package scheduler

import (
	"context"
	"database/sql"
	"testing"
	"time"
	"unicode/utf8"

	sqlmock "github.com/DATA-DOG/go-sqlmock"

	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
	"github.com/Molecule-AI/molecule-monorepo/platform/internal/textutil"
)

// errDBDown is a sentinel error used by tests to simulate a DB connection failure.
var errDBDown = sql.ErrConnDone

// setupTestDB replaces the global db.DB with a sqlmock and returns the mock
// handle. The real DB is restored (by closing the mock conn) via t.Cleanup.
func setupTestDB(t *testing.T) sqlmock.Sqlmock {
	t.Helper()
	mockDB, mock, err := sqlmock.New()
	if err != nil {
		t.Fatalf("failed to create sqlmock: %v", err)
	}
	db.DB = mockDB
	t.Cleanup(func() { mockDB.Close() })
	return mock
}

// panicProxy is a test double whose ProxyA2ARequest always panics.
// Used by TestPanicRecovery to verify the scheduler's goroutine-level
// panic recovery in fireSchedule.
type panicProxy struct{}

func (p *panicProxy) ProxyA2ARequest(
	_ context.Context, _ string, _ []byte, _ string, _ bool,
) (int, []byte, error) {
	panic("simulated A2A proxy panic")
}

// ── TestLastTickAt_zero ───────────────────────────────────────────────────────

// TestLastTickAt_zero confirms that LastTickAt returns a zero time.Time on a
// freshly-created scheduler that has never been started or ticked.
func TestLastTickAt_zero(t *testing.T) {
	s := New(nil, nil)
	if got := s.LastTickAt(); !got.IsZero() {
		t.Errorf("LastTickAt() before any tick = %v, want zero time.Time", got)
	}
}

// ── TestHealthy_beforeStart ───────────────────────────────────────────────────

// TestHealthy_beforeStart confirms that Healthy returns false when lastTickAt
// is zero (scheduler created but never ticked).
func TestHealthy_beforeStart(t *testing.T) {
	s := New(nil, nil)
	if s.Healthy() {
		t.Error("Healthy() = true on a scheduler that has never ticked, want false")
	}
}

// ── TestHealthy_freshTick ─────────────────────────────────────────────────────

// TestHealthy_freshTick sets lastTickAt to the current time — mirroring what
// tick() does after a completed poll cycle — and confirms Healthy returns true.
func TestHealthy_freshTick(t *testing.T) {
	s := New(nil, nil)

	// Simulate what tick() writes after wg.Wait() returns.
	s.mu.Lock()
	s.lastTickAt = time.Now()
	s.mu.Unlock()

	if !s.Healthy() {
		t.Error("Healthy() = false immediately after a fresh tick timestamp, want true")
	}
}

// ── TestHealthy_stale ─────────────────────────────────────────────────────────

// TestHealthy_stale backdates lastTickAt by 3×pollInterval (well beyond the
// 2×pollInterval liveness window) and confirms Healthy returns false.
func TestHealthy_stale(t *testing.T) {
	s := New(nil, nil)

	s.mu.Lock()
	s.lastTickAt = time.Now().Add(-3 * pollInterval) // 90 s ago; threshold is 60 s
	s.mu.Unlock()

	if s.Healthy() {
		t.Errorf("Healthy() = true when lastTickAt is 3×pollInterval (%s) ago, want false",
			3*pollInterval)
	}
}

// ── TestComputeNextRun_valid ──────────────────────────────────────────────────

// TestComputeNextRun_valid checks that "0 * * * *" (top-of-hour) returns a
// future time whose Minute() == 0 when the reference is mid-hour.
func TestComputeNextRun_valid(t *testing.T) {
	// 2025-01-01 12:30 UTC — clearly mid-hour so "next" top-of-hour is 13:00.
	ref := time.Date(2025, 1, 1, 12, 30, 0, 0, time.UTC)

	next, err := ComputeNextRun("0 * * * *", "UTC", ref)
	if err != nil {
		t.Fatalf("ComputeNextRun(valid expr) returned unexpected error: %v", err)
	}
	if !next.After(ref) {
		t.Errorf("ComputeNextRun() = %v, want a time strictly after ref %v", next, ref)
	}
	if next.Minute() != 0 {
		t.Errorf("ComputeNextRun() minute = %d, want 0 (top of hour)", next.Minute())
	}
}

// ── TestComputeNextRun_invalid ────────────────────────────────────────────────

// TestComputeNextRun_invalid confirms that an unparseable cron expression
// returns a non-nil error.
func TestComputeNextRun_invalid(t *testing.T) {
	_, err := ComputeNextRun("not-a-cron", "UTC", time.Now())
	if err == nil {
		t.Error("ComputeNextRun(invalid cron expr) = nil, want non-nil error")
	}
}

// ── TestComputeNextRun_invalidTimezone ────────────────────────────────────────

// TestComputeNextRun_invalidTimezone confirms that an unrecognised IANA
// timezone name returns a non-nil error (rather than silently falling back
// to UTC, which could mask misconfigured schedules).
func TestComputeNextRun_invalidTimezone(t *testing.T) {
	_, err := ComputeNextRun("0 * * * *", "Not/AZone", time.Now())
	if err == nil {
		t.Error("ComputeNextRun(invalid tz) = nil, want non-nil error")
	}
}

// ── TestPanicRecovery ─────────────────────────────────────────────────────────

// TestPanicRecovery verifies that a panic inside a fireSchedule goroutine does
// NOT crash the scheduler.
//
// The test calls tick() directly with a sqlmock that surfaces one due schedule.
// panicProxy causes ProxyA2ARequest to panic; the deferred recover() in
// fireSchedule catches it.  After tick() returns, lastTickAt must be set and
// Healthy() must return true — proving the scheduler survived.
//
// Without panic recovery an unrecovered goroutine panic terminates the entire
// test binary, so the test completing is itself evidence that recovery worked.
func TestPanicRecovery(t *testing.T) {
	mock := setupTestDB(t)

	// WorkspaceID must be ≥12 chars: fireSchedule slices it with [:12] for logging.
	schedRows := sqlmock.NewRows(
		[]string{"id", "workspace_id", "name", "cron_expr", "timezone", "prompt"},
	).AddRow(
		"sched-panic-01",       // id
		"ws-panic-workspace-1", // workspace_id (21 chars > 12)
		"panic-job",            // name
		"* * * * *",            // cron_expr
		"UTC",                  // timezone
		"fire and panic",       // prompt
	)
	mock.ExpectQuery(`SELECT id, workspace_id`).WillReturnRows(schedRows)

	s := New(&panicProxy{}, nil)

	// tick() launches fireSchedule in a goroutine that will panic.
	// If there is no recovery, the goroutine crash terminates the process here.
	s.tick(context.Background())

	// tick() returned normally → the panic was caught, wg.Wait() completed,
	// and lastTickAt was updated.
	if !s.Healthy() {
		t.Error("Healthy() = false after panic-recovery tick, want true " +
			"— scheduler must survive a panicking A2A proxy")
	}

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations: %v", err)
	}
}

// ── TestShort_helper ──────────────────────────────────────────────────────────
// Regression guard for the short() helper that replaced unsafe [:N] slices
// after code review. Panicked when IDs were shorter than the slice bound.

func TestShort_helper(t *testing.T) {
	cases := []struct {
		in   string
		n    int
		want string
	}{
		{"abcdef1234567890", 8, "abcdef12"},
		{"abc", 8, "abc"}, // shorter than n — no panic, no truncation
		{"", 8, ""},
		{"12345678", 8, "12345678"}, // exactly n
	}
	for _, tc := range cases {
		if got := short(tc.in, tc.n); got != tc.want {
			t.Errorf("short(%q, %d) = %q, want %q", tc.in, tc.n, got, tc.want)
		}
	}
}

// ── TestRecordSkipped_writesSkippedStatus ────────────────────────────────────
// #115 coverage gap: the recordSkipped path wasn't tested at all when it
// first landed. Exercises the UPDATE workspace_schedules + INSERT into
// activity_logs via sqlmock. Broadcaster is nil so we don't need to stub
// RecordAndBroadcast (the nil-check in recordSkipped handles that).

func TestRecordSkipped_writesSkippedStatus(t *testing.T) {
	mock := setupTestDB(t)
	s := New(nil, nil)

	sched := scheduleRow{
		ID:          "11111111-1111-1111-1111-111111111111",
		WorkspaceID: "22222222-2222-2222-2222-222222222222",
		Name:        "Hourly security audit",
		CronExpr:    "17 * * * *",
		Timezone:    "UTC",
		Prompt:      "audit",
	}

	// Expect the schedule-row UPDATE with last_status='skipped' and the
	// cron_run activity_logs INSERT with status='skipped' + error_detail
	// carrying the active_tasks reason.
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs(sched.ID, sqlmock.AnyArg(), sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectExec(`INSERT INTO activity_logs`).
		WithArgs(sched.WorkspaceID, sqlmock.AnyArg(), sqlmock.AnyArg(), sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))

	s.recordSkipped(context.Background(), sched, 3)

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet sqlmock expectations: %v", err)
	}
}

// ── successProxy ─────────────────────────────────────────────────────────────

// successProxy is a test double whose ProxyA2ARequest always returns HTTP 200
// with no error, simulating a healthy A2A round-trip.
type successProxy struct{}

func (p *successProxy) ProxyA2ARequest(
	_ context.Context, _ string, _ []byte, _ string, _ bool,
) (int, []byte, error) {
	return 200, []byte(`{"ok":true}`), nil
}

// ── TestFireSchedule_ComputeNextRunError (#722 Bug 1) ─────────────────────────
//
// When ComputeNextRun fails (bad cron expression), fireSchedule must NOT write
// NULL to next_run_at — it must use COALESCE so the existing DB value is kept.
// Proof: the UPDATE ExecContext must still be called (schedule not abandoned)
// and sqlmock satisfies all expectations (no unexpected SQL).

func TestFireSchedule_ComputeNextRunError(t *testing.T) {
	mock := setupTestDB(t)

	sched := scheduleRow{
		ID:          "11111111-dead-beef-0000-000000000001",
		WorkspaceID: "22222222-dead-beef-0000-000000000002",
		Name:        "bad-cron-job",
		CronExpr:    "not-a-valid-cron", // guaranteed to fail ComputeNextRun
		Timezone:    "UTC",
		Prompt:      "do something",
	}

	// active_tasks check → 0 (workspace is idle; proceed to fire)
	mock.ExpectQuery(`SELECT COALESCE`).
		WillReturnRows(sqlmock.NewRows([]string{"coalesce"}).AddRow(0))

	// #795 consecutive_empty_runs reset — successProxy returns {"ok":true}
	// which is non-empty, so the counter is reset to 0.
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs(sched.ID).
		WillReturnResult(sqlmock.NewResult(0, 1))

	// UPDATE must fire — COALESCE($2, next_run_at) keeps existing value when $2 is nil.
	// AnyArg for $2 because it will be nil (ComputeNextRun failed).
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs(sched.ID, sqlmock.AnyArg(), "ok", "").
		WillReturnResult(sqlmock.NewResult(0, 1))

	// activity_logs INSERT always fires
	mock.ExpectExec(`INSERT INTO activity_logs`).
		WithArgs(sched.WorkspaceID, sqlmock.AnyArg(), sqlmock.AnyArg(), "ok", "").
		WillReturnResult(sqlmock.NewResult(0, 1))

	s := New(&successProxy{}, nil)
	s.fireSchedule(context.Background(), sched)

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations — schedule update was skipped or next_run_at not preserved: %v", err)
	}
}

// ── TestRecordSkipped_ComputeNextRunError (#722 Bug 1 — skipped path) ─────────
//
// Same invariant as TestFireSchedule_ComputeNextRunError but for the
// recordSkipped path: a bad cron expression must not NULL out next_run_at.

func TestRecordSkipped_ComputeNextRunError(t *testing.T) {
	mock := setupTestDB(t)

	sched := scheduleRow{
		ID:          "33333333-dead-beef-0000-000000000003",
		WorkspaceID: "44444444-dead-beef-0000-000000000004",
		Name:        "bad-cron-skip",
		CronExpr:    "not-a-valid-cron",
		Timezone:    "UTC",
		Prompt:      "skipped task",
	}

	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs(sched.ID, sqlmock.AnyArg(), sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectExec(`INSERT INTO activity_logs`).
		WithArgs(sched.WorkspaceID, sqlmock.AnyArg(), sqlmock.AnyArg(), sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))

	s := New(nil, nil)
	s.recordSkipped(context.Background(), sched, 2)

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations: %v", err)
	}
}

// ── TestRepairNullNextRunAt_RepairsRows (#722 Bug 3) ──────────────────────────
//
// repairNullNextRunAt must SELECT enabled schedules with NULL next_run_at,
// compute the next fire time, and UPDATE each row.

func TestRepairNullNextRunAt_RepairsRows(t *testing.T) {
	mock := setupTestDB(t)

	// Two schedules whose next_run_at is NULL and whose cron exprs are valid.
	mock.ExpectQuery(`SELECT id, cron_expr, timezone`).
		WillReturnRows(sqlmock.NewRows([]string{"id", "cron_expr", "timezone"}).
			AddRow("sched-repair-01", "0 * * * *", "UTC").
			AddRow("sched-repair-02", "30 9 * * 1", "America/New_York"))

	// Expect one UPDATE per repaired row.
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs("sched-repair-01", sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs("sched-repair-02", sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))

	s := New(nil, nil)
	s.repairNullNextRunAt(context.Background())

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations: %v", err)
	}
}

// ── TestRepairNullNextRunAt_DBError_NoPanic (#722 Bug 3) ──────────────────────
//
// A DB error from the SELECT must be logged but must not panic — the scheduler
// startup should proceed normally.

func TestRepairNullNextRunAt_DBError_NoPanic(t *testing.T) {
	mock := setupTestDB(t)

	mock.ExpectQuery(`SELECT id, cron_expr, timezone`).
		WillReturnError(errDBDown)

	s := New(nil, nil)
	// Must not panic:
	s.repairNullNextRunAt(context.Background())

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations: %v", err)
	}
}

// ──────────────────────────────────────────────────────────────────────────────
// repairNullNextRunAt + hibernation (#711 + #722 integration)
// ──────────────────────────────────────────────────────────────────────────────

// TestRepairNullNextRunAt_HibernatedWorkspace_ScheduleRepaired verifies that
// repairNullNextRunAt() repairs schedules belonging to hibernated workspaces.
//
// Context: the repair query is:
//
//	SELECT id, cron_expr, timezone
//	FROM workspace_schedules
//	WHERE enabled = true AND next_run_at IS NULL
//
// Critically, there is NO "AND workspace.status != 'hibernated'" filter.
// This is intentional — a hibernated workspace should wake up on schedule
// (via the auto-wake A2A path). If the repair skipped hibernated workspaces,
// any schedule whose next_run_at was NULL'd before hibernation would never
// fire again even after the workspace wakes.
//
// This test simulates a schedule with a NULL next_run_at whose owning workspace
// is currently hibernated, and asserts the UPDATE fires to set next_run_at.
func TestRepairNullNextRunAt_HibernatedWorkspace_ScheduleRepaired(t *testing.T) {
	mock := setupTestDB(t)

	// The repair SELECT has no workspace status filter — a hibernated workspace's
	// schedule appears in the result set normally.
	mock.ExpectQuery(`SELECT id, cron_expr, timezone`).
		WillReturnRows(sqlmock.NewRows([]string{"id", "cron_expr", "timezone"}).
			AddRow("sched-hibernated-01", "0 9 * * *", "UTC"))

	// Repair must attempt the UPDATE (next_run_at computed from valid cron expr).
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs("sched-hibernated-01", sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))

	s := New(nil, nil)
	s.repairNullNextRunAt(context.Background())

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations: %v\n"+
			"repairNullNextRunAt must not filter out hibernated workspaces — "+
			"their schedules must still be repaired so they fire on wake", err)
	}
}

// ── TestRecordSkipped_shortWorkspaceIDNoPanic ─────────────────────────────────
// Guards against the short() regression: recordSkipped must not panic if
// WorkspaceID is unexpectedly shorter than the 12-char prefix used in logs.

func TestRecordSkipped_shortWorkspaceIDNoPanic(t *testing.T) {
	mock := setupTestDB(t)
	s := New(nil, nil)

	// 4-char workspace id — shorter than any substring bound in the code.
	sched := scheduleRow{
		ID:          "11111111-1111-1111-1111-111111111111",
		WorkspaceID: "ws-x",
		Name:        "test",
		CronExpr:    "0 * * * *",
		Timezone:    "UTC",
	}
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WillReturnResult(sqlmock.NewResult(0, 1))
	mock.ExpectExec(`INSERT INTO activity_logs`).
		WillReturnResult(sqlmock.NewResult(0, 1))

	defer func() {
		if r := recover(); r != nil {
			t.Errorf("recordSkipped panicked on short WorkspaceID: %v", r)
		}
	}()
	s.recordSkipped(context.Background(), sched, 1)
}

// ── Panic-recovery next_run_at advancement (#1029) ──────────────────────────
//
// Issue #1029: when fireSchedule panics (e.g. a nil-pointer in the A2A proxy
// or a bad JSON marshal), the deferred recover must advance next_run_at to the
// next cron window. Without this fix the schedule's next_run_at stays in the
// past and fires on every 30-second tick — a tight retry loop that amplifies
// the original failure.

// TestPanicRecovery_AdvancesNextRunAt verifies that the recover block in
// fireSchedule issues an UPDATE to advance next_run_at when the proxy panics.
//
// This is the core invariant of the #1029 fix: panic → recover → advance.
// The test calls fireSchedule directly (not via tick) so the sqlmock
// expectations are precise — we know exactly which queries fire and in what
// order.
func TestPanicRecovery_AdvancesNextRunAt(t *testing.T) {
	mock := setupTestDB(t)

	sched := scheduleRow{
		ID:          "aaa11111-1111-1111-1111-111111111111",
		WorkspaceID: "bbb22222-2222-2222-2222-222222222222",
		Name:        "panic-advance-test",
		CronExpr:    "0 * * * *", // every hour — valid expr so ComputeNextRun succeeds
		Timezone:    "UTC",
		Prompt:      "trigger panic",
	}

	// 1. fireSchedule first checks active_tasks on the workspace.
	//    Return 0 so the fire proceeds (not skipped).
	mock.ExpectQuery(`SELECT COALESCE`).
		WillReturnRows(sqlmock.NewRows([]string{"coalesce"}).AddRow(0))

	// 2. ProxyA2ARequest panics (panicProxy).
	//    The deferred recover catches it and calls:
	//      ComputeNextRun(cronExpr, tz, time.Now())
	//      db.DB.ExecContext(ctx, `UPDATE workspace_schedules SET next_run_at = $1 ... WHERE id = $2`, nextTime, sched.ID)
	//
	//    We expect this UPDATE with the schedule ID as arg 2.
	mock.ExpectExec(`UPDATE workspace_schedules SET next_run_at`).
		WithArgs(sqlmock.AnyArg(), sched.ID).
		WillReturnResult(sqlmock.NewResult(0, 1))

	s := New(&panicProxy{}, nil)
	// fireSchedule must not propagate the panic — the recover catches it.
	s.fireSchedule(context.Background(), sched)

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations: %v\n"+
			"The panic-recovery defer must advance next_run_at via UPDATE (#1029)", err)
	}
}

// TestFireSchedule_NormalSuccess_AdvancesNextRunAt is a regression guard for
// the happy path: when fireSchedule completes without error, next_run_at must
// be advanced as part of the normal UPDATE (not via the panic path).
//
// This ensures the #1029 panic-recovery change didn't accidentally break the
// normal flow where both the proxy call and the post-fire UPDATE succeed.
func TestFireSchedule_NormalSuccess_AdvancesNextRunAt(t *testing.T) {
	mock := setupTestDB(t)

	sched := scheduleRow{
		ID:          "ccc33333-3333-3333-3333-333333333333",
		WorkspaceID: "ddd44444-4444-4444-4444-444444444444",
		Name:        "normal-advance-test",
		CronExpr:    "30 * * * *", // every hour at :30
		Timezone:    "UTC",
		Prompt:      "do work",
	}

	// 1. active_tasks check → workspace idle
	mock.ExpectQuery(`SELECT COALESCE`).
		WillReturnRows(sqlmock.NewRows([]string{"coalesce"}).AddRow(0))

	// 2. #795 consecutive_empty_runs reset — successProxy returns {"ok":true}
	//    which is non-empty, so the counter is reset to 0.
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs(sched.ID).
		WillReturnResult(sqlmock.NewResult(0, 1))

	// 3. Normal UPDATE after successful proxy call.
	//    Args: $1=sched.ID, $2=nextRunPtr (computed time), $3=lastStatus, $4=lastError
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs(sched.ID, sqlmock.AnyArg(), "ok", "").
		WillReturnResult(sqlmock.NewResult(0, 1))

	// 4. activity_logs INSERT
	mock.ExpectExec(`INSERT INTO activity_logs`).
		WithArgs(sched.WorkspaceID, sqlmock.AnyArg(), sqlmock.AnyArg(), "ok", "").
		WillReturnResult(sqlmock.NewResult(0, 1))

	s := New(&successProxy{}, nil)
	s.fireSchedule(context.Background(), sched)

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations: %v\n"+
			"Normal fire must still advance next_run_at via the post-fire UPDATE", err)
	}
}

// TestRecordSkipped_AdvancesNextRunAt verifies that when a workspace is busy
// and the cron fire is skipped, recordSkipped advances next_run_at so the
// schedule doesn't re-fire on the very next tick.
//
// This is the third leg of the #1029 invariant: fire, panic, AND skip must
// all advance next_run_at.
//
// We call recordSkipped directly rather than going through fireSchedule
// because #969 added a deferral loop (poll every 10s for up to 2 min) that
// makes end-to-end testing via fireSchedule impractical with sqlmock.
func TestRecordSkipped_AdvancesNextRunAt(t *testing.T) {
	mock := setupTestDB(t)

	sched := scheduleRow{
		ID:          "eee55555-5555-5555-5555-555555555555",
		WorkspaceID: "fff66666-6666-6666-6666-666666666666",
		Name:        "skipped-advance-test",
		CronExpr:    "15 * * * *", // every hour at :15
		Timezone:    "UTC",
		Prompt:      "skipped work",
	}

	// 1. recordSkipped UPDATE — must include next_run_at ($2) and reason ($3).
	mock.ExpectExec(`UPDATE workspace_schedules`).
		WithArgs(sched.ID, sqlmock.AnyArg(), sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))

	// 2. activity_logs INSERT for the skip event
	mock.ExpectExec(`INSERT INTO activity_logs`).
		WithArgs(sched.WorkspaceID, sqlmock.AnyArg(), sqlmock.AnyArg(), sqlmock.AnyArg()).
		WillReturnResult(sqlmock.NewResult(0, 1))

	s := New(&successProxy{}, nil)
	// Call recordSkipped directly — simulates the skip path when workspace is busy.
	s.recordSkipped(context.Background(), sched, 2)

	if err := mock.ExpectationsWereMet(); err != nil {
		t.Errorf("unmet DB expectations: %v\n"+
			"recordSkipped must advance next_run_at when workspace is busy (#1029)", err)
	}
}
// trigger CI

// ── TestTruncate_utf8Safe_regression2026 ──────────────────────────────────────

// TestTruncate_utf8Safe_regression2026 locks in the #2026 fix: truncate must
// never split a multi-byte UTF-8 rune. Before the fix, a prompt whose byte-197
// landed mid-rune (e.g. U+2026 `…` = 0xe2 0x80 0xa6) would be sliced at
// maxLen-3 and produce the sequence 0xe2 0x80 0x2e when concatenated with
// "...", which Postgres rejects as invalid UTF-8 — wedging the activity_logs
// INSERT and stalling the entire scheduler.
func TestTruncate_utf8Safe_regression2026(t *testing.T) {
	// Build a prompt where the byte at position 197 is the middle of the
	// 3-byte rune U+2026 (`…`). With maxLen=200 the pre-fix code slices at
	// byte 197 (maxLen-3), which lands on `0x80` — a continuation byte.
	filler := ""
	for len(filler) < 195 {
		filler += "a"
	}
	input := filler + "…xxx" // 195 ASCII + 3-byte rune + 3 trailing
	out := textutil.TruncateBytes(input, 200)

	if !utf8.ValidString(out) {
		t.Fatalf("truncate produced invalid UTF-8: %x", []byte(out))
	}
	// Must not contain the 0xe2 0x80 0x2e wedge sequence (partial rune
	// followed by the "..." suffix).
	for i := 0; i < len(out)-2; i++ {
		if out[i] == 0xe2 && out[i+1] == 0x80 && out[i+2] == 0x2e {
			t.Fatalf("truncate produced the 0xe2 0x80 0x2e wedge sequence at byte %d", i)
		}
	}
	if len(out) > 200 {
		t.Fatalf("truncate returned %d bytes, want <= 200", len(out))
	}
}

// ── TestSanitizeUTF8 ──────────────────────────────────────────────────────────

// TestSanitizeUTF8 confirms sanitizeUTF8 leaves valid UTF-8 unchanged and
// replaces invalid sequences with the Unicode replacement character.
func TestSanitizeUTF8(t *testing.T) {
	// Valid UTF-8 passes through unchanged.
	valid := "hello … world"
	if got := sanitizeUTF8(valid); got != valid {
		t.Errorf("sanitizeUTF8(valid) = %q, want %q", got, valid)
	}
	// Invalid UTF-8 (orphan continuation byte) is sanitized.
	bad := "hello \x80 world"
	out := sanitizeUTF8(bad)
	if !utf8.ValidString(out) {
		t.Errorf("sanitizeUTF8 did not produce valid UTF-8: %x", []byte(out))
	}
}