export const RANDOM_UUID_POLYFILL = '<script>(function(){try{var c=globalThis.crypto;if(c&&typeof c.randomUUID!=="function"&&typeof c.getRandomValues==="function"){c.randomUUID=function(){var b=c.getRandomValues(new Uint8Array(16));b[6]=(b[6]&15)|64;b[8]=(b[8]&63)|128;var h="";for(var i=0;i<16;i++){h+=b[i].toString(16).padStart(2,"0")}return h.slice(0,8)+"-"+h.slice(8,12)+"-"+h.slice(12,16)+"-"+h.slice(16,20)+"-"+h.slice(20)}}}catch(e){}})();</script>'

export const LIFECYCLE_TRANSITION_GUARD = `<script>(function(){
try{
var api="/_dsh_platform/plugin-api/v1",wait="/_dsh_gateway/wait",navigating=false;
function transition(value){return ["restarting","switching","recovering","restart-failed"].includes(value.operation)||["snapshotting-data","switching","probation","restoring-data"].includes(value.update&&value.update.status)||["starting","stopping","stopped","restarting","recovering","failed"].includes(value.dshLifecycle&&value.dshLifecycle.state)}
function navigate(){if(navigating||location.pathname===wait)return;navigating=true;var back=location.pathname+location.search+location.hash;location.replace(wait+"?return="+encodeURIComponent(back))}
async function inspect(){try{var response=await fetch(api+"/status",{cache:"no-store"}),value=await response.json();if(transition(value))navigate()}catch(e){}}
var events=new EventSource(api+"/events");events.addEventListener("state",inspect);inspect();
}catch(e){}
})();</script>`

export const SESSION_VALIDITY_GUARD = `<script>(function(){
try{
var checking=false;
async function inspect(){if(checking)return;checking=true;try{var response=await fetch("/_dsh_platform/auth/session-context",{cache:"no-store",credentials:"same-origin"});if(response.status===401)location.reload()}catch(e){}finally{checking=false}}
setInterval(inspect,5000);addEventListener("focus",inspect);document.addEventListener("visibilitychange",function(){if(document.visibilityState==="visible")inspect()});
}catch(e){}
})();</script>`

export const PLUGIN_RECOVERY_GUARD = `<script>(function(){
try{
var nativeFetch=globalThis.fetch.bind(globalThis),markerKey="dsh-platform:plugin-load-recovery",waitPath="/_dsh_gateway/wait",failurePath="/_dsh_gateway/plugin-failure",navigating=false;
function plugin(url){var match=url.pathname.match(/^\\/plugins\\/(.+)\\/client\\.js$/);if(!match)return null;try{return decodeURIComponent(match[1])}catch(e){return match[1]}}
function target(input){try{return new URL(typeof input==="string"?input:input.url,location.href)}catch(e){return null}}
function marker(){try{var value=JSON.parse(sessionStorage.getItem(markerKey));return value&&Date.now()-value.createdAt<120000?value:null}catch(e){return null}}
function save(value){try{sessionStorage.setItem(markerKey,JSON.stringify(value))}catch(e){}}
function report(event,fields){nativeFetch("/_dsh_gateway/client-event",{method:"POST",headers:{"content-type":"application/json"},body:JSON.stringify(Object.assign({event:event,pathname:location.pathname},fields)),keepalive:true}).catch(function(){})}
async function json(path){try{var response=await nativeFetch(path,{cache:"no-store"});return await response.json()}catch(e){return {}}}
function transition(value){return ["restarting","switching","recovering","restart-failed"].includes(value.operation)||["snapshotting-data","switching","probation","restoring-data"].includes(value.update&&value.update.status)||["starting","stopping","stopped","restarting","recovering","failed"].includes(value.dshLifecycle&&value.dshLifecycle.state)}
async function recover(url,pluginId,reason){
var values=await Promise.all([json("/_dsh_gateway/readiness"),json("/_dsh_platform/plugin-api/v1/status")]),readiness=values[0],status=values[1],lifecycle=status.dshLifecycle||{},updated=Date.parse(lifecycle.updatedAt),recent=typeof lifecycle.taskId==="string"&&Number.isFinite(updated)&&Date.now()-updated<30000,eligible=transition(status)||recent||readiness.pluginRecoveryEligible===true;
var identity=typeof lifecycle.taskId==="string"?lifecycle.taskId:(lifecycle.updatedAt||readiness.state||"unknown"),previous=marker(),attempt=previous&&previous.identity===identity?previous.attempt+1:1,fields={pluginId:pluginId,revision:url.searchParams.get("rev"),lifecycleState:lifecycle.state||readiness.state||null,lifecycleTaskId:lifecycle.taskId||null,recoveryAttempt:attempt,reason:reason};
if(attempt>=3){report("browser.plugin-load.recovery.failed",Object.assign({level:"error"},fields));save({identity:identity,taskId:lifecycle.taskId||null,url:url.pathname+url.search,pluginId:pluginId,attempt:attempt,createdAt:Date.now(),completed:false});if(!navigating){navigating=true;location.replace(failurePath)}return true}
if(!eligible){report("browser.plugin-load.failed",Object.assign({level:"error"},fields));return false}
report("browser.plugin-load.failed",Object.assign({level:"warning"},fields));
save({identity:identity,taskId:lifecycle.taskId||null,url:url.pathname+url.search,pluginId:pluginId,attempt:attempt,createdAt:Date.now(),completed:false});
report("browser.plugin-load.recovery.started",Object.assign({level:"warning"},fields));
if(!navigating){navigating=true;var back=location.pathname+location.search+location.hash;location.replace(waitPath+"?return="+encodeURIComponent(back))}return true
}
function completed(url,pluginId){var value=marker();if(!value||value.completed||value.url!==url.pathname+url.search)return;value.completed=true;save(value);report("browser.plugin-load.recovery.completed",{level:"info",pluginId:pluginId,revision:url.searchParams.get("rev"),lifecycleTaskId:value.taskId||null,recoveryAttempt:value.attempt})}
globalThis.fetch=function(input,init){var url=target(input),pluginId=url&&plugin(url),pending=nativeFetch(input,init);if(!pluginId)return pending;return pending.then(function(response){if(response.ok){completed(url,pluginId);return response}if(response.status!==502&&response.status!==503)return response;return recover(url,pluginId,"HTTP "+response.status).then(function(active){return active?new Promise(function(){}):response})},function(error){return recover(url,pluginId,error&&error.name||"network error").then(function(active){if(active)return new Promise(function(){});throw error})})}
function errorUrl(value){
var candidates=[value&&value.filename,value&&value.error&&value.error.stack,value&&value.error&&value.error.message,value&&value.reason&&value.reason.stack,value&&value.reason&&value.reason.message];
for(var i=0;i<candidates.length;i++){if(typeof candidates[i]!=="string")continue;var match=candidates[i].match(/(?:https?:\\/\\/[^\\s)]+)?(\\/plugins\\/(?:@[^/\\s]+\\/)?[^/\\s]+\\/client\\.js(?:\\?[^\\s)]+)?)/);if(!match)continue;var url=target(match[1]);if(url)return url}
return null
}
function handleError(value,reason){var url=errorUrl(value);if(!url)return;var pluginId=plugin(url);if(!pluginId)return;recover(url,pluginId,reason).catch(function(){})}
addEventListener("error",function(event){handleError(event,"plugin module error")},true);
addEventListener("unhandledrejection",function(event){handleError({reason:event.reason},"plugin module rejection")},true);
}catch(e){}
})();</script>`

export function injectRandomUuidPolyfill(html) {
  const match = /<head(?:\s[^>]*)?>/i.exec(html)
  const injected = `${RANDOM_UUID_POLYFILL}${LIFECYCLE_TRANSITION_GUARD}${SESSION_VALIDITY_GUARD}${PLUGIN_RECOVERY_GUARD}`
  if (match === null) return `${injected}${html}`
  const end = match.index + match[0].length
  return `${html.slice(0, end)}${injected}${html.slice(end)}`
}