package database_test

import (
	"database/sql"
	"fmt"
	"os"
	"path/filepath"
	"testing"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	_ "modernc.org/sqlite"
	"sneak.berlin/go/webhooker/internal/database"
)

// testDataDirPerm is the mode the test data directory is created
// with.
const testDataDirPerm = 0o750

// eventDBDataDir returns a data directory that a WebhookDBManager
// can be pointed at.
func eventDBDataDir(t *testing.T) string {
	t.Helper()

	dir := filepath.Join(t.TempDir(), "events")
	require.NoError(t, os.MkdirAll(dir, testDataDirPerm))

	return dir
}

// openRawEventDB opens the per-webhook database file directly,
// without the manager, so a test can put a file on disk in a state
// the manager has to cope with, or inspect one afterwards.
func openRawEventDB(
	t *testing.T, dataDir, webhookID string,
) *sql.DB {
	t.Helper()

	path := filepath.Join(
		dataDir, fmt.Sprintf("events-%s.db", webhookID),
	)

	sqlDB, err := sql.Open(
		"sqlite",
		fmt.Sprintf("file:%s?mode=rwc", path),
	)
	require.NoError(t, err)

	t.Cleanup(func() { _ = sqlDB.Close() })

	return sqlDB
}

// countTargetRows returns the number of rows in the targets table of
// a per-webhook database file, or -1 if the table does not exist.
func countTargetRows(t *testing.T, sqlDB *sql.DB) int {
	t.Helper()

	var tables int

	require.NoError(t, sqlDB.QueryRowContext(
		t.Context(),
		"SELECT count(*) FROM sqlite_master "+
			"WHERE type = 'table' AND name = 'targets'",
	).Scan(&tables))

	if tables == 0 {
		return -1
	}

	var rows int

	require.NoError(t, sqlDB.QueryRowContext(
		t.Context(), "SELECT count(*) FROM targets",
	).Scan(&rows))

	return rows
}

// TestOpenPurgesLeakedTargetRows covers the sweep for event
// databases written by a build that let GORM upsert target rows
// into them: opening the database clears them, and opening it again
// is a no-op.
func TestOpenPurgesLeakedTargetRows(t *testing.T) {
	t.Parallel()

	dataDir := eventDBDataDir(t)
	webhookID := uuid.New().String()

	// Create the file the way the application does, so the targets
	// table has exactly the shape AutoMigrate gives it, then write
	// a leaked row into it the way the association upsert did.
	initial := database.NewTestWebhookDBManager(dataDir)

	_, err := initial.GetDB(webhookID)
	require.NoError(t, err)
	require.NoError(t, initial.CloseAll())

	seed := openRawEventDB(t, dataDir, webhookID)

	_, err = seed.ExecContext(
		t.Context(),
		"INSERT INTO targets "+
			"(id, webhook_id, name, type, config) "+
			"VALUES (?, '', ?, ?, ?)",
		uuid.New().String(),
		"leaked-target",
		"slack",
		`{"webhookUrl":"https://hooks.example/T000/B000/secret"}`,
	)
	require.NoError(t, err)
	require.Equal(t, 1, countTargetRows(t, seed))
	require.NoError(t, seed.Close())

	mgr := database.NewTestWebhookDBManager(dataDir)

	_, err = mgr.GetDB(webhookID)
	require.NoError(t, err)
	require.NoError(t, mgr.CloseAll())

	check := openRawEventDB(t, dataDir, webhookID)
	assert.Zero(t, countTargetRows(t, check))
	require.NoError(t, check.Close())

	// Idempotent: a second open leaves it at zero and does not
	// error.
	again := database.NewTestWebhookDBManager(dataDir)

	_, err = again.GetDB(webhookID)
	require.NoError(t, err)
	require.NoError(t, again.CloseAll())

	recheck := openRawEventDB(t, dataDir, webhookID)
	assert.Zero(t, countTargetRows(t, recheck))
}

// TestOpenSucceedsWithoutTargetsTable covers an existing event
// database that never grew a targets table. The sweep must not fail
// startup on it.
func TestOpenSucceedsWithoutTargetsTable(t *testing.T) {
	t.Parallel()

	dataDir := eventDBDataDir(t)
	webhookID := uuid.New().String()

	seed := openRawEventDB(t, dataDir, webhookID)

	_, err := seed.ExecContext(
		t.Context(),
		"CREATE TABLE events (id text PRIMARY KEY)",
	)
	require.NoError(t, err)
	require.NoError(t, seed.Close())

	mgr := database.NewTestWebhookDBManager(dataDir)

	db, err := mgr.GetDB(webhookID)
	require.NoError(t, err)
	assert.NotNil(t, db)
	require.NoError(t, mgr.CloseAll())
}

// TestEventDBCreateOmitsAssociations covers the connection-level
// guard directly: a Delivery carrying its Event and Target in
// memory, written through the manager's handle, must store only the
// delivery row.
func TestEventDBCreateOmitsAssociations(t *testing.T) {
	t.Parallel()

	dataDir := eventDBDataDir(t)
	webhookID := uuid.New().String()

	mgr := database.NewTestWebhookDBManager(dataDir)

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

	target := database.Target{
		WebhookID: webhookID,
		Name:      "leaky-target",
		Type:      database.TargetTypeSlack,
		Config:    `{"webhookUrl":"https://hooks.example/secret"}`,
	}
	target.ID = uuid.New().String()

	event := database.Event{
		WebhookID:    webhookID,
		EntrypointID: uuid.New().String(),
		Method:       "POST",
		Headers:      `{}`,
		Body:         `{}`,
	}
	event.ID = uuid.New().String()

	d := &database.Delivery{
		EventID:  event.ID,
		TargetID: target.ID,
		Status:   database.DeliveryStatusPending,
		Event:    event,
		Target:   target,
	}
	d.ID = uuid.New().String()

	require.NoError(t, db.Create(d).Error)
	require.NoError(t, db.Model(d).
		Update("status", database.DeliveryStatusDelivered).
		Error)
	require.NoError(t, mgr.CloseAll())

	check := openRawEventDB(t, dataDir, webhookID)
	assert.Zero(t, countTargetRows(t, check))
}