package handlers

import (
	"encoding/json"
	"fmt"
	"net/http"
	"path/filepath"
	"strings"
	"time"

	"github.com/rede5/gohorsejobs/backend/internal/api/middleware"
	"github.com/rede5/gohorsejobs/backend/internal/services"
)

type StorageHandler struct {
	storageService *services.StorageService
}

func NewStorageHandler(s *services.StorageService) *StorageHandler {
	return &StorageHandler{storageService: s}
}

// GetUploadURL returns a pre-signed URL for uploading a file.
// Clients upload directly to this URL.
// Query Params:
// - filename: Original filename
// - contentType: MIME type
// - folder: Optional folder (e.g. 'avatars', 'resumes')
func (h *StorageHandler) GetUploadURL(w http.ResponseWriter, r *http.Request) {
	// Authentication required
	userIDVal := r.Context().Value(middleware.ContextUserID)
	userID, ok := userIDVal.(string)
	if !ok || userID == "" {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	filename := r.URL.Query().Get("filename")
	contentType := r.URL.Query().Get("contentType")
	folder := r.URL.Query().Get("folder")

	if filename == "" {
		http.Error(w, "Filename is required", http.StatusBadRequest)
		return
	}
	if folder == "" {
		folder = "uploads" // Default
	}

	// Validate folder
	validFolders := map[string]bool{"avatars": true, "resumes": true, "logos": true, "uploads": true}
	if !validFolders[folder] {
		http.Error(w, "Invalid folder", http.StatusBadRequest)
		return
	}

	// Generate a unique key
	ext := filepath.Ext(filename)
	if ext == "" {
		// Attempt to guess from contentType if needed, or just allow no ext
	}

	// Key format: {folder}/{userID}/{timestamp}_{random}{ext}
	// Using user ID ensures isolation if needed, or use a UUID.
	key := fmt.Sprintf("%s/%s/%d_%s", folder, userID, time.Now().Unix(), strings.ReplaceAll(filename, " ", "_"))

	url, err := h.storageService.GetPresignedUploadURL(r.Context(), key, contentType)
	if err != nil {
		// If credentials missing, log error and return 500
		// "storage credentials incomplete" might mean admin needs to configure them.
		http.Error(w, "Failed to generate upload URL: "+err.Error(), http.StatusInternalServerError)
		return
	}

	// Return simple JSON
	resp := map[string]string{
		"url": url,
		"key": key, // Client needs key to save to DB profile
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(resp)
}