package handlers

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

	"go-crm/internal/whatsapp"

	"golang.org/x/crypto/bcrypt"
)

func newQRTestEnv(t *testing.T) (clientID int64, sessionID string, cleanup func()) {
	t.Helper()
	testDB, cleanupDB := SetupTestDB(t)

	DB = testDB
	WAConnector = whatsapp.NewFakeConnector()

	hashedPassword, _ := bcrypt.GenerateFromPassword([]byte("password"), bcrypt.DefaultCost)
	testDB.Exec(
		"INSERT INTO accounts (email, name, password, created_at) VALUES (?, ?, ?, ?)",
		"qr-test@example.com", "QR Test Account", string(hashedPassword), time.Now().Unix(),
	)

	var accountID int64
	testDB.QueryRow("SELECT account_id FROM accounts WHERE email = ?", "qr-test@example.com").Scan(&accountID)

	sessionID = "qr-test-session"
	testDB.Exec(
		"INSERT INTO sessions (session_id, account_id, expires) VALUES (?, ?, ?)",
		sessionID, accountID, time.Now().Add(time.Hour).Unix(),
	)

	testDB.QueryRow(
		"INSERT INTO clients (account_id, name, phone, created_at) VALUES (?, ?, ?, ?) RETURNING client_id",
		accountID, "QR Test Client", "+5521999999999", time.Now().Unix(),
	).Scan(&clientID)

	return clientID, sessionID, cleanupDB
}

func TestLeadsQR_FirstPollReturnsQRCode(t *testing.T) {
	clientID, sessionID, cleanup := newQRTestEnv(t)
	defer cleanup()

	req := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id="+strconv.FormatInt(clientID, 10), nil)
	req.AddCookie(&http.Cookie{Name: "session", Value: sessionID})
	w := httptest.NewRecorder()

	LeadsQR(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	var resp map[string]interface{}
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("invalid JSON: %v — body: %s", err, w.Body.String())
	}

	if resp["qr"] == nil || resp["qr"] == "" {
		t.Errorf("expected non-empty qr field, got: %v", resp)
	}
	if resp["status"] != "waiting" {
		t.Errorf("expected status=waiting, got: %v", resp["status"])
	}
}

func TestLeadsQR_AlreadyConnectedReturnsReady(t *testing.T) {
	clientID, sessionID, cleanup := newQRTestEnv(t)
	defer cleanup()

	// Mark the client as connected in the fake connector.
	WAConnector.(*whatsapp.FakeConnector).MarkConnected(clientID)

	req := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id="+strconv.FormatInt(clientID, 10), nil)
	req.AddCookie(&http.Cookie{Name: "session", Value: sessionID})
	w := httptest.NewRecorder()

	LeadsQR(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d: %s", w.Code, w.Body.String())
	}

	var resp map[string]interface{}
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("invalid JSON: %v", err)
	}

	if resp["status"] != "ready" {
		t.Errorf("expected status=ready, got: %v", resp["status"])
	}
	if resp["qr"] != nil {
		t.Errorf("expected no qr field when already connected, got: %v", resp["qr"])
	}
}

func TestLeadsQR_ConnectorErrorReturnsErrorStatus(t *testing.T) {
	clientID, sessionID, cleanup := newQRTestEnv(t)
	defer cleanup()

	fake := whatsapp.NewFakeConnector()
	fake.SetConnectError(fmt.Errorf("connector unavailable"))
	WAConnector = fake

	req := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id="+strconv.FormatInt(clientID, 10), nil)
	req.AddCookie(&http.Cookie{Name: "session", Value: sessionID})
	w := httptest.NewRecorder()

	LeadsQR(w, req)

	if w.Code != http.StatusOK {
		t.Fatalf("expected 200, got %d", w.Code)
	}

	var resp map[string]interface{}
	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
		t.Fatalf("invalid JSON: %v", err)
	}

	if resp["status"] != "error" {
		t.Errorf("expected status=error, got: %v", resp["status"])
	}
	if resp["error"] == nil || resp["error"] == "" {
		t.Errorf("expected non-empty error field")
	}
}

func TestLeadsQR_UnknownClientReturnsNotFound(t *testing.T) {
	_, sessionID, cleanup := newQRTestEnv(t)
	defer cleanup()

	req := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id=99999", nil)
	req.AddCookie(&http.Cookie{Name: "session", Value: sessionID})
	w := httptest.NewRecorder()

	LeadsQR(w, req)

	if w.Code != http.StatusNotFound {
		t.Errorf("expected 404, got %d: %s", w.Code, w.Body.String())
	}
}

func TestLeadsQR_NoSessionReturnsUnauthorized(t *testing.T) {
	clientID, _, cleanup := newQRTestEnv(t)
	defer cleanup()

	req := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id="+strconv.FormatInt(clientID, 10), nil)
	// No session cookie.
	w := httptest.NewRecorder()

	LeadsQR(w, req)

	// /leads/qr is API-mode: returns JSON {"error":"unauthorized"}, not a redirect.
	body := w.Body.String()
	if !strings.Contains(body, "unauthorized") {
		t.Errorf("expected unauthorized in response body, got: %s", body)
	}
	// Must not return a QR code or ready status.
	if strings.Contains(body, `"qr"`) || strings.Contains(body, `"ready"`) {
		t.Errorf("unauthenticated response must not contain qr or ready: %s", body)
	}
}

func TestLeadsQR_WAConnectorNilReturns503(t *testing.T) {
	clientID, sessionID, cleanup := newQRTestEnv(t)
	defer cleanup()

	WAConnector = nil

	req := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id="+strconv.FormatInt(clientID, 10), nil)
	req.AddCookie(&http.Cookie{Name: "session", Value: sessionID})
	w := httptest.NewRecorder()

	LeadsQR(w, req)

	if w.Code != http.StatusServiceUnavailable {
		t.Errorf("expected 503, got %d: %s", w.Code, w.Body.String())
	}
}

func TestLeadsQR_SecondPollBeforeScanStillReturnsQR(t *testing.T) {
	clientID, sessionID, cleanup := newQRTestEnv(t)
	defer cleanup()

	// Pre-queue two QR frames so both polls have something to read from the shared channel.
	fake := WAConnector.(*whatsapp.FakeConnector)
	fake.QueueQR(clientID,
		whatsapp.QRFrame{QR: "qr-code-poll-1", State: whatsapp.StateWaitingQR},
		whatsapp.QRFrame{QR: "qr-code-poll-2", State: whatsapp.StateWaitingQR},
	)

	// First poll.
	req1 := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id="+strconv.FormatInt(clientID, 10), nil)
	req1.AddCookie(&http.Cookie{Name: "session", Value: sessionID})
	w1 := httptest.NewRecorder()
	LeadsQR(w1, req1)

	var resp1 map[string]interface{}
	json.Unmarshal(w1.Body.Bytes(), &resp1)
	if resp1["status"] != "waiting" {
		t.Fatalf("first poll: expected waiting, got %v — body: %s", resp1["status"], w1.Body.String())
	}

	// Second poll — same channel reused, second QR frame available.
	req2 := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id="+strconv.FormatInt(clientID, 10), nil)
	req2.AddCookie(&http.Cookie{Name: "session", Value: sessionID})
	w2 := httptest.NewRecorder()
	LeadsQR(w2, req2)

	var resp2 map[string]interface{}
	if err := json.Unmarshal(w2.Body.Bytes(), &resp2); err != nil {
		t.Fatalf("second poll: invalid JSON: %v — body: %s", err, w2.Body.String())
	}

	if resp2["status"] == "ready" {
		t.Errorf("second poll: got ready before scan — IsConnected/IsLoggedIn mismatch bug present")
	}
	if resp2["qr"] == nil || resp2["qr"] == "" {
		t.Errorf("second poll: expected QR code, got: %v", resp2)
	}
}

func TestLeadsQR_QRCodeResponseContainsClientID(t *testing.T) {
	clientID, sessionID, cleanup := newQRTestEnv(t)
	defer cleanup()

	req := httptest.NewRequest(http.MethodGet, "/leads/qr?client_id="+strconv.FormatInt(clientID, 10), nil)
	req.AddCookie(&http.Cookie{Name: "session", Value: sessionID})
	w := httptest.NewRecorder()

	LeadsQR(w, req)

	body := w.Body.String()
	if !strings.Contains(body, strconv.FormatInt(clientID, 10)) {
		t.Errorf("response missing client_id: %s", body)
	}
}