package utils

import (
	"database/sql"
	_ "github.com/mattn/go-sqlite3"
	"log"
	"os"
	"time"
)

const (
	DbDriver    = "sqlite3"
	TableCreate = `
                create table IF NOT EXISTS telegram (
                    [tele_id] INTEGER PRIMARY KEY AUTOINCREMENT,
                    [tele_recv_time] TIMESTAMP NOT NULL DEFAULT (datetime('now', 'localtime')),
                    [tele_processed] int(1) NOT NULL DEFAULT 0,
                    [tele_text] TEXT NOT NULL    
                )
`
	TableInsert = "insert into telegram (tele_text) values (?)"
)

var (
	dbFile      string
	initTable   bool
	initialized bool
	isWriting   bool
)

func getDb() *sql.DB {
	log.Println("init database ", initTable)
	if initTable && !initialized {
		log.Println("remove database file", dbFile)
		os.Remove(dbFile)
	}
	db, err := sql.Open(DbDriver, dbFile)
	if err != nil {
		log.Fatal("error in open database ", err)
	}
	return db
}

func InitDb(file string, init bool) error {
	dbFile = file
	initTable = init
	var dbErr error
	db := getDb()
	defer db.Close()
	_, dbErr = db.Exec(TableCreate)
	if dbErr != nil {
		log.Fatal("error in create telegram table", dbErr)
	}
	log.Println("database ", db, " initialized")
	initialized = true
	return nil
}

func InsertTelegram(teleString string) {
	count := 0
	for isWriting && count < 5 {
		log.Println("waiting for write ")
		time.Sleep(3 * time.Second)
		count++
	}
	if count >= 5 {
		log.Fatalln("database locked")
	}
	isWriting = true
	db := getDb()
	defer db.Close()
	stmt, err := db.Prepare(TableInsert)
	if err != nil {
		log.Fatal(err)
	}
	defer stmt.Close()
	result, err := stmt.Exec(teleString)
	id, _ := result.LastInsertId()
	if err != nil {
		isWriting = false
		log.Fatalln("error in write telegram")
	}
	log.Println("telegram insert ", id)
	isWriting = false
}