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import { DocBase, Path, ShareAddress } from "../../util/doc-types.ts";import { ReplicaIsClosedError } from "../../util/errors.ts";import { DocDriverMemory } from "./memory.ts";
//--------------------------------------------------
import { Logger } from "../../util/log.ts";let logger = new Logger("storage driver localStorage", "gold");
//================================================================================type SerializedDriverDocs = {  byPathAndAuthor: Record<string, DocBase<string>>;  byPathNewestFirst: Record<Path, DocBase<string>[]>;  latestDocsByPath: Record<string, DocBase<string>>;};
function isSerializedDriverDocs(value: any): value is SerializedDriverDocs {  // check if data we've loaded from localStorage is actually in the format we expect  if (typeof value !== "object") {    return false;  }  return ("byPathAndAuthor" in value && "byPathNewestFirst" in value);}
/** A replica driver which perists to LocalStorage, which stores a maximum of five megabytes per domain. If you're storing multiple shares, this limit will be divided among all their replicas. * Works in browsers and Deno. */export class DocDriverLocalStorage extends DocDriverMemory {  _localStorageKeyConfig: string;  _localStorageKeyDocs: string;
  /**   * @param share - The address of the share the replica belongs to.   * @param key - An optional key you can use to differentiate storage for the same share on the same device.   */  constructor(share: ShareAddress, key?: string) {    super(share);    logger.debug("constructor");
    // each config item starts with this prefix and gets its own entry in localstorage    this._localStorageKeyConfig = `earthstar:config:${share}${      key ? `:${key}` : ""    }`;    // but all docs are stored together inside this one item, as a giant JSON object    this._localStorageKeyDocs = `earthstar:documents:${share}${      key ? `:${key}` : ""    }`;
    const existingData = localStorage.getItem(this._localStorageKeyDocs);
    if (existingData !== null) {      logger.debug("...constructor: loading data from localStorage");      const parsed = JSON.parse(existingData);
      if (!isSerializedDriverDocs(parsed)) {        console.warn(          `localStorage data could not be parsed for share ${share}`,        );        return;      }
      this.docByPathAndAuthor = new Map(        Object.entries(parsed.byPathAndAuthor),      );      this.docsByPathNewestFirst = new Map(        Object.entries(parsed.byPathNewestFirst),      );      this.latestDocsByPath = new Map(Object.entries(parsed.latestDocsByPath));
      const localIndexes = Array.from(this.docByPathAndAuthor.values()).map((        doc,      ) => doc._localIndex as number);      this._maxLocalIndex = Math.max(...localIndexes);    } else {      logger.debug(        "...constructor: there was no existing data in localStorage",      );    }
    logger.debug("...constructor is done.");  }
  //--------------------------------------------------  // LIFECYCLE
  // isClosed(): inherited  close(erase: boolean) {    logger.debug("close");    if (this._isClosed) throw new ReplicaIsClosedError();    if (erase) {      logger.debug("...close: and erase");      this._configKv = {};      this._maxLocalIndex = -1;      this.docsByPathNewestFirst.clear();      this.docByPathAndAuthor.clear();
      logger.debug("...close: erasing localStorage");
      localStorage.removeItem(this._localStorageKeyDocs);      for (const key of this._listConfigKeysSync()) {        this._deleteConfigSync(key);      }      logger.debug("...close: erasing is done");    }    this._isClosed = true;    logger.debug("...close is done.");
    return Promise.resolve();  }
  //--------------------------------------------------  // CONFIG
  // synchronous versions for internal use
  _getConfigSync(key: string): string | undefined {    if (this._isClosed) throw new ReplicaIsClosedError();    key = `${this._localStorageKeyConfig}:${key}`;    let result = localStorage.getItem(key);    return result === null ? undefined : result;  }
  _setConfigSync(key: string, value: string): void {    if (this._isClosed) throw new ReplicaIsClosedError();    key = `${this._localStorageKeyConfig}:${key}`;    localStorage.setItem(key, value);  }
  _listConfigKeysSync(): string[] {    if (this._isClosed) throw new ReplicaIsClosedError();    let keys = Object.keys(localStorage)      .filter((key) => key.startsWith(this._localStorageKeyConfig + ":"))      .map((key) => key.slice(this._localStorageKeyConfig.length + 1));    keys.sort();    return keys;  }
  _deleteConfigSync(key: string): boolean {    if (this._isClosed) throw new ReplicaIsClosedError();    let hadIt = this._getConfigSync(key);    key = `${this._localStorageKeyConfig}:${key}`;    localStorage.removeItem(key);    return hadIt !== undefined;  }
  // async versions to match the IStorageDriverAsync interface
  async getConfig(key: string): Promise<string | undefined> {    return this._getConfigSync(key);  }  async setConfig(key: string, value: string): Promise<void> {    return this._setConfigSync(key, value);  }  async listConfigKeys(): Promise<string[]> {    return this._listConfigKeysSync();  }  async deleteConfig(key: string): Promise<boolean> {    return this._deleteConfigSync(key);  }
  //--------------------------------------------------  // GET
  // getMaxLocalIndex(): inherited  // queryDocs(query: Query): inherited
  //--------------------------------------------------  // SET
  async upsert<FormatType extends string, DocType extends DocBase<FormatType>>(    doc: DocType,  ): Promise<DocType> {    if (this._isClosed) throw new ReplicaIsClosedError();
    const upsertedDoc = await super.upsert(doc);
    // After every upsert, for now, we save everything    // to localStorage as a single giant JSON attachment.    // TODO: debounce this, only do it every 1 second or something
    const docsToBeSerialised: SerializedDriverDocs = {      byPathAndAuthor: Object.fromEntries(this.docByPathAndAuthor),      byPathNewestFirst: Object.fromEntries(this.docsByPathNewestFirst),      latestDocsByPath: Object.fromEntries(this.latestDocsByPath),    };
    localStorage.setItem(      this._localStorageKeyDocs,      JSON.stringify(docsToBeSerialised),    );
    return upsertedDoc;  }}