package main

import (
	"crypto/rand"
	"database/sql"
	"fmt"
	"log"
	"math/big"
)

const createPinTableSql = `CREATE TABLE IF NOT EXISTS pin (
   "id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
	"pin" STRING NOT NULL,
	"active" BOOLEAN DEFAULT TRUE,
   "createdAt" DATETIME NOT NULL DEFAULT (datetime('now','localtime')),
   )`

const createPeerTableSql = `CREATE TABLE IF NOT EXISTS peer (
   "id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
   "publicKey" STRING NOT NULL,
	"createdAt" DATETIME NOT NULL DEFAULT (datetime('now','localtime')),
)`

func InitDb() *sql.DB {
	db, err := sql.Open("sqlite3", "./sqlite-database.db")
	_, err = db.Exec(createPinTableSql)
	if err != nil {
		log.Fatal(err.Error())
	}

	_, err = db.Exec(createPeerTableSql)
	if err != nil {
		log.Fatal(err.Error())
	}

	return db
}

func NewPin(db *sql.DB) (string, error) {
	pin := randomPin()
	_, err := db.Exec(`INSERT INTO PIN pin = ?`, pin)

	if err != nil {
		return "", err
	}

	return pin, nil
}

func VerifyPin(db *sql.DB, pin string) bool {
	row := db.QueryRow(`SELECT EXISTS (SELECT 1 FROM pin WHERE pin = ? AND active = True)`, pin)

	var exists bool
	row.Scan(&exists)

	return exists
}

func randomPin() string {
	num, _ := rand.Int(rand.Reader, big.NewInt(999999+1))
	return fmt.Sprintf("%06d", num)
}