceAsync(
                request.InputText, options);

            stopwatch.Stop();
            analysisData.Metadata.ProcessingDate = DateTime.UtcNow;

            _logger.LogInformation("Sentence analysis completed for request {RequestId} in {ElapsedMs}ms",
                requestId, stopwatch.ElapsedMilliseconds);

            var response = new SentenceAnalysisResponse
            {
                Success = true,
                ProcessingTime = stopwatch.Elapsed.TotalSeconds,
                Data = analysisData
            };

            return SuccessResponse(response);
        }
        catch (ArgumentException ex)
        {
            _logger.LogWarning(ex, "Invalid input for request {RequestId}", requestId);
            return ErrorResponse("INVALID_INPUT", ex.Message, null, 400);
        }
        catch (InvalidOperationException ex)
        {
            _logger.LogError(ex, "AI service error for request {RequestId}", requestId);
            return ErrorResponse("AI_SERVICE_ERROR", "AI服務暫時不可用", null, 500);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Unexpected error processing request {RequestId}", requestId);
            return ErrorResponse("INTERNAL_ERROR", "伺服器內部錯誤", null, 500);
        }
    }

    /// <summary>
    /// 健康檢查端點
    /// </summary>
    [HttpGet("health")]
    public IActionResult GetHealth()
    {
        var healthData = new
        {
            Status = "Healthy",
            Service = "AI Analysis Service",
            Timestamp = DateTime.UtcNow,
            Version = "1.0"
        };

        return SuccessResponse(healthData);
    }

    /// <summary>
    /// 取得分析統計資訊
    /// </summary>
    [HttpGet("stats")]
    public async Task<IActionResult> GetAnalysisStats()
    {
        try
        {
            var stats = await _analysisService.GetAnalysisStatsAsync();
            var statsData = new
            {
                TotalAnalyses = stats.TotalAnalyses,
                CachedAnalyses = stats.CachedAnalyses,
                CacheHitRate = stats.CacheHitRate,
                AverageResponseTimeMs = stats.AverageResponseTimeMs,
                LastAnalysisAt = stats.LastAnalysisAt,
                ProviderUsage = stats.ProviderUsageStats
            };

            return SuccessResponse(statsData);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error getting analysis stats");
            return ErrorResponse("INTERNAL_ERROR", "無法取得統計資訊");
        }
    }

}