package cmd

import (
	"context"
	"database/sql"
	"time"

	_ "modernc.org/sqlite"
)

type DB struct {
	*sql.DB
}

type Cache DB

var cacheAddr = "/tmp/turbomaps-er.db"

func NewCache(ctx context.Context) Cache {
	ctx, can := context.WithTimeout(ctx, 5*time.Second)
	defer can()

	db, err := sql.Open("sqlite", cacheAddr)
	if err != nil {
		panic(err)
	}

	if err := db.PingContext(ctx); err != nil {
		panic(err)
	}

	return Cache(DB{DB: db})
}

func (db Cache) Get(ctx context.Context, k string) ([]byte, error) {
	if err := db.init(ctx); err != nil {
		return nil, err
	}

	row := db.QueryRowContext(ctx, `
		SELECT v FROM cache WHERE k=$1
	`, k)

	var v []byte
	if err := row.Scan(&v); err != nil {
		return nil, err
	}

	return v, row.Err()
}

func (db Cache) Set(ctx context.Context, k string, v []byte) error {
	if err := db.init(ctx); err != nil {
		return err
	}

	_, err := db.ExecContext(ctx, `
		INSERT INTO cache (k, v) VALUES ($1, $2)
		ON CONFLICT DO UPDATE SET v=$2 WHERE k=$1
	`, k, v)
	return err
}

func (db Cache) init(ctx context.Context) error {
	_, err := db.ExecContext(ctx, `
		CREATE TABLE IF NOT EXISTS cache(k TEXT PRIMARY KEY, v TEXT)
	`)
	return err
}