package service

import (
	"context"
	"database/sql"
	"errors"
	"testing"
	"time"

	"github.com/DATA-DOG/go-sqlmock"
	"github.com/redis/go-redis/v9"
	"github.com/stretchr/testify/require"
)

func TestHealthService_Liveness_AlwaysOK(t *testing.T) {
	s := NewHealthService(nil, nil)
	require.NoError(t, s.Liveness())
}

func TestHealthService_Readiness_AllNilReturnsOK(t *testing.T) {
	// 当所有依赖都为 nil 时（早期启动或 unit test），readiness 应直接 OK。
	s := NewHealthService(nil, nil)
	report := s.Readiness(context.Background())
	require.True(t, report.OK)
	require.Empty(t, report.Details)
}

func TestHealthService_Readiness_DBPingFails(t *testing.T) {
	db, mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
	require.NoError(t, err)
	defer db.Close()

	mock.ExpectPing().WillReturnError(errors.New("connection refused"))

	s := NewHealthService(db, nil)
	report := s.Readiness(context.Background())
	require.False(t, report.OK)
	require.Contains(t, report.Details, "database")
	require.False(t, report.Details["database"].OK)
	require.Contains(t, report.Details["database"].Error, "connection refused")
}

func TestHealthService_Readiness_DBOK(t *testing.T) {
	db, mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
	require.NoError(t, err)
	defer db.Close()

	mock.ExpectPing()

	s := NewHealthService(db, nil)
	report := s.Readiness(context.Background())
	require.True(t, report.OK)
	require.True(t, report.Details["database"].OK)
}

func TestHealthService_Readiness_RedisFails(t *testing.T) {
	// 指向一个不可达端口让 redis ping 立刻失败。
	rdb := redis.NewClient(&redis.Options{
		Addr:        "127.0.0.1:1",
		DialTimeout: 200 * time.Millisecond,
		ReadTimeout: 200 * time.Millisecond,
	})
	defer rdb.Close()

	s := NewHealthService(nil, rdb)
	s.timeout = 500 * time.Millisecond
	report := s.Readiness(context.Background())
	require.False(t, report.OK)
	require.Contains(t, report.Details, "redis")
	require.False(t, report.Details["redis"].OK)
}

func TestHealthService_Readiness_PerComponentTimeout(t *testing.T) {
	// 验证 readiness 在超时时不会无限挂住。
	db, mock, err := sqlmock.New(sqlmock.MonitorPingsOption(true))
	require.NoError(t, err)
	defer db.Close()
	mock.ExpectPing().WillDelayFor(2 * time.Second)

	s := NewHealthService(db, nil)
	s.timeout = 100 * time.Millisecond

	start := time.Now()
	report := s.Readiness(context.Background())
	elapsed := time.Since(start)

	require.Less(t, elapsed, 1*time.Second, "readiness should respect per-component timeout")
	require.False(t, report.OK)
	require.NotEmpty(t, report.Details["database"].Error, "timeout should propagate as an error")
}

// 抑制未使用包警告（database/sql 在签名里使用）。
var _ = sql.ErrNoRows