// Browser-safe helpers shared by the preview, the session page and the Cloudflare deploy.

export const COLLECTION_RE = /^[a-zA-Z0-9_-]{1,40}$/;

/**
 * Injects Echo's tiny runtime into a generated page:
 * - window.EchoDB: shared cloud storage for the built app (backed by /api/public/apps/:appId/:collection)
 * - live testing: when shown inside Echo's preview iframe, reports runtime errors and a
 *   "ready" health check to the parent window.
 */
export function withEchoRuntime(html: string, appId: string, apiBase: string) {
  const script = `<script data-echo-runtime>(function(){var A=${JSON.stringify(appId)},B=${JSON.stringify(apiBase.replace(/\/$/, ""))};
try{window.localStorage.getItem("x")}catch(e){var mem=function(){var d={};return{getItem:function(k){return k in d?d[k]:null},setItem:function(k,v){d[k]=String(v)},removeItem:function(k){delete d[k]},clear:function(){d={}},key:function(i){return Object.keys(d)[i]||null},get length(){return Object.keys(d).length}}};try{Object.defineProperty(window,"localStorage",{value:mem(),configurable:true});Object.defineProperty(window,"sessionStorage",{value:mem(),configurable:true})}catch(x){}}
function u(c){return B+"/api/public/apps/"+A+"/"+encodeURIComponent(c)}
function j(r){return r.json().then(function(d){if(!r.ok)throw new Error(d&&d.error||"Request failed");return d})}
window.EchoDB={list:function(c){return fetch(u(c)).then(j).then(function(d){return d.records||[]})},
add:function(c,data){return fetch(u(c),{method:"POST",headers:{"Content-Type":"text/plain;charset=UTF-8"},body:JSON.stringify(data)}).then(j).then(function(d){return d.record})}};
if(window.parent===window)return;
function send(m){try{m.echo=1;parent.postMessage(m,"*")}catch(e){}}
window.addEventListener("error",function(e){send({kind:"error",text:String(e.message||"Script error")+(e.lineno?" (line "+e.lineno+")":"")})});
window.addEventListener("unhandledrejection",function(e){var r=e.reason;send({kind:"error",text:"Unhandled promise: "+String(r&&r.message||r)})});
var ce=console.error;console.error=function(){try{send({kind:"error",text:[].map.call(arguments,function(a){return a&&a.message||String(a)}).join(" ").slice(0,500)})}catch(x){}return ce.apply(console,arguments)};
window.addEventListener("load",function(){setTimeout(function(){var b=document.body;send({kind:"ready",controls:document.querySelectorAll("button,a,input,select,textarea").length,textLength:b?b.innerText.trim().length:0,elements:b?b.querySelectorAll("*").length:0})},2000)});
})();</script>`;
  html = pinLibraries(html);
  if (/<head[^>]*>/i.test(html)) return html.replace(/<head[^>]*>/i, (m) => `${m}${script}`);
  return script + html;
}

/** Pins CDN libraries whose "latest" builds break in-browser compiling (Babel 8 emits ES imports). */
export function pinLibraries(html: string) {
  return html
    .replace(/(unpkg\.com|cdn\.jsdelivr\.net\/npm)\/@babel\/standalone(@[^/"']*)?\//g, "$1/@babel/standalone@7/")
    .replace(/(unpkg\.com|cdn\.jsdelivr\.net\/npm)\/@babel\/standalone(@[^/"']*)?(["'])/g, "$1/@babel/standalone@7/babel.min.js$3")
    .replace(/(unpkg\.com|cdn\.jsdelivr\.net\/npm)\/lucide@latest(\/[^"']*)?(["'])/g, "$1/lucide@0.468.0/dist/umd/lucide.min.js$3");
}