package ws

import (
	"encoding/base64"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/gorilla/websocket"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"context"

	"github.com/hhs/camtalk/internal/logger"
	"github.com/hhs/camtalk/internal/models"
	"github.com/hhs/camtalk/internal/orchestrator"
	"github.com/hhs/camtalk/internal/session"
)

func init() {
	logger.Init("debug", "console")
	gin.SetMode(gin.TestMode)
}

// --- Mock Orchestrator ---

// MockOrchestrator 实现 orchestrator.Orchestrator 接口，
// 模拟完整的 STT → LLM → TTS 管道，通过 sender 推送消息。
type MockOrchestrator struct {
	// STTResult 模拟的语音识别结果
	STTResult string
	// LLMDeltas 模拟的 LLM 流式输出
	LLMDeltas []string
	// TTSAudios 模拟的 TTS 音频数据（每项一个 base64 编码的 MP3 片段）
	TTSAudios []string
	// Err 如果非 nil，ProcessQuery 直接返回此错误
	Err error
	// Delay 每个消息之间的延迟（用于 interrupt 测试）
	Delay time.Duration
}

func (m *MockOrchestrator) ProcessQuery(
	ctx context.Context,
	sessionID string,
	req models.WsQuery,
	history []models.Message,
	sender orchestrator.Sender,
) error {
	if m.Err != nil {
		sender.SendError(models.WsError{
			Type:      "error",
			RequestID: req.RequestID,
			Code:      "INTERNAL_ERROR",
			Message:   m.Err.Error(),
		})
		return m.Err
	}

	// Step 1: 发送 STT 结果
	if m.STTResult != "" {
		_ = sender.SendSTTResult(models.WsSTTResult{
			Type:      "stt_result",
			RequestID: req.RequestID,
			Text:      m.STTResult,
			IsFinal:   true,
		})
	}
	if m.Delay > 0 {
		select {
		case <-ctx.Done():
			return nil // 中断视为正常完成
		case <-time.After(m.Delay):
		}
	}

	// Step 2: 发送 LLM chunks
	var fullText strings.Builder
	for _, delta := range m.LLMDeltas {
		select {
		case <-ctx.Done():
			return nil // 中断视为正常完成
		default:
		}
		fullText.WriteString(delta)
		_ = sender.SendLLMChunk(models.WsLLMChunk{
			Type:      "llm_chunk",
			RequestID: req.RequestID,
			Delta:     delta,
			Role:      "assistant",
		})
		if m.Delay > 0 {
			select {
			case <-ctx.Done():
				return nil // 中断视为正常完成
			case <-time.After(m.Delay):
			}
		}
	}

	// Step 3: 发送 TTS 音频
	for i, audio := range m.TTSAudios {
		select {
		case <-ctx.Done():
			return nil // 中断视为正常完成
		default:
		}
		isLast := i == len(m.TTSAudios)-1
		_ = sender.SendTTSAudio(models.WsTTSAudio{
			Type:      "tts_audio",
			RequestID: req.RequestID,
			Audio:     audio,
			MimeType:  "audio/mp3",
			IsLast:    isLast,
		})
	}

	// Step 4: 发送 llm_done
	_ = sender.SendLLMDone(models.WsLLMDone{
		Type:      "llm_done",
		RequestID: req.RequestID,
		FullText:  fullText.String(),
		Model:     "gpt-4o",
		LatencyMs: 100,
	})

	return nil
}

// --- 测试辅助函数 ---

// setupTestServer 创建测试用 Gin 服务器和 WebSocket URL。
func setupTestServer(t *testing.T, orch orchestrator.Orchestrator) (*httptest.Server, string) {
	t.Helper()

	sessionMgr := session.NewMemoryManager(5*time.Minute, 20)
	t.Cleanup(func() { sessionMgr.Stop() })

	r := gin.New()
	r.GET("/ws", ServeWS(sessionMgr, orch))

	srv := httptest.NewServer(r)

	// 构造 WebSocket URL
	wsURL := "ws" + strings.TrimPrefix(srv.URL, "http") + "/ws"

	return srv, wsURL
}

// connectWS 建立 WebSocket 连接并返回 conn。
func connectWS(t *testing.T, wsURL string) *websocket.Conn {
	t.Helper()

	conn, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
	require.NoError(t, err, "WebSocket 连接失败")
	t.Cleanup(func() { conn.Close() })
	return conn
}

// readJSON 从 WebSocket 读取一条 JSON 消息。
func readJSON(t *testing.T, conn *websocket.Conn) map[string]any {
	t.Helper()

	conn.SetReadDeadline(time.Now().Add(5 * time.Second))
	var msg map[string]any
	err := conn.ReadJSON(&msg)
	require.NoError(t, err, "读取 WebSocket 消息失败")
	return msg
}

// --- 测试用例 ---

// TestWS_Connected 验证连接建立后收到 connected 消息。
func TestWS_Connected(t *testing.T) {
	srv, wsURL := setupTestServer(t, &MockOrchestrator{})
	defer srv.Close()

	conn := connectWS(t, wsURL)

	msg := readJSON(t, conn)
	assert.Equal(t, "connected", msg["type"])
	assert.NotEmpty(t, msg["session_id"])
	assert.Equal(t, "0.1.0", msg["server_version"])
}

// TestWS_PingPong 验证 ping/pong 心跳。
func TestWS_PingPong(t *testing.T) {
	srv, wsURL := setupTestServer(t, &MockOrchestrator{})
	defer srv.Close()

	conn := connectWS(t, wsURL)

	// 读取 connected 消息
	_ = readJSON(t, conn)

	// 发送 ping
	err := conn.WriteJSON(map[string]string{"type": "ping"})
	require.NoError(t, err)

	// 读取 pong
	msg := readJSON(t, conn)
	assert.Equal(t, "pong", msg["type"])
}

// TestWS_QueryFullFlow 验证完整的 query → stt_result → llm_chunk → tts_audio → llm_done 流程。
func TestWS_QueryFullFlow(t *testing.T) {
	audioB64 := base64.StdEncoding.EncodeToString([]byte("fake-audio-data"))
	imageB64 := base64.StdEncoding.EncodeToString([]byte("fake-image-data"))

	mock := &MockOrchestrator{
		STTResult:  "你好，世界",
		LLMDeltas:  []string{"你好", "，世界！"},
		TTSAudios:  []string{base64.StdEncoding.EncodeToString([]byte("mp3-data-1")), base64.StdEncoding.EncodeToString([]byte("mp3-data-2"))},
	}

	srv, wsURL := setupTestServer(t, mock)
	defer srv.Close()

	conn := connectWS(t, wsURL)

	// 1. 读取 connected
	connected := readJSON(t, conn)
	assert.Equal(t, "connected", connected["type"])
	sessionID := connected["session_id"].(string)
	assert.NotEmpty(t, sessionID)

	// 2. 发送 query
	queryMsg := models.WsQuery{
		Type:      "query",
		RequestID: "req-test-001",
		Image:     imageB64,
		Audio:     audioB64,
		MimeType:  "audio/pcm",
	}
	err := conn.WriteJSON(queryMsg)
	require.NoError(t, err)

	// 3. 读取 stt_result
	sttResult := readJSON(t, conn)
	assert.Equal(t, "stt_result", sttResult["type"])
	assert.Equal(t, "req-test-001", sttResult["request_id"])
	assert.Equal(t, "你好，世界", sttResult["text"])
	assert.Equal(t, true, sttResult["is_final"])

	// 4. 读取 llm_chunk 消息
	chunk1 := readJSON(t, conn)
	assert.Equal(t, "llm_chunk", chunk1["type"])
	assert.Equal(t, "req-test-001", chunk1["request_id"])
	assert.Equal(t, "你好", chunk1["delta"])
	assert.Equal(t, "assistant", chunk1["role"])

	chunk2 := readJSON(t, conn)
	assert.Equal(t, "llm_chunk", chunk2["type"])
	assert.Equal(t, "，世界！", chunk2["delta"])

	// 5. 读取 tts_audio 消息
	tts1 := readJSON(t, conn)
	assert.Equal(t, "tts_audio", tts1["type"])
	assert.Equal(t, "req-test-001", tts1["request_id"])
	assert.NotEmpty(t, tts1["audio"])
	assert.Equal(t, "audio/mp3", tts1["mime_type"])
	assert.Equal(t, false, tts1["is_last"])

	tts2 := readJSON(t, conn)
	assert.Equal(t, "tts_audio", tts2["type"])
	assert.Equal(t, true, tts2["is_last"])

	// 6. 读取 llm_done
	llmDone := readJSON(t, conn)
	assert.Equal(t, "llm_done", llmDone["type"])
	assert.Equal(t, "req-test-001", llmDone["request_id"])
	assert.Equal(t, "你好，世界！", llmDone["full_text"])
	assert.Equal(t, "gpt-4o", llmDone["model"])
	assert.NotNil(t, llmDone["latency_ms"])
}

// TestWS_QuerySTTOnly 验证只有 STT 结果、无 LLM 输出的场景。
func TestWS_QuerySTTOnly(t *testing.T) {
	audioB64 := base64.StdEncoding.EncodeToString([]byte("audio"))

	mock := &MockOrchestrator{
		STTResult: "测试语音",
		// LLMDeltas 为空 → 不发送 llm_chunk
		// TTSAudios 为空 → 不发送 tts_audio
	}

	srv, wsURL := setupTestServer(t, mock)
	defer srv.Close()

	conn := connectWS(t, wsURL)
	_ = readJSON(t, conn) // connected

	err := conn.WriteJSON(models.WsQuery{
		Type:      "query",
		RequestID: "req-stt-only",
		Audio:     audioB64,
	})
	require.NoError(t, err)

	// 应收到 stt_result
	stt := readJSON(t, conn)
	assert.Equal(t, "stt_result", stt["type"])
	assert.Equal(t, "测试语音", stt["text"])

	// 应收到 llm_done（即使没有 chunk）
	done := readJSON(t, conn)
	assert.Equal(t, "llm_done", done["type"])
	assert.Equal(t, "", done["full_text"])
}

// TestWS_UnknownMessageType 验证未知消息类型返回 error。
func TestWS_UnknownMessageType(t *testing.T) {
	srv, wsURL := setupTestServer(t, &MockOrchestrator{})
	defer srv.Close()

	conn := connectWS(t, wsURL)
	_ = readJSON(t, conn) // connected

	err := conn.WriteJSON(map[string]string{"type": "unknown_type"})
	require.NoError(t, err)

 errMsg := readJSON(t, conn)
	assert.Equal(t, "error", errMsg["type"])
	assert.Equal(t, "INVALID_MESSAGE", errMsg["code"])
	assert.Contains(t, errMsg["message"], "unknown message type")
}

// TestWS_InvalidJSON 验证无效 JSON 返回 error。
func TestWS_InvalidJSON(t *testing.T) {
	srv, wsURL := setupTestServer(t, &MockOrchestrator{})
	defer srv.Close()

	conn := connectWS(t, wsURL)
	_ = readJSON(t, conn) // connected

	err := conn.WriteMessage(websocket.TextMessage, []byte("not-json"))
	require.NoError(t, err)

	errMsg := readJSON(t, conn)
	assert.Equal(t, "error", errMsg["type"])
	assert.Equal(t, "INVALID_MESSAGE", errMsg["code"])
}

// TestWS_MultipleQueries 验证同一连接上可以发送多次 query。
func TestWS_MultipleQueries(t *testing.T) {
	mock := &MockOrchestrator{
		STTResult: "识别结果",
		LLMDeltas: []string{"回复"},
	}

	srv, wsURL := setupTestServer(t, mock)
	defer srv.Close()

	conn := connectWS(t, wsURL)
	_ = readJSON(t, conn) // connected

	audioB64 := base64.StdEncoding.EncodeToString([]byte("audio"))

	for i := 0; i < 3; i++ {
		reqID := "req-multi-" + string(rune('0'+i))
		err := conn.WriteJSON(models.WsQuery{
			Type:      "query",
			RequestID: reqID,
			Audio:     audioB64,
		})
		require.NoError(t, err)

		// 每次应收到完整的响应序列
		stt := readJSON(t, conn)
		assert.Equal(t, "stt_result", stt["type"], "第 %d 次 query", i+1)

		chunk := readJSON(t, conn)
		assert.Equal(t, "llm_chunk", chunk["type"], "第 %d 次 query", i+1)

		done := readJSON(t, conn)
		assert.Equal(t, "llm_done", done["type"], "第 %d 次 query", i+1)
	}
}

// TestWS_Interrupt 验证 interrupt 取消正在进行的请求。
func TestWS_Interrupt(t *testing.T) {
	// 使用较长延迟模拟慢请求
	mock := &MockOrchestrator{
		STTResult: "识别文本",
		LLMDeltas: []string{"第一句", "第二句", "第三句", "第四句", "第五句"},
		Delay:     200 * time.Millisecond,
	}

	srv, wsURL := setupTestServer(t, mock)
	defer srv.Close()

	conn := connectWS(t, wsURL)
	_ = readJSON(t, conn) // connected

	audioB64 := base64.StdEncoding.EncodeToString([]byte("audio"))

	// 发送 query
	err := conn.WriteJSON(models.WsQuery{
		Type:      "query",
		RequestID: "req-interrupt",
		Audio:     audioB64,
	})
	require.NoError(t, err)

	// 收到 stt_result
	stt := readJSON(t, conn)
	assert.Equal(t, "stt_result", stt["type"])

	// 收到第一个 llm_chunk
	chunk1 := readJSON(t, conn)
	assert.Equal(t, "llm_chunk", chunk1["type"])

	// 发送 interrupt
	err = conn.WriteJSON(map[string]string{"type": "interrupt"})
	require.NoError(t, err)

	// 等待 interrupt 生效
	time.Sleep(500 * time.Millisecond)

	// 验证连接仍然存活（可以发 ping 收 pong）
	require.NoError(t, conn.WriteJSON(map[string]string{"type": "ping"}))

	var pong map[string]any
	conn.SetReadDeadline(time.Now().Add(5 * time.Second))
	require.NoError(t, conn.ReadJSON(&pong), "interrupt 后连接应仍存活")
	assert.Equal(t, "pong", pong["type"])
}

// TestWS_DisconnectCleanup 验证断开连接时清理资源。
func TestWS_DisconnectCleanup(t *testing.T) {
	// 使用较长延迟模拟慢请求
	mock := &MockOrchestrator{
		STTResult: "识别文本",
		LLMDeltas: []string{"长回复第一部分", "长回复第二部分"},
		Delay:     500 * time.Millisecond,
	}

	srv, wsURL := setupTestServer(t, mock)
	defer srv.Close()

	conn := connectWS(t, wsURL)
	_ = readJSON(t, conn) // connected

	audioB64 := base64.StdEncoding.EncodeToString([]byte("audio"))

	// 发送 query
	err := conn.WriteJSON(models.WsQuery{
		Type:      "query",
		RequestID: "req-disconnect",
		Audio:     audioB64,
	})
	require.NoError(t, err)

	// 收到 stt_result
	stt := readJSON(t, conn)
	assert.Equal(t, "stt_result", stt["type"])

	// 关闭连接（模拟客户端断开）
	conn.Close()

	// 等待一小段时间让服务器处理断开
	time.Sleep(300 * time.Millisecond)

	// 如果没有 panic 或 goroutine 泄漏，测试通过
	// （Go test 的 -race 检测器会捕获数据竞争）
}

// TestWS_SessionCreated 验证每次连接都创建新会话。
func TestWS_SessionCreated(t *testing.T) {
	srv, wsURL := setupTestServer(t, &MockOrchestrator{})
	defer srv.Close()

	// 第一次连接
	conn1 := connectWS(t, wsURL)
	msg1 := readJSON(t, conn1)
	sid1 := msg1["session_id"].(string)
	conn1.Close()

	time.Sleep(100 * time.Millisecond)

	// 第二次连接
	conn2 := connectWS(t, wsURL)
	sid2 := readJSON(t, conn2)["session_id"].(string)

	assert.NotEmpty(t, sid1)
	assert.NotEmpty(t, sid2)
	assert.NotEqual(t, sid1, sid2, "两次连接应创建不同的会话")
}

// TestWS_QueryWithoutImage 验证不带图片的 query。
func TestWS_QueryWithoutImage(t *testing.T) {
	mock := &MockOrchestrator{
		STTResult: "纯语音输入",
		LLMDeltas: []string{"收到"},
	}

	srv, wsURL := setupTestServer(t, mock)
	defer srv.Close()

	conn := connectWS(t, wsURL)
	_ = readJSON(t, conn) // connected

	audioB64 := base64.StdEncoding.EncodeToString([]byte("audio"))

	err := conn.WriteJSON(models.WsQuery{
		Type:      "query",
		RequestID: "req-no-image",
		Audio:     audioB64,
		// Image 为空
	})
	require.NoError(t, err)

	stt := readJSON(t, conn)
	assert.Equal(t, "stt_result", stt["type"])
	assert.Equal(t, "纯语音输入", stt["text"])

	chunk := readJSON(t, conn)
	assert.Equal(t, "llm_chunk", chunk["type"])

	done := readJSON(t, conn)
	assert.Equal(t, "llm_done", done["type"])
}

// TestWS_QueryWithTTSDisabled 验证 TTS 未启用时不应收到 tts_audio。
func TestWS_QueryWithTTSDisabled(t *testing.T) {
	// MockOrchestrator 的 TTSAudios 为空 → 不发送 tts_audio
	mock := &MockOrchestrator{
		STTResult: "语音",
		LLMDeltas: []string{"回复"},
		// TTSAudios 留空
	}

	srv, wsURL := setupTestServer(t, mock)
	defer srv.Close()

	conn := connectWS(t, wsURL)
	_ = readJSON(t, conn) // connected

	audioB64 := base64.StdEncoding.EncodeToString([]byte("audio"))

	err := conn.WriteJSON(models.WsQuery{
		Type:      "query",
		RequestID: "req-no-tts",
		Audio:     audioB64,
	})
	require.NoError(t, err)

	stt := readJSON(t, conn)
	assert.Equal(t, "stt_result", stt["type"])

	chunk := readJSON(t, conn)
	assert.Equal(t, "llm_chunk", chunk["type"])

	done := readJSON(t, conn)
	assert.Equal(t, "llm_done", done["type"])

	// 不应有 tts_audio 消息；设置短超时验证
	conn.SetReadDeadline(time.Now().Add(200 * time.Millisecond))
	var extra map[string]any
	err = conn.ReadJSON(&extra)
	assert.Error(t, err, "不应有额外消息")
}