package handlers

import (
	"fmt"
	"io"
	"log"
	"strconv"

	"jd-book-uploader/models"
	"jd-book-uploader/services"
	"jd-book-uploader/utils"

	"github.com/gofiber/fiber/v2"
)

// UploadBook handles book upload requests
func UploadBook(c *fiber.Ctx) error {
	ctx := c.Context()

	// Parse multipart form
	form, err := c.MultipartForm()
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"error":   "Failed to parse form data",
		})
	}

	// Extract image file
	imageFiles := form.File["image"]
	if len(imageFiles) == 0 {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"error":   "Image file is required",
		})
	}

	imageFile := imageFiles[0]

	// Validate file type
	allowedTypes := map[string]bool{
		"image/png":  true,
		"image/jpeg": true,
		"image/jpg":  true,
		"image/webp": true,
	}

	if !allowedTypes[imageFile.Header.Get("Content-Type")] {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"error":   "Invalid file type. Only PNG, JPEG, and WEBP are allowed",
		})
	}

	// Validate file size (max 10MB)
	maxSize := int64(10 * 1024 * 1024) // 10MB
	if imageFile.Size > maxSize {
		return c.Status(fiber.StatusRequestEntityTooLarge).JSON(fiber.Map{
			"success": false,
			"error":   "File size exceeds 10MB limit",
		})
	}

	// Read image file
	file, err := imageFile.Open()
	if err != nil {
		log.Printf("Failed to open image file: %v", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"error":   "Failed to read image file",
		})
	}
	defer file.Close()

	imageData, err := io.ReadAll(file)
	if err != nil {
		log.Printf("Failed to read image data: %v", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"error":   "Failed to read image data",
		})
	}

	// Extract form fields
	bookName := c.FormValue("book_name")
	costStr := c.FormValue("cost")
	priceStr := c.FormValue("price")
	discountStr := c.FormValue("discount")
	quantityStr := c.FormValue("quantity")
	publisherAuthor := c.FormValue("publisher_author")
	category := c.FormValue("category")
	description := c.FormValue("description")

	// Validate required fields
	if err := validateBookFields(bookName, costStr, priceStr, quantityStr, publisherAuthor, category); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"error":   err.Error(),
		})
	}

	// Parse numeric fields
	cost, err := strconv.ParseFloat(costStr, 64)
	if err != nil || cost <= 0 {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"error":   "Invalid cost value",
		})
	}

	price, err := strconv.ParseFloat(priceStr, 64)
	if err != nil || price <= 0 {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"error":   "Invalid price value",
		})
	}

	discount := 0.0
	if discountStr != "" {
		discount, err = strconv.ParseFloat(discountStr, 64)
		if err != nil || discount < 0 {
			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
				"success": false,
				"error":   "Invalid discount value",
			})
		}
	}

	quantity, err := strconv.Atoi(quantityStr)
	if err != nil || quantity <= 0 {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"success": false,
			"error":   "Invalid quantity value",
		})
	}

	// Generate slug from book name
	slug := utils.GenerateSlug(utils.CleanString(bookName))

	// Check if slug already exists
	slugExists, err := services.BookSlugExists(ctx, slug)
	if err != nil {
		log.Printf("Failed to check slug existence: %v", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"error":   "Failed to validate product",
		})
	}

	if slugExists {
		return c.Status(fiber.StatusConflict).JSON(fiber.Map{
			"success": false,
			"error":   fmt.Sprintf("A book with slug '%s' already exists", slug),
		})
	}

	// Prepare filename: slug.png
	filename := fmt.Sprintf("%s.png", slug)

	// Upload image to Firebase Storage with correct path
	imageURL, err := services.UploadImage(ctx, imageData, "/jd-bookshop/books", filename)
	if err != nil {
		log.Printf("Firebase upload failed: %v", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"error":   "Failed to upload image",
		})
	}

	// Create book request
	bookReq := &models.BookCreateRequest{
		BookName:        utils.CleanString(bookName),
		Cost:            cost,
		Price:           price,
		Discount:        discount,
		Quantity:        quantity,
		PublisherAuthor: utils.CleanString(publisherAuthor),
		Category:        utils.CleanString(category),
		Description:     utils.CleanString(description),
		ImageURL:        imageURL,
	}

	// Create book in database
	book, err := services.CreateBook(ctx, bookReq)
	if err != nil {
		log.Printf("Database insert failed: %v", err)
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"success": false,
			"error":   "Failed to create book",
		})
	}

	// Return success response
	return c.Status(fiber.StatusCreated).JSON(fiber.Map{
		"success": true,
		"data": fiber.Map{
			"book_code":  book.BookCode,
			"book_name":  book.BookName,
			"image_url":  book.ImageURL,
			"slug":       book.Slug,
			"created_at": book.CreatedAt,
		},
	})
}

// validateBookFields validates required book fields
func validateBookFields(bookName, cost, price, quantity, publisherAuthor, category string) error {
	if bookName == "" {
		return fmt.Errorf("book_name is required")
	}
	if len(bookName) > 200 {
		return fmt.Errorf("book_name exceeds 200 characters")
	}
	if cost == "" {
		return fmt.Errorf("cost is required")
	}
	if price == "" {
		return fmt.Errorf("price is required")
	}
	if quantity == "" {
		return fmt.Errorf("quantity is required")
	}
	if publisherAuthor == "" {
		return fmt.Errorf("publisher_author is required")
	}
	if len(publisherAuthor) > 200 {
		return fmt.Errorf("publisher_author exceeds 200 characters")
	}
	if category == "" {
		return fmt.Errorf("category is required")
	}
	if len(category) > 100 {
		return fmt.Errorf("category exceeds 100 characters")
	}
	return nil
}