package migrate

import (
	"fmt"
	"strings"
)

// Sqlite3 returns a SQLite dialect implementation
func Sqlite3() Dialect {
	return sqlite3{}
}

type sqlite3 struct{}

// quoteIdentifier safely quotes a SQL identifier to prevent SQL injection
func (s sqlite3) quoteIdentifier(identifier string) string {
	// Replace any existing quotes with double quotes (SQL escape mechanism)
	escaped := strings.ReplaceAll(identifier, `"`, `""`)
	return fmt.Sprintf(`"%s"`, escaped)
}

func (s sqlite3) CreateTable(table string) string {
	return fmt.Sprintf(`CREATE TABLE %s (
	id INTEGER PRIMARY KEY AUTOINCREMENT,
	description VARCHAR,
	applied TIMESTAMP);`, s.quoteIdentifier(table))
}

func (s sqlite3) TableExists(table string) string {
	return fmt.Sprintf("SELECT * FROM %s;", s.quoteIdentifier(table))
}

func (s sqlite3) CheckVersion(table string) string {
	return fmt.Sprintf("SELECT id FROM %s ORDER BY id DESC LIMIT 0, 1;", s.quoteIdentifier(table))
}

func (s sqlite3) InsertVersion(table string) string {
	return fmt.Sprintf("INSERT INTO %s(description, applied) VALUES (?,?);", s.quoteIdentifier(table))
}