golang-fave/engine/engine.go

package engine

import (
	"net/http"
	"os"
	"strings"

	"golang-fave/assets"
	"golang-fave/engine/wrapper"
	"golang-fave/logger"
	"golang-fave/modules"
	"golang-fave/utils"

	"github.com/vladimirok5959/golang-server-sessions/session"
)

type Engine struct {
	Wrap *wrapper.Wrapper
	Mods *modules.Modules
}

func Response(l *logger.Logger, m *modules.Modules, w http.ResponseWriter, r *http.Request, s *session.Session, host, port, chost, dirConfig, dirHtdocs, dirLogs, dirTemplate, dirTmp string) bool {
	wrap := wrapper.New(l, w, r, s, host, port, chost, dirConfig, dirHtdocs, dirLogs, dirTemplate, dirTmp)
	eng := &Engine{
		Wrap: wrap,
		Mods: m,
	}
	return eng.Process()
}

func (this *Engine) Process() bool {
	// Check and set session user
	if !this.Wrap.S.IsSetInt("UserId") {
		this.Wrap.S.SetInt("UserId", 0)
	}

	this.Wrap.IsBackend = this.Wrap.R.URL.Path == "/cp" || strings.HasPrefix(this.Wrap.R.URL.Path, "/cp/")
	this.Wrap.ConfMysqlExists = utils.IsMySqlConfigExists(this.Wrap.DConfig + string(os.PathSeparator) + "mysql.json")
	this.Wrap.UrlArgs = append(this.Wrap.UrlArgs, utils.UrlToArray(this.Wrap.R.URL.Path)...)
	if this.Wrap.IsBackend && len(this.Wrap.UrlArgs) >= 1 && this.Wrap.UrlArgs[0] == "cp" {
		this.Wrap.UrlArgs = this.Wrap.UrlArgs[1:]
	}

	// Action
	if this.Mods.XXXActionFire(this.Wrap) {
		return true
	}

	// Redirect to CP for creating MySQL config file
	if !this.Wrap.IsBackend && !this.Wrap.ConfMysqlExists {
		this.Wrap.W.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
		http.Redirect(this.Wrap.W, this.Wrap.R, this.Wrap.R.URL.Scheme+"://"+this.Wrap.R.Host+"/cp/", 302)
		return true
	}

	// Display MySQL install page on backend
	if this.Wrap.IsBackend && !this.Wrap.ConfMysqlExists {
		utils.SystemRenderTemplate(this.Wrap.W, assets.TmplCpMySql, nil)
		return true
	}

	// Separated logic
	if !this.Wrap.IsBackend {
		// Render frontend
		return this.Mods.XXXFrontEnd(this.Wrap)
	}

	// Backend must use MySQL anyway, so, check and connect
	err := this.Wrap.UseDatabase()
	if err != nil {
		utils.SystemErrorPageEngine(this.Wrap.W, err)
		return true
	}
	defer this.Wrap.DB.Close()

	// ---
	// TODO: Very expensive operation, optimize that by file flag
	// Show add first user form if no any user in database
	var count int
	err = this.Wrap.DB.QueryRow(`
		SELECT
			COUNT(*)
		FROM
			users
		;`,
	).Scan(
		&count,
	)
	if err != nil {
		utils.SystemErrorPageEngine(this.Wrap.W, err)
		return true
	}
	if count <= 0 {
		utils.SystemRenderTemplate(this.Wrap.W, assets.TmplCpFirstUser, nil)
		return true
	}
	// ---

	// Show login page if need
	if this.Wrap.S.GetInt("UserId", 0) <= 0 {
		// Redirect to main url if needs
		if this.Wrap.R.URL.Path != "/cp/" {
			http.Redirect(this.Wrap.W, this.Wrap.R, "/cp/"+utils.ExtractGetParams(this.Wrap.R.RequestURI), 302)
			return true
		}

		// Show login form
		utils.SystemRenderTemplate(this.Wrap.W, assets.TmplCpLogin, nil)
		return true
	}

	// Try load current user data
	if !this.Wrap.LoadSessionUser() {
		http.Redirect(this.Wrap.W, this.Wrap.R, "/", 302)
		return true
	}

	// Only active admins can use backend
	if !(this.Wrap.User.A_admin == 1 && this.Wrap.User.A_active == 1) {
		// Redirect to main url if needs
		if this.Wrap.R.URL.Path != "/cp/" {
			http.Redirect(this.Wrap.W, this.Wrap.R, "/cp/"+utils.ExtractGetParams(this.Wrap.R.RequestURI), 302)
			return true
		}

		// Show login form
		utils.SystemRenderTemplate(this.Wrap.W, assets.TmplCpLogin, nil)
		return true
	}

	// Render backend
	return this.Mods.XXXBackEnd(this.Wrap)
}