package service

import (
	"context"
	"errors"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
	"pay-bridge/internal/model"
)

// mockMerchantRepo 实现 merchantRepo interface
type mockMerchantRepo struct {
	mock.Mock
}

func (m *mockMerchantRepo) Create(ctx context.Context, merchant *model.Merchant) error {
	return m.Called(ctx, merchant).Error(0)
}
func (m *mockMerchantRepo) GetByMerchantID(ctx context.Context, merchantID string) (*model.Merchant, error) {
	args := m.Called(ctx, merchantID)
	return args.Get(0).(*model.Merchant), args.Error(1)
}
func (m *mockMerchantRepo) GetByMerchantIDAndAppID(ctx context.Context, merchantID, appID string) (*model.Merchant, error) {
	args := m.Called(ctx, merchantID, appID)
	v, _ := args.Get(0).(*model.Merchant)
	return v, args.Error(1)
}
func (m *mockMerchantRepo) UpdateStatus(ctx context.Context, merchantID string, status model.MerchantStatus, updates map[string]any) error {
	return m.Called(ctx, merchantID, status, updates).Error(0)
}
func (m *mockMerchantRepo) List(ctx context.Context, status model.MerchantStatus, limit, offset int) ([]*model.Merchant, error) {
	args := m.Called(ctx, status, limit, offset)
	return args.Get(0).([]*model.Merchant), args.Error(1)
}
func (m *mockMerchantRepo) ListByAppID(ctx context.Context, appID string, status model.MerchantStatus, limit, offset int) ([]*model.Merchant, error) {
	args := m.Called(ctx, appID, status, limit, offset)
	return args.Get(0).([]*model.Merchant), args.Error(1)
}
func (m *mockMerchantRepo) ListAnomalous(ctx context.Context) ([]*model.Merchant, error) {
	args := m.Called(ctx)
	return args.Get(0).([]*model.Merchant), args.Error(1)
}
func (m *mockMerchantRepo) CreateApplication(ctx context.Context, app *model.MerchantApplication) error {
	return m.Called(ctx, app).Error(0)
}
func (m *mockMerchantRepo) GetLatestApplication(ctx context.Context, merchantID string) (*model.MerchantApplication, error) {
	args := m.Called(ctx, merchantID)
	v, _ := args.Get(0).(*model.MerchantApplication)
	return v, args.Error(1)
}
func (m *mockMerchantRepo) GetApprovedApplicationByChannel(ctx context.Context, merchantID, channelCode string) (*model.MerchantApplication, error) {
	args := m.Called(ctx, merchantID, channelCode)
	v, _ := args.Get(0).(*model.MerchantApplication)
	return v, args.Error(1)
}
func (m *mockMerchantRepo) UpdateApplication(ctx context.Context, applicationID string, updates map[string]any) error {
	return m.Called(ctx, applicationID, updates).Error(0)
}

// newTestMerchantService 创建注入了 mock repo 的 service（channelSvc 为 nil，仅测不涉及渠道的方法）
func newTestMerchantService(repo merchantRepo) *MerchantService {
	return &MerchantService{merchantRepo: repo}
}

var ctx = context.Background()

// --- GetMerchantForApp ---

func TestGetMerchantForApp_OK(t *testing.T) {
	repo := new(mockMerchantRepo)
	want := &model.Merchant{MerchantID: "m001", AppID: "app1"}
	repo.On("GetByMerchantIDAndAppID", ctx, "m001", "app1").Return(want, nil)

	svc := newTestMerchantService(repo)
	got, err := svc.GetMerchantForApp(ctx, "app1", "m001")

	assert.NoError(t, err)
	assert.Equal(t, want, got)
	repo.AssertExpectations(t)
}

func TestGetMerchantForApp_NotFound(t *testing.T) {
	repo := new(mockMerchantRepo)
	repo.On("GetByMerchantIDAndAppID", ctx, "m001", "app1").Return((*model.Merchant)(nil), nil)

	svc := newTestMerchantService(repo)
	_, err := svc.GetMerchantForApp(ctx, "app1", "m001")

	assert.EqualError(t, err, "30001")
}

func TestGetMerchantForApp_WrongAppID(t *testing.T) {
	repo := new(mockMerchantRepo)
	// 商户存在但属于 other_app，GetByMerchantIDAndAppID 返回 nil
	repo.On("GetByMerchantIDAndAppID", ctx, "m001", "evil_app").Return((*model.Merchant)(nil), nil)

	svc := newTestMerchantService(repo)
	_, err := svc.GetMerchantForApp(ctx, "evil_app", "m001")

	assert.EqualError(t, err, "30001", "跨 appID 访问应返回 not found，而不是泄露商户信息")
}

func TestGetMerchantForApp_DBError(t *testing.T) {
	repo := new(mockMerchantRepo)
	repo.On("GetByMerchantIDAndAppID", ctx, "m001", "app1").Return((*model.Merchant)(nil), errors.New("db error"))

	svc := newTestMerchantService(repo)
	_, err := svc.GetMerchantForApp(ctx, "app1", "m001")

	assert.EqualError(t, err, "db error")
}

// --- CreateMerchantForApp ---

func TestCreateMerchantForApp_SetsAppID(t *testing.T) {
	repo := new(mockMerchantRepo)
	repo.On("Create", ctx, mock.MatchedBy(func(m *model.Merchant) bool {
		return m.AppID == "app1" && m.MerchantID == "m001"
	})).Return(nil)

	svc := newTestMerchantService(repo)
	m := &model.Merchant{MerchantID: "m001"}
	err := svc.CreateMerchantForApp(ctx, "app1", m)

	assert.NoError(t, err)
	assert.Equal(t, "app1", m.AppID, "AppID 应被强制写入")
	repo.AssertExpectations(t)
}

// --- ListMerchantsForApp ---

func TestListMerchantsForApp_OnlyReturnsOwnApp(t *testing.T) {
	repo := new(mockMerchantRepo)
	want := []*model.Merchant{{MerchantID: "m001", AppID: "app1"}}
	repo.On("ListByAppID", ctx, "app1", model.MerchantStatus(""), 20, 0).Return(want, nil)

	svc := newTestMerchantService(repo)
	got, err := svc.ListMerchantsForApp(ctx, "app1", "", 20, 0)

	assert.NoError(t, err)
	assert.Len(t, got, 1)
	repo.AssertExpectations(t)
}

// --- ApplyForApp ---

func TestApplyForApp_MerchantNotBelongToApp(t *testing.T) {
	repo := new(mockMerchantRepo)
	repo.On("GetByMerchantIDAndAppID", ctx, "m001", "app1").Return((*model.Merchant)(nil), nil)

	svc := newTestMerchantService(repo)
	_, err := svc.ApplyForApp(ctx, "app1", "m001", "HEEPAY", nil)

	assert.EqualError(t, err, "30001", "不属于该 app 的商户不能提交进件")
}

// --- GetChannelMerchantID ---

func TestGetChannelMerchantID_Approved(t *testing.T) {
	repo := new(mockMerchantRepo)
	app := &model.MerchantApplication{
		ChannelMerchantID: "ch_m_999",
	}
	repo.On("GetApprovedApplicationByChannel", ctx, "m001", "HEEPAY").Return(app, nil)

	svc := newTestMerchantService(repo)
	id, err := svc.GetChannelMerchantID(ctx, "m001", "HEEPAY")

	assert.NoError(t, err)
	assert.Equal(t, "ch_m_999", id)
}

func TestGetChannelMerchantID_NotApproved(t *testing.T) {
	repo := new(mockMerchantRepo)
	repo.On("GetApprovedApplicationByChannel", ctx, "m001", "ALIPAY").Return((*model.MerchantApplication)(nil), nil)

	svc := newTestMerchantService(repo)
	id, err := svc.GetChannelMerchantID(ctx, "m001", "ALIPAY")

	assert.NoError(t, err)
	assert.Empty(t, id, "未在该渠道进件时返回空字符串")
}

func TestGetChannelMerchantID_MultiChannel(t *testing.T) {
	repo := new(mockMerchantRepo)
	repo.On("GetApprovedApplicationByChannel", ctx, "m001", "HEEPAY").
		Return(&model.MerchantApplication{ChannelMerchantID: "hee_001"}, nil)
	repo.On("GetApprovedApplicationByChannel", ctx, "m001", "ALIPAY").
		Return(&model.MerchantApplication{ChannelMerchantID: "ali_001"}, nil)

	svc := newTestMerchantService(repo)

	heeID, _ := svc.GetChannelMerchantID(ctx, "m001", "HEEPAY")
	aliID, _ := svc.GetChannelMerchantID(ctx, "m001", "ALIPAY")

	assert.Equal(t, "hee_001", heeID, "不同渠道应返回各自的 channel_merchant_id")
	assert.Equal(t, "ali_001", aliID)
}