package handlers

import (
	"context"
	"errors"
	"net/http"

	"github.com/labstack/echo/v4"
	"gorm.io/gorm"

	appmiddleware "git.ma-al.com/goc_marek/ps_shop/internal/http/middleware"
	pscart "git.ma-al.com/goc_marek/ps_shop/internal/prestashop/cart"
	pscatalog "git.ma-al.com/goc_marek/ps_shop/internal/prestashop/catalog"
	psconfig "git.ma-al.com/goc_marek/ps_shop/internal/prestashop/config"
	pscustomer "git.ma-al.com/goc_marek/ps_shop/internal/prestashop/customer"
	psroutes "git.ma-al.com/goc_marek/ps_shop/internal/prestashop/routes"
	"git.ma-al.com/goc_marek/ps_shop/internal/render"
	"git.ma-al.com/goc_marek/ps_shop/internal/viewmodel"
)

type CartPageHandler struct {
	catalog    *pscatalog.Service
	customers  *pscustomer.Service
	carts      *pscart.Service
	renderer   *render.Engine
	config     psconfig.Config
	products   *psroutes.ProductRoute
	categories *psroutes.CategoryRoute
}

func NewCartPageHandler(catalog *pscatalog.Service, customers *pscustomer.Service, carts *pscart.Service, renderer *render.Engine, cfg psconfig.Config, products *psroutes.ProductRoute, categories *psroutes.CategoryRoute) *CartPageHandler {
	return &CartPageHandler{
		catalog:    catalog,
		customers:  customers,
		carts:      carts,
		renderer:   renderer,
		config:     cfg,
		products:   products,
		categories: categories,
	}
}

func (h *CartPageHandler) Show(c echo.Context) error {
	session := appmiddleware.GetSession(c)
	if h == nil || h.catalog == nil || h.carts == nil || h.renderer == nil {
		return echo.NewHTTPError(http.StatusInternalServerError, "cart page handler is not initialized")
	}

	languageID := int64Default(session.LanguageID, 1)
	languageID = h.catalog.ResolveLanguageID(c.Request().Context(), c.Request(), languageID)
	shopID := int64Default(session.ShopID, 1)
	currencyID := int64Default(session.CurrencyID, 1)

	var profile *pscustomer.Profile
	var err error
	if session.CustomerID != nil && h.customers != nil {
		profile, err = h.customers.GetByID(c.Request().Context(), *session.CustomerID)
		if err != nil && !errors.Is(err, gorm.ErrRecordNotFound) {
			return echo.NewHTTPError(http.StatusInternalServerError, "customer query failed: "+err.Error())
		}
	}

	cartPage := pscart.Page{}
	cartSummary := &pscart.Summary{}
	if session.CartID != nil {
		cartPage, cartSummary, err = h.loadCart(c.Request().Context(), *session.CartID, languageID, shopID, currencyID)
		if err != nil {
			return echo.NewHTTPError(http.StatusInternalServerError, "cart query failed: "+err.Error())
		}
		assignCartProductLinks(c.Request(), h.products, &cartPage)
		assignCartProductImages(requestBaseURL(c.Request()), &cartPage)
	}

	page := viewmodel.CartPageData{
		Cart:        cartPage,
		Session:     session,
		Customer:    profile,
		CartSummary: cartSummary,
		ShopBaseURL: h.config.PrestaShopBaseURL,
	}
	menu, err := loadMenu(c.Request(), h.catalog, h.categories, languageID, shopID)
	if err != nil {
		return echo.NewHTTPError(http.StatusInternalServerError, "menu query failed: "+err.Error())
	}
	page.Menu = menu
	locale, err := loadHeaderLocale(c.Request(), h.catalog, session, languageID)
	if err != nil {
		return echo.NewHTTPError(http.StatusInternalServerError, "locale query failed: "+err.Error())
	}
	page.Locale = locale

	return h.renderer.Cart(c.Response(), c.Request(), page)
}

func (h *CartPageHandler) loadCart(ctx context.Context, cartID, languageID, shopID, currencyID int64) (pscart.Page, *pscart.Summary, error) {
	page, err := h.carts.PageByID(ctx, cartID, languageID, shopID, currencyID)
	if err != nil {
		return pscart.Page{}, nil, err
	}
	summary := &pscart.Summary{
		ID:         page.ID,
		TotalItems: page.TotalItems,
	}
	return *page, summary, nil
}

func assignCartProductLinks(req *http.Request, route *psroutes.ProductRoute, page *pscart.Page) {
	if page == nil || route == nil {
		return
	}
	langPrefix := requestLanguagePrefix(req)
	for i := range page.Items {
		product := &page.Items[i]
		product.URL = route.BuildPath(psroutes.ProductURLData{
			ID:             product.ProductID,
			Slug:           product.Slug,
			CategoryPath:   product.CategoryPath,
			EAN13:          product.EAN13,
			LanguagePrefix: langPrefix,
		})
	}
}

func assignCartProductImages(baseURL string, page *pscart.Page) {
	if page == nil {
		return
	}
	for i := range page.Items {
		page.Items[i].ImageURL = prestashopImageURL(baseURL, page.Items[i].CoverImageID, "home_default")
	}
}