package service

import (
	"context"
	"encoding/json"
	"net"
	"testing"

	"github.com/gochat/gochat/internal/geoip"
	"github.com/gochat/gochat/internal/model"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

type fakeVisitorGeoResolver struct {
	location geoip.Location
	ok       bool
	seenIP   net.IP
}

func (f *fakeVisitorGeoResolver) Lookup(ip net.IP) (geoip.Location, bool) {
	f.seenIP = append(net.IP(nil), ip...)
	return f.location, f.ok
}

func TestFormatVisitorName(t *testing.T) {
	tests := []struct {
		name     string
		province string
		city     string
		want     string
	}{
		{name: "province and city", province: "河北省", city: "保定市", want: "河北保定客户"},
		{name: "municipality", province: "北京市", city: "北京市", want: "北京客户"},
		{name: "province only", province: "河北省", want: "河北客户"},
		{name: "empty", want: ""},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			assert.Equal(t, tt.want, formatVisitorName(tt.province, tt.city))
		})
	}
}

func TestWidgetService_InitUsesGeoIPNameWithoutPersistingIP(t *testing.T) {
	db, svc := setupWidgetServiceTest(t)
	_, inbox := seedWidgetInbox(t, db)
	resolver := &fakeVisitorGeoResolver{
		location: geoip.Location{Province: "河北省", City: "保定市"},
		ok:       true,
	}
	svc.SetVisitorGeoResolver(resolver)

	resp, err := svc.Init(context.Background(), WidgetInitRequest{
		WebsiteToken: "test_ws_token_123",
		ClientIP:     "203.0.113.10",
	})
	require.NoError(t, err)
	require.NotNil(t, resp.Contact)
	assert.Equal(t, inbox.ID, resp.InboxID)
	assert.Equal(t, "203.0.113.10", resolver.seenIP.String())
	assert.Equal(t, "河北保定客户", resp.Contact.Name)

	var attributes map[string]any
	require.NoError(t, json.Unmarshal(resp.Contact.AdditionalAttributes, &attributes))
	assert.Equal(t, visitorNameSourceGeoIP, attributes[visitorNameSourceKey])
	assert.Equal(t, "河北", attributes[visitorProvinceKey])
	assert.Equal(t, "保定", attributes[visitorCityKey])
	assert.NotContains(t, attributes, "client_ip")
	assert.NotContains(t, attributes, "created_at_ip")
}

func TestWidgetService_InitFallsBackWhenGeoIPHasNoRecord(t *testing.T) {
	db, svc := setupWidgetServiceTest(t)
	seedWidgetInbox(t, db)
	svc.SetVisitorGeoResolver(&fakeVisitorGeoResolver{ok: false})

	resp, err := svc.Init(context.Background(), WidgetInitRequest{
		WebsiteToken: "test_ws_token_123",
		ClientIP:     "198.51.100.20",
	})
	require.NoError(t, err)
	assert.Equal(t, anonymousVisitorName, resp.Contact.Name)
}

func TestWidgetService_InitPreservesRealName(t *testing.T) {
	db, svc := setupWidgetServiceTest(t)
	seedWidgetInbox(t, db)
	resolver := &fakeVisitorGeoResolver{location: geoip.Location{Province: "河北", City: "保定"}, ok: true}
	svc.SetVisitorGeoResolver(resolver)

	resp, err := svc.Init(context.Background(), WidgetInitRequest{
		WebsiteToken: "test_ws_token_123",
		ContactName:  "张三",
		ClientIP:     "203.0.113.11",
	})
	require.NoError(t, err)
	assert.Equal(t, "张三", resp.Contact.Name)
	assert.Nil(t, resolver.seenIP)
}

func TestWidgetService_InitUpgradesLegacyAnonymousName(t *testing.T) {
	db, svc := setupWidgetServiceTest(t)
	account, _ := seedWidgetInbox(t, db)
	legacy := &model.Contact{
		AccountID:   account.ID,
		Name:        legacyAnonymousVisitorName,
		Email:       "legacy@example.com",
		ContactType: "visitor",
	}
	require.NoError(t, db.Create(legacy).Error)
	resolver := &fakeVisitorGeoResolver{location: geoip.Location{Province: "北京市", City: "北京市"}, ok: true}
	svc.SetVisitorGeoResolver(resolver)

	resp, err := svc.Init(context.Background(), WidgetInitRequest{
		WebsiteToken: "test_ws_token_123",
		ContactEmail: "legacy@example.com",
		ClientIP:     "203.0.113.12",
	})
	require.NoError(t, err)
	assert.Equal(t, legacy.ID, resp.ContactID)
	assert.Equal(t, "北京客户", resp.Contact.Name)
}

func TestWidgetService_RealNameWinsOverGeneratedName(t *testing.T) {
	db, svc := setupWidgetServiceTest(t)
	account, _ := seedWidgetInbox(t, db)
	contact := &model.Contact{
		AccountID: account.ID,
		Name:      anonymousVisitorName,
		AdditionalAttributes: mustJSON(map[string]any{
			visitorNameSourceKey: visitorNameSourceFallback,
		}),
	}
	require.NoError(t, db.Create(contact).Error)
	svc.SetVisitorGeoResolver(&fakeVisitorGeoResolver{
		location: geoip.Location{Province: "河北", City: "保定"},
		ok:       true,
	})

	updated, err := svc.updateContactFields(context.Background(), contact, WidgetContactUpdate{Name: "张三"})
	require.NoError(t, err)
	assert.Equal(t, "张三", updated.Name)
	assert.Empty(t, jsonMap(updated.AdditionalAttributes)[visitorNameSourceKey])

	updated, err = svc.enrichAnonymousWidgetContact(context.Background(), updated, "203.0.113.14")
	require.NoError(t, err)
	assert.Equal(t, "张三", updated.Name)
}

func TestWidgetService_DoesNotOverwriteManuallyRenamedFallbackContact(t *testing.T) {
	_, svc := setupWidgetServiceTest(t)
	contact := &model.Contact{
		Name: "客服改名",
		AdditionalAttributes: mustJSON(map[string]any{
			visitorNameSourceKey: visitorNameSourceFallback,
		}),
	}
	svc.SetVisitorGeoResolver(&fakeVisitorGeoResolver{
		location: geoip.Location{Province: "河北", City: "保定"},
		ok:       true,
	})

	updated, err := svc.enrichAnonymousWidgetContact(context.Background(), contact, "203.0.113.15")
	require.NoError(t, err)
	assert.Equal(t, "客服改名", updated.Name)
}

func TestWidgetService_ProtectsVisitorAttributesFromClientUpdates(t *testing.T) {
	db, svc := setupWidgetServiceTest(t)
	account, _ := seedWidgetInbox(t, db)
	contact := &model.Contact{
		AccountID: account.ID,
		Name:      "河北保定客户",
		AdditionalAttributes: mustJSON(map[string]any{
			visitorNameSourceKey: visitorNameSourceGeoIP,
			visitorProvinceKey:   "河北",
			visitorCityKey:       "保定",
		}),
	}
	require.NoError(t, db.Create(contact).Error)

	updated, err := svc.updateContactFields(context.Background(), contact, WidgetContactUpdate{
		AdditionalAttributes: map[string]any{
			visitorNameSourceKey: "spoofed",
			visitorProvinceKey:   "北京",
			"customer_note":      "kept",
		},
	})
	require.NoError(t, err)
	attributes := map[string]any{}
	require.NoError(t, json.Unmarshal(updated.AdditionalAttributes, &attributes))
	assert.Equal(t, visitorNameSourceGeoIP, attributes[visitorNameSourceKey])
	assert.Equal(t, "河北", attributes[visitorProvinceKey])
	assert.Equal(t, "kept", attributes["customer_note"])
}

func TestWidgetService_PublicContactUsesGeoIPNameAndFiltersClientMetadata(t *testing.T) {
	db, svc := setupWidgetServiceTest(t)
	account, _ := seedWidgetInbox(t, db)
	svc.SetVisitorGeoResolver(&fakeVisitorGeoResolver{
		location: geoip.Location{Province: "北京市", City: "北京市"},
		ok:       true,
	})

	contact, err := svc.findPublicContact(context.Background(), account.ID, PublicContactRequest{
		AdditionalAttributes: map[string]any{
			visitorNameSourceKey: "spoofed",
			"customer_note":      "kept",
		},
		ClientIP: "203.0.113.16",
	})
	require.NoError(t, err)
	assert.Equal(t, "北京客户", contact.Name)
	attributes := jsonMap(contact.AdditionalAttributes)
	assert.Equal(t, visitorNameSourceGeoIP, attributes[visitorNameSourceKey])
	assert.Equal(t, "kept", attributes["customer_note"])
}

func TestPublicWidgetAdditionalAttributesHidesVisitorMetadata(t *testing.T) {
	public := PublicWidgetAdditionalAttributes(mustJSON(map[string]any{
		visitorNameSourceKey: visitorNameSourceGeoIP,
		visitorProvinceKey:   "河北",
		"created_at_ip":      "203.0.113.10",
		"customer_note":      "kept",
	}))
	assert.Equal(t, map[string]any{"customer_note": "kept"}, public)
}

func TestWidgetService_SubmitOfflineMessageUsesGeoIPName(t *testing.T) {
	db, svc := setupWidgetOfflineMessageTest(t)
	account := createTestAccountForWidget(t, db)
	inbox := createTestInboxForWidget(t, db, account.ID)
	svc.SetVisitorGeoResolver(&fakeVisitorGeoResolver{
		location: geoip.Location{Province: "河北省", City: "保定市"},
		ok:       true,
	})

	msg, err := svc.SubmitOfflineMessage(context.Background(), inbox.ID, account.ID, &model.WidgetOfflineMessageSubmission{
		Message:  "Need help",
		ClientIP: "203.0.113.13",
	}, "", "")
	require.NoError(t, err)
	assert.Equal(t, "河北保定客户", msg.ContactName)
}