package usecase

import (
	"context"
	"encoding/base64"
	"errors"
	"testing"
	"time"

	"code.30cm.net/digimon/app-cloudep-comment-server/pkg/domain/comment"
	"code.30cm.net/digimon/app-cloudep-comment-server/pkg/domain/entity"
	"code.30cm.net/digimon/app-cloudep-comment-server/pkg/domain/repository"
	"code.30cm.net/digimon/app-cloudep-comment-server/pkg/domain/usecase"

	"github.com/golang/snappy"
	"github.com/stretchr/testify/assert"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.uber.org/mock/gomock"

	mockRepo "code.30cm.net/digimon/app-cloudep-comment-server/pkg/mock/repository"
	err "code.30cm.net/digimon/app-cloudep-comment-server/pkg/repository"
)

func TestCommentUseCase_CreateCommentItem(t *testing.T) {
	mockCtrl := gomock.NewController(t)
	defer mockCtrl.Finish()

	mockCommentRepository := mockRepo.NewMockCommentRepository(mockCtrl)

	uc := MustCommentUseCase(CommentUseCaseParam{
		Comment: mockCommentRepository,
	})

	tests := []struct {
		name      string
		req       usecase.CreateCommentDocs
		mockSetup func()
		wantErr   bool
	}{
		{
			name: "successfully create top-level comment",
			req: usecase.CreateCommentDocs{
				UID:         "user-123",
				ReferenceID: "ref-001",
				Message:     "This is a top-level comment",
			},
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					CreateComment(gomock.Any(), gomock.Any()).
					DoAndReturn(func(ctx context.Context, e *entity.Comments) error {
						// 驗證插入內容是否正確
						assert.Equal(t, "user-123", e.UID)
						assert.Equal(t, "ref-001", e.ReferenceID)
						assert.Equal(t, comment.TopLevelComment, e.Level)
						return nil
					})
			},
			wantErr: false,
		},
		{
			name: "successfully create sub-level comment",
			req: usecase.CreateCommentDocs{
				UID:             "user-456",
				ReferenceID:     "ref-002",
				ParentCommentID: "parent-001",
				Message:         "This is a sub-level comment",
			},
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					CreateComment(gomock.Any(), gomock.Any()).
					DoAndReturn(func(ctx context.Context, e *entity.Comments) error {
						// 驗證插入內容是否正確
						assert.Equal(t, "user-456", e.UID)
						assert.Equal(t, "ref-002", e.ReferenceID)
						assert.Equal(t, "parent-001", e.ParentCommentID)
						assert.Equal(t, comment.SubLevelComment, e.Level)
						return nil
					})
			},
			wantErr: false,
		},
		{
			name: "failed to create comment due to repository error",
			req: usecase.CreateCommentDocs{
				UID:         "user-789",
				ReferenceID: "ref-003",
				Message:     "This is a failing comment",
			},
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					CreateComment(gomock.Any(), gomock.Any()).
					Return(errors.New("database error"))
			},
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			tt.mockSetup()
			err := uc.CreateCommentItem(context.Background(), tt.req)

			if tt.wantErr {
				assert.Error(t, err)
				if err != nil {
					assert.Contains(t, err.Error(), "failed to create comment")
				}
			} else {
				assert.NoError(t, err)
			}
		})
	}
}

func TestCommentUseCase_GetCommentItem(t *testing.T) {
	mockCtrl := gomock.NewController(t)
	defer mockCtrl.Finish()

	mockCommentRepository := mockRepo.NewMockCommentRepository(mockCtrl)

	uc := MustCommentUseCase(CommentUseCaseParam{
		Comment: mockCommentRepository,
	})

	tests := []struct {
		name      string
		id        string
		mockSetup func()
		wantErr   bool
		expected  *usecase.CommentDocs
	}{
		{
			name: "successfully get comment item",
			id:   "64a1f2e9347e1a001d345678",
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					ListComments(gomock.Any(), gomock.Any()).
					DoAndReturn(func(ctx context.Context, req repository.ListCommentRequest) ([]*entity.Comments, int64, error) {
						assert.Equal(t, "64a1f2e9347e1a001d345678", *req.ReferenceID)
						return []*entity.Comments{
							{
								ID:              primitive.NewObjectID(),
								UID:             "user-123",
								ReferenceID:     "64a1f2e9347e1a001d345678",
								ParentCommentID: "",
								Message:         base64.StdEncoding.EncodeToString(snappy.Encode(nil, []byte("This is a test comment"))),
								UpdatedAt:       time.Now().UTC().UnixNano(),
								CreatedAt:       time.Now().UTC().UnixNano(),
							},
						}, 1, nil
					})
			},
			wantErr: false,
			expected: &usecase.CommentDocs{
				UID:             "user-123",
				ReferenceID:     "64a1f2e9347e1a001d345678",
				ParentCommentID: "",
				Message:         "This is a test comment",
			},
		},
		{
			name: "comment not found",
			id:   "64a1f2e9347e1a001d345679",
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					ListComments(gomock.Any(), gomock.Any()).
					Return([]*entity.Comments{}, int64(0), err.ErrNotFound)
			},
			wantErr: true,
		},
		{
			name: "database error",
			id:   "64a1f2e9347e1a001d345680",
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					ListComments(gomock.Any(), gomock.Any()).
					Return([]*entity.Comments{}, int64(0), errors.New("database error"))
			},
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			tt.mockSetup()
			comment, err := uc.GetCommentItem(context.Background(), tt.id)

			if tt.wantErr {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
				assert.NotNil(t, comment)
				assert.Equal(t, tt.expected.UID, comment.UID)
				assert.Equal(t, tt.expected.ReferenceID, comment.ReferenceID)
				assert.Equal(t, tt.expected.Message, comment.Message)
				assert.Equal(t, tt.expected.ParentCommentID, comment.ParentCommentID)
			}
		})
	}
}

func TestCommentUseCase_UpdateCommentMessage(t *testing.T) {
	mockCtrl := gomock.NewController(t)
	defer mockCtrl.Finish()

	// Mock Repository
	mockCommentRepository := mockRepo.NewMockCommentRepository(mockCtrl)

	// UseCase Initialization
	uc := MustCommentUseCase(CommentUseCaseParam{
		Comment: mockCommentRepository,
	})

	tests := []struct {
		name      string
		id        string
		message   string
		mockSetup func()
		wantErr   bool
	}{
		{
			name:    "successfully update comment message",
			id:      "64a1f2e9347e1a001d345678", // Valid ObjectID
			message: "Updated comment message",
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					UpdateCommentMessage(gomock.Any(), "64a1f2e9347e1a001d345678", "Updated comment message").
					Return(nil)
			},
			wantErr: false,
		},
		{
			name:    "invalid ObjectID format",
			id:      "invalid-id", // Invalid ObjectID
			message: "Invalid ID test",
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					UpdateCommentMessage(gomock.Any(), "invalid-id", "Invalid ID test").
					Return(err.ErrInvalidObjectID)
			},
			wantErr: true,
		},
		{
			name:    "comment not found",
			id:      "64a1f2e9347e1a001d345679", // Non-existent ObjectID
			message: "Non-existent comment",
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					UpdateCommentMessage(gomock.Any(), "64a1f2e9347e1a001d345679", "Non-existent comment").
					Return(err.ErrNotFound)
			},
			wantErr: true,
		},
		{
			name:    "database error while updating",
			id:      "64a1f2e9347e1a001d345680",
			message: "Database error test",
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					UpdateCommentMessage(gomock.Any(), "64a1f2e9347e1a001d345680", "Database error test").
					Return(errors.New("database error"))
			},
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Mock Setup
			tt.mockSetup()

			// Execute UseCase
			err := uc.UpdateCommentMessage(context.Background(), tt.id, tt.message)

			// Assert Results
			if tt.wantErr {
				assert.Error(t, err)
				if err != nil {
					assert.Contains(t, err.Error(), "failed to update comment")
				}
			} else {
				assert.NoError(t, err)
			}
		})
	}
}

func TestCommentUseCase_RemoveCommentItem(t *testing.T) {
	mockCtrl := gomock.NewController(t)
	defer mockCtrl.Finish()

	// Mock Repository
	mockCommentRepository := mockRepo.NewMockCommentRepository(mockCtrl)

	// UseCase Initialization
	uc := MustCommentUseCase(CommentUseCaseParam{
		Comment: mockCommentRepository,
	})

	tests := []struct {
		name      string
		id        string
		mockSetup func()
		wantErr   bool
	}{
		{
			name: "successfully remove comment item",
			id:   "64a1f2e9347e1a001d345678", // Valid ObjectID
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					DeleteCommentByID(gomock.Any(), "64a1f2e9347e1a001d345678").
					Return(nil)
			},
			wantErr: false,
		},
		{
			name: "invalid ObjectID format",
			id:   "invalid-id", // Invalid ObjectID
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					DeleteCommentByID(gomock.Any(), "invalid-id").
					Return(err.ErrInvalidObjectID)
			},
			wantErr: true,
		},
		{
			name: "comment not found",
			id:   "64a1f2e9347e1a001d345679", // Non-existent ObjectID
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					DeleteCommentByID(gomock.Any(), "64a1f2e9347e1a001d345679").
					Return(err.ErrNotFound)
			},
			wantErr: true,
		},
		{
			name: "database error while deleting",
			id:   "64a1f2e9347e1a001d345680",
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					DeleteCommentByID(gomock.Any(), "64a1f2e9347e1a001d345680").
					Return(errors.New("database error"))
			},
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Mock Setup
			tt.mockSetup()

			// Execute UseCase
			err := uc.RemoveCommentItem(context.Background(), tt.id)

			// Assert Results
			if tt.wantErr {
				assert.Error(t, err)
				if err != nil {
					assert.Contains(t, err.Error(), "failed to del comment")
				}
			} else {
				assert.NoError(t, err)
			}
		})
	}
}

func TestCommentUseCase_ListComment(t *testing.T) {
	mockCtrl := gomock.NewController(t)
	defer mockCtrl.Finish()

	// Mock Repository
	mockCommentRepository := mockRepo.NewMockCommentRepository(mockCtrl)

	// UseCase Initialization
	uc := MustCommentUseCase(CommentUseCaseParam{
		Comment: mockCommentRepository,
	})

	tests := []struct {
		name      string
		req       usecase.ListCommentRequest
		mockSetup func()
		wantErr   bool
		expected  []*usecase.CommentDocs
		total     int64
	}{
		{
			name: "successfully list comments with replies",
			req: usecase.ListCommentRequest{
				PageSize:  10,
				PageIndex: 1,
			},
			mockSetup: func() {
				// Mock main layer comments
				mockCommentRepository.EXPECT().
					ListComments(gomock.Any(), gomock.Any()).
					Return([]*entity.Comments{
						{
							ID:          primitive.NewObjectID(),
							UID:         "user-123",
							ReferenceID: "ref-001",
							Message:     base64.StdEncoding.EncodeToString(snappy.Encode(nil, []byte("Comment 1"))),
							UpdatedAt:   time.Now().UnixNano(),
							CreatedAt:   time.Now().UnixNano(),
						},
					}, int64(1), nil)

				// Mock replies
				mockCommentRepository.EXPECT().
					ListComments(gomock.Any(), gomock.Any()).
					Return([]*entity.Comments{
						{
							ID:              primitive.NewObjectID(),
							UID:             "user-456",
							ReferenceID:     "ref-001",
							ParentCommentID: "parent-001",
							Message:         base64.StdEncoding.EncodeToString(snappy.Encode(nil, []byte("Reply 1"))),
							UpdatedAt:       time.Now().UnixNano(),
							CreatedAt:       time.Now().UnixNano(),
						},
					}, int64(1), nil)
			},
			wantErr: false,
			expected: []*usecase.CommentDocs{
				{
					UID:         "user-123",
					ReferenceID: "ref-001",
					Message:     "Comment 1",
					Replies: []*usecase.CommentDocs{
						{
							UID:             "user-456",
							ReferenceID:     "ref-001",
							ParentCommentID: "parent-001",
							Message:         "Reply 1",
						},
					},
				},
			},
			total: 1,
		},
		{
			name: "database error while listing comments",
			req: usecase.ListCommentRequest{
				PageSize:  10,
				PageIndex: 1,
			},
			mockSetup: func() {
				mockCommentRepository.EXPECT().
					ListComments(gomock.Any(), gomock.Any()).
					Return([]*entity.Comments{}, int64(0), errors.New("database error"))
			},
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Mock Setup
			tt.mockSetup()

			// Execute UseCase
			results, total, err := uc.ListComment(context.Background(), tt.req)

			// Assert Results
			if tt.wantErr {
				assert.Error(t, err)
				assert.Nil(t, results)
				assert.Equal(t, int64(0), total)
			} else {
				assert.NoError(t, err)
				assert.Equal(t, tt.total, total)
				assert.Len(t, results, len(tt.expected))
				for i, expectedComment := range tt.expected {
					assert.Equal(t, expectedComment.Message, results[i].Message)
				}
			}
		})
	}
}