using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using DysonNetwork.Drive.Interfaces;
using DysonNetwork.Drive.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;

namespace DysonNetwork.Drive.Controllers
{
    [ApiController]
    [Route("api/files")]
    [Authorize]
    public class FileController : ControllerBase
    {
        private readonly IFileService _fileService;
        private readonly ILogger<FileController> _logger;

        public FileController(IFileService fileService, ILogger<FileController> logger)
        {
            _fileService = fileService ?? throw new ArgumentNullException(nameof(fileService));
            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
        }

        [HttpGet("{fileId}")]
        [ProducesResponseType(typeof(FileResult), StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<IActionResult> GetFile(Guid fileId, CancellationToken cancellationToken = default)
        {
            try
            {
                var file = await _fileService.GetFileAsync(fileId, cancellationToken);
                var stream = await _fileService.DownloadFileAsync(fileId, cancellationToken);
                
                return File(stream, file.MimeType, file.OriginalName);
            }
            catch (FileNotFoundException ex)
            {
                _logger.LogWarning(ex, "File not found: {FileId}", fileId);
                return NotFound(new { message = $"File with ID {fileId} not found." });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error retrieving file: {FileId}", fileId);
                return StatusCode(StatusCodes.Status500InternalServerError, new { message = "An error occurred while retrieving the file." });
            }
        }

        [HttpPost("upload")]
        [ProducesResponseType(typeof(CloudFile), StatusCodes.Status201Created)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        public async Task<IActionResult> UploadFile(IFormFile file, CancellationToken cancellationToken = default)
        {
            if (file == null || file.Length == 0)
            {
                return BadRequest(new { message = "No file uploaded." });
            }

            try
            {
                using var stream = file.OpenReadStream();
                var uploadedFile = await _fileService.UploadFileAsync(
                    stream,
                    file.FileName,
                    file.ContentType,
                    null,
                    cancellationToken);

                return CreatedAtAction(
                    nameof(GetFile),
                    new { fileId = uploadedFile.Id },
                    uploadedFile);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error uploading file: {FileName}", file?.FileName);
                return StatusCode(StatusCodes.Status500InternalServerError, new { message = "An error occurred while uploading the file." });
            }
        }

        [HttpDelete("{fileId}")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<IActionResult> DeleteFile(Guid fileId, CancellationToken cancellationToken = default)
        {
            try
            {
                var deleted = await _fileService.DeleteFileAsync(fileId, cancellationToken);
                if (!deleted)
                {
                    return NotFound(new { message = $"File with ID {fileId} not found." });
                }

                return NoContent();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error deleting file: {FileId}", fileId);
                return StatusCode(StatusCodes.Status500InternalServerError, new { message = "An error occurred while deleting the file." });
            }
        }

        [HttpGet("{fileId}/metadata")]
        [ProducesResponseType(typeof(CloudFile), StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<IActionResult> GetFileMetadata(Guid fileId, CancellationToken cancellationToken = default)
        {
            try
            {
                var file = await _fileService.GetFileAsync(fileId, cancellationToken);
                return Ok(file);
            }
            catch (FileNotFoundException ex)
            {
                _logger.LogWarning(ex, "File not found: {FileId}", fileId);
                return NotFound(new { message = $"File with ID {fileId} not found." });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error retrieving file metadata: {FileId}", fileId);
                return StatusCode(StatusCodes.Status500InternalServerError, new { message = "An error occurred while retrieving file metadata." });
            }
        }

        [HttpPut("{fileId}/metadata")]
        [ProducesResponseType(typeof(CloudFile), StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status400BadRequest)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<IActionResult> UpdateFileMetadata(
            Guid fileId,
            [FromBody] Dictionary<string, string> metadata,
            CancellationToken cancellationToken = default)
        {
            if (metadata == null || metadata.Count == 0)
            {
                return BadRequest(new { message = "No metadata provided." });
            }

            try
            {
                var updatedFile = await _fileService.UpdateFileMetadataAsync(fileId, metadata, cancellationToken);
                return Ok(updatedFile);
            }
            catch (FileNotFoundException ex)
            {
                _logger.LogWarning(ex, "File not found: {FileId}", fileId);
                return NotFound(new { message = $"File with ID {fileId} not found." });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error updating file metadata: {FileId}", fileId);
                return StatusCode(StatusCodes.Status500InternalServerError, new { message = "An error occurred while updating file metadata." });
            }
        }

        [HttpGet("{fileId}/url")]
        [ProducesResponseType(typeof(string), StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<IActionResult> GetFileUrl(Guid fileId, [FromQuery] int? expiresInSeconds = null, CancellationToken cancellationToken = default)
        {
            try
            {
                TimeSpan? expiry = expiresInSeconds.HasValue 
                    ? TimeSpan.FromSeconds(expiresInSeconds.Value) 
                    : null;

                var url = await _fileService.GetFileUrlAsync(fileId, expiry, cancellationToken);
                return Ok(new { url });
            }
            catch (FileNotFoundException ex)
            {
                _logger.LogWarning(ex, "File not found: {FileId}", fileId);
                return NotFound(new { message = $"File with ID {fileId} not found." });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error generating file URL: {FileId}", fileId);
                return StatusCode(StatusCodes.Status500InternalServerError, new { message = "An error occurred while generating the file URL." });
            }
        }

        [HttpGet("{fileId}/thumbnail")]
        [ProducesResponseType(StatusCodes.Status200OK)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        public async Task<IActionResult> GetFileThumbnail(
            Guid fileId,
            [FromQuery] int? width = null,
            [FromQuery] int? height = null,
            [FromQuery] int? expiresInSeconds = null,
            CancellationToken cancellationToken = default)
        {
            try
            {
                TimeSpan? expiry = expiresInSeconds.HasValue 
                    ? TimeSpan.FromSeconds(expiresInSeconds.Value) 
                    : null;

                var url = await _fileService.GetFileThumbnailUrlAsync(
                    fileId, 
                    width, 
                    height, 
                    expiry, 
                    cancellationToken);

                return Ok(new { url });
            }
            catch (FileNotFoundException ex)
            {
                _logger.LogWarning(ex, "File not found: {FileId}", fileId);
                return NotFound(new { message = $"File with ID {fileId} not found." });
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error generating thumbnail URL: {FileId}", fileId);
                return StatusCode(StatusCodes.Status500InternalServerError, new { message = "An error occurred while generating the thumbnail URL." });
            }
        }
    }
}