package main

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"github.com/gorilla/sessions"
	_ "github.com/lib/pq"
	"html/template"
	"net/http"
	"os"
	"path/filepath"
	"regexp"
	"flag"
)

const (
	VERSION = "0.1"
	MAX_DB_CONNS = 10 // already excessive for personal app
)

type Config struct {
	Sql struct {
		Host     string
		Dbname   string
		Username string
		Password string
	}
	Port string
	Url string
}

const (
	flash_err  = "_flash_err"
	flash_info = "_flash_info"
)

var (
	config    Config
	db        *sql.DB
	store     = sessions.NewCookieStore([]byte("key-store-auth-secret"))
	templates = map[string]*template.Template{}
)

func loadConfig(env string) {
	file, err := os.Open("config/" + env + ".json")
	if err != nil {
		fmt.Println("Error: cannot open config file: config/" + env + ".json")
		os.Exit(-1)
	}
	decoder := json.NewDecoder(file)
	err = decoder.Decode(&config)
	if err != nil {
		fmt.Println("Error: cannot decode config file: ", err)
		os.Exit(-1)
	}
}

func dbConnect() {
	var err error
	db, err = sql.Open("postgres", fmt.Sprintf("postgres://%s:%s@%s/%s?sslmode=require", config.Sql.Username, config.Sql.Password, config.Sql.Host, config.Sql.Dbname))

	if err != nil {
		fmt.Println("DB ERROR: ", err)
	}
	db.SetMaxIdleConns(MAX_DB_CONNS)
	err = db.Ping()
	if err != nil {
		fmt.Println("DB Error on Ping(): ", err)
		os.Exit(-1)
	}
}

func initTemplates() {
	files, _ := filepath.Glob("templates/pages/*.html")
	re := regexp.MustCompile("templates/pages/(.*).html")
	fmt.Println("Loading Templates:")
	for _, t := range files {
		name := re.FindStringSubmatch(t)
		fmt.Println("  ", name[1])
		var err error
		templates[name[1]], err = template.ParseFiles("templates/layout.html", t)
		if err != nil {
			fmt.Println("Template load error: ", err)
			os.Exit(-1)
		}
	}
}

func main() {
	fmt.Println("transmet ", VERSION)
	
	envFlag := flag.String("env", "local", "load config/{env}.json")
	flag.Parse()

	
	fmt.Println("Loading...")
	
	loadConfig(*envFlag)
	dbConnect()
	initTemplates()
	init_route_handlers()

	fmt.Println("Listening on", config.Port, "...")
	err := http.ListenAndServe(":"+config.Port, nil)
	if err != nil {
		fmt.Println("Fatal Error: ", err)
	}

	db.Close()
}