package routes

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/gorilla/mux"
)

type ProductImageItem struct {
	ID         int64  `json:"id"`
	FileName   string `json:"file_name"`
	FileSize   int64  `json:"file_size"`
	Storage    string `json:"storage_path"`
	ContentURL string `json:"content_url"`
}

// GET /api/product-images?code=...&color=...
func GetProductImagesHandler(pg *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		code := strings.TrimSpace(r.URL.Query().Get("code"))
		color := strings.TrimSpace(r.URL.Query().Get("color"))

		if code == "" {
			http.Error(w, "Eksik parametre: code gerekli", http.StatusBadRequest)
			return
		}

		query := `
SELECT
    b.id,
    b.file_name,
    COALESCE(b.file_size, 0) AS file_size,
    COALESCE(b.storage_path, '') AS storage_path
FROM dfblob b
JOIN mmitem i
  ON i.id = b.src_id
WHERE b.typ = 'img'
  AND b.src_table = 'mmitem'
  AND i.code = $1
  AND ($2 = '' OR b.file_name ILIKE '%' || '-' || $2 || '-%')
ORDER BY COALESCE(b.sort_order, 999999), b.zlins_dttm DESC, b.id DESC
`

		rows, err := pg.Query(query, code, color)
		if err != nil {
			http.Error(w, "Görsel sorgu hatası: "+err.Error(), http.StatusInternalServerError)
			return
		}
		defer rows.Close()

		items := make([]ProductImageItem, 0, 16)
		for rows.Next() {
			var it ProductImageItem
			if err := rows.Scan(&it.ID, &it.FileName, &it.FileSize, &it.Storage); err != nil {
				continue
			}
			it.ContentURL = fmt.Sprintf("/api/product-images/%d/content", it.ID)
			items = append(items, it)
		}

		w.Header().Set("Content-Type", "application/json; charset=utf-8")
		_ = json.NewEncoder(w).Encode(items)
	}
}

// GET /api/product-images/{id}/content
func GetProductImageContentHandler(pg *sql.DB) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		idStr := mux.Vars(r)["id"]
		id, err := strconv.ParseInt(idStr, 10, 64)
		if err != nil || id <= 0 {
			http.Error(w, "Geçersiz görsel id", http.StatusBadRequest)
			return
		}

		var (
			fileName    string
			storagePath string
			storedInDB  bool
			binData     []byte
		)

		err = pg.QueryRow(`
SELECT
    COALESCE(file_name, ''),
    COALESCE(storage_path, ''),
    COALESCE(stored_in_db, false),
    bin
FROM dfblob
WHERE id = $1
  AND typ = 'img'
`, id).Scan(&fileName, &storagePath, &storedInDB, &binData)
		if err != nil {
			if err == sql.ErrNoRows {
				http.NotFound(w, r)
				return
			}
			http.Error(w, "Görsel okunamadı: "+err.Error(), http.StatusInternalServerError)
			return
		}

		if storedInDB && len(binData) > 0 {
			w.Header().Set("Content-Type", http.DetectContentType(binData))
			w.Header().Set("Cache-Control", "public, max-age=3600")
			_, _ = w.Write(binData)
			return
		}

		resolved := resolveStoragePath(storagePath)
		if resolved == "" {
			http.NotFound(w, r)
			return
		}

		w.Header().Set("Cache-Control", "public, max-age=3600")
		http.ServeFile(w, r, resolved)
	}
}

func resolveStoragePath(storagePath string) string {
	raw := strings.TrimSpace(storagePath)
	if raw == "" {
		return ""
	}

	raw = strings.TrimPrefix(raw, "./")
	candidates := []string{
		filepath.Clean(storagePath),
		filepath.Clean(raw),
		filepath.Join(".", raw),
		filepath.Join("..", raw),
	}

	if root := strings.TrimSpace(os.Getenv("BLOB_ROOT")); root != "" {
		candidates = append(candidates, filepath.Join(root, raw))
	}

	for _, p := range candidates {
		if p == "" {
			continue
		}
		if st, err := os.Stat(p); err == nil && !st.IsDir() {
			return p
		}
	}

	return ""
}