using Microsoft.AspNetCore.Mvc;

namespace TuneRipper.Api.Controllers;

[ApiController]
[Route("api/[controller]")]
public class DownloadController : ControllerBase
{
    private readonly IWebHostEnvironment _environment;
    private readonly ILogger<DownloadController> _logger;

    public DownloadController(IWebHostEnvironment environment, ILogger<DownloadController> logger)
    {
        _environment = environment;
        _logger = logger;
    }

    [HttpGet("{jobId}")]
    public IActionResult DownloadFile(string jobId)
    {
        if (string.IsNullOrWhiteSpace(jobId))
        {
            return BadRequest("Job ID is required");
        }

        try
        {
            var downloadsDir = Path.Combine(_environment.WebRootPath, "downloads");
            
            if (!Directory.Exists(downloadsDir))
            {
                _logger.LogWarning("Downloads directory not found: {Path}", downloadsDir);
                return NotFound("Downloads directory not found");
            }

            // Find files related to this job ID
            var jobFiles = Directory.GetFiles(downloadsDir, $"*{jobId}*.*")
                .Where(f => !f.EndsWith(".part") && !f.EndsWith(".tmp"))
                .OrderByDescending(System.IO.File.GetCreationTime)
                .ToArray();

            if (jobFiles.Length == 0)
            {
                // Fallback: look for any audio files that might match the pattern
                var audioFiles = Directory.GetFiles(downloadsDir, "*.*")
                    .Where(f => f.EndsWith(".mp3", StringComparison.OrdinalIgnoreCase) ||
                               f.EndsWith(".m4a", StringComparison.OrdinalIgnoreCase) ||
                               f.EndsWith(".webm", StringComparison.OrdinalIgnoreCase))
                    .Where(f => !f.EndsWith(".part") && !f.EndsWith(".tmp"))
                    .OrderByDescending(System.IO.File.GetCreationTime)
                    .ToArray();

                if (audioFiles.Length == 0)
                {
                    _logger.LogWarning("No files found for job ID: {JobId}", jobId);
                    return NotFound("File not found");
                }

                jobFiles = audioFiles.Take(1).ToArray();
            }

            var filePath = jobFiles[0];
            var fileName = Path.GetFileName(filePath);
            
            if (!System.IO.File.Exists(filePath))
            {
                _logger.LogWarning("File not found: {FilePath}", filePath);
                return NotFound("File not found");
            }

            _logger.LogInformation("Serving file: {FileName} for job: {JobId}", fileName, jobId);

            // Determine content type based on file extension
            var contentType = Path.GetExtension(fileName).ToLowerInvariant() switch
            {
                ".mp3" => "audio/mpeg",
                ".m4a" => "audio/mp4",
                ".webm" => "audio/webm",
                ".wav" => "audio/wav",
                ".ogg" => "audio/ogg",
                _ => "application/octet-stream"
            };

            // Create a safe download filename
            var safeFileName = fileName;
            if (fileName.Contains("_"))
            {
                // Try to create a more user-friendly filename
                var parts = fileName.Split('_');
                if (parts.Length >= 2)
                {
                    var extension = Path.GetExtension(fileName);
                    safeFileName = $"TuneRipper_{parts[0]}{extension}";
                }
            }

            var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            return File(fileStream, contentType, safeFileName);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error downloading file for job ID: {JobId}", jobId);
            return StatusCode(500, $"Error downloading file: {ex.Message}");
        }
    }

    [HttpGet("info/{jobId}")]
    public IActionResult GetDownloadInfo(string jobId)
    {
        if (string.IsNullOrWhiteSpace(jobId))
        {
            return BadRequest("Job ID is required");
        }

        try
        {
            var downloadsDir = Path.Combine(_environment.WebRootPath, "downloads");
            
            if (!Directory.Exists(downloadsDir))
            {
                return NotFound("Downloads directory not found");
            }

            // Find files related to this job ID
            var jobFiles = Directory.GetFiles(downloadsDir, $"*{jobId}*.*")
                .Where(f => !f.EndsWith(".part") && !f.EndsWith(".tmp"))
                .OrderByDescending(System.IO.File.GetCreationTime)
                .ToArray();

            if (jobFiles.Length == 0)
            {
                return NotFound("File not found");
            }

            var filePath = jobFiles[0];
            var fileName = Path.GetFileName(filePath);
            var fileInfo = new FileInfo(filePath);

            // Return download metadata
            var info = new
            {
                jobId,
                fileName,
                fileSize = FormatFileSize(fileInfo.Length),
                fileSizeBytes = fileInfo.Length,
                format = Path.GetExtension(fileName).TrimStart('.').ToUpperInvariant(),
                createdAt = fileInfo.CreationTime,
                lastModified = fileInfo.LastWriteTime,
                downloadUrl = $"/api/download/{jobId}"
            };

            return Ok(info);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error getting download info for job ID: {JobId}", jobId);
            return StatusCode(500, $"Error getting download info: {ex.Message}");
        }
    }

    [HttpDelete("{jobId}")]
    public IActionResult DeleteFile(string jobId)
    {
        if (string.IsNullOrWhiteSpace(jobId))
        {
            return BadRequest("Job ID is required");
        }

        try
        {
            var downloadsDir = Path.Combine(_environment.WebRootPath, "downloads");
            
            if (!Directory.Exists(downloadsDir))
            {
                return NotFound("Downloads directory not found");
            }

            // Find and delete files related to this job ID
            var jobFiles = Directory.GetFiles(downloadsDir, $"*{jobId}*.*");
            var deletedCount = 0;

            foreach (var filePath in jobFiles)
            {
                try
                {
                    System.IO.File.Delete(filePath);
                    deletedCount++;
                    _logger.LogInformation("Deleted file: {FilePath}", filePath);
                }
                catch (Exception ex)
                {
                    _logger.LogWarning(ex, "Failed to delete file: {FilePath}", filePath);
                }
            }

            if (deletedCount == 0)
            {
                return NotFound("No files found to delete");
            }

            return Ok(new { message = $"Deleted {deletedCount} file(s)", deletedCount });
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error deleting files for job ID: {JobId}", jobId);
            return StatusCode(500, $"Error deleting files: {ex.Message}");
        }
    }

    private static string FormatFileSize(long bytes)
    {
        string[] sizes = { "B", "KB", "MB", "GB" };
        double len = bytes;
        int order = 0;
        while (len >= 1024 && order < sizes.Length - 1)
        {
            order++;
            len = len / 1024;
        }
        return $"{len:0.##} {sizes[order]}";
    }
}