package handlers

import (
	"html/template"
	"log"
	"net/http"
	"strconv"

	"shop/internal/auth"
	"shop/internal/models"
	"shop/internal/repository"
	"shop/internal/upload"
)

type AdminHandler struct {
	repo      *repository.AdminRepository
	products  *repository.ProductRepository
	stats     *repository.StatsRepository
	storage   *upload.Storage
	session   *auth.Session
	templates *template.Template
}

type adminLayoutData struct {
	Title   string
	Email   string
	Active  string
	Content template.HTML
}

type adminLoginData struct {
	Title string
	Error string
	Email string
}

type adminDashboardData struct {
	Title        string
	Email        string
	ProductCount int
	CategoryCount int
	TotalVisits  int64
	TodayVisits  int
	Categories   []models.Category
	Products     []models.Product
}

type adminProductsData struct {
	Title    string
	Email    string
	Products []models.Product
}

type adminProductFormData struct {
	Title   string
	Email   string
	Product models.Product
	IsNew   bool
	Error   string
}

func NewAdminHandler(
	adminRepo *repository.AdminRepository,
	productRepo *repository.ProductRepository,
	statsRepo *repository.StatsRepository,
	storage *upload.Storage,
	session *auth.Session,
	templates *template.Template,
) *AdminHandler {
	return &AdminHandler{
		repo:      adminRepo,
		products:  productRepo,
		stats:     statsRepo,
		storage:   storage,
		session:   session,
		templates: templates,
	}
}

func (h *AdminHandler) requireAuth(w http.ResponseWriter, r *http.Request) (string, bool) {
	email, ok := h.session.FromRequest(r)
	if !ok {
		http.Redirect(w, r, "/admin/login", http.StatusSeeOther)
		return "", false
	}
	return email, true
}

func (h *AdminHandler) render(w http.ResponseWriter, name string, data any) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := h.templates.ExecuteTemplate(w, name, data); err != nil {
		log.Printf("render %s: %v", name, err)
	}
}

func (h *AdminHandler) LoginPage(w http.ResponseWriter, r *http.Request) {
	if email, ok := h.session.FromRequest(r); ok && email != "" {
		http.Redirect(w, r, "/admin/", http.StatusSeeOther)
		return
	}
	h.render(w, "admin_login.html", adminLoginData{Title: "Вход в админку"})
}

func (h *AdminHandler) Login(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}

	email := r.FormValue("email")
	password := r.FormValue("password")

	ok, err := h.repo.Authenticate(r.Context(), email, password)
	if err != nil {
		log.Printf("admin auth: %v", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}
	if !ok {
		h.renderLoginError(w, email, "Неверный email или пароль")
		return
	}

	token, err := h.session.Create(email)
	if err != nil {
		log.Printf("session: %v", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}

	h.session.SetCookie(w, r, token)
	http.Redirect(w, r, "/admin/", http.StatusSeeOther)
}

func (h *AdminHandler) Logout(w http.ResponseWriter, r *http.Request) {
	h.session.ClearCookie(w, r)
	http.Redirect(w, r, "/admin/login", http.StatusSeeOther)
}

func (h *AdminHandler) Dashboard(w http.ResponseWriter, r *http.Request) {
	email, ok := h.requireAuth(w, r)
	if !ok {
		return
	}

	ctx := r.Context()
	products, err := h.products.All(ctx)
	if err != nil {
		log.Printf("admin products: %v", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}

	categories, err := h.products.Categories(ctx)
	if err != nil {
		log.Printf("admin categories: %v", err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}

	stats, err := h.stats.Get(ctx)
	if err != nil {
		log.Printf("admin stats: %v", err)
	}

	h.render(w, "admin_dashboard.html", adminDashboardData{
		Title:         "Админ-панель",
		Email:         email,
		ProductCount:  len(products),
		CategoryCount: len(categories),
		TotalVisits:   stats.TotalVisits,
		TodayVisits:   stats.TodayVisits,
		Categories:    categories,
		Products:      products,
	})
}

func (h *AdminHandler) renderLoginError(w http.ResponseWriter, email, msg string) {
	data := adminLoginData{Title: "Вход в админку", Error: msg, Email: email}
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	w.WriteHeader(http.StatusUnauthorized)
	_ = h.templates.ExecuteTemplate(w, "admin_login.html", data)
}

func parseProductID(r *http.Request) (int, error) {
	return strconv.Atoi(r.PathValue("id"))
}