package delivery_test

import (
	"database/sql"
	"fmt"
	"log/slog"
	"net/http"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/google/uuid"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
	_ "modernc.org/sqlite" // Pure Go SQLite driver.
	"sneak.berlin/go/webhooker/internal/database"
	"sneak.berlin/go/webhooker/internal/delivery"
)

func archiveTestLogger() *slog.Logger {
	return slog.New(slog.NewTextHandler(
		os.Stderr,
		&slog.HandlerOptions{Level: slog.LevelDebug},
	))
}

// openArchiveDBForRead opens an archive file read-only so a
// test can inspect the rows the writer persisted.
func openArchiveDBForRead(
	t *testing.T, path string,
) *gorm.DB {
	t.Helper()

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

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

	gdb, err := gorm.Open(
		sqlite.Dialector{Conn: sqlDB}, &gorm.Config{},
	)
	require.NoError(t, err)

	return gdb
}

// removeArchiveFiles simulates an operator moving the archive
// away by deleting the SQLite file and its sidecar files.
func removeArchiveFiles(t *testing.T, path string) {
	t.Helper()

	for _, suffix := range []string{
		"", "-wal", "-shm", "-journal",
	} {
		err := os.Remove(path + suffix)
		if err != nil && !os.IsNotExist(err) {
			t.Fatalf("removing %s%s: %v", path, suffix, err)
		}
	}
}

// TestDeliverDatabase_ArchivesEvent verifies that delivering to
// a database target marks the delivery delivered and archives
// the full event into a separate per-webhook archive file.
func TestDeliverDatabase_ArchivesEvent(t *testing.T) {
	t.Parallel()

	dataDir := t.TempDir()
	dbMgr := database.NewTestWebhookDBManager(dataDir)

	e := delivery.NewTestEngineWithDB(
		nil, dbMgr,
		archiveTestLogger(),
		&http.Client{Timeout: 5 * time.Second},
		1,
	)

	webhookDB := testWebhookDB(t)
	event := seedEvent(t, webhookDB, `{"archived":true}`)
	d := seedDatabaseTargetDelivery(t, webhookDB, event, "")

	e.ExportDeliverDatabase(webhookDB, d)

	var updated database.Delivery

	require.NoError(t, webhookDB.First(
		&updated, "id = ?", d.ID,
	).Error)
	assert.Equal(t,
		database.DeliveryStatusDelivered, updated.Status,
		"database target should mark the delivery delivered",
	)

	archivePath := filepath.Join(
		dataDir,
		fmt.Sprintf("archive-%s.db", event.WebhookID),
	)
	assert.FileExists(t, archivePath)

	rdb := openArchiveDBForRead(t, archivePath)

	var rows []delivery.ExportArchivedEvent

	require.NoError(t, rdb.Find(&rows).Error)
	require.Len(t, rows, 1)
	assert.Equal(t, event.ID, rows[0].EventID)
	assert.Equal(t, event.WebhookID, rows[0].WebhookID)
	assert.Equal(t, event.Method, rows[0].Method)
	assert.JSONEq(t, `{"archived":true}`, rows[0].Body)
}

func TestArchiveWriter_WritesRow(t *testing.T) {
	t.Parallel()

	path := filepath.Join(t.TempDir(), "archive-wh.db")
	w := delivery.NewExportArchiveWriter(
		path, archiveTestLogger(), 0,
	)

	row := delivery.ExportArchivedEvent{
		EventID:      "ev-1",
		WebhookID:    "wh-1",
		EntrypointID: "ep-1",
		Method:       "POST",
		Headers:      `{"X":"Y"}`,
		Body:         `{"hello":"world"}`,
		ContentType:  "application/json",
	}

	require.NoError(t, w.Write(row, 0))
	assert.FileExists(t, path)

	var got []delivery.ExportArchivedEvent

	require.NoError(t, w.DB().Find(&got).Error)
	require.Len(t, got, 1)
	assert.Equal(t, "ev-1", got[0].EventID)
	assert.Equal(t, "wh-1", got[0].WebhookID)
	assert.Equal(t, "ep-1", got[0].EntrypointID)
	assert.Equal(t, row.Method, got[0].Method)
	assert.Equal(t, row.ContentType, got[0].ContentType)
	assert.JSONEq(t, `{"hello":"world"}`, got[0].Body)
	assert.False(t, got[0].ArchivedAt.IsZero())
}

func TestArchiveWriter_RecreatesAfterRemoval(
	t *testing.T,
) {
	t.Parallel()

	path := filepath.Join(t.TempDir(), "archive-wh.db")
	w := delivery.NewExportArchiveWriter(
		path, archiveTestLogger(), 0,
	)

	require.NoError(t, w.Write(
		delivery.ExportArchivedEvent{EventID: "a"}, 0,
	))
	assert.FileExists(t, path)

	// The operator moves the archive away while the handle is
	// still open.
	removeArchiveFiles(t, path)
	require.NoFileExists(t, path)

	// The next write recreates the file with a fresh schema and
	// only the new row.
	require.NoError(t, w.Write(
		delivery.ExportArchivedEvent{EventID: "b"}, 0,
	))
	assert.FileExists(t, path)

	var got []delivery.ExportArchivedEvent

	require.NoError(t, w.DB().Find(&got).Error)
	require.Len(t, got, 1)
	assert.Equal(t, "b", got[0].EventID)
}

func TestArchiveWriter_ReopenDebounce(t *testing.T) {
	t.Parallel()

	// A generous debounce keeps the two rapid writes inside
	// the window even on a heavily loaded test machine.
	path := filepath.Join(t.TempDir(), "archive-wh.db")
	w := delivery.NewExportArchiveWriter(
		path, archiveTestLogger(), 2*time.Second,
	)

	require.NoError(t, w.Write(
		delivery.ExportArchivedEvent{EventID: "a"}, 0,
	))
	require.NoError(t, w.Write(
		delivery.ExportArchivedEvent{EventID: "b"}, 0,
	))

	// Two writes inside the debounce window trigger only the
	// initial open — no extra close/reopen.
	assert.Equal(t, 1, w.Reopens())

	time.Sleep(2100 * time.Millisecond)

	require.NoError(t, w.Write(
		delivery.ExportArchivedEvent{EventID: "c"}, 0,
	))

	// A write after the window elapses closes and reopens once.
	assert.Equal(t, 2, w.Reopens())
}

func TestArchiveWriter_ExpiryPrune(t *testing.T) {
	t.Parallel()

	path := filepath.Join(t.TempDir(), "archive-wh.db")
	w := delivery.NewExportArchiveWriter(
		path, archiveTestLogger(), 0,
	)

	require.NoError(t, w.Open(0))

	old := delivery.ExportArchivedEvent{
		EventID:    "old",
		ArchivedAt: time.Now().Add(-2 * time.Hour),
	}
	fresh := delivery.ExportArchivedEvent{
		EventID:    "fresh",
		ArchivedAt: time.Now(),
	}

	require.NoError(t, w.DB().Create(&old).Error)
	require.NoError(t, w.DB().Create(&fresh).Error)

	// Reopening with a one-hour expiry prunes the old row.
	require.NoError(t, w.Reopen(time.Hour))

	var got []delivery.ExportArchivedEvent

	require.NoError(t, w.DB().Find(&got).Error)
	require.Len(t, got, 1)
	assert.Equal(t, "fresh", got[0].EventID)
}

func TestParseArchiveExpiry(t *testing.T) {
	t.Parallel()

	cases := []struct {
		name string
		in   string
		want time.Duration
	}{
		{"empty config", "", 0},
		{"explicit never", `{"expiry":"never"}`, 0},
		{"empty expiry", `{"expiry":""}`, 0},
		{"duration", `{"expiry":"1h"}`, time.Hour},
		{"zero duration", `{"expiry":"0s"}`, 0},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			t.Parallel()

			got, err := delivery.ExportParseArchiveExpiry(tc.in)
			require.NoError(t, err)
			assert.Equal(t, tc.want, got)
		})
	}

	_, err := delivery.ExportParseArchiveExpiry(
		`{"expiry":"nonsense"}`,
	)
	require.Error(t, err)
}

// seedDatabaseTargetDelivery seeds a pending delivery for a
// database target with the given config JSON and returns the
// in-memory delivery the target handler is invoked with.
func seedDatabaseTargetDelivery(
	t *testing.T,
	webhookDB *gorm.DB,
	event database.Event,
	config string,
) *database.Delivery {
	t.Helper()

	dlv := seedDelivery(
		t, webhookDB, event.ID, uuid.New().String(),
		database.DeliveryStatusPending,
	)

	d := &database.Delivery{
		EventID:  event.ID,
		TargetID: dlv.TargetID,
		Status:   database.DeliveryStatusPending,
		Event:    event,
		Target: database.Target{
			Name:   "test-db",
			Type:   database.TargetTypeDatabase,
			Config: config,
		},
	}
	d.ID = dlv.ID

	return d
}

// TestDeliverDatabase_ArchiveFailureFailsDelivery verifies that
// an archive error (here: an unparseable expiry in the target
// config) fails the delivery loudly: the attempt is recorded as
// failed with the error and the delivery is marked failed, not
// delivered.
func TestDeliverDatabase_ArchiveFailureFailsDelivery(
	t *testing.T,
) {
	t.Parallel()

	dataDir := t.TempDir()

	e := delivery.NewTestEngineWithDB(
		nil, database.NewTestWebhookDBManager(dataDir),
		archiveTestLogger(),
		&http.Client{Timeout: 5 * time.Second},
		1,
	)

	webhookDB := testWebhookDB(t)
	event := seedEvent(t, webhookDB, `{"archived":false}`)
	d := seedDatabaseTargetDelivery(
		t, webhookDB, event, `{"expiry":"nonsense"}`,
	)

	e.ExportDeliverDatabase(webhookDB, d)

	var updated database.Delivery

	require.NoError(t, webhookDB.First(
		&updated, "id = ?", d.ID,
	).Error)
	assert.Equal(t,
		database.DeliveryStatusFailed, updated.Status,
		"archive failure must mark the delivery failed",
	)

	var results []database.DeliveryResult

	require.NoError(t, webhookDB.Where(
		"delivery_id = ?", d.ID,
	).Find(&results).Error)
	require.Len(t, results, 1)
	assert.False(t,
		results[0].Success,
		"the attempt must be recorded as failed",
	)
	assert.Contains(t,
		results[0].Error, "nonsense",
		"the archive error must be recorded on the attempt",
	)

	assert.NoFileExists(t,
		filepath.Join(
			dataDir,
			fmt.Sprintf("archive-%s.db", event.WebhookID),
		),
		"no archive file should exist for a failed config",
	)
}

func TestValidateArchiveExpiry(t *testing.T) {
	t.Parallel()

	valid := []string{"", "never", "1h", "720h", "30m"}
	for _, in := range valid {
		require.NoError(t,
			delivery.ValidateArchiveExpiry(in),
			"expiry %q should be accepted", in,
		)
	}

	invalid := []string{"nonsense", "7d", "-5h", "0s", "0"}
	for _, in := range invalid {
		require.Error(t,
			delivery.ValidateArchiveExpiry(in),
			"expiry %q should be rejected", in,
		)
	}
}