@veramo/data-store-json/src/browser-local-storage-store.ts

Veramo data storage based on a JSON tree

import { IIdentifier, IMessage, ManagedKeyInfo } from '@veramo/core-types'
import { ManagedPrivateKey } from '@veramo/key-manager'
import {
  DiffCallback,
  VeramoJsonCache,
  ClaimTableEntry,
  CredentialTableEntry,
  PresentationTableEntry,
  VeramoJsonStore,
} from './types.js'

/**
 * Implementation of {@link VeramoJsonStore} that uses browser localStorage to store data.
 * 
 * @example
 * ```
 * const dataStore = BrowserLocalStorageStore.fromLocalStorage('veramo-state')
 * const plugin = new DataStoreJson(dataStore)
 * ```
 *
 * @public
 */
export class BrowserLocalStorageStore implements VeramoJsonStore {
  notifyUpdate: DiffCallback
  dids: Record<string, IIdentifier>
  keys: Record<string, ManagedKeyInfo>
  privateKeys: Record<string, ManagedPrivateKey>
  credentials: Record<string, CredentialTableEntry>
  claims: Record<string, ClaimTableEntry>
  presentations: Record<string, PresentationTableEntry>
  messages: Record<string, IMessage>

  private constructor(private localStorageKey: string) {
    this.notifyUpdate = async (
      oldState: VeramoJsonCache,
      newState: VeramoJsonCache,
    ) => {
      this.save(newState)
    }
    this.dids = {}
    this.keys = {}
    this.privateKeys = {}
    this.credentials = {}
    this.claims = {}
    this.presentations = {}
    this.messages = {}
  }

  public static fromLocalStorage(localStorageKey: string): BrowserLocalStorageStore {
    const store = new BrowserLocalStorageStore(localStorageKey)
    return store.load()
  }

  private load(): BrowserLocalStorageStore {
    if (typeof window !== 'undefined') {
      const rawCache = window.localStorage.getItem(this.localStorageKey) || '{}'
      let cache: VeramoJsonCache
      try {
        cache = JSON.parse(rawCache)
      } catch (e: any) {
        cache = {}
      }
      ({
        dids: this.dids,
        keys: this.keys,
        credentials: this.credentials,
        claims: this.claims,
        presentations: this.presentations,
        messages: this.messages,
        privateKeys: this.privateKeys,
      } = {
        dids: {},
        keys: {},
        credentials: {},
        claims: {},
        presentations: {},
        messages: {},
        privateKeys: {},
        ...cache,
      })
    }
    return this
  }

  private save(newState: VeramoJsonCache): void {
    if (typeof window !== 'undefined') {
      window.localStorage.setItem(this.localStorageKey, JSON.stringify(newState))
    }
  }

}