package jobs_test

import (
	"context"
	"errors"
	"testing"
	"time"

	"github.com/descrybe/descrybe-v2/apps/api/internal/jobs"
	"github.com/jackc/pgx/v5"
)

type stubRow struct {
	scan func(dest ...any) error
}

func (r stubRow) Scan(dest ...any) error {
	if r.scan == nil {
		return pgx.ErrNoRows
	}
	return r.scan(dest...)
}

type stubQuerier struct {
	pending    int64
	pendingErr error
	lastSeen   time.Time
	seenErr    error
	calls      int
}

func (q *stubQuerier) QueryRow(ctx context.Context, sql string, args ...any) pgx.Row {
	q.calls++
	if q.calls == 1 {
		return stubRow{scan: func(dest ...any) error {
			if q.pendingErr != nil {
				return q.pendingErr
			}
			*(dest[0].(*int64)) = q.pending
			return nil
		}}
	}
	return stubRow{scan: func(dest ...any) error {
		if q.seenErr != nil {
			return q.seenErr
		}
		*(dest[0].(*time.Time)) = q.lastSeen
		return nil
	}}
}

func TestProbeWorkerReadinessOK(t *testing.T) {
	t.Parallel()
	q := &stubQuerier{pending: 3, lastSeen: time.Now()}
	probe := jobs.ProbeWorkerReadiness(context.Background(), q, time.Minute)
	if !probe.OK || probe.WorkerCheck != "ok" || probe.QueueCheck != "ok" || probe.PendingJobs != 3 {
		t.Fatalf("probe = %#v", probe)
	}
}

func TestProbeWorkerReadinessMissing(t *testing.T) {
	t.Parallel()
	q := &stubQuerier{seenErr: pgx.ErrNoRows}
	probe := jobs.ProbeWorkerReadiness(context.Background(), q, time.Minute)
	if probe.OK || probe.WorkerCheck != "missing" || probe.ErrMsg == "" || probe.Reason == "" {
		t.Fatalf("probe = %#v", probe)
	}
}

func TestProbeWorkerReadinessStale(t *testing.T) {
	t.Parallel()
	q := &stubQuerier{lastSeen: time.Now().Add(-2 * time.Minute)}
	probe := jobs.ProbeWorkerReadiness(context.Background(), q, time.Minute)
	if probe.OK || probe.WorkerCheck != "stale" || probe.Reason == "" {
		t.Fatalf("probe = %#v", probe)
	}
}

func TestProbeWorkerReadinessNil(t *testing.T) {
	t.Parallel()
	probe := jobs.ProbeWorkerReadiness(context.Background(), nil, 0)
	if probe.OK || probe.WorkerCheck != "unavailable" || probe.Reason == "" {
		t.Fatalf("probe = %#v", probe)
	}
}

func TestProbeWorkerReadinessQueueFail(t *testing.T) {
	t.Parallel()
	q := &stubQuerier{pendingErr: errors.New("closed")}
	probe := jobs.ProbeWorkerReadiness(context.Background(), q, time.Minute)
	if probe.OK || probe.QueueCheck != "fail" || probe.WorkerCheck != "fail" {
		t.Fatalf("probe = %#v", probe)
	}
}