package handlers

import (
	"messenger/internal/api/middleware"
	"messenger/internal/api/responses"
	"messenger/internal/service"
	"net/http"
	"strconv"
	"time"

	"github.com/go-chi/chi/v5"
)

type FileHandler struct {
	fileService *service.FileService
}

func NewFileHandler(fileService *service.FileService) *FileHandler {
	return &FileHandler{
		fileService: fileService,
	}
}

func (h *FileHandler) UploadFile(w http.ResponseWriter, r *http.Request) {
	user := middleware.GetUserFromContext(r.Context())
	if user == nil {
		responses.Unauthorized(w, "user not found")
		return
	}

	chatID, err := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
	if err != nil {
		responses.BadRequest(w, "invalid chat id")
		return
	}

	// Parse multipart form (20 MB max)
	if err := r.ParseMultipartForm(20 << 20); err != nil {
		responses.BadRequest(w, "failed to parse form")
		return
	}

	file, header, err := r.FormFile("file")
	if err != nil {
		responses.BadRequest(w, "file is required")
		return
	}
	defer file.Close()

	attachment, err := h.fileService.UploadFile(r.Context(), chatID, user.ID, header)
	if err != nil {
		responses.BadRequest(w, err.Error())
		return
	}

	responses.Success(w, http.StatusOK, attachment)
}

func (h *FileHandler) DownloadFile(w http.ResponseWriter, r *http.Request) {
	user := middleware.GetUserFromContext(r.Context())
	if user == nil {
		responses.Unauthorized(w, "user not found")
		return
	}

	attachmentID, err := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
	if err != nil {
		responses.BadRequest(w, "invalid attachment id")
		return
	}

	fileName, file, mimeType, err := h.fileService.DownloadFile(r.Context(), attachmentID, user.ID)
	if err != nil {
		responses.NotFound(w, err.Error())
		return
	}
	defer file.Close()

	w.Header().Set("Content-Type", mimeType)
	w.Header().Set("Content-Disposition", "attachment; filename="+strconv.Quote(fileName))
	http.ServeContent(w, r, fileName, time.Now(), file)
}