// Initialize
document.addEventListener('DOMContentLoaded', async () => {
    // Check if multi-user mode is enabled (retry if server not ready yet)
    for (let attempt = 0; attempt < 5; attempt++) {
        try {
            const configResp = await fetch('/api/config');
            const config = await configResp.json();
            IS_MULTI_USER = config.multiUser;
            if (config.multiUser && !SESSION_ID) {
                await showUsernameOverlay();
            }
            break;
        } catch (e) {
            if (attempt < 4) {
                await new Promise(r => setTimeout(r, 1000));
            }
            // After all retries fail, continue in single-user mode
        }
    }

    // Fetch agent registry from backend (single source of truth)
    try {
        const agentsResp = await apiFetch('/api/agents');
        const agentsData = await agentsResp.json();
        for (const agent of agentsData.agents) {
            AGENT_REGISTRY[agent.key] = agent;
        }
    } catch (e) {
        console.error('Failed to fetch agent registry, using fallback');
        // Minimal fallback so the app still works if backend is slow
        AGENT_REGISTRY = {
            command:  { label: 'MAIN',     hasCounter: false, inMenu: false, inLauncher: false, placeholder: 'Enter message...' },
            agent:    { label: 'AGENT',    hasCounter: true,  inMenu: true,  inLauncher: true,  placeholder: 'Enter message...' },
            code:     { label: 'CODE',     hasCounter: true,  inMenu: true,  inLauncher: true,  placeholder: 'Enter message...' },
            research: { label: 'RESEARCH', hasCounter: true,  inMenu: true,  inLauncher: true,  placeholder: 'Enter message...' },
            image:    { label: 'IMAGE',    hasCounter: true,  inMenu: true,  inLauncher: true,  placeholder: 'Describe an image or paste a URL...' },
        };
    }
    // Initialize settings.agents with registry keys (before loadSettings merges saved values)
    settings.agents = Object.fromEntries(Object.keys(AGENT_REGISTRY).map(k => [k, '']));

    await loadSettings();
    applyTheme(settings.themeColor || 'forest');
    initializeEventListeners();
    initializeSessionListeners();
    updateUserIndicator();

    // Always show session selector on load (don't auto-resume last session)
    const sessionsData = await fetchSessions();
    showSessionSelector(sessionsData.sessions);

    // Compute line heights for the static welcome diagram (after layout)
    requestAnimationFrame(() => updateTimelineLines());
});

// ============================================================
// Dynamic HTML generation from AGENT_REGISTRY
// ============================================================

function renderNewTabMenu() {
    const menu = document.getElementById('newTabMenu');
    if (!menu) return;
    menu.innerHTML = '';
    for (const [key, agent] of Object.entries(AGENT_REGISTRY)) {
        if (!agent.inMenu) continue;
        const item = document.createElement('div');
        item.className = 'menu-item';
        item.dataset.type = key;
        item.textContent = agent.label;
        menu.appendChild(item);
    }
}

function renderLauncherButtons() {
    const container = document.getElementById('launcherButtons');
    if (!container) return;
    // Insert before the debug button (keep it at the end)
    const debugBtn = container.querySelector('#debugBtn');
    for (const [key, agent] of Object.entries(AGENT_REGISTRY)) {
        if (!agent.inLauncher) continue;
        const btn = document.createElement('button');
        btn.className = 'launcher-btn';
        btn.dataset.type = key;
        btn.textContent = agent.label;
        container.insertBefore(btn, debugBtn);
    }
}

function renderAgentModelSelectors() {
    const grid = document.getElementById('agentModelsGrid');
    if (!grid) return;
    grid.innerHTML = '';
    for (const [key, agent] of Object.entries(AGENT_REGISTRY)) {
        const label = document.createElement('label');
        label.textContent = `${agent.label}:`;
        const select = document.createElement('select');
        select.id = `setting-agent-${key}`;
        select.className = 'settings-select';
        grid.appendChild(label);
        grid.appendChild(select);
    }
}

function initializeEventListeners() {
    // Generate dynamic UI elements from registry
    renderLauncherButtons();
    renderNewTabMenu();
    renderAgentModelSelectors();

    // Launcher buttons in command center
    document.querySelectorAll('.launcher-btn').forEach(btn => {
        btn.addEventListener('click', (e) => {
            e.stopPropagation();
            const type = btn.dataset.type;
            createAgentTab(type);
        });
    });

    // Command center chat functionality
    const commandContent = document.querySelector('.tab-content[data-content-id="0"]');
    if (commandContent) {
        setupInputListeners(commandContent, 0);
    }

    // Sidebar checkboxes
    const compactViewCheckbox = document.getElementById('compactViewCheckbox');
    const collapseAgentsCheckbox = document.getElementById('collapseAgentsCheckbox');
    const collapseToolsCheckbox = document.getElementById('collapseToolsCheckbox');

    // Compact view: affects timeline only (collapse agents + hide turns)
    if (compactViewCheckbox) {
        compactViewCheckbox.addEventListener('change', () => {
            const compact = compactViewCheckbox.checked;
            if (compact) {
                // Collapse all agent boxes in timeline
                Object.entries(timelineData).forEach(([id, data]) => {
                    if (data.parentTabId !== null) {
                        collapsedAgents.add(String(id));
                    }
                });
                showAllTurns = false;
            } else {
                collapsedAgents.clear();
                showAllTurns = true;
            }
            renderTimeline();
        });
    }

    // Chat collapse: agents — affects action-widgets in chat only
    if (collapseAgentsCheckbox) {
        collapseAgentsCheckbox.addEventListener('change', () => {
            const collapse = collapseAgentsCheckbox.checked;
            document.querySelectorAll('.action-widget').forEach(w => {
                const toggle = w.querySelector('.widget-collapse-toggle');
                if (collapse) {
                    w.classList.add('collapsed');
                    if (toggle) toggle.classList.add('collapsed');
                } else {
                    w.classList.remove('collapsed');
                    if (toggle) toggle.classList.remove('collapsed');
                }
            });
        });
    }

    // Chat collapse: tools — affects tool-cells in chat only
    if (collapseToolsCheckbox) {
        collapseToolsCheckbox.addEventListener('change', () => {
            const collapse = collapseToolsCheckbox.checked;
            document.querySelectorAll('.tool-cell').forEach(w => {
                const toggle = w.querySelector('.widget-collapse-toggle');
                if (collapse) {
                    w.classList.add('collapsed');
                    if (toggle) toggle.classList.add('collapsed');
                } else {
                    w.classList.remove('collapsed');
                    if (toggle) toggle.classList.remove('collapsed');
                }
            });
        });
    }

    // New tab button - toggle menu
    const newTabBtn = document.getElementById('newTabBtn');
    const newTabMenu = document.getElementById('newTabMenu');

    if (newTabBtn && newTabMenu) {
        newTabBtn.addEventListener('click', (e) => {
            e.stopPropagation();
            e.preventDefault();

            // Position the menu below the button
            const rect = newTabBtn.getBoundingClientRect();
            newTabMenu.style.top = `${rect.bottom}px`;
            newTabMenu.style.left = `${rect.left}px`;

            newTabMenu.classList.toggle('active');
        });
    }

    // Close menu when clicking outside
    document.addEventListener('click', (e) => {
        if (!e.target.closest('.new-tab-wrapper')) {
            newTabMenu.classList.remove('active');
        }
    });

    // Menu items
    document.querySelectorAll('.menu-item').forEach(item => {
        item.addEventListener('click', () => {
            const type = item.dataset.type;
            createAgentTab(type);
            newTabMenu.classList.remove('active');
        });
    });

    // Tab switching
    document.addEventListener('click', (e) => {
        const tab = e.target.closest('.tab');
        if (tab && !e.target.closest('.new-tab-wrapper')) {
            if (e.target.classList.contains('tab-close')) {
                closeTab(parseInt(tab.dataset.tabId));
            } else {
                switchToTab(parseInt(tab.dataset.tabId));
            }
        }
    });

    // Settings button - now handled in settings panel section below
    // (removed old openSettings() call)

    // Save settings button
    const saveSettingsBtn = document.getElementById('saveSettingsBtn');
    if (saveSettingsBtn) {
        saveSettingsBtn.addEventListener('click', () => {
            saveSettings();
        });
    }

    // Cancel settings button
    const cancelSettingsBtn = document.getElementById('cancelSettingsBtn');
    if (cancelSettingsBtn) {
        cancelSettingsBtn.addEventListener('click', () => closeAllPanels());
    }

    // Theme color picker
    const themePicker = document.getElementById('theme-color-picker');
    if (themePicker) {
        themePicker.addEventListener('click', (e) => {
            const themeOption = e.target.closest('.theme-option');
            if (themeOption) {
                // Remove selected from all
                themePicker.querySelectorAll('.theme-option').forEach(opt => {
                    opt.classList.remove('selected');
                });
                // Add selected to clicked
                themeOption.classList.add('selected');
                // Update hidden input
                const themeValue = themeOption.dataset.theme;
                document.getElementById('setting-theme-color').value = themeValue;
            }
        });
    }

    // Settings group collapse/expand
    document.addEventListener('click', (e) => {
        const header = e.target.closest('.settings-group-header');
        if (!header) return;
        const group = header.closest('.settings-group');
        if (!group) return;
        group.classList.toggle('collapsed');
        const toggle = header.querySelector('.widget-collapse-toggle');
        if (toggle) toggle.classList.toggle('collapsed');
    });

    // Double-click on collapse toggle: collapse/uncollapse all widgets in the same chat
    document.addEventListener('dblclick', (e) => {
        const toggle = e.target.closest('.widget-collapse-toggle');
        if (!toggle) return;
        e.stopPropagation();
        const chatContainer = toggle.closest('.chat-container');
        if (!chatContainer) return;
        const widgets = chatContainer.querySelectorAll('.tool-cell, .code-cell, .action-widget');
        if (widgets.length === 0) return;
        // If clicked widget is now collapsed, collapse all; otherwise uncollapse all
        const clickedWidget = toggle.closest('.tool-cell, .code-cell, .action-widget');
        const shouldCollapse = !clickedWidget?.classList.contains('collapsed');
        widgets.forEach(w => {
            w.classList.toggle('collapsed', shouldCollapse);
            const t = w.querySelector('.widget-collapse-toggle');
            if (t) t.classList.toggle('collapsed', shouldCollapse);
        });
    });

    // Resizable sidebar
    const sidebar = document.getElementById('agentsSidebar');
    const resizeHandle = document.getElementById('sidebarResizeHandle');
    if (sidebar && resizeHandle) {
        const savedWidth = localStorage.getItem('agentui_sidebar_width');
        if (savedWidth) {
            const w = parseInt(savedWidth);
            if (w >= 140 && w <= 400) {
                sidebar.style.setProperty('--sidebar-width', w + 'px');
                sidebar.style.width = w + 'px';
            }
        }

        let dragging = false;
        resizeHandle.addEventListener('mousedown', (e) => {
            e.preventDefault();
            dragging = true;
            resizeHandle.classList.add('dragging');
            document.body.style.cursor = 'col-resize';
            document.body.style.userSelect = 'none';
        });
        document.addEventListener('mousemove', (e) => {
            if (!dragging) return;
            const w = Math.min(400, Math.max(140, e.clientX));
            sidebar.style.setProperty('--sidebar-width', w + 'px');
            sidebar.style.width = w + 'px';
        });
        document.addEventListener('mouseup', () => {
            if (!dragging) return;
            dragging = false;
            resizeHandle.classList.remove('dragging');
            document.body.style.cursor = '';
            document.body.style.userSelect = '';
            const w = parseInt(sidebar.style.width);
            if (w) localStorage.setItem('agentui_sidebar_width', w);
        });
    }
}