package repository

import (
	"backend/pkg/chat/domain/entity"
	"backend/pkg/chat/domain/repository"
	"backend/pkg/library/cassandra"
	"context"
	"os"
	"strconv"
	"testing"
	"time"

	"github.com/gocql/gocql"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"github.com/testcontainers/testcontainers-go"
	"github.com/testcontainers/testcontainers-go/wait"
)

var (
	// 全局變量：所有測試共享的資源
	testDB           *cassandra.DB
	testRepo         repository.MessageRepository
	testContainer    testcontainers.Container
	cleanupContainer func()
)

// TestMain 在所有測試之前執行一次，設置共享的資料庫
func TestMain(m *testing.M) {
	// 使用更長的 context 超時時間（Cassandra 啟動需要較長時間）
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
	defer cancel()

	// 啟動 Cassandra 容器（只執行一次）
	// 不指定固定 port，讓 testcontainers 自動分配，避免與本地開發環境衝突
	req := testcontainers.ContainerRequest{
		Image:        "cassandra:4.1",
		ExposedPorts: []string{"9042/tcp"},
		// 等待 Cassandra 日誌確認啟動完成（Cassandra 啟動需要較長時間）
		WaitingFor: wait.ForLog("Startup complete").
			WithStartupTimeout(3 * time.Minute).
			WithOccurrence(1),
		Env: map[string]string{
			"CASSANDRA_CLUSTER_NAME": "test-cluster",
			"HEAP_NEWSIZE":           "128M",
			"MAX_HEAP_SIZE":          "512M",
		},
	}

	var err error
	testContainer, err = testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
		ContainerRequest: req,
		Started:          true,
	})
	if err != nil {
		panic("Failed to start Cassandra container: " + err.Error())
	}

	port, err := testContainer.MappedPort(ctx, "9042")
	if err != nil {
		testContainer.Terminate(ctx)
		panic("Failed to get mapped port: " + err.Error())
	}

	host, err := testContainer.Host(ctx)
	if err != nil {
		testContainer.Terminate(ctx)
		panic("Failed to get host: " + err.Error())
	}

	portInt, err := strconv.Atoi(port.Port())
	if err != nil {
		testContainer.Terminate(ctx)
		panic("Failed to convert port to int: " + err.Error())
	}

	// 先創建 DB 連接（不指定 keyspace，因為 keyspace 還不存在）
	testDB, err = cassandra.New(
		cassandra.WithHosts(host),
		cassandra.WithPort(portInt),
		// 不指定 keyspace，先連接後再創建
	)
	if err != nil {
		testContainer.Terminate(ctx)
		panic("Failed to create DB: " + err.Error())
	}

	// 創建 keyspace（需要在連接後才能創建）
	createKeyspaceStmt := "CREATE KEYSPACE IF NOT EXISTS test_keyspace WITH replication = {'class': 'SimpleStrategy', 'replication_factor': 1}"
	if err := testDB.GetSession().Query(createKeyspaceStmt, nil).Exec(); err != nil {
		testDB.Close()
		testContainer.Terminate(ctx)
		panic("Failed to create keyspace: " + err.Error())
	}

	// 等待 keyspace 創建完成
	time.Sleep(500 * time.Millisecond)

	// 創建 messages_by_room 表（需要指定 keyspace）
	createTableStmt := `CREATE TABLE IF NOT EXISTS test_keyspace.messages_by_room (
		room_id uuid,
		bucket_day text,
		ts bigint,
		uid text,
		content text,
		PRIMARY KEY ((room_id, bucket_day), ts)
	) WITH CLUSTERING ORDER BY (ts DESC)`
	if err := testDB.GetSession().Query(createTableStmt, nil).Exec(); err != nil {
		testDB.Close()
		testContainer.Terminate(ctx)
		panic("Failed to create table: " + err.Error())
	}

	// 創建 messages repository
	testRepo, err = NewMessageRepository(testDB, "test_keyspace")
	if err != nil {
		testDB.Close()
		testContainer.Terminate(ctx)
		panic("Failed to create message repository: " + err.Error())
	}

	// 創建 room 相關表（供 room_test.go 使用）
	createRoomTableStmt := `CREATE TABLE IF NOT EXISTS test_keyspace.room (
		room_id uuid PRIMARY KEY,
		name text,
		status text,
		created_at bigint,
		updated_at bigint
	)`
	if err := testDB.GetSession().Query(createRoomTableStmt, nil).Exec(); err != nil {
		testDB.Close()
		testContainer.Terminate(ctx)
		panic("Failed to create room table: " + err.Error())
	}

	createMemberTableStmt := `CREATE TABLE IF NOT EXISTS test_keyspace.room_member (
		room_id uuid,
		uid text,
		role text,
		joined_at bigint,
		PRIMARY KEY (room_id, uid)
	)`
	if err := testDB.GetSession().Query(createMemberTableStmt, nil).Exec(); err != nil {
		testDB.Close()
		testContainer.Terminate(ctx)
		panic("Failed to create room_member table: " + err.Error())
	}

	createUserRoomTableStmt := `CREATE TABLE IF NOT EXISTS test_keyspace.user_room (
		uid text,
		room_id uuid,
		joined_at bigint,
		PRIMARY KEY (uid, room_id)
	)`
	if err := testDB.GetSession().Query(createUserRoomTableStmt, nil).Exec(); err != nil {
		testDB.Close()
		testContainer.Terminate(ctx)
		panic("Failed to create user_room table: " + err.Error())
	}

	// 設置清理函數
	cleanupContainer = func() {
		if testDB != nil {
			testDB.Close()
		}
		if testContainer != nil {
			_ = testContainer.Terminate(ctx)
		}
	}

	// 執行所有測試
	code := m.Run()

	// 清理資源
	cleanupContainer()

	// 退出
	os.Exit(code)
}

// clearMessages 清空 messages_by_room 表的所有數據
func clearMessages(t *testing.T) {
	ctx := context.Background()
	// 使用完整的 keyspace.table 名稱
	truncateStmt := "TRUNCATE test_keyspace.messages_by_room"
	if err := testDB.GetSession().Query(truncateStmt, nil).WithContext(ctx).Exec(); err != nil {
		t.Fatalf("Failed to truncate messages_by_room table: %v", err)
	}
	// 等待數據清空
	time.Sleep(50 * time.Millisecond)
}

func TestNewMessageRepository(t *testing.T) {
	clearMessages(t)
	assert.NotNil(t, testRepo)
}

func TestMessageRepository_Insert(t *testing.T) {
	clearMessages(t)
	ctx := context.Background()

	tests := []struct {
		name    string
		message *entity.Message
		wantErr bool
	}{
		{
			name: "successful insert",
			message: &entity.Message{
				RoomID:    gocql.TimeUUID(),
				BucketDay: "20250117",
				TS:        time.Now().UnixNano(),
				UID:       "user-1",
				Content:   "Hello, world!",
			},
			wantErr: false,
		},
		{
			name: "insert with auto timestamp",
			message: &entity.Message{
				RoomID:    gocql.TimeUUID(),
				BucketDay: "20250117",
				UID:       "user-2",
				Content:   "Test message",
			},
			wantErr: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			err := testRepo.Insert(ctx, tt.message)
			if tt.wantErr {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
				// 驗證 TS 和 BucketDay 是否被自動設置
				if tt.message.TS == 0 {
					assert.NotZero(t, tt.message.TS)
				}
				if tt.message.BucketDay == "" {
					assert.NotEmpty(t, tt.message.BucketDay)
				}
			}
		})
	}
}

func TestMessageRepository_ListMessages(t *testing.T) {
	clearMessages(t)
	ctx := context.Background()
	roomID := gocql.TimeUUID()
	roomIDStr := roomID.String()
	bucketDay := time.Now().Format(time.DateOnly)

	// 插入測試數據（使用相同的 roomID）
	messages := []*entity.Message{
		{RoomID: roomID, BucketDay: bucketDay, TS: time.Now().UnixNano(), UID: "user-1", Content: "Message 1"},
		{RoomID: roomID, BucketDay: bucketDay, TS: time.Now().Add(time.Second).UnixNano(), UID: "user-2", Content: "Message 2"},
		{RoomID: roomID, BucketDay: bucketDay, TS: time.Now().Add(2 * time.Second).UnixNano(), UID: "user-3", Content: "Message 3"},
	}

	for _, msg := range messages {
		require.NoError(t, testRepo.Insert(ctx, msg))
	}

	// 等待數據寫入
	time.Sleep(100 * time.Millisecond)

	tests := []struct {
		name    string
		param   repository.ListMessagesReq
		wantLen int
		wantErr bool
	}{
		{
			name: "list all messages",
			param: repository.ListMessagesReq{
				RoomID:    roomIDStr,
				BucketDay: bucketDay,
				PageSize:  10,
				LastTS:    0,
			},
			wantLen: 3,
			wantErr: false,
		},
		{
			name: "list with page size limit",
			param: repository.ListMessagesReq{
				RoomID:    roomIDStr,
				BucketDay: bucketDay,
				PageSize:  2,
				LastTS:    0,
			},
			wantLen: 2,
			wantErr: false,
		},
		{
			name: "list with cursor pagination",
			param: repository.ListMessagesReq{
				RoomID:    roomIDStr,
				BucketDay: bucketDay,
				PageSize:  10,
				LastTS:    messages[1].TS, // 使用第二條訊息的 TS 作為 cursor
			},
			wantLen: 1, // 應該只返回比 LastTS 更早的訊息
			wantErr: false,
		},
		{
			name: "list with default page size",
			param: repository.ListMessagesReq{
				RoomID:    roomIDStr,
				BucketDay: bucketDay,
				PageSize:  0, // 應該使用預設值 20
				LastTS:    0,
			},
			wantLen: 3,
			wantErr: false,
		},
		{
			name: "list empty room",
			param: repository.ListMessagesReq{
				RoomID:    gocql.TimeUUID().String(), // 使用不存在的 UUID
				BucketDay: bucketDay,
				PageSize:  10,
				LastTS:    0,
			},
			wantLen: 0,
			wantErr: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result, err := testRepo.ListMessages(ctx, tt.param)
			if tt.wantErr {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
				assert.Len(t, result, tt.wantLen)
				// 驗證排序（應該按 TS DESC 排序）
				if len(result) > 1 {
					for i := 0; i < len(result)-1; i++ {
						assert.GreaterOrEqual(t, result[i].TS, result[i+1].TS, "Messages should be sorted by TS DESC")
					}
				}
			}
		})
	}
}

func TestMessageRepository_Count(t *testing.T) {
	clearMessages(t)
	ctx := context.Background()
	roomID := gocql.TimeUUID()
	roomIDStr := roomID.String()
	bucketDay := time.Now().Format(time.DateOnly)

	// 插入測試數據（使用相同的 roomID）
	for i := 0; i < 5; i++ {
		msg := &entity.Message{
			RoomID:    roomID,
			BucketDay: bucketDay,
			TS:        time.Now().Add(time.Duration(i) * time.Second).UnixNano(),
			UID:       "user-1",
			Content:   "Message",
		}
		require.NoError(t, testRepo.Insert(ctx, msg))
	}

	// 等待數據寫入
	time.Sleep(100 * time.Millisecond)

	tests := []struct {
		name    string
		roomID  string
		want    int64
		wantErr bool
	}{
		{
			name:    "count existing room",
			roomID:  roomIDStr,
			want:    5,
			wantErr: false,
		},
		{
			name:    "count non-existent room",
			roomID:  gocql.TimeUUID().String(), // 使用不存在的 UUID
			want:    0,
			wantErr: false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			count, err := testRepo.Count(ctx, tt.roomID)
			if tt.wantErr {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
				assert.Equal(t, tt.want, count)
			}
		})
	}
}

func TestMessageRepository_Insert_ListMessages_Integration(t *testing.T) {
	clearMessages(t)
	ctx := context.Background()
	roomID := gocql.TimeUUID()
	roomIDStr := roomID.String()
	bucketDay := time.Now().Format(time.DateOnly)

	// 插入多條訊息（使用相同的 roomID）
	messages := make([]*entity.Message, 10)
	for i := 0; i < 10; i++ {
		msg := &entity.Message{
			RoomID:    roomID,
			BucketDay: bucketDay,
			TS:        time.Now().Add(time.Duration(i) * time.Second).UnixNano(),
			UID:       "user-1",
			Content:   "Message",
		}
		messages[i] = msg
		require.NoError(t, testRepo.Insert(ctx, msg))
	}

	// 等待數據寫入
	time.Sleep(100 * time.Millisecond)

	// 驗證可以查詢到所有訊息
	result, err := testRepo.ListMessages(ctx, repository.ListMessagesReq{
		RoomID:    roomIDStr,
		BucketDay: bucketDay,
		PageSize:  20,
		LastTS:    0,
	})
	require.NoError(t, err)
	assert.Len(t, result, 10)

	// 驗證分頁功能
	firstPage, err := testRepo.ListMessages(ctx, repository.ListMessagesReq{
		RoomID:    roomIDStr,
		BucketDay: bucketDay,
		PageSize:  5,
		LastTS:    0,
	})
	require.NoError(t, err)
	assert.Len(t, firstPage, 5)

	// 使用 cursor 獲取下一頁
	if len(firstPage) > 0 {
		lastTS := firstPage[len(firstPage)-1].TS
		secondPage, err := testRepo.ListMessages(ctx, repository.ListMessagesReq{
			RoomID:    roomIDStr,
			BucketDay: bucketDay,
			PageSize:  5,
			LastTS:    lastTS,
		})
		require.NoError(t, err)
		assert.Len(t, secondPage, 5)
		// 驗證第二頁的訊息都比第一頁的最後一條更早
		if len(secondPage) > 0 {
			assert.Less(t, secondPage[0].TS, lastTS)
		}
	}

	// 驗證計數
	count, err := testRepo.Count(ctx, roomIDStr)
	require.NoError(t, err)
	assert.Equal(t, int64(10), count)
}

func TestMessageRepository_DifferentBuckets(t *testing.T) {
	clearMessages(t)
	ctx := context.Background()
	roomID := gocql.TimeUUID()
	roomIDStr := roomID.String()
	today := time.Now().Format(time.DateOnly)
	yesterday := time.Now().AddDate(0, 0, -1).Format(time.DateOnly)

	// 插入不同 bucket 的訊息（使用相同的 roomID）
	todayMsg := &entity.Message{
		RoomID:    roomID,
		BucketDay: today,
		TS:        time.Now().UnixNano(),
		UID:       "user-1",
		Content:   "Today's message",
	}
	yesterdayMsg := &entity.Message{
		RoomID:    roomID,
		BucketDay: yesterday,
		TS:        time.Now().UnixNano(),
		UID:       "user-1",
		Content:   "Yesterday's message",
	}

	require.NoError(t, testRepo.Insert(ctx, todayMsg))
	require.NoError(t, testRepo.Insert(ctx, yesterdayMsg))

	// 等待數據寫入
	time.Sleep(100 * time.Millisecond)

	// 查詢今天的訊息
	todayMessages, err := testRepo.ListMessages(ctx, repository.ListMessagesReq{
		RoomID:    roomIDStr,
		BucketDay: today,
		PageSize:  10,
		LastTS:    0,
	})
	require.NoError(t, err)
	assert.Len(t, todayMessages, 1)
	assert.Equal(t, "Today's message", todayMessages[0].Content)

	// 查詢昨天的訊息
	yesterdayMessages, err := testRepo.ListMessages(ctx, repository.ListMessagesReq{
		RoomID:    roomIDStr,
		BucketDay: yesterday,
		PageSize:  10,
		LastTS:    0,
	})
	require.NoError(t, err)
	assert.Len(t, yesterdayMessages, 1)
	assert.Equal(t, "Yesterday's message", yesterdayMessages[0].Content)
}