package service

import (
	"context"
	"encoding/json"
	"io"
	"net/http"
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
	"gorm.io/gorm/logger"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
)

func setupSlackIntegrationServiceTestDB(t *testing.T) *gorm.DB {
	t.Helper()

	db, err := gorm.Open(sqlite.Open("file::memory:"), &gorm.Config{
		Logger: logger.Default.LogMode(logger.Silent),
	})
	require.NoError(t, err, "failed to open SQLite test database")

	require.NoError(t, db.AutoMigrate(
		&model.Account{},
		&model.IntegrationHook{},
		&model.IntegrationApp{},
	), "failed to auto-migrate models")

	t.Cleanup(func() {
		sqlDB, _ := db.DB()
		sqlDB.Close()
	})

	return db
}

func setupSlackIntegrationService(t *testing.T) (*SlackIntegrationService, *gorm.DB) {
	t.Helper()
	db := setupSlackIntegrationServiceTestDB(t)
	hookRepo := repository.NewIntegrationHookRepo(db)
	svc := NewSlackIntegrationService(hookRepo)
	return svc, db
}

type slackRoundTripFunc func(*http.Request) (*http.Response, error)

func (f slackRoundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
	return f(req)
}

func slackJSONResponse(body string) *http.Response {
	return &http.Response{
		StatusCode: http.StatusOK,
		Header:     make(http.Header),
		Body:       io.NopCloser(strings.NewReader(body)),
	}
}

func setFakeSlackClient(svc *SlackIntegrationService, rt slackRoundTripFunc) {
	svc.client = &slackAPIClient{baseURL: "https://slack.test/api", httpClient: &http.Client{Transport: rt}}
}

func seedSlackAccount(db *gorm.DB, t *testing.T) uint {
	t.Helper()
	account := &model.Account{Name: "Test Slack Account"}
	require.NoError(t, db.Create(account).Error, "failed to seed account")
	return account.ID
}

// ========================================
// SlackIntegrationService — Create tests
// ========================================

func TestSlackIntegrationService_Create(t *testing.T) {
	svc, db := setupSlackIntegrationService(t)
	accountID := seedSlackAccount(db, t)
	t.Setenv("SLACK_CLIENT_ID", "client-id")
	t.Setenv("SLACK_CLIENT_SECRET", "client-secret")
	t.Setenv("FRONTEND_URL", "https://gochat.test")
	setFakeSlackClient(svc, func(req *http.Request) (*http.Response, error) {
		assert.Equal(t, "/api/oauth.v2.access", req.URL.Path)
		assert.Equal(t, http.MethodPost, req.Method)
		body, _ := io.ReadAll(req.Body)
		values := string(body)
		assert.Contains(t, values, "code=oauth-code")
		assert.Contains(t, values, "redirect_uri=https%3A%2F%2Fgochat.test%2Fapp%2Faccounts%2F1%2Fsettings%2Fintegrations%2Fslack")
		return slackJSONResponse(`{"ok":true,"access_token":"xoxb-oauth-token"}`), nil
	})

	req := CreateSlackRequest{
		Code: "oauth-code",
	}

	hook, err := svc.Create(context.Background(), accountID, req)
	assert.NoError(t, err)
	assert.NotZero(t, hook.ID)
	assert.Equal(t, "slack", hook.AppID)
	assert.Equal(t, model.HookTypeSlack, hook.HookType)
	assert.Equal(t, model.HookStatusInactive, hook.Status)
	assert.Equal(t, accountID, hook.AccountID)
	assert.Equal(t, "xoxb-oauth-token", hook.AccessToken)
	assert.NotNil(t, hook.Settings)
}

func TestSlackIntegrationService_Create_SettingsStored(t *testing.T) {
	svc, db := setupSlackIntegrationService(t)
	accountID := seedSlackAccount(db, t)

	req := CreateSlackRequest{
		ChannelID:   "C99999999",
		ChannelName: "notifications",
		SlackToken:  "xoxb-special-token",
	}

	hook, err := svc.Create(context.Background(), accountID, req)
	require.NoError(t, err)

	// Verify that the settings JSON contains the Slack fields
	var settings model.SlackSettings
	err = json.Unmarshal(hook.Settings, &settings)
	require.NoError(t, err, "failed to unmarshal settings JSON")

	assert.Equal(t, "C99999999", settings.ChannelID)
	assert.Equal(t, "notifications", settings.ChannelName)
	assert.Equal(t, "xoxb-special-token", settings.SlackToken)
}

// ========================================
// SlackIntegrationService — Update tests
// ========================================

func TestSlackIntegrationService_Update(t *testing.T) {
	svc, db := setupSlackIntegrationService(t)
	accountID := seedSlackAccount(db, t)

	// Create first
	createReq := CreateSlackRequest{
		ChannelID:   "C10000001",
		ChannelName: "old-channel",
		SlackToken:  "xoxb-old-token",
	}
	_, err := svc.Create(context.Background(), accountID, createReq)
	require.NoError(t, err)

	// Update
	setFakeSlackClient(svc, func(req *http.Request) (*http.Response, error) {
		switch req.URL.Path {
		case "/api/conversations.list":
			if req.URL.Query().Get("types") == "private_channel" {
				return slackJSONResponse(`{"ok":true,"channels":[],"response_metadata":{"next_cursor":""}}`), nil
			}
			return slackJSONResponse(`{"ok":true,"channels":[{"id":"C20000002","name":"new-channel","is_private":false}],"response_metadata":{"next_cursor":""}}`), nil
		case "/api/conversations.join":
			return slackJSONResponse(`{"ok":true}`), nil
		default:
			t.Fatalf("unexpected Slack API path: %s", req.URL.Path)
		}
		return nil, nil
	})
	updateReq := UpdateSlackRequest{
		ReferenceID: "C20000002",
	}

	updated, err := svc.Update(context.Background(), accountID, updateReq)
	assert.NoError(t, err)

	// Verify updated settings
	var settings model.SlackSettings
	err = json.Unmarshal(updated.Settings, &settings)
	require.NoError(t, err)
	assert.Equal(t, "", settings.ChannelID)
	assert.Equal(t, "new-channel", settings.ChannelName)
	assert.Equal(t, "", settings.SlackToken)
	assert.Equal(t, "C20000002", updated.ReferenceID)
	assert.Equal(t, model.HookStatusActive, updated.Status)
}

func TestSlackIntegrationService_Update_NotFound(t *testing.T) {
	svc, db := setupSlackIntegrationService(t)
	accountID := seedSlackAccount(db, t)

	// No Slack hook created for this account — update should fail
	updateReq := UpdateSlackRequest{
		ChannelID: "C00000000",
	}

	updated, err := svc.Update(context.Background(), accountID, updateReq)
	assert.Error(t, err)
	assert.Nil(t, updated)
	assert.Contains(t, err.Error(), "not found")
}

// ========================================
// SlackIntegrationService — Delete tests
// ========================================

func TestSlackIntegrationService_Delete(t *testing.T) {
	svc, db := setupSlackIntegrationService(t)
	accountID := seedSlackAccount(db, t)

	// Create first
	createReq := CreateSlackRequest{
		ChannelID:   "C30000003",
		ChannelName: "delete-me",
		SlackToken:  "xoxb-delete-token",
	}
	_, err := svc.Create(context.Background(), accountID, createReq)
	require.NoError(t, err)

	// Delete
	err = svc.Delete(context.Background(), accountID)
	assert.NoError(t, err)

	// Verify it's gone — no Slack hooks should remain for this account
	hookRepo := repository.NewIntegrationHookRepo(db)
	hooks, err := hookRepo.FindByAccountAndType(context.Background(), accountID, model.HookTypeSlack)
	assert.NoError(t, err)
	assert.Empty(t, hooks)
}

func TestSlackIntegrationService_Delete_NotFound(t *testing.T) {
	svc, db := setupSlackIntegrationService(t)
	accountID := seedSlackAccount(db, t)

	// No Slack hook exists for this account — delete should fail
	err := svc.Delete(context.Background(), accountID)
	assert.Error(t, err)
	assert.Contains(t, err.Error(), "not found")
}

// ========================================
// SlackIntegrationService — ListAllChannels tests
// ========================================

func TestSlackIntegrationService_ListAllChannels(t *testing.T) {
	svc, db := setupSlackIntegrationService(t)
	accountID := seedSlackAccount(db, t)

	// Create a Slack integration first
	createReq := CreateSlackRequest{
		ChannelID:   "C40000004",
		ChannelName: "list-channels",
		SlackToken:  "xoxb-list-token",
	}
	_, err := svc.Create(context.Background(), accountID, createReq)
	require.NoError(t, err)
	setFakeSlackClient(svc, func(req *http.Request) (*http.Response, error) {
		require.Equal(t, "/api/conversations.list", req.URL.Path)
		require.Equal(t, "Bearer xoxb-list-token", req.Header.Get("Authorization"))
		if req.URL.Query().Get("types") == "private_channel" {
			return slackJSONResponse(`{"ok":true,"channels":[{"id":"G40000004","name":"private-room","is_private":true}],"response_metadata":{"next_cursor":""}}`), nil
		}
		return slackJSONResponse(`{"ok":true,"channels":[{"id":"C40000004","name":"list-channels","is_private":false}],"response_metadata":{"next_cursor":""}}`), nil
	})

	channels, err := svc.ListAllChannels(context.Background(), accountID)
	assert.NoError(t, err)
	assert.Len(t, channels, 2)

	assert.Equal(t, "G40000004", channels[0]["id"])
	assert.Equal(t, "private-room", channels[0]["name"])
	assert.Equal(t, true, channels[0]["is_private"])
	assert.Equal(t, "C40000004", channels[1]["id"])
	assert.Equal(t, "list-channels", channels[1]["name"])
	assert.Equal(t, false, channels[1]["is_private"])
}

func TestSlackIntegrationService_ListAllChannels_NotFound(t *testing.T) {
	svc, db := setupSlackIntegrationService(t)
	accountID := seedSlackAccount(db, t)

	// No Slack integration exists for this account
	channels, err := svc.ListAllChannels(context.Background(), accountID)
	assert.Error(t, err)
	assert.Nil(t, channels)
	assert.Contains(t, err.Error(), "not found")
}