package service

import (
	"context"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

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

// ========== Test Setup ==========

func setupCategoryService(t *testing.T) (*CategoryService, uint, uint) {
	t.Helper()

	db := setupServiceTestDB(t)
	repo := repository.NewCategoryRepo(db)
	relatedRepo := repository.NewRelatedCategoryRepo(db)
	svc := NewCategoryService(repo, relatedRepo)

	account := createTestAccount(t, db)
	portal := createTestPortal(t, db, account.ID)

	return svc, portal.ID, account.ID
}

// ========== Create ==========

func TestCategoryService_Create(t *testing.T) {
	svc, portalID, accountID := setupCategoryService(t)

	req := &CreateCategoryRequest{
		Name:        "Announcements",
		Slug:        "announcements",
		Description: "Official announcements",
		Icon:        "📢",
		Position:    1,
		Locale:      "en",
	}

	category, err := svc.Create(context.Background(), portalID, accountID, req)
	require.NoError(t, err)
	assert.NotZero(t, category.ID)
	assert.Equal(t, portalID, category.PortalID)
	assert.Equal(t, accountID, category.AccountID)
	assert.Equal(t, "Announcements", category.Name)
	assert.Equal(t, "announcements", category.Slug)
	assert.Equal(t, "Official announcements", category.Description)
	assert.Equal(t, "📢", category.Icon)
	assert.Equal(t, 1, category.Position)
	assert.Equal(t, "en", category.Locale)
}

// ========== GetByID ==========

func TestCategoryService_GetByID(t *testing.T) {
	svc, portalID, accountID := setupCategoryService(t)

	req := &CreateCategoryRequest{
		Name: "FAQ",
		Slug: "faq",
	}
	created, err := svc.Create(context.Background(), portalID, accountID, req)
	require.NoError(t, err)

	category, err := svc.GetByID(context.Background(), created.ID)
	require.NoError(t, err)
	assert.Equal(t, created.ID, category.ID)
	assert.Equal(t, "FAQ", category.Name)
	assert.Equal(t, "faq", category.Slug)
}

func TestCategoryService_GetByID_NotFound(t *testing.T) {
	svc, _, _ := setupCategoryService(t)

	category, err := svc.GetByID(context.Background(), 99999)
	assert.Nil(t, category)
	assert.Error(t, err)
}

// ========== Update ==========

func TestCategoryService_Update(t *testing.T) {
	svc, portalID, accountID := setupCategoryService(t)

	req := &CreateCategoryRequest{
		Name:     "Guides",
		Slug:     "guides",
		Position: 0,
		Locale:   "en",
	}
	created, err := svc.Create(context.Background(), portalID, accountID, req)
	require.NoError(t, err)

	newPos := 5
	updateReq := &UpdateCategoryRequest{
		Name:        "User Guides",
		Description: "Updated description",
		Icon:        "📖",
		Position:    &newPos,
		Locale:      "zh",
	}

	updated, err := svc.Update(context.Background(), created.ID, updateReq)
	require.NoError(t, err)
	assert.Equal(t, "User Guides", updated.Name)
	assert.Equal(t, "Updated description", updated.Description)
	assert.Equal(t, "📖", updated.Icon)
	assert.Equal(t, 5, updated.Position)
	assert.Equal(t, "zh", updated.Locale)
}

func TestCategoryService_Update_NotFound(t *testing.T) {
	svc, _, _ := setupCategoryService(t)

	newPos := 1
	updateReq := &UpdateCategoryRequest{
		Name:     "Nonexistent",
		Position: &newPos,
	}

	updated, err := svc.Update(context.Background(), 99999, updateReq)
	assert.Nil(t, updated)
	assert.Error(t, err)
}

func TestCategoryService_Update_WithRelatedCategories(t *testing.T) {
	svc, portalID, accountID := setupCategoryService(t)

	// Create three categories in the same portal so related links can reference real IDs
	cat1, err := svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
		Name: "Cat1", Slug: "cat1", Locale: "en",
	})
	require.NoError(t, err)

	cat2, err := svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
		Name: "Cat2", Slug: "cat2", Locale: "en",
	})
	require.NoError(t, err)

	cat3, err := svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
		Name: "Cat3", Slug: "cat3", Locale: "en",
	})
	require.NoError(t, err)

	// Update cat1 to have cat2 and cat3 as related categories
	updateReq := &UpdateCategoryRequest{
		RelatedCategoryIDs: []uint{cat2.ID, cat3.ID},
	}

	updated, err := svc.Update(context.Background(), cat1.ID, updateReq)
	require.NoError(t, err)
	assert.Equal(t, cat1.ID, updated.ID)

	// Verify the related categories were saved by fetching the category again
	fetched, err := svc.GetByID(context.Background(), cat1.ID)
	require.NoError(t, err)
	assert.Len(t, fetched.RelatedCategories, 2)

	// Verify the related IDs match
	relatedIDs := make([]uint, 0, len(fetched.RelatedCategories))
	for _, rc := range fetched.RelatedCategories {
		relatedIDs = append(relatedIDs, rc.RelatedCategoryID)
	}
	assert.Contains(t, relatedIDs, cat2.ID)
	assert.Contains(t, relatedIDs, cat3.ID)

	// Now update to replace with only cat3
	updateReq2 := &UpdateCategoryRequest{
		RelatedCategoryIDs: []uint{cat3.ID},
	}
	_, err = svc.Update(context.Background(), cat1.ID, updateReq2)
	require.NoError(t, err)

	fetched2, err := svc.GetByID(context.Background(), cat1.ID)
	require.NoError(t, err)
	assert.Len(t, fetched2.RelatedCategories, 1)
	assert.Equal(t, cat3.ID, fetched2.RelatedCategories[0].RelatedCategoryID)
}

// ========== Delete ==========

func TestCategoryService_Delete(t *testing.T) {
	svc, portalID, accountID := setupCategoryService(t)

	req := &CreateCategoryRequest{
		Name: "Temporary",
		Slug: "temporary",
	}
	created, err := svc.Create(context.Background(), portalID, accountID, req)
	require.NoError(t, err)

	err = svc.Delete(context.Background(), created.ID)
	require.NoError(t, err)

	// Verify it's gone
	category, err := svc.GetByID(context.Background(), created.ID)
	assert.Error(t, err)
	assert.Nil(t, category)
}

func TestCategoryService_Delete_NotFound(t *testing.T) {
	svc, _, _ := setupCategoryService(t)

	err := svc.Delete(context.Background(), 99999)
	assert.Error(t, err)
}

func TestCategoryService_Delete_CleansUpRelatedCategories(t *testing.T) {
	svc, portalID, accountID := setupCategoryService(t)

	// Create two categories
	cat1, err := svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
		Name: "Main", Slug: "main", Locale: "en",
	})
	require.NoError(t, err)

	cat2, err := svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
		Name: "Related", Slug: "related", Locale: "en",
	})
	require.NoError(t, err)

	// Link cat1 → cat2 as related
	updateReq := &UpdateCategoryRequest{
		RelatedCategoryIDs: []uint{cat2.ID},
	}
	_, err = svc.Update(context.Background(), cat1.ID, updateReq)
	require.NoError(t, err)

	// Delete cat1 — should clean up the related category link
	err = svc.Delete(context.Background(), cat1.ID)
	require.NoError(t, err)

	// cat2 should still exist
	cat2Fetched, err := svc.GetByID(context.Background(), cat2.ID)
	require.NoError(t, err)
	assert.Equal(t, cat2.ID, cat2Fetched.ID)
}

// ========== ListByPortalID ==========

func TestCategoryService_ListByPortalID(t *testing.T) {
	svc, portalID, accountID := setupCategoryService(t)

	// Create several categories with different positions
	names := []string{"First", "Second", "Third"}
	for i, name := range names {
		_, err := svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
			Name: name,
			Slug: name,
			Position: i + 1,
			Locale: "en",
		})
		require.NoError(t, err)
	}

	// List page 1, perPage 2
	categories, count, err := svc.ListByPortalID(context.Background(), portalID, "", 1, 2)
	require.NoError(t, err)
	assert.Equal(t, int64(3), count)
	assert.Len(t, categories, 2)

	// List page 2, perPage 2
	categories2, count2, err := svc.ListByPortalID(context.Background(), portalID, "", 2, 2)
	require.NoError(t, err)
	assert.Equal(t, int64(3), count2)
	assert.Len(t, categories2, 1)

	// List all at once
	categories3, count3, err := svc.ListByPortalID(context.Background(), portalID, "", 1, 10)
	require.NoError(t, err)
	assert.Equal(t, int64(3), count3)
	assert.Len(t, categories3, 3)

	// Verify ordering by position
	assert.Equal(t, "First", categories3[0].Name)
	assert.Equal(t, "Second", categories3[1].Name)
	assert.Equal(t, "Third", categories3[2].Name)
}

func TestCategoryService_ListByPortalID_WithLocale(t *testing.T) {
	svc, portalID, accountID := setupCategoryService(t)

	// Create categories with different locales
	_, err := svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
		Name: "English Cat", Slug: "english-cat", Locale: "en",
	})
	require.NoError(t, err)

	_, err = svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
		Name: "Chinese Cat", Slug: "chinese-cat", Locale: "zh",
	})
	require.NoError(t, err)

	_, err = svc.Create(context.Background(), portalID, accountID, &CreateCategoryRequest{
		Name: "Another English", Slug: "another-english", Locale: "en",
	})
	require.NoError(t, err)

	// Filter by locale "en"
	categories, count, err := svc.ListByPortalID(context.Background(), portalID, "en", 1, 10)
	require.NoError(t, err)
	assert.Equal(t, int64(2), count)
	assert.Len(t, categories, 2)
	for _, cat := range categories {
		assert.Equal(t, "en", cat.Locale)
	}
}