// friends, DM list, and friend request logic

async function loadFriends() {
    try {
        const res = await fetch(`${API_URL}/friends`, {
            headers: { 'Authorization': `Bearer ${token}` }
        });

        if (res.ok) {
            friends = await res.json();
            // seed lastSeen for each DM
            friends.forEach(f => {
                const key = conversationKey('d', f.id);
                if (!lastSeen[key]) lastSeen[key] = Date.now();
            });
            displayFriends();
            displayDMList();
            
            // Update Service Worker with friends list for background notifications
            updateServiceWorkerFriends();
        }
    } catch (error) {
        console.error('Error loading friends:', error);
    }
}

async function loadFriendRequests() {
    try {
        const res = await fetch(`${API_URL}/friend-requests`, {
            headers: { 'Authorization': `Bearer ${token}` }
        });

        if (res.ok) {
            const requests = await res.json();
            displayFriendRequests(requests);
        }
    } catch (error) {
        console.error('Error loading friend requests:', error);
    }
}

function displayFriends() {
    friendsList.innerHTML = '';
    if (friends.length === 0) {
        friendsList.innerHTML = '<div class="empty-state">No friends yet. Add some!</div>';
        return;
    }
    friends.forEach(friend => {
        const friendEl = document.createElement('div');
        friendEl.className = 'friend-item';
        let av = friend.avatar_url ? `<img class="msg-avatar" src="${friend.avatar_url}" alt="av"/>` : '';
        
        // Generate badge HTML if user has a system badge
        let badgeHtml = '';
        if (friend.badge) {
            const badgeClass = friend.badge.toLowerCase().replace(/\s+/g, '-');
            badgeHtml = `<span class="user-badge ${badgeClass}">${friend.badge}</span>`;
        }
        
        friendEl.innerHTML = `${av}<span>@${friend.username}</span>${badgeHtml}`;
        friendEl.onclick = () => selectDM(friend.id, friend.username);
        friendsList.appendChild(friendEl);
    });
}

function displayDMList() {
    dmList.innerHTML = '';
    if (friends.length === 0) {
        dmList.innerHTML = '<div class="empty-state">No friends</div>';
        return;
    }
    friends.forEach(friend => {
        const userEl = document.createElement('div');
        userEl.className = 'dm-user';
        userEl.setAttribute('data-user-id', friend.id);
        let av = friend.avatar_url ? `<img class="msg-avatar" src="${friend.avatar_url}" alt="av"/>` : '';
        
        // Generate badge HTML if user has a system badge
        let badgeHtml = '';
        if (friend.badge) {
            const badgeClass = friend.badge.toLowerCase().replace(/\s+/g, '-');
            badgeHtml = `<span class="user-badge ${badgeClass}">${friend.badge}</span>`;
        }
        
        userEl.innerHTML = `${av}<span>@${friend.username}</span>${badgeHtml}`;
        const count = unreadCounts[conversationKey('d', friend.id)];
        if (count) {
            const badge = document.createElement('span');
            badge.className = 'unread-badge';
            badge.textContent = count;
            userEl.appendChild(badge);
        }
        userEl.onclick = () => selectDM(friend.id, friend.username);
        dmList.appendChild(userEl);
    });
}

function displayFriendRequests(requests) {
    friendRequestsList.innerHTML = '';
    if (requests.length === 0) {
        friendRequestsList.innerHTML = '<div class="empty-state">No pending requests</div>';
        return;
    }
    requests.forEach(req => {
        const reqEl = document.createElement('div');
        reqEl.className = 'friend-request-item';
        reqEl.innerHTML = `
            <span>@${req.username}</span>
            <div class="request-actions">
                <button class="accept-btn" onclick="respondFriendRequest(${req.id}, 'accept')">✓</button>
                <button class="reject-btn" onclick="respondFriendRequest(${req.id}, 'reject')">✗</button>
            </div>
        `;
        friendRequestsList.appendChild(reqEl);
    });
}

function displayAddFriendModal() {
    modalError.textContent = '';
    modalError.className = 'modal-error';
    friendUsernameInput.value = '';
    friendUsernameInput.focus();
}

async function sendFriendRequest(username) {
    if (!username || !username.trim()) {
        modalError.textContent = 'Please enter a username';
        modalError.className = 'modal-error show';
        return;
    }

    try {
        const res = await fetch(`${API_URL}/friend-request`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${token}`
            },
            body: JSON.stringify({ username: username.trim() })
        });

        const data = await res.json();

        if (res.ok) {
            modalError.textContent = 'Friend request sent!';
            modalError.className = 'modal-error show success';
            friendUsernameInput.value = '';
            setTimeout(() => {
                addFriendModal.style.display = 'none';
                loadFriendRequests();
            }, 1000);
        } else {
            modalError.textContent = data.error || 'Error sending request';
            modalError.className = 'modal-error show';
        }
    } catch (error) {
        modalError.textContent = 'Error: ' + error.message;
        modalError.className = 'modal-error show';
    }
}

async function respondFriendRequest(requestId, action) {
    try {
        const res = await fetch(`${API_URL}/friend-request/${requestId}`, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${token}`
            },
            body: JSON.stringify({ action: action })
        });

        if (res.ok) {
            loadFriends();
            loadFriendRequests();
        }
    } catch (error) {
        console.error('Error responding to friend request:', error);
    }
}

// event hooks for friend UI
function initFriendListeners() {
    addFriendBtn.addEventListener('click', () => {
        displayAddFriendModal();
        addFriendModal.style.display = 'flex';
    });
    closeModal.addEventListener('click', () => {
        addFriendModal.style.display = 'none';
    });
    addFriendModal.addEventListener('click', (e) => {
        if (e.target === addFriendModal) {
            addFriendModal.style.display = 'none';
        }
    });
    modalAddBtn.addEventListener('click', () => {
        sendFriendRequest(friendUsernameInput.value);
    });
    friendUsernameInput.addEventListener('keypress', (e) => {
        if (e.key === 'Enter') {
            e.preventDefault();
            sendFriendRequest(friendUsernameInput.value);
        }
    });
}