package controllers

import (
	"fmt"
	"net/http"
	"strconv"
	"strings"

	"service-warungpos-go/config"
	"service-warungpos-go/models"
	"service-warungpos-go/services"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
	"math/rand"
)

// DTOs untuk Kategori & Produk
type CategoryCreateRequest struct {
	Name        string `json:"name" binding:"required"`
	Description string `json:"description"`
}

type CategoryResponse struct {
	ID          uint      `json:"id"`
	CompanyID   uint      `json:"company_id"`
	Name        string    `json:"name"`
	Description string    `json:"description"`
	CreatedAt   string    `json:"created_at"`
}

type ProductCreateRequest struct {
	Name             string  `json:"name" binding:"required"`
	SKU              *string `json:"sku"`
	Price            int     `json:"price" binding:"required"`
	Stock            int     `json:"stock"`
	IsUnlimitedStock bool    `json:"is_unlimited_stock"`
	CategoryID       *uint   `json:"category_id"`
	ImageURL         string  `json:"image_url"`
}

// ==================== IMAGE UPLOAD ====================

func UploadProductImage(c *gin.Context) {
	file, err := c.FormFile("file")
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "File tidak ditemukan dalam request"})
		return
	}

	// Validasi jenis file
	allowedTypes := map[string]bool{
		"image/jpeg": true,
		"image/png":  true,
		"image/webp": true,
		"image/gif":  true,
	}

	contentType := file.Header.Get("Content-Type")
	if !allowedTypes[contentType] {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "Hanya file gambar (JPG, PNG, WebP, GIF) yang diizinkan"})
		return
	}

	// Validasi ukuran (maksimal 5MB)
	if file.Size > 5*1024*1024 {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "Ukuran gambar maksimal 5MB"})
		return
	}

	// Upload langsung ke Cloudinary
	secureURL, err := services.UploadToCloudinary(file)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": fmt.Sprintf("Gagal upload gambar: %v", err)})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"image_url": secureURL,
	})
}

// ==================== CATEGORY CONTROLLER ====================

func ListCategories(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	var branchID *uint
	// Periksa query param branch_id
	if qBranchID := c.Query("branch_id"); qBranchID != "" {
		if val, err := strconv.ParseUint(qBranchID, 10, 32); err == nil {
			uVal := uint(val)
			branchID = &uVal
		}
	}

	// Jika kasir, paksa filter berdasarkan branch_id kasir
	if user.Role == "kasir" && user.BranchID != nil {
		branchID = user.BranchID
	}

	var allCategories []models.Category
	if err := config.DB.Select("id, company_id, name, description, created_at").Where("company_id = ?", *user.CompanyID).Find(&allCategories).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal mengambil data kategori"})
		return
	}

	// Jika tidak ada filter branch_id, kembalikan semua kategori langsung
	if branchID == nil {
		c.JSON(http.StatusOK, allCategories)
		return
	}

	// Ambil daftar product_id yang tidak tersedia di cabang ini
	var unavailableProductIDs []uint
	config.DB.Model(&models.BranchProduct{}).
		Where("branch_id = ? AND is_available = ?", *branchID, false).
		Pluck("product_id", &unavailableProductIDs)

	// Cari kategori dari produk aktif yang tersedia di cabang ini
	var availableCategoryIDs []uint
	query := config.DB.Model(&models.Product{}).
		Where("company_id = ? AND is_active = ?", *user.CompanyID, true)

	if len(unavailableProductIDs) > 0 {
		query = query.Where("id NOT IN ?", unavailableProductIDs)
	}

	query.Pluck("distinct category_id", &availableCategoryIDs)

	// Filter allCategories agar hanya mengembalikan kategori yang memiliki produk tersedia di cabang
	catMap := make(map[uint]bool)
	for _, catID := range availableCategoryIDs {
		catMap[catID] = true
	}

	var resp []models.Category
	for _, cat := range allCategories {
		if catMap[cat.ID] {
			resp = append(resp, cat)
		}
	}

	c.JSON(http.StatusOK, resp)
}

func GetCategory(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	catIDStr := c.Param("category_id")
	catID, err := strconv.Atoi(catIDStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "ID kategori tidak valid"})
		return
	}

	var category models.Category
	if err := config.DB.Select("id, company_id, name, description, created_at").Where("id = ? AND company_id = ?", catID, *user.CompanyID).First(&category).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Kategori tidak ditemukan"})
		return
	}

	c.JSON(http.StatusOK, category)
}

func CreateCategory(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	var req CategoryCreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": err.Error()})
		return
	}

	// Cek duplikasi nama kategori di perusahaan yang sama
	var count int64
	config.DB.Model(&models.Category{}).Where("name = ? AND company_id = ?", req.Name, *user.CompanyID).Count(&count)
	if count > 0 {
		c.JSON(http.StatusBadRequest, gin.H{"detail": fmt.Sprintf("Kategori '%s' sudah ada", req.Name)})
		return
	}

	newCat := models.Category{
		CompanyID:   *user.CompanyID,
		Name:        req.Name,
		Description: req.Description,
	}

	if err := config.DB.Create(&newCat).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal menyimpan kategori baru"})
		return
	}

	c.JSON(http.StatusCreated, newCat)
}

func UpdateCategory(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	catIDStr := c.Param("category_id")
	catID, err := strconv.Atoi(catIDStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "ID kategori tidak valid"})
		return
	}

	var req CategoryCreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": err.Error()})
		return
	}

	var category models.Category
	if err := config.DB.Select("id, company_id, name, description").Where("id = ? AND company_id = ?", catID, *user.CompanyID).First(&category).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Kategori tidak ditemukan"})
		return
	}

	if req.Name != "" {
		var count int64
		config.DB.Model(&models.Category{}).Where("name = ? AND company_id = ? AND id != ?", req.Name, *user.CompanyID, catID).Count(&count)
		if count > 0 {
			c.JSON(http.StatusBadRequest, gin.H{"detail": fmt.Sprintf("Kategori '%s' sudah ada", req.Name)})
			return
		}
		category.Name = req.Name
	}
	category.Description = req.Description

	if err := config.DB.Save(&category).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal meng-update kategori"})
		return
	}

	c.JSON(http.StatusOK, category)
}

func DeleteCategory(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	catIDStr := c.Param("category_id")
	catID, err := strconv.Atoi(catIDStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "ID kategori tidak valid"})
		return
	}

	var productCount int64
	config.DB.Model(&models.Product{}).Where("category_id = ?", catID).Count(&productCount)
	if productCount > 0 {
		c.JSON(http.StatusBadRequest, gin.H{"detail": fmt.Sprintf("Kategori masih memiliki %d produk. Pindahkan produk dulu.", productCount)})
		return
	}

	var category models.Category
	if err := config.DB.Select("id, name").Where("id = ? AND company_id = ?", catID, *user.CompanyID).First(&category).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Kategori tidak ditemukan"})
		return
	}

	if err := config.DB.Delete(&category).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal menghapus kategori"})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"message": fmt.Sprintf("Kategori '%s' berhasil dihapus", category.Name),
	})
}

// ==================== PRODUCT CONTROLLER ====================

func ListProducts(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	var branchID *uint
	// Cek filter branch_id query param (owner di POS)
	if qBranchID := c.Query("branch_id"); qBranchID != "" {
		if val, err := strconv.ParseUint(qBranchID, 10, 32); err == nil {
			uVal := uint(val)
			branchID = &uVal
		}
	}

	// Kasir terikat branch
	if user.Role == "kasir" && user.BranchID != nil {
		branchID = user.BranchID
	}

	categoryFilter := c.Query("category_id")
	activeOnlyStr := c.DefaultQuery("active_only", "true")
	activeOnly := activeOnlyStr == "true"
	searchQuery := c.Query("search")
	limitStr := c.Query("limit")
	skipStr := c.Query("skip")

	query := config.DB.Select("id, company_id, category_id, name, sku, price, stock, is_unlimited_stock, image_url, is_active, created_at, updated_at").
		Preload("Category", func(db *gorm.DB) *gorm.DB {
			return db.Select("id, name")
		}).
		Where("company_id = ?", *user.CompanyID)

	if activeOnly {
		query = query.Where("is_active = ?", true)
	}

	if categoryFilter != "" {
		if catID, err := strconv.Atoi(categoryFilter); err == nil {
			query = query.Where("category_id = ?", catID)
		}
	}

	if searchQuery != "" {
		query = query.Where("LOWER(name) LIKE ? OR LOWER(sku) LIKE ?", "%"+strings.ToLower(searchQuery)+"%", "%"+strings.ToLower(searchQuery)+"%")
	}

	// Filter ketersediaan cabang (BranchProduct) di level database
	if branchID != nil {
		query = query.Where("id NOT IN (SELECT product_id FROM branch_products WHERE branch_id = ? AND is_available = ?)", *branchID, false)
	}

	// Terapkan pagination jika limit diisi
	if limitStr != "" {
		if limit, err := strconv.Atoi(limitStr); err == nil {
			query = query.Limit(limit)
		}
	}
	if skipStr != "" {
		if skip, err := strconv.Atoi(skipStr); err == nil {
			query = query.Offset(skip)
		}
	}

	products := []models.Product{}
	if err := query.Find(&products).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal mengambil data produk"})
		return
	}

	c.JSON(http.StatusOK, products)
}

func GetProduct(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	productIDStr := c.Param("product_id")
	productID, err := strconv.Atoi(productIDStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "ID produk tidak valid"})
		return
	}

	var product models.Product
	if err := config.DB.Select("id, company_id, category_id, name, sku, price, stock, is_unlimited_stock, image_url, is_active, created_at, updated_at").
		Preload("Category", func(db *gorm.DB) *gorm.DB {
			return db.Select("id, name")
		}).
		Where("id = ? AND company_id = ?", productID, *user.CompanyID).
		First(&product).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Produk tidak ditemukan"})
		return
	}

	c.JSON(http.StatusOK, product)
}

func CreateProduct(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	var req ProductCreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": err.Error()})
		return
	}

	if req.SKU == nil || *req.SKU == "" {
		generated := fmt.Sprintf("SKU-%04X%04X", rand.Intn(65536), rand.Intn(65536))
		req.SKU = &generated
	}

	// Verifikasi SKU jika diisi
	if req.SKU != nil && *req.SKU != "" {
		var count int64
		config.DB.Model(&models.Product{}).Where("sku = ?", *req.SKU).Count(&count)
		if count > 0 {
			c.JSON(http.StatusBadRequest, gin.H{"detail": fmt.Sprintf("Produk dengan SKU '%s' sudah ada", *req.SKU)})
			return
		}
	}

	newProduct := models.Product{
		CompanyID:        *user.CompanyID,
		Name:             req.Name,
		SKU:              req.SKU,
		Price:            req.Price,
		Stock:            req.Stock,
		IsUnlimitedStock: req.IsUnlimitedStock,
		CategoryID:       req.CategoryID,
		ImageURL:         req.ImageURL,
		IsActive:         true,
	}

	if err := config.DB.Create(&newProduct).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal menyimpan produk baru"})
		return
	}

	if newProduct.CategoryID != nil {
		config.DB.Select("id, name").First(&newProduct.Category, *newProduct.CategoryID)
	}

	c.JSON(http.StatusCreated, newProduct)
}

func UpdateProduct(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	productIDStr := c.Param("product_id")
	productID, err := strconv.Atoi(productIDStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "ID produk tidak valid"})
		return
	}

	var req ProductCreateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": err.Error()})
		return
	}

	if req.SKU != nil && *req.SKU == "" {
		req.SKU = nil
	}

	var product models.Product
	if err := config.DB.Where("id = ? AND company_id = ?", productID, *user.CompanyID).First(&product).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Produk tidak ditemukan"})
		return
	}

	// Verifikasi SKU jika berubah
	if req.SKU != nil && *req.SKU != "" {
		if product.SKU == nil || *product.SKU != *req.SKU {
			var count int64
			config.DB.Model(&models.Product{}).Where("sku = ? AND id != ?", *req.SKU, productID).Count(&count)
			if count > 0 {
				c.JSON(http.StatusBadRequest, gin.H{"detail": fmt.Sprintf("Produk dengan SKU '%s' sudah ada", *req.SKU)})
				return
			}
			product.SKU = req.SKU
		}
	} else {
		product.SKU = nil
	}

	product.Name = req.Name
	product.Price = req.Price
	product.Stock = req.Stock
	product.IsUnlimitedStock = req.IsUnlimitedStock
	product.CategoryID = req.CategoryID
	product.ImageURL = req.ImageURL

	if err := config.DB.Save(&product).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal meng-update produk"})
		return
	}

	if product.CategoryID != nil {
		config.DB.Select("id, name").First(&product.Category, *product.CategoryID)
	}

	c.JSON(http.StatusOK, product)
}

func DeleteProduct(c *gin.Context) {
	userVal, _ := c.Get("user")
	user := userVal.(*models.User)

	productIDStr := c.Param("product_id")
	productID, err := strconv.Atoi(productIDStr)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": "ID produk tidak valid"})
		return
	}

	result := config.DB.Model(&models.Product{}).
		Where("id = ? AND company_id = ?", productID, *user.CompanyID).
		Update("is_active", false)
	if result.Error != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"detail": "Gagal menghapus produk"})
		return
	}
	if result.RowsAffected == 0 {
		c.JSON(http.StatusNotFound, gin.H{"detail": "Produk tidak ditemukan"})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"message": "Produk berhasil dinonaktifkan",
	})
}