package handlers

import (
	"log"
	"net/http"
	"strconv"
	"time"

	"shop/internal/auth"
	"shop/internal/compare"
	"shop/internal/models"
)

func (h *CustomerHandler) BuyNow(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}
	productID, _ := strconv.Atoi(r.FormValue("product_id"))
	qty, _ := strconv.Atoi(r.FormValue("quantity"))
	if qty < 1 {
		qty = 1
	}
	if productID <= 0 {
		http.Redirect(w, r, "/", http.StatusSeeOther)
		return
	}
	cartID, err := h.resolveCart(r, w)
	if err == nil {
		_ = h.cart.AddItem(r.Context(), cartID, productID, qty)
	}
	http.Redirect(w, r, "/checkout", http.StatusSeeOther)
}

func (h *CustomerHandler) ProductReserve(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}
	id, err := strconv.Atoi(r.PathValue("id"))
	if err != nil {
		http.NotFound(w, r)
		return
	}
	ctx := r.Context()
	if _, err := h.products.GetActiveByID(ctx, id); err != nil {
		http.NotFound(w, r)
		return
	}

	sessionKey := h.cartSession.EnsureKey(w, r)
	if active, err := h.reservations.ActiveByProduct(ctx, id); err == nil {
		if active.SessionKey != sessionKey {
			var uid int
			if u, ok := auth.UserIDFromSession(h.userSession, r); ok {
				uid = u
			}
			if active.UserID == nil || uid == 0 || *active.UserID != uid {
				http.Redirect(w, r, "/product/"+strconv.Itoa(id)+"?err=reserved", http.StatusSeeOther)
				return
			}
		}
	}

	name := r.FormValue("name")
	phone := r.FormValue("phone")
	if uid, ok := auth.UserIDFromSession(h.userSession, r); ok {
		if u, err := h.users.GetByID(ctx, uid); err == nil {
			if name == "" {
				name = u.Name
			}
			if phone == "" {
				phone = u.Phone
			}
		}
	}
	if name == "" {
		name = "Гость"
	}

	res := models.Reservation{
		ProductID:     id,
		SessionKey:    sessionKey,
		CustomerName:  name,
		CustomerPhone: phone,
		ExpiresAt:     time.Now().Add(h.reservations.ExpiresIn()),
	}
	if uid, ok := auth.UserIDFromSession(h.userSession, r); ok {
		res.UserID = &uid
	}
	if err := h.reservations.ReplaceForProduct(ctx, &res); err != nil {
		log.Printf("reserve: %v", err)
		http.Redirect(w, r, "/product/"+strconv.Itoa(id), http.StatusSeeOther)
		return
	}
	http.Redirect(w, r, "/product/"+strconv.Itoa(id)+"?ok=reserve", http.StatusSeeOther)
}

func (h *CustomerHandler) CompareAdd(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}
	productID, _ := strconv.Atoi(r.FormValue("product_id"))
	otherID, _ := strconv.Atoi(r.FormValue("other_id"))
	redirect := r.FormValue("redirect")
	if redirect == "" {
		redirect = "/compare"
	}
	raw, _ := h.compareSession.FromRequest(r)
	next := raw
	if productID > 0 {
		next = compare.Add(next, productID)
	}
	if otherID > 0 {
		next = compare.Add(next, otherID)
	}
	if next == raw && productID <= 0 {
		http.Redirect(w, r, redirect, http.StatusSeeOther)
		return
	}
	token, _ := h.compareSession.Create(next)
	h.compareSession.SetCookie(w, r, token)
	http.Redirect(w, r, redirect, http.StatusSeeOther)
}

func (h *CustomerHandler) CompareRemove(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		http.Error(w, "Bad Request", http.StatusBadRequest)
		return
	}
	productID, _ := strconv.Atoi(r.FormValue("product_id"))
	raw, _ := h.compareSession.FromRequest(r)
	next := compare.Remove(raw, productID)
	token, _ := h.compareSession.Create(next)
	h.compareSession.SetCookie(w, r, token)
	http.Redirect(w, r, "/compare", http.StatusSeeOther)
}

func (h *CustomerHandler) ComparePage(w http.ResponseWriter, r *http.Request) {
	raw, _ := h.compareSession.FromRequest(r)
	ids := compare.Parse(raw)
	ctx := r.Context()

	var products []models.Product
	for _, id := range ids {
		if p, err := h.products.GetActiveByID(ctx, id); err == nil {
			products = append(products, p)
		}
	}

	p := comparePage{
		shopPage: h.basePage(r, w, "Сравнение товаров"),
		Products: products,
	}
	h.render(w, "compare.html", p)
}

func (h *CustomerHandler) compareCount(r *http.Request) int {
	raw, _ := h.compareSession.FromRequest(r)
	return len(compare.Parse(raw))
}