package migrate

import (
	"strings"
	"testing"
)

func TestPostgresDialect(t *testing.T) {
	pg := Postgres()

	t.Run("CreateTable", func(t *testing.T) {
		sql := pg.CreateTable("dbversion")
		if !strings.Contains(sql, "SERIAL PRIMARY KEY") {
			t.Errorf("Expected SERIAL PRIMARY KEY, got: %s", sql)
		}
		if !strings.Contains(sql, `"dbversion"`) {
			t.Errorf("Expected quoted table name, got: %s", sql)
		}
	})

	t.Run("TableExists", func(t *testing.T) {
		sql := pg.TableExists("dbversion")
		if !strings.Contains(sql, `"dbversion"`) {
			t.Errorf("Expected quoted table name, got: %s", sql)
		}
		if !strings.Contains(sql, "SELECT 1") {
			t.Errorf("Expected SELECT 1 for existence check, got: %s", sql)
		}
	})

	t.Run("CheckVersion", func(t *testing.T) {
		sql := pg.CheckVersion("dbversion")
		if !strings.Contains(sql, "ORDER BY id DESC") {
			t.Errorf("Expected ORDER BY id DESC, got: %s", sql)
		}
		if !strings.Contains(sql, "LIMIT 1") {
			t.Errorf("Expected LIMIT 1, got: %s", sql)
		}
	})

	t.Run("InsertVersion", func(t *testing.T) {
		sql := pg.InsertVersion("dbversion")
		// PostgreSQL uses $1, $2 placeholders
		if !strings.Contains(sql, "$1") || !strings.Contains(sql, "$2") {
			t.Errorf("Expected PostgreSQL placeholders ($1, $2), got: %s", sql)
		}
		if !strings.Contains(sql, `"dbversion"`) {
			t.Errorf("Expected quoted table name, got: %s", sql)
		}
	})

	t.Run("QuoteIdentifier", func(t *testing.T) {
		pg := postgres{}

		// Test normal identifier
		quoted := pg.quoteIdentifier("tablename")
		if quoted != `"tablename"` {
			t.Errorf("Expected quoted identifier, got: %s", quoted)
		}

		// Test identifier with quotes (SQL injection attempt)
		quoted = pg.quoteIdentifier(`table"; DROP TABLE users; --`)
		if !strings.Contains(quoted, `""`) {
			t.Errorf("Expected escaped quotes, got: %s", quoted)
		}
	})
}