(function() {
    'use strict';

    var accessibleProjects = []; // [{name, url}, ...] from server
    var presets = [];            // [{name, projects[]}, ...] from localStorage
    var PRESETS_KEY = 'zddc_landing_presets';

    // ── Initialise ──────────────────────────────────────────────────────────

    async function init() {
        loadPresets();

        var urlProjects = getUrlProjects();

        var projectList = document.getElementById('projectList');
        projectList.innerHTML = '<div class="project-list-loading">Loading projects…<\/div>';

        try {
            var resp = await fetch(location.origin + location.pathname.replace(/\/[^\/]*$/, '/'), {
                headers: { 'Accept': 'application/json' }
            });
            if (!resp.ok) throw new Error('HTTP ' + resp.status);
            accessibleProjects = await resp.json();
        } catch (e) {
            projectList.innerHTML = '<div class="project-list-empty">Could not load project list: ' + escapeHtml(e.message) + '<\/div>';
            return;
        }

        // Warn about URL projects that are not accessible
        if (urlProjects.size > 0) {
            var missing = Array.from(urlProjects).filter(function(p) {
                return !accessibleProjects.some(function(ap) { return ap.name === p; });
            });
            if (missing.length > 0) {
                showWarning('This link includes projects you don\'t have access to: ' + missing.map(escapeHtml).join(', '));
            }
        }

        renderProjects(urlProjects);
        renderPresetMenu();

        // Close preset menu on outside click
        document.addEventListener('click', function(e) {
            var menu = document.getElementById('presetMenu');
            var btn = document.getElementById('presetMenuBtn');
            if (menu && !menu.classList.contains('hidden') && !menu.contains(e.target) && e.target !== btn) {
                menu.classList.add('hidden');
            }
        });
    }

    function getUrlProjects() {
        var params = new URLSearchParams(location.search);
        var val = params.get('projects');
        if (!val) return new Set();
        return new Set(val.split(',').map(function(p) { return p.trim(); }).filter(Boolean));
    }

    // ── Rendering ────────────────────────────────────────────────────────────

    function renderProjects(preCheck) {
        var container = document.getElementById('projectList');
        if (accessibleProjects.length === 0) {
            container.innerHTML = '<div class="project-list-empty">No projects available.<\/div>';
            return;
        }
        var html = accessibleProjects.map(function(p) {
            var checked = (preCheck.size === 0 || preCheck.has(p.name)) ? ' checked' : '';
            return '<div class="project-item" onclick="LandingApp.toggleProject(this)">' +
                '<input type="checkbox" value="' + escapeHtml(p.name) + '"' + checked + ' onclick="event.stopPropagation()">' +
                '<span class="project-item-name">' + escapeHtml(p.name) + '<\/span>' +
                '<\/div>';
        }).join('');
        container.innerHTML = html;
    }

    function renderPresetMenu() {
        var menu = document.getElementById('presetMenu');
        if (!menu) return;
        if (presets.length === 0) {
            menu.innerHTML = '<div class="preset-menu-empty">No presets saved.<\/div>';
            return;
        }
        menu.innerHTML = presets.map(function(preset) {
            return '<div class="preset-menu-item">' +
                '<span class="preset-menu-item-name" onclick="LandingApp.applyPreset(' + JSON.stringify(preset.name) + ')">' +
                escapeHtml(preset.name) + '<\/span>' +
                '<button class="preset-delete-btn" onclick="LandingApp.deletePreset(' + JSON.stringify(preset.name) + ')" title="Delete preset">&times;<\/button>' +
                '<\/div>';
        }).join('');
    }

    // ── Actions ──────────────────────────────────────────────────────────────

    function selectAll() {
        document.querySelectorAll('#projectList input[type="checkbox"]').forEach(function(cb) {
            cb.checked = true;
        });
    }

    function selectNone() {
        document.querySelectorAll('#projectList input[type="checkbox"]').forEach(function(cb) {
            cb.checked = false;
        });
    }

    function toggleProject(row) {
        var cb = row.querySelector('input[type="checkbox"]');
        if (cb) cb.checked = !cb.checked;
    }

    function openArchive() {
        var checked = Array.from(document.querySelectorAll('#projectList input[type="checkbox"]:checked'))
            .map(function(cb) { return cb.value; });
        if (checked.length === 0) {
            alert('Select at least one project to open.');
            return;
        }
        var base = location.pathname.replace(/\/[^\/]*$/, '/');
        location.href = base + 'archive.html?projects=' + checked.map(encodeURIComponent).join(',');
    }

    function savePreset() {
        var name = prompt('Enter a name for this preset:');
        if (!name || !name.trim()) return;
        name = name.trim();
        var checked = Array.from(document.querySelectorAll('#projectList input[type="checkbox"]:checked'))
            .map(function(cb) { return cb.value; });
        // Replace existing preset with same name
        presets = presets.filter(function(p) { return p.name !== name; });
        presets.push({ name: name, projects: checked });
        savePresets();
        renderPresetMenu();
    }

    function togglePresetMenu() {
        var menu = document.getElementById('presetMenu');
        if (menu) menu.classList.toggle('hidden');
    }

    function applyPreset(name) {
        var preset = presets.find(function(p) { return p.name === name; });
        if (!preset) return;
        var projectSet = new Set(preset.projects);
        document.querySelectorAll('#projectList input[type="checkbox"]').forEach(function(cb) {
            cb.checked = projectSet.has(cb.value);
        });
        document.getElementById('presetMenu').classList.add('hidden');
    }

    function deletePreset(name) {
        presets = presets.filter(function(p) { return p.name !== name; });
        savePresets();
        renderPresetMenu();
    }

    function dismissWarning() {
        var el = document.getElementById('accessWarningBanner');
        if (el) el.classList.add('hidden');
    }

    // ── Warning ───────────────────────────────────────────────────────────────

    function showWarning(message) {
        var el = document.getElementById('accessWarningBanner');
        var txt = document.getElementById('accessWarningText');
        if (!el || !txt) return;
        txt.textContent = message;
        el.classList.remove('hidden');
    }

    // ── Persistence ───────────────────────────────────────────────────────────

    function loadPresets() {
        try {
            var raw = localStorage.getItem(PRESETS_KEY);
            presets = raw ? JSON.parse(raw) : [];
            if (!Array.isArray(presets)) presets = [];
        } catch (e) {
            presets = [];
        }
    }

    function savePresets() {
        try {
            localStorage.setItem(PRESETS_KEY, JSON.stringify(presets));
        } catch (e) { /* quota exceeded or private browsing */ }
    }

    // ── Utilities ─────────────────────────────────────────────────────────────

    function escapeHtml(text) {
        var div = document.createElement('div');
        div.textContent = String(text);
        return div.innerHTML;
    }

    // ── Bootstrap ─────────────────────────────────────────────────────────────

    document.addEventListener('DOMContentLoaded', init);

    window.LandingApp = {
        init: init,
        selectAll: selectAll,
        selectNone: selectNone,
        toggleProject: toggleProject,
        openArchive: openArchive,
        savePreset: savePreset,
        togglePresetMenu: togglePresetMenu,
        applyPreset: applyPreset,
        deletePreset: deletePreset,
        dismissWarning: dismissWarning
    };

})();