package database_test

import (
	"os"
	"regexp"
	"testing"

	"github.com/DATA-DOG/go-sqlmock"
	"github.com/rede5/gohorsejobs/backend/internal/database"
)

func TestBuildConnectionString(t *testing.T) {
	// Backup env vars
	oldURL := os.Getenv("DATABASE_URL")

	defer func() {
		os.Setenv("DATABASE_URL", oldURL)
	}()

	// Case 1: DATABASE_URL
	os.Setenv("DATABASE_URL", "postgres://foo:bar@localhost:5432/db?sslmode=disable")
	s, err := database.BuildConnectionString()
	if err != nil {
		t.Errorf("Unexpected error: %v", err)
	}
	if s != "postgres://foo:bar@localhost:5432/db?sslmode=disable" {
		t.Errorf("Mismatch URL")
	}

	// Case 2: Missing DATABASE_URL
	os.Unsetenv("DATABASE_URL")
	_, err = database.BuildConnectionString()
	if err == nil {
		t.Error("Expected error for missing DATABASE_URL")
	}
}

func TestRunMigrations(t *testing.T) {
	// Setup Mock DB
	db, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("an error '%s' was not expected when opening a stub database connection", err)
	}
	defer db.Close()

	// Inject DB
	database.DB = db

	// Create temp migrations dir
	err = os.Mkdir("migrations", 0755)
	if err != nil && !os.IsExist(err) {
		t.Fatalf("Failed to create migrations dir: %v", err)
	}
	defer os.RemoveAll("migrations")

	// Create dummy migration file
	content := "CREATE TABLE test (id int);"
	err = os.WriteFile("migrations/001_test.sql", []byte(content), 0644)
	if err != nil {
		t.Fatalf("Failed to write migration file: %v", err)
	}

	// Mock Expectations
	mock.ExpectExec(regexp.QuoteMeta(`
		CREATE TABLE IF NOT EXISTS schema_migrations (
			filename TEXT PRIMARY KEY,
			applied_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
		)
	`)).WillReturnResult(sqlmock.NewResult(0, 0))
	mock.ExpectQuery(regexp.QuoteMeta("SELECT EXISTS(SELECT 1 FROM schema_migrations WHERE filename = $1)")).
		WithArgs("001_test.sql").
		WillReturnRows(sqlmock.NewRows([]string{"exists"}).AddRow(false))
	mock.ExpectBegin()
	mock.ExpectExec(regexp.QuoteMeta(content)).WillReturnResult(sqlmock.NewResult(0, 0))
	mock.ExpectExec(regexp.QuoteMeta("INSERT INTO schema_migrations (filename) VALUES ($1)")).
		WithArgs("001_test.sql").
		WillReturnResult(sqlmock.NewResult(1, 1))
	mock.ExpectCommit()

	// Run
	database.RunMigrations()

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("there were unfulfilled expectations: %s", err)
	}
}