// @ts-check

/**
 * PromptJS v1.0.0 — Runtime Helper Emitter / Emitor Helper Runtime
 * ============================================================================
 *
 * v0.5 changes:
 * - Split RUNTIME_HELPERS monolith → per-helper map for tree shaking
 * - Add __pjs_handleError helper for error boundaries
 * - emitRuntimeHelpers() only emits helpers present in compiler.helpers Set
 *
 * Helper yang di-emit (tree-shaken berdasarkan penggunaan):
 * - `__createReactive(val)` — Proxy-based reactive state
 * - `__createComputed(fn)` — computed value dari reactive lain
 * - `__watch(reactive, cb)` — subscribe ke perubahan reactive
 * - `__setState(reactive, val)` — set nilai reactive (trigger subscribers)
 * - `__cleanup(reactive)` — unsubscribe semua dependency reactive
 * - `__pjs_handleError(error, context, hook)` — error boundary handler
 * - `__promptjs_panjang/apakahKosong/apakahAda` — builtins yang perlu runtime
 *
 * Helper yang TIDAK di-emit (legacy, sudah tidak dipakai langsung):
 * - `__createElement` — visitBuatStatement pakai document.createElement langsung
 * - `__mount` — visitBuatStatement pakai appendChild langsung
 */

'use strict';

// ============================================================================
// SHARED REACTIVE INFRASTRUCTURE
// ============================================================================
// Globals yang dibutuhkan oleh beberapa helper — selalu di-emit kalau
// ADA helper reaktif yang dipakai.

const REACTIVE_INFRA = `
var __subscribers = new WeakMap();
var __effectMap = new WeakMap();
var __activeEffect = null;
var __effectId = 0;
`.trim();

// ============================================================================
// PER-HELPER CODE MAP
// ============================================================================
// Setiap helper punya kode mandiri. Di-emit hanya jika namanya ada
// di compiler.helpers Set.

/**
 * @type {Object<string, string>}
 * Map nama helper → kode JS-nya.
 */
const RUNTIME_HELPER_MAP = {
  // ── Reactive Core ────────────────────────────────────────────────────
  __createReactive: `
function __createReactive(val) {
  var obj = { value: val, __id: ++__effectId };
  var proxy = new Proxy(obj, {
    get: function(target, prop) {
      if (__activeEffect && prop === 'value') {
        var subs = __subscribers.get(proxy) || new Set();
        subs.add(__activeEffect);
        __subscribers.set(proxy, subs);
        if (__activeEffect.__deps) __activeEffect.__deps.add(proxy);
      }
      return target[prop];
    },
    set: function(target, prop, newVal) {
      var oldVal = target[prop];
      target[prop] = newVal;
      if (prop === 'value' && oldVal !== newVal) {
        var subs = __subscribers.get(proxy);
        if (subs) {
          var subsCopy = Array.from(subs);
          for (var i = 0; i < subsCopy.length; i++) subsCopy[i](newVal, oldVal);
        }
      }
      return true;
    }
  });
  return proxy;
}`.trim(),

  __createComputed: `
function __createComputed(fn) {
  var reactive = __createReactive(null);
  var effect = function computedEffect() {
    __activeEffect = effect;
    try { reactive.value = fn(); } catch(e) { /* defer if deps not ready */ }
    __activeEffect = null;
  };
  effect.__deps = new Set();
  effect.__isComputed = true;
  effect();
  __effectMap.set(reactive, effect);
  return reactive;
}`.trim(),

  __watch: `
function __watch(reactive, cb) {
  var effect = function watchEffect(n, o) { cb(n, o); };
  effect.__deps = new Set();
  var subs = __subscribers.get(reactive) || new Set();
  subs.add(effect);
  __subscribers.set(reactive, subs);
  try { cb(reactive.value, undefined); } catch(e) { /* defer if deps not ready */ }
  var unsub = function unsubscribe() {
    var s = __subscribers.get(reactive);
    if (s) s.delete(effect);
  };
  return unsub;
}`.trim(),

  __setState: `
function __setState(reactive, val) {
  reactive.value = val;
}`.trim(),

  __cleanup: `
function __cleanup(reactive) {
  var effect = __effectMap.get(reactive);
  if (effect && effect.__deps) {
    effect.__deps.forEach(function(dep) {
      var subs = __subscribers.get(dep);
      if (subs) subs.delete(effect);
    });
    effect.__deps.clear();
  }
  var subs = __subscribers.get(reactive);
  if (subs) subs.clear();
}`.trim(),

  // ── Error Boundary (v0.5) ────────────────────────────────────────────
  __pjs_handleError: `
function __pjs_handleError(error, context, hook) {
  console.error("[PromptJS] Error di " + context + "." + hook + ":", error);
  if (window.__pjsClearError) { window.__pjsClearError(); }
}`.trim(),

  // ── PromptJS Builtin Helpers ─────────────────────────────────────────
  __promptjs_panjang: `
function __promptjs_panjang(val) {
  if (val === null || val === undefined) return 0;
  if (typeof val === 'string' || Array.isArray(val)) return val.length;
  if (typeof val === 'object' && val.hasOwnProperty('value')) return __promptjs_panjang(val.value);
  return 0;
}`.trim(),

  __promptjs_apakahKosong: `
function __promptjs_apakahKosong(val) {
  if (val === null || val === undefined) return true;
  if (typeof val === 'string' && val === '') return true;
  if (Array.isArray(val) && val.length === 0) return true;
  if (typeof val === 'object' && val.hasOwnProperty('value')) return __promptjs_apakahKosong(val.value);
  return false;
}`.trim(),

  __promptjs_apakahAda: `
function __promptjs_apakahAda(arr, item) {
  if (arr === null || arr === undefined) return false;
  if (typeof arr === 'object' && arr.hasOwnProperty('value')) return __promptjs_apakahAda(arr.value, item);
  if (Array.isArray(arr)) return arr.includes(item);
  if (typeof arr === 'string') return arr.indexOf(item) !== -1;
  return false;
}`.trim(),

  // ── HTML Sanitizer (v1.0.0) ────────────────────────────────────────
  // S-2: Sanitizer berbasis PARSING DOM dengan ALLOWLIST — bukan blocklist regex.
  // Strategi aman-secara-default (safe-by-default):
  //   1. Pakai Sanitizer API native (Element.prototype.setHTML) bila tersedia.
  //   2. Jika tidak, parse via DOMParser lalu buang segala tag/atribut di luar
  //      allowlist (termasuk event handler on*, srcdoc, dan URL javascript:/data:).
  //   3. Tanpa DOM (mis. SSR) -> escape penuh ke teks (tidak pernah dieksekusi).
  // Catatan: untuk HTML kaya tak-tepercaya, gunakan DOMPurify — lihat docs.
  __sanitizeHTML: `
function __sanitizeHTML(html) {
  if (typeof html !== 'string') html = String(html == null ? '' : html);
  var ALLOWED_TAGS = {
    A:1,ABBR:1,B:1,BLOCKQUOTE:1,BR:1,CODE:1,DD:1,DIV:1,DL:1,DT:1,EM:1,
    FIGCAPTION:1,FIGURE:1,H1:1,H2:1,H3:1,H4:1,H5:1,H6:1,HR:1,I:1,IMG:1,
    LI:1,MARK:1,OL:1,P:1,PRE:1,S:1,SMALL:1,SPAN:1,STRONG:1,SUB:1,SUP:1,
    TABLE:1,TBODY:1,TD:1,TFOOT:1,TH:1,THEAD:1,TR:1,U:1,UL:1
  };
  var ALLOWED_ATTR = { href:1, src:1, alt:1, title:1, colspan:1, rowspan:1, id:1, 'class':1 };
  var URL_ATTR = { href:1, src:1 };
  function safeUrl(v) {
    var s = String(v).replace(/[\\u0000-\\u001F\\u007F\\s]/g, '').toLowerCase();
    return !/^(javascript|data|vbscript):/.test(s);
  }
  function escapeText(s) {
    return String(s)
      .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;').replace(/'/g, '&#39;');
  }
  if (typeof document === 'undefined' || !document.createElement) {
    return escapeText(html);
  }
  try {
    var tplN = document.createElement('template');
    if (typeof tplN.setHTML === 'function') { tplN.setHTML(html); return tplN.innerHTML; }
  } catch (e) { /* fallthrough ke parser allowlist */ }
  var doc;
  try {
    doc = new DOMParser().parseFromString('<body>' + html + '</body>', 'text/html');
  } catch (e2) { return escapeText(html); }
  function clean(node) {
    var child = node.firstChild;
    while (child) {
      var next = child.nextSibling;
      if (child.nodeType === 1) {
        if (!ALLOWED_TAGS[child.tagName]) {
          node.removeChild(child);
        } else {
          var attrs = child.attributes;
          for (var i = attrs.length - 1; i >= 0; i--) {
            var name = attrs[i].name;
            var lname = name.toLowerCase();
            if (!ALLOWED_ATTR[lname] || lname.indexOf('on') === 0) {
              child.removeAttribute(name);
            } else if (URL_ATTR[lname] && !safeUrl(attrs[i].value)) {
              child.removeAttribute(name);
            }
          }
          clean(child);
        }
      } else if (child.nodeType === 8) {
        node.removeChild(child);
      }
      child = next;
    }
  }
  clean(doc.body);
  return doc.body.innerHTML;
}`.trim(),

  // ── Safe Attribute Setter (v1.0.0) ──────────────────────────────────────
  // S-4: Atribut elemen di-emit dari nilai .pjs yang tak-tepercaya. Tanpa
  // filter, penulis dapat menyuntik event-handler (`onclick`, `onerror`, …)
  // atau URL skema aktif (`href="javascript:…"`, `src="data:…"`) yang langsung
  // menjadi XSS pada aplikasi hasil. Helper ini adalah TITIK TUNGGAL yang
  // dilalui semua setAttribute dinamis:
  //   • Atribut event-handler (`on*`) DITOLAK total.
  //   • Atribut pembawa-URL dengan skema javascript:/data:/vbscript: DITOLAK.
  //   • Sisanya di-set normal.
  // Mengembalikan true bila atribut ter-set, false bila ditolak (di-warn).
  __safeAttr: `
function __safeAttr(el, name, value) {
  if (!el || typeof name !== 'string') return false;
  var lname = name.toLowerCase();
  // Tolak semua event-handler inline (onclick, onerror, onmouseover, ...).
  if (lname.indexOf('on') === 0) {
    if (typeof console !== 'undefined') console.warn('[PromptJS] PJS-W1001: atribut event-handler diblokir demi keamanan: ' + name + ' (saran: gunakan addEventListener atau pengikat acara PromptJS, jangan atribut on* inline)');
    return false;
  }
  // Atribut 'style' tidak boleh memuat skema/ekspresi aktif (clickjacking,
  // CSS expression injection). Difilter secara konservatif (LOW-3).
  if (lname === 'style') {
    var sv = String(value == null ? '' : value).replace(/[\\u0000-\\u001F\\u007F]/g, '').toLowerCase();
    if (/(javascript:|vbscript:|expression\\s*\\(|-moz-binding|behavior\\s*:)/.test(sv)) {
      if (typeof console !== 'undefined') console.warn('[PromptJS] PJS-W1003: nilai style tidak aman diblokir: ' + value + ' (saran: hindari javascript:, expression(), atau -moz-binding di CSS inline)');
      return false;
    }
    el.setAttribute(name, value == null ? '' : value);
    return true;
  }
  function __badScheme(raw) {
    var cs = String(raw == null ? '' : raw).replace(/[\\u0000-\\u001F\\u007F\\s]/g, '').toLowerCase();
    return /^(javascript|data|vbscript):/.test(cs);
  }
  var URL_ATTR = { href:1, src:1, action:1, formaction:1, poster:1, 'xlink:href':1, background:1, cite:1, srcset:1, 'data':1 };
  if (URL_ATTR[lname]) {
    if (lname === 'srcset') {
      // srcset = daftar kandidat dipisah koma; skema dicek PER kandidat,
      // bukan hanya di awal string (LOW-2).
      var cands = String(value == null ? '' : value).split(',');
      for (var ci = 0; ci < cands.length; ci++) {
        var url = cands[ci].trim().split(/\\s+/)[0];
        if (url && __badScheme(url)) {
          if (typeof console !== 'undefined') console.warn('[PromptJS] PJS-W1002: URL skema tidak aman diblokir pada atribut ' + name + ': ' + value + ' (saran: gunakan URL http(s): atau path relatif)');
          return false;
        }
      }
    } else if (__badScheme(value)) {
      if (typeof console !== 'undefined') console.warn('[PromptJS] PJS-W1002: URL skema tidak aman diblokir pada atribut ' + name + ': ' + value + ' (saran: gunakan URL http(s):, mailto:, atau path relatif)');
      return false;
    }
  }
  el.setAttribute(name, value == null ? '' : value);
  return true;
}`.trim(),
};

// ============================================================================
// HELPERS YANG MEMBUTUHKAN REACTIVE INFRASTRUCTURE
// ============================================================================
const REACTIVE_HELPERS = new Set(['__createReactive', '__createComputed', '__watch', '__cleanup']);

// ============================================================================
// BACKWARD COMPAT: RUNTIME_HELPERS monolith (untuk snapshot tests)
// ============================================================================

/**
 * Full monolith string — for backward compatibility with any code
 * that imports RUNTIME_HELPERS directly.
 * @type {string}
 */
const RUNTIME_HELPERS = REACTIVE_INFRA + '\n\n' + Object.values(RUNTIME_HELPER_MAP).join('\n\n');

// ============================================================================
// EMIT FUNCTION
// ============================================================================

/**
 * Emit runtime helpers ke `compiler.output` — hanya yang dipakai (tree shaking).
 *
 * Algoritma:
 * 1. Jika compiler.helpers kosong → skip seluruh runtime (output minimal)
 * 2. Jika ada reactive helper → emit shared infra dulu
 * 3. Emit setiap helper yang ada di Set, urut sesuai definisi
 *
 * @param {Object} compiler - Instance PromptJSCompiler
 * @returns {void}
 */
function emitRuntimeHelpers(compiler) {
  const needed = compiler.helpers;

  // Jika tidak ada helper yang dipakai, skip seluruh blok
  if (!needed || needed.size === 0) {
    return;
  }

  compiler.emit('// === Runtime Helpers ===');

  // Emit shared reactive infrastructure jika ada helper reaktif yang dipakai
  const needsReactive = [...needed].some((h) => REACTIVE_HELPERS.has(h));
  if (needsReactive) {
    compiler.output.push(REACTIVE_INFRA);
    compiler.emit('');
  }

  // Emit helpers yang dipakai, urut sesuai urusan logis
  const emitOrder = [
    // Reactive core dulu
    '__createReactive',
    '__createComputed',
    '__watch',
    '__setState',
    '__cleanup',
    // Error boundary
    '__pjs_handleError',
    // Builtins
    '__promptjs_panjang',
    '__promptjs_apakahKosong',
    '__promptjs_apakahAda',
    '__sanitizeHTML',
    '__safeAttr',
  ];

  for (const name of emitOrder) {
    if (needed.has(name) && RUNTIME_HELPER_MAP[name]) {
      compiler.output.push(RUNTIME_HELPER_MAP[name]);
      compiler.emit('');
    }
  }
}

module.exports = {
  RUNTIME_HELPERS,
  RUNTIME_HELPER_MAP,
  REACTIVE_HELPERS,
  emitRuntimeHelpers,
};