// events.js — wires up DOM listeners. Idempotent so app.js can call
// init() once on load.
(function () {
    'use strict';

    var state = window.app.state;
    var tree = window.app.modules.tree;
    var loader = window.app.modules.loader;
    // preview module is loaded later (concat order); look it up at
    // call time, not at IIFE-eval time.
    function previewMod() { return window.app.modules.preview; }

    function status(msg, kind) {
        var el = document.getElementById('statusBar');
        if (!el) return;
        el.textContent = msg || '';
        el.classList.remove('status-bar--error', 'status-bar--info');
        if (kind === 'error') el.classList.add('status-bar--error');
        if (kind === 'info')  el.classList.add('status-bar--info');
    }

    function statusError(msg) { status(msg, 'error'); }
    function statusInfo(msg)  { status(msg, 'info'); }
    function statusClear()    { status('', null); }

    async function pickLocalDir() {
        if (typeof window.showDirectoryPicker !== 'function') {
            statusError('Your browser does not support local folder selection. Use a recent Chromium-based browser, or open this page via zddc-server.');
            return;
        }
        var handle;
        try {
            handle = await window.showDirectoryPicker({ mode: 'read' });
        } catch (e) {
            // User cancelled — silent
            return;
        }
        state.source = 'fs';
        state.rootHandle = handle;
        state.currentPath = handle.name + '/';
        var raw;
        try {
            raw = await loader.fetchFsChildren(handle);
        } catch (e) {
            statusError('Failed to read directory: ' + e.message);
            return;
        }
        tree.setRoot(raw);
        showBrowseRoot();
        tree.render();
        statusInfo('Loaded ' + raw.length + ' item' + (raw.length === 1 ? '' : 's'));
    }

    function showBrowseRoot() {
        var empty = document.getElementById('emptyState');
        var root = document.getElementById('browseRoot');
        if (empty) empty.classList.add('hidden');
        if (root) root.classList.remove('hidden');
        applySourceUI();
    }

    // Visual state of the "Select Directory" button + the refresh
    // button depends on the source. In server mode the user is
    // already viewing a server-backed listing — Select Directory
    // becomes a quiet "switch to local" affordance (subtle styling),
    // and the refresh button is shown. In FS mode the button is
    // primary (it's how you got here) and refresh is hidden (the
    // listing was already a fresh enumeration).
    function applySourceUI() {
        var add = document.getElementById('addDirectoryBtn');
        var refresh = document.getElementById('refreshHeaderBtn');
        if (add) {
            if (state.source === 'server') {
                add.classList.remove('btn-primary');
                add.classList.add('btn--subtle');
            } else {
                add.classList.add('btn-primary');
                add.classList.remove('btn--subtle');
            }
        }
        if (refresh) {
            if (state.source) {
                refresh.classList.remove('hidden');
            } else {
                refresh.classList.add('hidden');
            }
        }
    }

    async function refreshListing() {
        if (state.source === 'server') {
            var raw;
            try {
                raw = await loader.fetchServerChildren(state.currentPath);
            } catch (e) {
                statusError('Refresh failed: ' + e.message);
                return;
            }
            tree.setRoot(raw);
            tree.render();
            statusInfo('Refreshed (' + raw.length + ' item'
                + (raw.length === 1 ? '' : 's') + ')');
        } else if (state.source === 'fs' && state.rootHandle) {
            var raw2;
            try {
                raw2 = await loader.fetchFsChildren(state.rootHandle);
            } catch (e) {
                statusError('Refresh failed: ' + e.message);
                return;
            }
            tree.setRoot(raw2);
            tree.render();
            statusInfo('Refreshed');
        }
    }

    function init() {
        // Header buttons
        var btn = document.getElementById('addDirectoryBtn');
        if (btn) btn.addEventListener('click', pickLocalDir);

        var refresh = document.getElementById('refreshHeaderBtn');
        if (refresh) refresh.addEventListener('click', refreshListing);

        // Filter input
        var filter = document.getElementById('filterInput');
        if (filter) {
            filter.addEventListener('input', function () {
                tree.setFilter(filter.value);
            });
        }

        // Extension multi-select
        var extSel = document.getElementById('extFilter');
        if (extSel) {
            extSel.addEventListener('change', function () {
                var picked = [];
                for (var i = 0; i < extSel.options.length; i++) {
                    if (extSel.options[i].selected) picked.push(extSel.options[i].value);
                }
                tree.setExtFilter(picked);
            });
        }

        // Sort headers
        var ths = document.querySelectorAll('#browseTable thead th.sortable');
        for (var i = 0; i < ths.length; i++) {
            (function (th) {
                th.addEventListener('click', function () {
                    tree.setSort(th.dataset.sort);
                });
            })(ths[i]);
        }

        // Tree-row clicks (event delegation on tbody).
        // Click semantics on a folder row:
        //   - plain click  → toggle just this folder
        //   - shift-click  → recursive expand/collapse of the whole
        //                    subtree (matches common file-explorer
        //                    convention; e.g. Finder, VSCode tree,
        //                    Windows Explorer)
        //   - alt-click    → ALSO recursive (alt is sometimes the
        //                    expand-all key on Linux DEs; bind both
        //                    so muscle memory works either way)
        // File rows: let the <a> tag's natural target=_blank do its
        // job — don't intercept.
        var tbody = document.getElementById('browseTbody');
        if (tbody) {
            tbody.addEventListener('click', function (e) {
                var row = e.target.closest('tr.tree-row');
                if (!row) return;
                var id = parseInt(row.dataset.id, 10);
                var node = state.nodes.get(id);
                if (!node) return;

                var isExpandable = row.dataset.isdir === 'true' || row.dataset.iszip === 'true';
                var clickedChevron = !!e.target.closest('.tree-name__chevron');

                if (isExpandable) {
                    // For folders + zips: click anywhere on the row
                    // toggles. Modifier-click → recursive expand.
                    e.preventDefault();
                    if (e.shiftKey || e.altKey) {
                        if (node.expanded) tree.collapseSubtree(id);
                        else tree.expandSubtree(id);
                    } else {
                        tree.toggleFolder(id);
                    }
                    return;
                }

                // Plain file row.
                // Modifier-click (ctrl/cmd) and middle-click → fall
                // through to the <a> tag's natural target=_blank
                // behavior (open in new tab). For server-backed
                // files, that opens the real URL via zddc-server.
                if (e.ctrlKey || e.metaKey || e.shiftKey || e.button === 1) {
                    return;
                }
                // Plain click → preview popup. Intercept default nav.
                e.preventDefault();
                var p = previewMod();
                if (p) p.showFilePreview(node);
            });

            // Middle-click (auxclick) — same fall-through logic.
            tbody.addEventListener('auxclick', function (e) {
                if (e.button !== 1) return; // middle only
                // Browser handles target=_blank natively for middle
                // click; don't preventDefault, just don't intercept.
            });
        }
    }

    // Public API
    window.app.modules.events = {
        init: init,
        statusError: statusError,
        statusInfo: statusInfo,
        statusClear: statusClear,
        showBrowseRoot: showBrowseRoot
    };
})();