using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using QuotifyBE.Data;
using QuotifyBE.Entities;
using QuotifyBE.DTOs;
using QuotifyBE.Mapping;
using Microsoft.AspNetCore.Cors;
using Microsoft.EntityFrameworkCore;

namespace QuotifyBE.Controllers;


[ApiController]
[EnableCors]
[Route("api/v1/uc")]
[Produces("application/json")]
public class UserContentController : ControllerBase
{

    private readonly IConfiguration _appsettings;
    private readonly ApplicationDbContext _db;
    private readonly GeneralUseHelpers guhf;
    List<string> _allowedExtensions = new List<string>() { ".jpg", ".jpeg", ".jfif", ".png", ".gif", ".avif", ".webp" };

    public UserContentController(IConfiguration appsettings, ApplicationDbContext db, GeneralUseHelpers GUHF)
    {
        _appsettings = appsettings;
        _db = db;
        guhf = GUHF;
    }

    // GET /api/v1/uc/images
    /// <summary>
    /// [AUTHED] Get every image
    /// </summary>
    /// <remarks>
    /// Can (and will) return an empty list if no images are found in DB. <br/>
    /// Requires authorization with a JWT, has CORS set.
    /// </remarks>
    /// <response code="200">Returned on valid request</response>
    [HttpGet("images")]
    [Authorize]
    [EnableCors]
    [ProducesResponseType(typeof(List<Image>), 200)]
    public async Task<IActionResult> GetImages()
    {

        // Get all the images
        List<Image> images = await _db.Images
                                        .ToListAsync();

        // Return to user
        return Ok(images);

    }


    // POST /api/v1/uc/images
    /// <summary>
    /// [AUTHED] Upload an image and get an its URI
    /// </summary>
    /// <remarks>
    /// Allows authorized users to publish images.
    /// A user-reachable path and image id is returned on success.<br/>
    /// </remarks>
    /// <response code="200">Returned on valid request</response>
    /// <response code="400">Returned when request does not contain a file or the file is blank</response>
    /// <response code="413">Returned when image size is too large</response>
    /// <response code="415">Returned when file extension/mimetype is unknown</response>
    [HttpPost("images")]
    [Authorize]
    [EnableCors]
    [ProducesResponseType(200)]
    [ProducesResponseType(typeof(ErrorDTO), 400)]
    [ProducesResponseType(typeof(ErrorDTO), 413)]
    [ProducesResponseType(typeof(ErrorDTO), 415)]
    public IActionResult PostNewImage(IFormFile file)
    {
        // Obsługa braku pliku
        if (file == null || file.Length == 0)
        {
            return BadRequest(new ErrorDTO
            {
                Status = "error",
                Error_msg = "No file was uploaded."
            });
        }

        // Dozwolone rozszerzenia
        string fileExtension = Path.GetExtension(file.FileName).ToLower();

        if (!_allowedExtensions.Contains(fileExtension))
        {
            return StatusCode(415, new ErrorDTO
            {
                Status = "error",
                Error_msg = $"Unknown file extension. Allowed: {string.Join(", ", _allowedExtensions)}"
            });
        }

        // Sprawdzenie typu MIME (opcjonalnie dokładniejsze)
        if (!file.ContentType.StartsWith("image/"))
        {
            return StatusCode(415, new ErrorDTO
            {
                Status = "error",
                Error_msg = "Uploaded file is not an image."
            });
        }

        // Ograniczenie rozmiaru pliku do tego, ustawionego przez użytkownika
        int MaxFileSize = int.TryParse(_appsettings.GetSection("UserContent")["MaxFileSize"], out int r)
            ? r
            : 5 * 1024 * 1024;
        if (file.Length > MaxFileSize)
        {
            return StatusCode(413, new ErrorDTO
            {
                Status = "error",
                Error_msg = $"File size exceeds {MaxFileSize / 1024 / 1024} MB."
            });
        }

        // Generowanie unikalnej nazwy
        string uniqueFileName = $"{Guid.NewGuid()}{fileExtension}";
        string relativePath = $"/uploads/images/{uniqueFileName}";
        string absolutePath = Path.Combine(Directory.GetCurrentDirectory(), "wwwroot", "uploads", "images", uniqueFileName);

        // Upewnij się, że katalog istnieje
        Directory.CreateDirectory(Path.GetDirectoryName(absolutePath)!);

        // Zapis pliku na dysk
        using (var stream = new FileStream(absolutePath, FileMode.Create))
        {
            file.CopyTo(stream);
        }

        // Dodaj do bazy
        Image image = new Image { Url = relativePath };
        _db.Images.Add(image);
        _db.SaveChanges();

        // Zwracany adres URL (np. do użytku w cytacie)
        return Ok(new
        {
            Status = "ok",
            Filepath = relativePath,
            ImageId = image.Id
        });
    }

    // GET /api/v1/uc/restrictions
    /// <summary>
    /// [AUTHED] Get server restrictions for file upload
    /// </summary>
    /// <remarks>
    /// Returns a list of allowed file extensions and mimetypes for upload.
    /// </remarks>
    /// <response code="200">Returned on valid request</response>
    [HttpGet("restrictions")]
    [Authorize]
    [EnableCors]
    [ProducesResponseType(200)]
    public IActionResult GetFileUploadRestrictions()
    {
        return Ok(new
        {
            Status = "ok",
            AllowedMimeTypes = new List<string>
            {
                "image/" // this could be done dynamically ~eee4
            },
            AllowedExtensions = _allowedExtensions,
            MaxFileSize = int.TryParse(_appsettings.GetSection("UserContent")["MaxFileSize"], out int r)
            ? r
            : 5 * 1024 * 1024
    });
    }

    // DELETE /api/v1/uc/images/{id}
    /// <summary>
    /// [AUTHED] Delete an image
    /// </summary>
    /// <remarks>
    /// Deletes an image, granted it exists.
    /// <br/><br/>
    /// <b>Note</b>:
    /// If the image is a file on disk, it's also deleted. 
    /// <br/><br/>
    /// <b>Warning</b>:
    /// Any reference to deleted image in Quotes table will also be deleted (nullified).
    /// </remarks>
    /// <returns>Json with status</returns>
    /// <param name="id">Image id which will be deleted</param>
    /// <response code="200">Returned on valid request</response>
    /// <response code="404">Returned when no such image exists</response>
    [HttpDelete("images/{id}")]
    [Authorize]
    [EnableCors]
    [ProducesResponseType(200)]
    [ProducesResponseType(typeof(ErrorDTO), 404)]
    public async Task<IActionResult> DeleteImage(int id)
    {
        // (Attempt to) find the image
        Image? image = await _db.Images
                            .FirstOrDefaultAsync(q => q.Id == id);
        // Failed?
        if (image == null)
            return NotFound(new { status = "error", error_msg = "Image not found" });

        // If succeded, remove the image:
        // - from disk - if saved locally
        if (!string.IsNullOrEmpty(image.Url)) {
            if (image.Url.StartsWith("/uploads/images/")) {
                // delete from disk
                int fileNameStart = image.Url.LastIndexOf('/');
                string uniqueFileName = image.Url.Substring(fileNameStart + 1);
                string absolutePath = Path.Combine(Directory.GetCurrentDirectory(), "wwwroot", "uploads", "images", uniqueFileName);
                System.IO.File.Delete(absolutePath);
            }
        }

        // - from db
        //    - first, from any quotes that reference it
        List<Quote> quotesToModify = await _db.Quotes
                                            .Include(q => q.Image)
                                            .Where(q => q.Image == image)
                                            .ToListAsync();

        foreach (Quote quote in quotesToModify)
        {
            quote.Image = null;
        }

        //    - finally, from images table
        _db.Images.Remove(image);
        await _db.SaveChangesAsync();

        // Return ok
        return Ok(new { Status = "ok" });
    }

}