package connection_test

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

	"github.com/gorilla/websocket"
	"github.com/qy/hw-ws-service/internal/connection"
)

// makeWSPair creates a real WebSocket pair for testing.
// Returns the server-side conn (what our code uses) and the client-side conn
// (what simulates the hardware). Call cleanup() after the test.
func makeWSPair(t *testing.T) (svrWS *websocket.Conn, cliWS *websocket.Conn, cleanup func()) {
	t.Helper()

	ch := make(chan *websocket.Conn, 1)
	done := make(chan struct{})

	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		up := websocket.Upgrader{CheckOrigin: func(*http.Request) bool { return true }}
		c, err := up.Upgrade(w, r, nil)
		if err != nil {
			t.Logf("upgrade error: %v", err)
			return
		}
		ch <- c
		<-done // hold handler open until cleanup
	}))

	wsURL := "ws" + strings.TrimPrefix(srv.URL, "http")
	cli, _, err := websocket.DefaultDialer.Dial(wsURL, nil)
	if err != nil {
		close(done)
		srv.Close()
		t.Fatalf("dial error: %v", err)
	}

	svr := <-ch
	return svr, cli, func() {
		close(done)
		svr.Close()
		cli.Close()
		srv.Close()
	}
}

func TestConnection_InitialState(t *testing.T) {
	svrWS, _, cleanup := makeWSPair(t)
	defer cleanup()

	conn := connection.New(svrWS, "AA:BB:CC:DD:EE:FF", "client-uuid")
	if conn.DeviceID != "AA:BB:CC:DD:EE:FF" {
		t.Errorf("DeviceID = %q", conn.DeviceID)
	}
	if conn.ClientID != "client-uuid" {
		t.Errorf("ClientID = %q", conn.ClientID)
	}
	if conn.IsPlaying() {
		t.Error("new connection should not be playing")
	}
}

func TestConnection_StartStopPlayback(t *testing.T) {
	svrWS, _, cleanup := makeWSPair(t)
	defer cleanup()

	conn := connection.New(svrWS, "dev1", "cli1")

	ch := conn.StartPlayback()
	if ch == nil {
		t.Fatal("StartPlayback should return a non-nil channel")
	}
	if !conn.IsPlaying() {
		t.Error("IsPlaying should be true after StartPlayback")
	}

	// Channel must still be open
	select {
	case <-ch:
		t.Error("abortCh should not be closed yet")
	default:
	}

	conn.StopPlayback()
	if conn.IsPlaying() {
		t.Error("IsPlaying should be false after StopPlayback")
	}
}

// TestConnection_StartPlayback_AbortsOld verifies that calling StartPlayback a second
// time closes the previous abort channel, stopping any in-progress streaming.
func TestConnection_StartPlayback_AbortsOld(t *testing.T) {
	svrWS, _, cleanup := makeWSPair(t)
	defer cleanup()

	conn := connection.New(svrWS, "dev1", "cli1")

	ch1 := conn.StartPlayback()
	ch2 := conn.StartPlayback() // should close ch1

	// ch1 must be closed now
	select {
	case <-ch1:
		// expected
	case <-time.After(100 * time.Millisecond):
		t.Error("first abortCh should be closed by second StartPlayback call")
	}

	// ch2 must still be open
	select {
	case <-ch2:
		t.Error("second abortCh should not be closed yet")
	default:
	}
}

// TestConnection_SendJSON verifies JSON messages are delivered to the client.
func TestConnection_SendJSON(t *testing.T) {
	svrWS, cliWS, cleanup := makeWSPair(t)
	defer cleanup()

	conn := connection.New(svrWS, "dev1", "cli1")

	if err := conn.SendJSON(map[string]string{"type": "tts", "state": "start"}); err != nil {
		t.Fatalf("SendJSON error: %v", err)
	}

	cliWS.SetReadDeadline(time.Now().Add(2 * time.Second))
	msgType, data, err := cliWS.ReadMessage()
	if err != nil {
		t.Fatalf("client read error: %v", err)
	}
	if msgType != websocket.TextMessage {
		t.Errorf("message type = %d, want TextMessage (%d)", msgType, websocket.TextMessage)
	}

	var got map[string]string
	if err := json.Unmarshal(data, &got); err != nil {
		t.Fatalf("json.Unmarshal error: %v", err)
	}
	if got["type"] != "tts" {
		t.Errorf("type = %q, want %q", got["type"], "tts")
	}
	if got["state"] != "start" {
		t.Errorf("state = %q, want %q", got["state"], "start")
	}
}

// TestConnection_SendBinary verifies binary (Opus) frames are delivered to the client.
func TestConnection_SendBinary(t *testing.T) {
	svrWS, cliWS, cleanup := makeWSPair(t)
	defer cleanup()

	conn := connection.New(svrWS, "dev1", "cli1")

	payload := []byte{0x01, 0x02, 0x03, 0x04}
	if err := conn.SendBinary(payload); err != nil {
		t.Fatalf("SendBinary error: %v", err)
	}

	cliWS.SetReadDeadline(time.Now().Add(2 * time.Second))
	msgType, data, err := cliWS.ReadMessage()
	if err != nil {
		t.Fatalf("client read error: %v", err)
	}
	if msgType != websocket.BinaryMessage {
		t.Errorf("message type = %d, want BinaryMessage (%d)", msgType, websocket.BinaryMessage)
	}
	if string(data) != string(payload) {
		t.Errorf("payload = %v, want %v", data, payload)
	}
}