plist.ts

export class Plist {
  options: Record<string, any>;

  constructor(options: Record<string, any>) {
    this.options = options;
  }

  toXML(): string {
    const plistHeader = `<?xml version="1.0" encoding="UTF-8"?>
        <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
        <plist version="1.0">`;

    const plistFooter = `</plist>`;

    const dictEntries = Object.entries(this.options)
      .map(([key, value]) => {
        if (typeof value === "boolean") {
          return `<key>${key}</key><${value ? "true" : "false"}/>`;
        } else if (typeof value === "string") {
          return `<key>${key}</key><string>${value}</string>`;
        } else if (Array.isArray(value)) {
          return `<key>${key}</key><array>${value.map((item) => `<string>${item}</string>`).join("")}</array>`;
        } else if (typeof value === "number") {
          return `<key>${key}</key><integer>${value}</integer>`;
        }
        return "";
      })
      .join("");

    return `${plistHeader}<dict>${dictEntries}</dict>${plistFooter}`;
  }

  /**
   * Converts the plist options to a SEB JSON format.
   * https://safeexambrowser.org/developer/seb-config-key.html
   *
   * @return {string} The SEB JSON string representation of the options.
   */
  toSebJSON(): string {
    const json = { ...this.options };
    if (json.originatorVersion) delete json.originatorVersion; // Remove originatorVersion if it exists

    // Order the the JSON by keys alphabetically
    const orderedJson = Object.keys(json)
      .sort()
      .reduce((acc, key) => {
        acc[key] = json[key];
        return acc;
      }, {});

    return JSON.stringify(orderedJson);
  }

  async _hash(str: string): Promise<string> {
    const encoder = new TextEncoder();
    const data = encoder.encode(str);
    const hash = await crypto.subtle.digest("SHA-256", data);
    const hashArray = Array.from(new Uint8Array(hash));
    return hashArray
      .map((byte) => byte.toString(16).padStart(2, "0"))
      .join("")
      .toLowerCase();
  }

  /**
   * Generate a SHA256 hash from the SEB-JSON string
   * Encode the hash value as a Base16 string. The result should be a 32 Bytes, 64 chars string.
   *
   * @returns {Promise<string>} The SHA256 hash of the SEB JSON string, for a specific start URL.
   */
  async getConfigKey(): Promise<string> {
    const sebJson = this.toSebJSON();
    const configKey = await this._hash(sebJson);

    return await this._hash(this.options.startURL + configKey);
  }
}