// edit.js — editing a node's content.
//
// Text nodes get the vendored CodeMirror editor in place, positioned over the
// node in *screen* coordinates rather than mounted inside the zoomed world.
// CodeMirror measures its own layout in device pixels, so a CSS-scaled parent
// wrecks caret placement and selection maths; a fixed-position panel sidesteps
// that entirely and stays sharp at every zoom level.
//
// The other node types have nothing to type into, so they reuse the existing
// tree picker and modal instead of an editor.
window.Canvas = window.Canvas || {};

Canvas.Edit = (function () {
    var Doc = Canvas.Doc;
    var View = Canvas.View;

    var MIN_WIDTH = 360;
    var MIN_HEIGHT = 200;

    var panel = null;
    var view = null;
    var currentId = null;
    var original = '';

    function destroy() {
        if (view) { view.destroy(); view = null; }
        if (panel) { panel.remove(); panel = null; }
        currentId = null;
        original = '';
        document.removeEventListener('pointerdown', onOutside, true);
    }

    function commit() {
        if (!panel || !view) return;
        var text = view.state.doc.toString();
        var id = currentId;
        destroy();
        var n = Doc.node(id);
        if (!n || text === original) return;
        Doc.begin('edit text');
        n.text = text;
        Doc.commit();
    }

    function onOutside(e) {
        if (!panel || panel.contains(e.target)) return;
        commit();
    }

    // screenRect places the editor over the node it edits, clamped to a usable
    // minimum and kept inside the viewport — a 60x60 node still needs a panel
    // big enough to type in.
    function screenRect(n) {
        var s = View.scale();
        var tl = View.toScreen(n.x, n.y);
        var w = Math.max(MIN_WIDTH, n.width * s);
        var h = Math.max(MIN_HEIGHT, n.height * s);
        w = Math.min(w, window.innerWidth - 16);
        h = Math.min(h, window.innerHeight - 16);
        var left = Math.max(8, Math.min(tl.x, window.innerWidth - w - 8));
        var top = Math.max(8, Math.min(tl.y, window.innerHeight - h - 8));
        return { left: left, top: top, width: w, height: h };
    }

    function openText(n) {
        var rect = screenRect(n);
        panel = document.createElement('div');
        panel.className = 'canvas-editor panel panel-floating';
        panel.style.left = rect.left + 'px';
        panel.style.top = rect.top + 'px';
        panel.style.width = rect.width + 'px';
        panel.style.height = rect.height + 'px';

        var hint = document.createElement('div');
        hint.className = 'panel-header';
        hint.textContent = 'Ctrl+Enter or click away to apply · Escape to cancel';
        panel.appendChild(hint);

        var mount = document.createElement('div');
        mount.className = 'canvas-editor-mount';
        panel.appendChild(mount);
        document.body.appendChild(panel);

        currentId = n.id;
        original = n.text || '';

        view = new CM.EditorView({
            state: CM.EditorState.create({
                doc: original,
                selection: { anchor: original.length },
                extensions: [
                    CM.history(),
                    CM.drawSelection(),
                    CM.indentOnInput(),
                    CM.EditorView.lineWrapping,
                    CM.EditorView.contentAttributes.of({ spellcheck: 'true', autocapitalize: 'sentences' }),
                    CM.markdown({ base: CM.markdownLanguage }),
                    CM.syntaxHighlighting(CM.highlightStyle),
                    CM.closeBrackets(),
                    CM.autocompletion({ override: [WikiComplete.source] }),
                    CM.theme,
                    // Mod-Enter goes first (nothing else claims it); Escape goes
                    // last so an open completion popup still gets first refusal
                    // on it and closes itself instead of discarding the edit.
                    CM.keymap.of([{ key: 'Mod-Enter', run: function () { commit(); return true; } }]
                        .concat(
                            CM.closeBracketsKeymap,
                            CM.completionKeymap,
                            CM.markdownKeymap,
                            CM.defaultKeymap,
                            CM.historyKeymap,
                            [CM.indentWithTab],
                            [{ key: 'Escape', run: function () { destroy(); return true; } }]
                        ))
                ]
            }),
            parent: mount
        });
        view.focus();
        // Capture phase: a click on a toolbar button should apply the edit
        // before that button's own handler reads the document.
        document.addEventListener('pointerdown', onOutside, true);
    }

    function openFile(n) {
        var start = (n.file || '/').replace(/\/+$/, '') || '/';
        openTreePicker({
            title: 'File node — pick a target',
            mode: 'any',
            initialPath: start,
            preselect: start,
            confirmLabel: 'USE',
            onSelect: function (p) {
                if (!p || p === n.file) return;
                Doc.begin('retarget file node');
                n.file = p;
                n.subpath = '';
                Doc.commit();
            }
        });
    }

    function promptValue(title, label, value, onValue) {
        var input = document.createElement('input');
        input.type = 'text';
        input.className = 'input';
        input.placeholder = label;
        input.value = value || '';
        openModal({
            title: title,
            body: input,
            confirm: {
                label: 'OK',
                onConfirm: function () {
                    closeModal();
                    onValue(input.value.trim());
                }
            }
        });
    }

    function openLink(n) {
        promptValue('Link node', 'https://example.com', n.url, function (v) {
            if (!v || v === n.url) return;
            Doc.begin('edit link');
            n.url = v;
            Doc.commit();
        });
    }

    function openGroup(n) {
        promptValue('Group label', 'Label', n.label, function (v) {
            if (v === (n.label || '')) return;
            Doc.begin('edit group label');
            if (v) n.label = v; else delete n.label;
            Doc.commit();
        });
    }

    // close applies whatever is currently open, if anything.
    function close() {
        if (panel) commit();
    }

    return {
        open: function (id) {
            var n = Doc.node(id);
            if (!n) return;
            close();
            switch (n.type) {
                case 'text': openText(n); break;
                case 'file': openFile(n); break;
                case 'link': openLink(n); break;
                case 'group': openGroup(n); break;
            }
        },

        // Called from the gesture layer on any pointerdown on the surface, so
        // starting a drag never silently drops an edit.
        close: close,

        isOpen: function () { return panel !== null; }
    };
})();