package scrobble

import (
	"context"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"sync/atomic"
	"testing"
	"time"

	"github.com/jackc/pgx/v5/pgtype"

	"git.fabledsword.com/bvandeusen/minstrel/internal/scrobble/listenbrainz"
)

// helperEnqueue inserts a queue row directly so we don't go through the
// threshold path. Reuses the `setup` struct from queue_test.go.
func helperEnqueue(t *testing.T, s setup) {
	t.Helper()
	if _, err := s.pool.Exec(context.Background(),
		`INSERT INTO scrobble_queue (user_id, play_event_id, status) VALUES ($1, $2, 'pending')`,
		s.user, s.playEvent); err != nil {
		t.Fatalf("enqueue: %v", err)
	}
}

func helperPendingCount(t *testing.T, s setup) int {
	t.Helper()
	var n int
	if err := s.pool.QueryRow(context.Background(),
		`SELECT count(*) FROM scrobble_queue WHERE status = 'pending' AND play_event_id = $1`, s.playEvent).Scan(&n); err != nil {
		t.Fatalf("pending: %v", err)
	}
	return n
}

func helperFailedCount(t *testing.T, s setup) int {
	t.Helper()
	var n int
	if err := s.pool.QueryRow(context.Background(),
		`SELECT count(*) FROM scrobble_queue WHERE status = 'failed' AND play_event_id = $1`, s.playEvent).Scan(&n); err != nil {
		t.Fatalf("failed: %v", err)
	}
	return n
}

func helperPlayEventScrobbledAt(t *testing.T, s setup) bool {
	t.Helper()
	var v *time.Time
	if err := s.pool.QueryRow(context.Background(),
		`SELECT scrobbled_at FROM play_events WHERE id = $1`, s.playEvent).Scan(&v); err != nil {
		t.Fatalf("scrobbled_at: %v", err)
	}
	return v != nil
}

func helperLogger() *slog.Logger { return slog.New(slog.NewTextHandler(io.Discard, nil)) }

func newTestWorker(s setup, lb *listenbrainz.Client) *Worker {
	return NewWorker(s.pool, lb, helperLogger())
}

func TestWorker_Success_DeletesQueueRowAndStampsScrobbledAt(t *testing.T) {
	s := seed(t, seedOpts{lbToken: "tk", lbEnabled: true, durationMs: 250_000, ratio: 0.83})
	helperEnqueue(t, s)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusOK)
	}))
	defer srv.Close()
	lb := &listenbrainz.Client{BaseURL: srv.URL, HTTP: srv.Client()}
	w := newTestWorker(s, lb)

	if err := w.tickOnce(context.Background()); err != nil {
		t.Fatalf("tickOnce: %v", err)
	}
	if helperPendingCount(t, s) != 0 {
		t.Error("queue row should be deleted on success")
	}
	if helperFailedCount(t, s) != 0 {
		t.Error("no failed row expected on success")
	}
	if !helperPlayEventScrobbledAt(t, s) {
		t.Error("play_events.scrobbled_at should be populated on success")
	}
}

func TestWorker_503Once_RowRemainsAttempts1(t *testing.T) {
	s := seed(t, seedOpts{lbToken: "tk", lbEnabled: true, durationMs: 250_000, ratio: 0.83})
	helperEnqueue(t, s)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusServiceUnavailable)
	}))
	defer srv.Close()
	lb := &listenbrainz.Client{BaseURL: srv.URL, HTTP: srv.Client()}
	w := newTestWorker(s, lb)
	_ = w.tickOnce(context.Background())

	var attempts int
	if err := s.pool.QueryRow(context.Background(),
		`SELECT attempts FROM scrobble_queue WHERE play_event_id = $1`, s.playEvent).Scan(&attempts); err != nil {
		t.Fatalf("attempts: %v", err)
	}
	if attempts != 1 {
		t.Errorf("attempts = %d, want 1 after 503", attempts)
	}
	if helperPendingCount(t, s) != 1 {
		t.Error("row should remain pending after transient failure")
	}
}

// TestWorker_503SixTimes_MarksFailed: 6 ticks of 503. Tick 1-5 reschedule
// (attempts goes 1,2,3,4,5; backoffDelay returns OK for those). Tick 6
// hits backoffDelay(6) = false and marks failed (attempts stays at 5).
func TestWorker_503SixTimes_MarksFailed(t *testing.T) {
	s := seed(t, seedOpts{lbToken: "tk", lbEnabled: true, durationMs: 250_000, ratio: 0.83})
	helperEnqueue(t, s)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusServiceUnavailable)
	}))
	defer srv.Close()
	lb := &listenbrainz.Client{BaseURL: srv.URL, HTTP: srv.Client()}
	w := newTestWorker(s, lb)
	for i := 0; i < 6; i++ {
		if _, err := s.pool.Exec(context.Background(),
			`UPDATE scrobble_queue SET next_attempt_at = now() WHERE play_event_id = $1`, s.playEvent); err != nil {
			t.Fatalf("reset: %v", err)
		}
		_ = w.tickOnce(context.Background())
	}
	if helperFailedCount(t, s) != 1 {
		t.Errorf("expected row marked failed after 6 attempts; pending=%d failed=%d",
			helperPendingCount(t, s), helperFailedCount(t, s))
	}
	var attempts int
	var lastErr *string
	_ = s.pool.QueryRow(context.Background(),
		`SELECT attempts, last_error FROM scrobble_queue WHERE play_event_id = $1`, s.playEvent).Scan(&attempts, &lastErr)
	if attempts != 5 {
		t.Errorf("attempts = %d, want 5 (max retries reached)", attempts)
	}
	if lastErr == nil || *lastErr == "" {
		t.Error("last_error should be populated")
	}
}

func TestWorker_401_MarksFailedAndDisablesUser(t *testing.T) {
	s := seed(t, seedOpts{lbToken: "tk", lbEnabled: true, durationMs: 250_000, ratio: 0.83})
	helperEnqueue(t, s)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusUnauthorized)
	}))
	defer srv.Close()
	lb := &listenbrainz.Client{BaseURL: srv.URL, HTTP: srv.Client()}
	w := newTestWorker(s, lb)
	_ = w.tickOnce(context.Background())

	if helperFailedCount(t, s) != 1 {
		t.Error("401 should mark failed immediately")
	}
	cfg, _ := s.q.GetListenBrainzConfig(context.Background(), s.user)
	if cfg.ListenbrainzEnabled {
		t.Error("user listenbrainz_enabled should be set to false on auth failure")
	}
}

func TestWorker_429_RespectsRetryAfterWithoutIncrementingAttempts(t *testing.T) {
	s := seed(t, seedOpts{lbToken: "tk", lbEnabled: true, durationMs: 250_000, ratio: 0.83})
	helperEnqueue(t, s)
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Retry-After", "300")
		w.WriteHeader(http.StatusTooManyRequests)
	}))
	defer srv.Close()
	lb := &listenbrainz.Client{BaseURL: srv.URL, HTTP: srv.Client()}
	w := newTestWorker(s, lb)
	_ = w.tickOnce(context.Background())

	var attempts int
	var nextAttemptAt time.Time
	_ = s.pool.QueryRow(context.Background(),
		`SELECT attempts, next_attempt_at FROM scrobble_queue WHERE play_event_id = $1`, s.playEvent).
		Scan(&attempts, &nextAttemptAt)
	if attempts != 0 {
		t.Errorf("attempts = %d, want 0 (429 should not increment)", attempts)
	}
	if d := time.Until(nextAttemptAt); d < 250*time.Second || d > 350*time.Second {
		t.Errorf("next_attempt_at = +%v, want ~+5m (Retry-After 300)", d)
	}
}

func TestWorker_BatchOfTen_OnePost(t *testing.T) {
	s := seed(t, seedOpts{lbToken: "tk", lbEnabled: true, durationMs: 250_000, ratio: 0.83})
	// Enqueue 10 distinct play_events to test batching. We synthesize new
	// play_events by copying the seeded one; each gets its own queue row.
	for i := 0; i < 10; i++ {
		var newPE pgtype.UUID
		if err := s.pool.QueryRow(context.Background(),
			`INSERT INTO play_events (user_id, track_id, session_id, started_at, ended_at, duration_played_ms, completion_ratio, was_skipped)
			 SELECT user_id, track_id, session_id, now(), now(), duration_played_ms, completion_ratio, was_skipped FROM play_events WHERE id = $1
			 RETURNING id`, s.playEvent).Scan(&newPE); err != nil {
			t.Fatalf("dup play_event: %v", err)
		}
		if _, err := s.pool.Exec(context.Background(),
			`INSERT INTO scrobble_queue (user_id, play_event_id, status) VALUES ($1, $2, 'pending')`,
			s.user, newPE); err != nil {
			t.Fatalf("enqueue: %v", err)
		}
	}
	var posts atomic.Int32
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		posts.Add(1)
		w.WriteHeader(http.StatusOK)
	}))
	defer srv.Close()
	lb := &listenbrainz.Client{BaseURL: srv.URL, HTTP: srv.Client()}
	w := newTestWorker(s, lb)
	_ = w.tickOnce(context.Background())

	if posts.Load() != 1 {
		t.Errorf("LB POSTs = %d, want 1 (batch)", posts.Load())
	}
}