package database_test

import (
	"context"
	"io/fs"
	"net/http"
	"os"
	"path/filepath"
	"testing"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/fx/fxtest"
	"sneak.berlin/go/webhooker/internal/config"
	"sneak.berlin/go/webhooker/internal/database"
	"sneak.berlin/go/webhooker/internal/globals"
	"sneak.berlin/go/webhooker/internal/logger"
)

// ownerOnly is the mode every SQLite file the service owns must have.
// Spelled out rather than referencing database.SQLiteFilePerm so the
// test fails if the constant itself is loosened.
const ownerOnly fs.FileMode = 0o600

// requireOwnerOnly asserts that path exists and is readable and
// writable by its owner and by nobody else.
func requireOwnerOnly(t *testing.T, path string) {
	t.Helper()

	info, err := os.Stat(path)
	require.NoError(t, err, "%s must exist", path)
	assert.Equal(
		t,
		ownerOnly,
		info.Mode().Perm(),
		"%s holds credentials and must not be readable by "+
			"anyone but its owner",
		path,
	)
}

// requireDatabaseSetOwnerOnly asserts the mode of a database file and
// of both WAL sidecars. The sidecars carry the same rows as the
// database, so tightening only the main file fixes nothing.
func requireDatabaseSetOwnerOnly(t *testing.T, dbPath string) {
	t.Helper()

	requireOwnerOnly(t, dbPath)
	requireOwnerOnly(t, dbPath+"-wal")
	requireOwnerOnly(t, dbPath+"-shm")
}

// TestMainDatabaseFilesAreOwnerOnly covers the tier the defect was
// reported against: webhooker.db holds targets.config in plaintext —
// bearer tokens, API keys, Slack webhook URLs — and the session
// encryption key.
func TestMainDatabaseFilesAreOwnerOnly(t *testing.T) {
	t.Parallel()

	lc := fxtest.NewLifecycle(t)

	l, err := logger.New(lc, logger.LoggerParams{
		Globals: &globals.Globals{
			Appname: testAppname,
			Version: testVersion,
		},
	})
	require.NoError(t, err)

	// A directory the application creates itself, not one t.TempDir
	// made at 0700, so the mode below is the application's.
	dataDir := filepath.Join(t.TempDir(), "data")

	db, err := database.New(lc, database.DatabaseParams{
		Config: &config.Config{DataDir: dataDir},
		Logger: l,
	})
	require.NoError(t, err)

	ctx := context.Background()
	require.NoError(t, lc.Start(ctx))

	defer func() { require.NoError(t, lc.Stop(ctx)) }()

	// Write through the real model so the WAL is populated and both
	// sidecars are on disk while the handle is open.
	require.NoError(t, db.DB().Create(&database.Webhook{
		Name: testWebhookName,
	}).Error)

	requireDatabaseSetOwnerOnly(
		t, filepath.Join(dataDir, database.MainDBFileName),
	)

	// The data directory grants nothing to `other`. Asserted as a
	// property rather than as an exact 0750, because MkdirAll applies
	// the ambient umask: the exact mode is the developer's umask as
	// much as the application's request, and pinning it would make
	// `make check` pass or fail on where it is run. The group bits are
	// deliberately left unasserted — deployments may rely on them.
	info, err := os.Stat(dataDir)
	require.NoError(t, err)
	assert.Zero(
		t,
		info.Mode().Perm()&0o007,
		"the data directory must not be world-accessible",
	)
}

// TestPerWebhookEventDatabaseFilesAreOwnerOnly covers the events-*.db
// tier. These carry no credential canaries since
// https://git.eeqj.de/sneak/webhooker/issues/206, but they hold every
// received request body and header.
func TestPerWebhookEventDatabaseFilesAreOwnerOnly(t *testing.T) {
	t.Parallel()

	mgr, lc := setupTestWebhookDBManager(t)
	ctx := context.Background()
	require.NoError(t, lc.Start(ctx))

	defer func() { require.NoError(t, lc.Stop(ctx)) }()

	webhookID := uuid.New().String()

	db, err := mgr.GetDB(webhookID)
	require.NoError(t, err)

	require.NoError(t, db.Create(&database.Event{
		WebhookID:    webhookID,
		EntrypointID: uuid.New().String(),
		Method:       http.MethodPost,
		Body:         "{}",
	}).Error)

	requireDatabaseSetOwnerOnly(t, mgr.DBPath(webhookID))
}

// TestArchiveDatabaseFilesAreOwnerOnly covers the archive-*.db tier.
// internal/delivery builds that path and opens it through OpenSQLite,
// the same single open path exercised here, so the mode is settled for
// all three tiers in one place.
func TestArchiveDatabaseFilesAreOwnerOnly(t *testing.T) {
	t.Parallel()

	ctx := context.Background()
	path := filepath.Join(
		t.TempDir(), "archive-"+uuid.New().String()+".db",
	)

	sqlDB, err := database.OpenSQLite(path, database.SQLiteModeCreate)
	require.NoError(t, err)

	defer func() { require.NoError(t, sqlDB.Close()) }()

	_, err = sqlDB.ExecContext(ctx, "create table t (id integer)")
	require.NoError(t, err)

	requireDatabaseSetOwnerOnly(t, path)
}

// TestOpenSQLiteTightensFilesLeftWorldReadable is the upgrade case: a
// data directory an earlier build left at 0644, including a
// developer's own scratch directory, is fixed when it is opened rather
// than staying exposed until it is recreated.
func TestOpenSQLiteTightensFilesLeftWorldReadable(t *testing.T) {
	t.Parallel()

	dir := t.TempDir()
	path := filepath.Join(dir, database.MainDBFileName)

	// A database and both sidecars as the pre-fix build left them.
	for _, p := range []string{path, path + "-wal", path + "-shm"} {
		require.NoError(t, os.WriteFile(p, nil, 0o644)) //nolint:gosec // the mode under test
	}

	sqlDB, err := database.OpenSQLite(path, database.SQLiteModeCreate)
	require.NoError(t, err)

	require.NoError(t, sqlDB.Close())

	requireDatabaseSetOwnerOnly(t, path)
}

// TestOpenSQLiteExistingModeDoesNotCreateTheFile guards the mechanism
// the fix uses: OpenSQLite now creates the database file itself, and
// must not do so for a caller that asked for an existing database. An
// empty file materialized here would turn a missing-database error
// into a silently empty one.
func TestOpenSQLiteExistingModeDoesNotCreateTheFile(t *testing.T) {
	t.Parallel()

	ctx := context.Background()
	path := filepath.Join(t.TempDir(), "absent.db")

	sqlDB, err := database.OpenSQLite(path, database.SQLiteModeExisting)
	if err == nil {
		// sql.Open is lazy: force the connection that fails.
		require.Error(t, sqlDB.PingContext(ctx))
		require.NoError(t, sqlDB.Close())
	}

	_, statErr := os.Stat(path)
	assert.ErrorIs(t, statErr, fs.ErrNotExist)
}

// TestReopenAfterRestartKeepsFilesOwnerOnly is the restart case: a
// process that closed its files must be able to open them again at
// 0600, including through a gorm handle, and the sidecars must come
// back at 0600 too rather than at SQLite's own default.
func TestReopenAfterRestartKeepsFilesOwnerOnly(t *testing.T) {
	t.Parallel()

	ctx := context.Background()
	dir := t.TempDir()
	path := filepath.Join(dir, database.MainDBFileName)

	first, err := database.OpenSQLite(path, database.SQLiteModeCreate)
	require.NoError(t, err)

	_, err = first.ExecContext(ctx, "create table t (id integer)")
	require.NoError(t, err)
	require.NoError(t, first.Close())

	second, err := database.OpenSQLite(path, database.SQLiteModeCreate)
	require.NoError(t, err)

	defer func() { require.NoError(t, second.Close()) }()

	_, err = second.ExecContext(ctx, "insert into t (id) values (1)")
	require.NoError(t, err)

	requireDatabaseSetOwnerOnly(t, path)

	var got int

	require.NoError(t,
		second.QueryRowContext(ctx, "select id from t").Scan(&got))
	assert.Equal(t, 1, got)
}