// preview-zddc-form.js — schema-driven FORM view for .zddc files.
//
// The user shouldn't have to understand YAML cascades to configure a project.
// This renders the .zddc as a form: the OPTION fields (the blanks an operator
// fills — title, admins, role members) are editable widgets; the STRUCTURE
// (paths, WORM, tools, behaviours — what a ZDDC project IS) is shown read-only
// for context. The split is driven by the server's .zddc JSON Schema
// (/.api/zddc-schema, x-zddc-tier: structure|option). Saving merges the edited
// option values back into the file (preserving all structure keys) and PUTs the
// YAML — which works for an on-disk .zddc and for a .zddc.zip bundle member
// (the server's ServeZipWrite). An "Edit raw YAML" escape hands off to the
// CodeMirror editor for anything the form doesn't cover (field_codes, display,
// convert, advanced acl).
//
// This is the primary .zddc editor; the raw-YAML plugin (preview-yaml.js) is
// the power-user fallback.
(function (app) {
    'use strict';

    var util = app.modules.util || window.app.modules.util;
    var escapeHtml = util.escapeHtml;
    var saveFile = util.saveFile;
    var isEditableZipMember = util.isEditableZipMember;

    var current = null; // { node, dirty, etag, lastModified }

    // Cached .zddc schema (property → {tier, description}).
    var schemaProps = null;
    function loadSchema() {
        if (schemaProps) return Promise.resolve(schemaProps);
        return fetch('/.api/zddc-schema', { headers: { 'Accept': 'application/json' }, credentials: 'same-origin' })
            .then(function (r) { return r.ok ? r.json() : null; })
            .then(function (j) { schemaProps = (j && j.properties) || {}; return schemaProps; })
            .catch(function () { schemaProps = {}; return schemaProps; });
    }

    function handles(node) {
        return !!node && (node.name === '.zddc' || /\.zddc$/i.test(node.name || ''));
    }

    function canSave(node) {
        if (isEditableZipMember(node)) return true;
        if (node.url && window.app.state.source === 'server' && window.zddc.cap) {
            // A .zddc edit is an ActionAdmin write — needs the 'a' verb.
            return window.zddc.cap.has(node, 'a');
        }
        return false;
    }

    function isDirty() { return !!(current && current.dirty); }
    function currentNode() { return current ? current.node : null; }
    function dispose() { current = null; }

    function desc(name) {
        return (schemaProps && schemaProps[name] && schemaProps[name].description) || '';
    }

    // ── small DOM helpers ───────────────────────────────────────────────────
    function el(tag, cls, text) {
        var e = document.createElement(tag);
        if (cls) e.className = cls;
        if (text != null) e.textContent = text;
        return e;
    }
    // A growable list of single-string rows (used for admins + role members).
    function listEditor(values, placeholder, onChange, readOnly) {
        var wrap = el('div', 'zf-list');
        function addRow(val) {
            var row = el('div', 'zf-list__row');
            row.style.cssText = 'display:flex;gap:.4rem;margin:.2rem 0;';
            var input = el('input');
            input.type = 'text';
            input.value = val || '';
            input.placeholder = placeholder || '';
            input.style.cssText = 'flex:1;padding:.3rem;font-family:var(--code,monospace);';
            input.disabled = !!readOnly;
            input.addEventListener('input', onChange);
            row.appendChild(input);
            if (!readOnly) {
                var del = el('button', null, '−');
                del.type = 'button';
                del.title = 'Remove';
                del.addEventListener('click', function () { row.remove(); onChange(); });
                row.appendChild(del);
            }
            wrap.appendChild(row);
        }
        (values || []).forEach(addRow);
        if (!readOnly) {
            var add = el('button', 'zf-add', '+ add');
            add.type = 'button';
            add.style.cssText = 'margin-top:.2rem;';
            add.addEventListener('click', function () { addRow(''); onChange(); });
            wrap.appendChild(add);
        }
        wrap._values = function () {
            return Array.prototype.slice.call(wrap.querySelectorAll('.zf-list__row input'))
                .map(function (i) { return i.value.trim(); })
                .filter(function (v) { return v; });
        };
        return wrap;
    }

    async function render(node, container, ctx) {
        dispose();
        var text, etag = null, lastModified = null;
        try {
            if (ctx.getContentWithVersion) {
                var loaded = await ctx.getContentWithVersion(node);
                text = new TextDecoder('utf-8', { fatal: false }).decode(loaded.buf);
                etag = loaded.etag;
                lastModified = loaded.lastModified;
            } else {
                text = new TextDecoder('utf-8', { fatal: false }).decode(await ctx.getArrayBuffer(node));
            }
        } catch (e) {
            container.innerHTML = '<div class="preview-empty" style="color:var(--danger)">'
                + 'Could not read ' + escapeHtml(node.name) + ': ' + escapeHtml(e.message || String(e)) + '</div>';
            return;
        }

        var data = {};
        try { data = (window.jsyaml && window.jsyaml.load(text)) || {}; } catch (_) { data = {}; }
        if (typeof data !== 'object' || Array.isArray(data)) data = {};
        await loadSchema();

        var editable = canSave(node);
        current = { node: node, dirty: false, etag: etag, lastModified: lastModified };

        container.innerHTML = '';
        var shell = el('div', 'yaml-shell zddc-form');
        shell.style.cssText = 'padding:.75rem 1rem;overflow:auto;height:100%;box-sizing:border-box;';
        container.appendChild(shell);

        // Header.
        var hdr = el('div', 'md-shell__infohdr');
        hdr.appendChild(el('span', 'md-shell__title', node.name));
        var srcTag = el('span', 'md-shell__source', isEditableZipMember(node) ? 'config bundle' : (editable ? '.zddc form' : 'read-only'));
        hdr.appendChild(srcTag);
        var dirtyEl = el('span', 'md-shell__dirty');
        hdr.appendChild(dirtyEl);
        var statusEl = el('span', 'md-shell__status');
        hdr.appendChild(statusEl);
        var rawBtn = el('button', 'btn btn-sm btn-secondary', 'Edit raw YAML');
        rawBtn.type = 'button';
        rawBtn.title = 'Switch to the raw YAML editor (covers every key).';
        rawBtn.addEventListener('click', function () {
            var ym = window.app.modules.yamledit;
            if (ym && ym.render) { dispose(); ym.render(node, container, ctx); }
        });
        hdr.appendChild(rawBtn);
        var saveBtn = el('button', 'btn btn-sm btn-primary', 'Save');
        saveBtn.type = 'button';
        saveBtn.disabled = true;
        hdr.appendChild(saveBtn);
        shell.appendChild(hdr);

        function markDirty() {
            if (!current) return;
            current.dirty = true;
            dirtyEl.textContent = '● modified';
            if (editable) saveBtn.disabled = false;
        }

        var help = el('p', 'help');
        help.style.cssText = 'color:var(--color-text-muted,#666);font-size:.85rem;margin:.3rem 0 .5rem;';
        help.textContent = editable
            ? 'Fill in the project options below. Structure (the folder shape, WORM, tools) is managed by the baseline and shown read-only — edit it via raw YAML if you must.'
            : 'Read-only — you need admin authority over this path to edit it.';
        shell.appendChild(help);

        // ── OPTION fields ───────────────────────────────────────────────────
        function section(title, hint, tight) {
            var s = el('section', 'zf-section');
            s.style.cssText = 'margin:0 0 1rem;';
            var h = el('h3', null, title);
            // `tight` drops the heading's top margin for the FIRST section so
            // it doesn't stack with the intro's bottom margin (the gap above
            // Title was reading as excessive). Later sections keep the gap.
            h.style.cssText = 'font-size:1em;margin:' + (tight ? '0' : '.6rem') + ' 0 .2rem;';
            s.appendChild(h);
            if (hint) {
                var p = el('p', 'help', hint);
                p.style.cssText = 'color:var(--color-text-muted,#888);font-size:.8rem;margin:0 0 .3rem;';
                s.appendChild(p);
            }
            shell.appendChild(s);
            return s;
        }

        // title
        var titleSec = section('Title', desc('title'), true);
        var titleInput = el('input');
        titleInput.type = 'text';
        titleInput.value = (typeof data.title === 'string') ? data.title : '';
        titleInput.disabled = !editable;
        titleInput.style.cssText = 'width:100%;max-width:32rem;padding:.35rem;';
        titleInput.addEventListener('input', markDirty);
        titleSec.appendChild(titleInput);

        // admins
        var adminsSec = section('Admins', desc('admins'));
        var adminsList = listEditor(Array.isArray(data.admins) ? data.admins : [], 'email or *@domain', markDirty, !editable);
        adminsSec.appendChild(adminsList);

        // roles (map name → {members:[]})
        var rolesSec = section('Roles', desc('roles') || 'Who belongs to each project role.');
        var rolesHost = el('div', 'zf-roles');
        rolesSec.appendChild(rolesHost);
        var roleEditors = []; // {name, membersEl, getName}
        function addRole(name, members) {
            var box = el('div', 'zf-role');
            box.style.cssText = 'border:1px solid rgba(0,0,0,0.1);border-radius:4px;padding:.4rem .6rem;margin:.3rem 0;';
            var nameRow = el('div');
            nameRow.style.cssText = 'display:flex;gap:.4rem;align-items:center;margin-bottom:.2rem;';
            var nameInput = el('input');
            nameInput.type = 'text';
            nameInput.value = name || '';
            nameInput.placeholder = 'role name (e.g. document_controller)';
            nameInput.style.cssText = 'font-family:var(--code,monospace);font-weight:600;flex:1;padding:.25rem;';
            nameInput.disabled = !editable;
            nameInput.addEventListener('input', markDirty);
            nameRow.appendChild(el('span', null, '👥'));
            nameRow.appendChild(nameInput);
            box.appendChild(nameRow);
            var membersList = listEditor(members || [], 'member email or *@domain', markDirty, !editable);
            box.appendChild(membersList);
            rolesHost.appendChild(box);
            roleEditors.push({ getName: function () { return nameInput.value.trim(); }, members: membersList });
        }
        var roles = (data.roles && typeof data.roles === 'object') ? data.roles : {};
        Object.keys(roles).forEach(function (rn) {
            var m = (roles[rn] && Array.isArray(roles[rn].members)) ? roles[rn].members : [];
            addRole(rn, m);
        });
        if (editable) {
            var addRoleBtn = el('button', 'zf-add', '+ add role');
            addRoleBtn.type = 'button';
            addRoleBtn.addEventListener('click', function () { addRole('', []); markDirty(); });
            rolesSec.appendChild(addRoleBtn);
        }

        // ── STRUCTURE (read-only) ───────────────────────────────────────────
        var structKeys = Object.keys(data).filter(function (k) {
            return schemaProps[k] && schemaProps[k].tier === 'structure';
        });
        // Also surface option keys this form doesn't render yet, as read-only.
        var rawHandled = { title: 1, admins: 1, roles: 1 };
        var otherKeys = Object.keys(data).filter(function (k) {
            return !rawHandled[k] && !(schemaProps[k] && schemaProps[k].tier === 'structure');
        });
        if (structKeys.length || otherKeys.length) {
            var det = el('details', 'zf-structure');
            det.style.cssText = 'margin-top:.5rem;';
            var sum = el('summary', null, 'Structure & advanced (read-only — edit via raw YAML)');
            sum.style.cssText = 'cursor:pointer;color:var(--color-text-muted,#666);font-size:.85rem;';
            det.appendChild(sum);
            var subset = {};
            structKeys.concat(otherKeys).forEach(function (k) { subset[k] = data[k]; });
            var pre = el('pre');
            pre.style.cssText = 'background:var(--code-bg,#f6f8fa);padding:.5rem;border-radius:4px;overflow:auto;font-size:.8rem;';
            try { pre.textContent = window.jsyaml ? window.jsyaml.dump(subset) : JSON.stringify(subset, null, 2); }
            catch (_) { pre.textContent = JSON.stringify(subset, null, 2); }
            det.appendChild(pre);
            shell.appendChild(det);
        }

        // ── Save ────────────────────────────────────────────────────────────
        function buildContent() {
            var out = {};
            // Preserve everything not managed by the form (structure + unrendered options).
            Object.keys(data).forEach(function (k) { if (!rawHandled[k]) out[k] = data[k]; });
            var t = titleInput.value.trim();
            if (t) out.title = t;
            var admins = adminsList._values();
            if (admins.length) out.admins = admins;
            var rolesOut = {};
            roleEditors.forEach(function (re) {
                var n = re.getName();
                if (!n) return;
                var mem = re.members._values();
                rolesOut[n] = mem.length ? { members: mem } : { members: [] };
            });
            if (Object.keys(rolesOut).length) out.roles = rolesOut;
            return window.jsyaml.dump(out);
        }

        saveBtn.addEventListener('click', async function () {
            if (!current || !editable) return;
            saveBtn.disabled = true;
            statusEl.textContent = 'Saving…';
            var content;
            try { content = buildContent(); }
            catch (e) { statusEl.textContent = 'Serialize failed: ' + (e.message || e); return; }
            try {
                var res = await saveFile(node, content, 'application/yaml; charset=utf-8',
                    { etag: current.etag, lastModified: current.lastModified });
                if (!current) return;
                current.etag = (res && res.etag) || current.etag;
                current.dirty = false;
                dirtyEl.textContent = '';
                statusEl.textContent = 'Saved ' + new Date().toLocaleTimeString();
                if (window.zddc && window.zddc.toast) window.zddc.toast('Saved ' + node.name, 'success');
            } catch (e) {
                if (e && e.status === 412 && window.app.modules.conflict) {
                    window.app.modules.conflict.open({
                        name: node.name, theirsText: '', minePut: function () { return saveFile(node, content, 'application/yaml; charset=utf-8', {}); }
                    });
                    statusEl.textContent = 'Conflict — changed on server.';
                } else {
                    statusEl.textContent = 'Save failed: ' + (e && e.message ? e.message : e);
                }
                saveBtn.disabled = false;
            }
        });
    }

    app.modules.zddcform = {
        handles: handles,
        render: render,
        isDirty: isDirty,
        currentNode: currentNode,
        dispose: dispose
    };
})(window.app);