package main

import (
	"context"
	"fmt"
	"io/fs"
	"net/http"
	"os"
	"os/signal"
	"path/filepath"
	"syscall"
	"time"

	"git.noctra.dev/noctra/servtex/backend"
	"git.noctra.dev/noctra/servtex/frontend"
	"git.noctra.dev/noctra/servtex/globals"
)

// Exit Codes:
//	0 - ok
//	1 - log file could not be accessed
//	2 - config file could not be read
func main() {
	// temporary logfile
	var err error
	globals.LogFile, err = os.OpenFile("./servtex.log", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	defer globals.LogFile.Close()

	// parse configuration
	err = backend.ConfigReader("config.json", &globals.AppConfig)
	if err != nil { os.Exit(1) }

	// user-chosen logfile
	globals.LogFile, err = os.OpenFile(globals.AppConfig.LogFilePath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil { os.Exit(2) }

	// webserver init
	server := &http.Server{Addr: globals.AppConfig.WebserverDomain + ":" + globals.AppConfig.WebserverPort}
	serverSecure := &http.Server{Addr: globals.AppConfig.WebserverDomain + ":" + globals.AppConfig.WebserverPortSecure}

	// website url paths
	http.HandleFunc("/", frontend.MainHandler)
	http.HandleFunc("/sse", frontend.SSEventHandler)
	http.HandleFunc("/pdf", frontend.PDFHandler)
	http.HandleFunc("/compile", frontend.PDFCompile)
	jscss, _ := fs.Sub(frontend.WebFiles, "jscss")
	http.Handle("/jscss/", http.StripPrefix("/jscss/", http.FileServer(http.FS(jscss))))

	// rocket
	go server.ListenAndServe()
	if globals.AppConfig.WebserverSecure {
		go serverSecure.ListenAndServeTLS(globals.AppConfig.CertificatePath, globals.AppConfig.CertificateKeyPath)
	}

	// file system change watch
	absTexPath, err := filepath.Abs(globals.AppConfig.LatexSourceFilePath)
	if err == nil {
		backend.ChangeWatch(filepath.Dir(absTexPath), backend.LatexCompile)
	} else {
		backend.LogLine("Absolute TeX file path could not be gotten", 4)
	}

	backend.LogLine("Started", 2)
	fmt.Println("Press CTRL-C to Exit ServTeX")

	// wait for signal to quit
	stop := make(chan os.Signal, 1)
	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
	<-stop

	// remove ^C from stdout
	fmt.Print("\r")

	// shutdown
	context, cancel := context.WithTimeout(context.Background(), 2*time.Second)
	defer cancel()
	if err = server.Shutdown(context); err != nil {
		backend.LogLine("Graceful Shutdown failed", 4)
	}
	if err = serverSecure.Shutdown(context); err != nil {
		backend.LogLine("Graceful Shutdown failed", 4)
	}
	backend.LogLine("Stopped", 2)
}