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// ESM Hot Module Replacement (ESM-HMR) Specification// https://github.com/withastro/esm-hmr
import util from "../../shared/util.ts";import events from "./events.ts";
class Module {  private _specifier: string;  private _isAccepted = false;  private _isDeclined = false;  private _isLocked = false;  private _data: Record<string, unknown> = {};  private _acceptCallbacks: CallableFunction[] = [];  private _disposeCallbacks: CallableFunction[] = [];
  constructor(specifier: string) {    this._specifier = specifier;  }
  get data(): Record<string, unknown> {    return this._data;  }
  accept(callback?: CallableFunction): void {    if (this._isLocked) {      return;    }    if (!this._isAccepted) {      sendMessage({ specifier: this._specifier, type: "hotAccept" });      this._isAccepted = true;    }    if (typeof callback === "function") {      this._acceptCallbacks.push(callback);    }  }
  decline(): void {    this._isDeclined = true;    this.accept();  }
  dispose(callback: CallableFunction) {    if (typeof callback === "function") {      this._disposeCallbacks.push(callback);    }  }
  invalidate(): void {    location.reload();  }
  watchFile(filename: string, callback: () => void) {    const specifier = "." + util.cleanPath(filename);    const handler = (data: Record<string, unknown>) => {      if (data.specifier === specifier) {        callback();      }    };    events.on("hmr:modify", handler);    sendMessage({ specifier, type: "hotAccept" });    return () => events.off("hmr:modify", handler);  }
  // don't accept updates if the module is locked  lock(): void {    this._isLocked = true;  }
  async applyUpdate() {    if (this._isDeclined) {      location.reload();      return;    }
    const disposeCallbacks = this._disposeCallbacks;    const data = this._data;    this._disposeCallbacks = [];    this._data = {};    disposeCallbacks.map((callback) => callback(data));
    try {      const url = this._specifier.slice(1) + (this._specifier.endsWith(".css") ? "?module&" : "?") + "t=" + Date.now();      const module = await import(url);      this._acceptCallbacks.forEach((cb) => cb(module));    } catch (err) {      console.error(err);    }  }}
export default function createHotContext(specifier: string) {  if (modules.has(specifier)) {    const mod = modules.get(specifier)!;    mod.lock();    return mod;  }  const mod = new Module(specifier);  modules.set(specifier, mod);  return mod;}
const modules: Map<string, Module> = new Map();const messageQueue: string[] = [];
let conn: WebSocket | null = null;function sendMessage(msg: Record<string, unknown>) {  const json = JSON.stringify(msg);  if (!conn || conn.readyState !== WebSocket.OPEN) {    messageQueue.push(json);  } else {    conn.send(json);  }}
function connect() {  const { location, __hmrWebSocketUrl } = window as { location: Location; __hmrWebSocketUrl?: string };  const { protocol, host } = location;  const wsUrl = __hmrWebSocketUrl || `${protocol === "https:" ? "wss" : "ws"}://${host}/-/hmr`;  const ws = new WebSocket(wsUrl);  const ping = (callback: () => void) => {    setTimeout(() => {      const ws = new WebSocket(wsUrl);      ws.addEventListener("open", callback);      ws.addEventListener("close", () => {        ping(callback); // retry      });    }, 500);  };  const colors = {    modify: "#056CF0",    create: "#20B44B",    remove: "#F00C08",  };
  ws.addEventListener("open", () => {    conn = ws;    messageQueue.splice(0, messageQueue.length).forEach((msg) => ws.send(msg));    console.log("%c[HMR]", "color:#999", "listening for file changes...");  });
  ws.addEventListener("close", () => {    if (conn !== null) {      conn = null;      console.log("[HMR] closed.");      // try to re-connect      connect();    } else {      // ping to reload the page      ping(() => location.reload());    }  });
  ws.addEventListener("message", ({ data }: { data?: string }) => {    if (data) {      try {        const { type, specifier, ...rest } = JSON.parse(data);        if (specifier) {          for (const node of document.body.children) {            if (              node.classList.contains("transform-error") &&              node.getAttribute("data-specifier") === specifier            ) {              node.remove();              break;            }          }        }        switch (type) {          case "create": {            events.emit("hmr:create", { specifier, ...rest });            break;          }          case "modify": {            const mod = modules.get(specifier);            if (mod) {              mod.applyUpdate();            }            events.emit("hmr:modify", { specifier });            break;          }          case "remove": {            if (modules.has(specifier)) {              modules.delete(specifier);            }            events.emit("hmr:remove", { specifier });            break;          }          case "reload": {            location.reload();          }        }        console.log(          `%c[HMR] %c${type}`,          "color:#999",          `color:${colors[type as keyof typeof colors]}`,          `${JSON.stringify(specifier)}`,        );      } catch (err) {        console.warn(err);      }    }  });}
addEventListener("load", connect);