package handlers

import (
	"database/sql"
	"net/http"
	"strconv"
	"strings"
)

func prestashopImageURL(baseURL string, imageID sql.NullInt64, imageType string) string {
	if !imageID.Valid || imageID.Int64 == 0 {
		return ""
	}
	id := strconv.FormatInt(imageID.Int64, 10)
	var path strings.Builder
	path.Grow(len(baseURL) + len(id)*2 + len(imageType) + 16)
	path.WriteString(strings.TrimRight(baseURL, "/"))
	path.WriteString("/img/p")
	for _, ch := range id {
		path.WriteByte('/')
		path.WriteRune(ch)
	}
	path.WriteByte('/')
	path.WriteString(id)
	if strings.TrimSpace(imageType) != "" {
		path.WriteByte('-')
		path.WriteString(strings.TrimSpace(imageType))
	}
	path.WriteString(".webp")
	return path.String()
}

func requestBaseURL(req *http.Request) string {
	if req == nil {
		return ""
	}

	scheme := "http"
	if req.TLS != nil {
		scheme = "https"
	} else if forwarded := req.Header.Get("X-Forwarded-Proto"); forwarded != "" {
		if strings.Contains(forwarded, ",") {
			forwarded = strings.TrimSpace(strings.Split(forwarded, ",")[0])
		}
		if strings.TrimSpace(forwarded) != "" {
			scheme = strings.TrimSpace(forwarded)
		}
	}

	host := req.Header.Get("X-Forwarded-Host")
	if host == "" {
		host = req.Host
	}
	if strings.Contains(host, ",") {
		host = strings.TrimSpace(strings.Split(host, ",")[0])
	}
	host = strings.TrimSpace(host)
	if host == "" {
		return ""
	}

	return scheme + "://" + host
}