let html5QrCode = null;
let currentToken = null;
let availableCameras = [];
let autoResetTimer = null;
const csrfToken = document.querySelector('meta[name="csrf-token"]').content;

const qrReader = document.getElementById("qr-reader");
const cameraSelect = document.getElementById("camera-select");
const startScanBtn = document.getElementById("start-scan");
const stopScanBtn = document.getElementById("stop-scan");
const searchInput = document.getElementById("search-input");
const searchResults = document.getElementById("search-results");
const guestCard = document.getElementById("guest-card");
const guestPhoto = document.getElementById("guest-photo");
const guestName = document.getElementById("guest-name");
const guestDepartment = document.getElementById("guest-department");
const guestPosition = document.getElementById("guest-position");
const guestEmail = document.getElementById("guest-email");
const guestEvent = document.getElementById("guest-event");
const eventSelect = document.getElementById("event-select");
const checkInStatus = document.getElementById("check-in-status");
const checkInBtn = document.getElementById("check-in-btn");
const undoCheckInBtn = document.getElementById("undo-check-in-btn");
const resetBtn = document.getElementById("reset-btn");

function signalResult(success) {
    if (navigator.vibrate) navigator.vibrate(success ? 180 : [100, 80, 100]);
    try {
        const AudioContext = window.AudioContext || window.webkitAudioContext;
        const context = new AudioContext();
        const oscillator = context.createOscillator();
        const gain = context.createGain();
        oscillator.frequency.value = success ? 880 : 220;
        gain.gain.setValueAtTime(0.12, context.currentTime);
        gain.gain.exponentialRampToValueAtTime(0.001, context.currentTime + 0.2);
        oscillator.connect(gain); gain.connect(context.destination);
        oscillator.onended = () => context.close();
        oscillator.start(); oscillator.stop(context.currentTime + 0.2);
    } catch (_error) {}
}

function scheduleReset(delay = 8000) {
    clearTimeout(autoResetTimer);
    autoResetTimer = setTimeout(resetGuestCard, delay);
}

function resetGuestCard() {
    clearTimeout(autoResetTimer);
    guestCard.classList.add("d-none");
    currentToken = null;
    guestPhoto.src = "";
    guestName.textContent = "";
    guestDepartment.textContent = "";
    guestPosition.textContent = "";
    guestEmail.textContent = "";
    const placeholder = guestPhoto.nextElementSibling;
    if (placeholder && placeholder.classList.contains("guest-photo-placeholder")) placeholder.remove();
    if (guestEvent) guestEvent.textContent = "";
    checkInStatus.classList.add("d-none");
    checkInStatus.className = "alert d-none";
    checkInBtn.disabled = false;
    checkInBtn.textContent = "Отметить вход";
    undoCheckInBtn.classList.add("d-none");
}

function showGuest(guest) {
    clearTimeout(autoResetTimer);
    currentToken = guest.token;
    guestCard.classList.remove("d-none");

    if (guest.photo_url) {
        guestPhoto.src = guest.photo_url;
        guestPhoto.classList.remove("d-none");
        const placeholder = guestPhoto.nextElementSibling;
        if (placeholder && placeholder.classList.contains("guest-photo-placeholder")) placeholder.remove();
    } else {
        guestPhoto.src = "";
        guestPhoto.classList.add("d-none");
        // Show placeholder
        if (!guestPhoto.nextElementSibling || !guestPhoto.nextElementSibling.classList.contains("guest-photo-placeholder")) {
            const placeholder = document.createElement("div");
            placeholder.className = "guest-photo-placeholder mx-auto mb-3";
            placeholder.textContent = "Нет фото";
            guestPhoto.parentNode.insertBefore(placeholder, guestPhoto.nextSibling);
        }
    }

    guestName.textContent = guest.full_name;
    guestDepartment.textContent = guest.department;
    guestPosition.textContent = guest.position || "";
    guestEmail.textContent = guest.email;
    if (guestEvent) {
        guestEvent.textContent = guest.event_name ? `Мероприятие: ${guest.event_name}` : "";
    }

    if (guest.checked_in) {
        checkInStatus.classList.remove("d-none", "alert-success", "alert-warning");
        checkInStatus.classList.add("alert-warning");
        checkInStatus.textContent = "Гость уже отмечен как вошедший";
        checkInBtn.disabled = true;
        undoCheckInBtn.classList.remove("d-none");
    } else {
        checkInStatus.classList.add("d-none");
        checkInBtn.disabled = false;
        undoCheckInBtn.classList.add("d-none");
    }

    window.scrollTo({ top: guestCard.offsetTop - 20, behavior: "smooth" });
}

function loadGuestByToken(token) {
    fetch(`/api/guest/${token}`)
        .then(response => {
            if (!response.ok) throw new Error("Гость не найден");
            return response.json();
        })
        .then(guest => showGuest(guest))
        .catch(error => {
            alert(error.message);
        });
}

// Camera selection
function populateCameras() {
    Html5Qrcode.getCameras()
        .then(cameras => {
            availableCameras = cameras || [];
            cameraSelect.innerHTML = '<option value="">-- Выберите камеру --</option>';

            if (availableCameras.length === 0) {
                cameraSelect.innerHTML += '<option value="" disabled>Камеры не найдены</option>';
                return;
            }

            availableCameras.forEach((camera, index) => {
                const option = document.createElement("option");
                option.value = camera.id;
                option.textContent = camera.label || `Камера ${index + 1}`;
                cameraSelect.appendChild(option);
            });

            // Try to select back camera by default
            const backCamera = availableCameras.find(c =>
                c.label.toLowerCase().includes("back") ||
                c.label.toLowerCase().includes("задняя") ||
                c.label.toLowerCase().includes("environment")
            );
            if (backCamera) {
                cameraSelect.value = backCamera.id;
            } else if (availableCameras.length > 0) {
                cameraSelect.value = availableCameras[availableCameras.length - 1].id;
            }
        })
        .catch(err => {
            console.error("Ошибка получения списка камер:", err);
            cameraSelect.innerHTML = '<option value="">Ошибка доступа к камерам</option>';
        });
}

// QR Scanner
startScanBtn.addEventListener("click", () => {
    const cameraId = cameraSelect.value;
    if (!cameraId) {
        alert("Сначала выберите камеру");
        return;
    }

    html5QrCode = new Html5Qrcode("qr-reader");
    html5QrCode.start(
        cameraId,
        { fps: 10, qrbox: { width: 250, height: 250 } },
        (decodedText) => {
            html5QrCode.stop();
            stopScanBtn.classList.add("d-none");
            startScanBtn.classList.remove("d-none");

            // Extract token from URL
            try {
                const url = new URL(decodedText);
                const token = url.searchParams.get("token");
                if (token) {
                    loadGuestByToken(token);
                }
            } catch (e) {
                // If decodedText is not a URL, treat it as token
                loadGuestByToken(decodedText);
            }
        },
        (errorMessage) => {}
    );
    startScanBtn.classList.add("d-none");
    stopScanBtn.classList.remove("d-none");
});

stopScanBtn.addEventListener("click", () => {
    if (html5QrCode) {
        html5QrCode.stop();
    }
    stopScanBtn.classList.add("d-none");
    startScanBtn.classList.remove("d-none");
});

// Search by name
let searchTimeout = null;
searchInput.addEventListener("input", (e) => {
    const query = e.target.value.trim();
    searchResults.innerHTML = "";

    if (query.length < 2) return;

    clearTimeout(searchTimeout);
    searchTimeout = setTimeout(() => {
        const eventId = eventSelect ? eventSelect.value : "";
        let url = `/api/guests/search?q=${encodeURIComponent(query)}`;
        if (eventId) {
            url += `&event_id=${encodeURIComponent(eventId)}`;
        }
        fetch(url)
            .then(response => {
                if (!response.ok) {
                    return response.json().then(data => {
                        throw new Error(data.error || "Ошибка поиска");
                    });
                }
                return response.json();
            })
            .then(guests => {
                searchResults.innerHTML = "";
                guests.forEach(guest => {
                    const item = document.createElement("button");
                    item.className = "list-group-item list-group-item-action";
                    const name = document.createElement("strong");
                    name.textContent = guest.full_name;
                    const department = document.createElement("small");
                    department.textContent = guest.department || "";
                    item.append(name, document.createElement("br"), department);
                    item.addEventListener("click", () => {
                        searchResults.innerHTML = "";
                        searchInput.value = "";
                        showGuest(guest);
                    });
                    searchResults.appendChild(item);
                });
            })
            .catch(error => {
                const item = document.createElement("div");
                item.className = "list-group-item text-danger";
                item.textContent = error.message;
                searchResults.replaceChildren(item);
            });
    }, 300);
});

// Check-in button
checkInBtn.addEventListener("click", () => {
    if (!currentToken) return;

    checkInBtn.disabled = true;
    checkInBtn.textContent = "Отметка...";

    fetch(`/api/check-in/${currentToken}`, {
        method: "POST",
        headers: { "X-CSRFToken": csrfToken },
    })
        .then(response => response.json().then(data => ({ status: response.status, data })))
        .then(({ status, data }) => {
            checkInStatus.classList.remove("d-none", "alert-success", "alert-warning", "alert-danger");
            if (data.success) {
                checkInStatus.classList.add("alert-success");
                checkInStatus.textContent = "Вход успешно отмечен!";
                checkInBtn.textContent = "Вход отмечен";
                undoCheckInBtn.classList.remove("d-none"); signalResult(true); scheduleReset();
            } else if (status === 409) {
                checkInStatus.classList.add("alert-warning");
                checkInStatus.textContent = "Гость уже отмечен как вошедший";
                checkInBtn.textContent = "Уже отмечен";
                undoCheckInBtn.classList.remove("d-none"); signalResult(false); scheduleReset();
            } else {
                checkInStatus.classList.add("alert-danger");
                checkInStatus.textContent = data.message || "Ошибка";
                checkInBtn.disabled = false;
                checkInBtn.textContent = "Отметить вход";
            }
        })
        .catch(error => {
            checkInStatus.classList.remove("d-none", "alert-success", "alert-warning", "alert-danger");
            checkInStatus.classList.add("alert-danger");
            checkInStatus.textContent = "Ошибка сети: " + error.message;
            checkInBtn.disabled = false;
            checkInBtn.textContent = "Отметить вход";
        });
});

undoCheckInBtn.addEventListener("click", () => {
    if (!currentToken) return;
    clearTimeout(autoResetTimer);
    const reason = window.prompt("Укажите причину отмены отметки входа:");
    if (!reason || reason.trim().length < 3) return;
    undoCheckInBtn.disabled = true;
    fetch(`/api/check-in/${currentToken}/undo`, {
        method: "POST",
        headers: {"Content-Type": "application/json", "X-CSRFToken": csrfToken},
        body: JSON.stringify({reason: reason.trim()}),
    })
        .then(response => response.json().then(data => ({status: response.status, data})))
        .then(({status, data}) => {
            checkInStatus.classList.remove("d-none", "alert-success", "alert-warning", "alert-danger");
            if (status === 200 && data.success) {
                checkInStatus.classList.add("alert-warning");
                checkInStatus.textContent = "Отметка входа отменена";
                checkInBtn.disabled = false; checkInBtn.textContent = "Отметить вход";
                undoCheckInBtn.classList.add("d-none");
            } else {
                checkInStatus.classList.add("alert-danger");
                checkInStatus.textContent = data.message || "Не удалось отменить отметку";
            }
        })
        .catch(error => { checkInStatus.className = "alert alert-danger"; checkInStatus.textContent = "Ошибка сети: " + error.message; })
        .finally(() => { undoCheckInBtn.disabled = false; });
});

resetBtn.addEventListener("click", resetGuestCard);

// If token is in URL (scanned via external scanner)
document.addEventListener("DOMContentLoaded", () => {
    populateCameras();

    const urlParams = new URLSearchParams(window.location.search);
    const token = urlParams.get("token");
    if (token) {
        loadGuestByToken(token);
    }
});