From ef555c71e74279304f4fdeb51592db2664df106a Mon Sep 17 00:00:00 2001
From: Evan Hahn <me@evanhahn.com>
Date: Tue, 27 Aug 2024 09:52:17 -0500
Subject: [PATCH] feat: emit updates from CoreOwnership and Roles, add
 CoreOwnership#get (#781)

This is part of the solution for [#268].

[#268]: https://github.com/digidem/mapeo-core-next/issues/268

Co-authored-by: Gregor MacLennan <gmaclennan@digital-democracy.org>
---
 src/core-ownership.js   | 36 +++++++++++++++++++++++++++++++-----
 src/datatype/index.d.ts |  5 +++--
 src/datatype/index.js   |  5 +++--
 src/roles.js            | 15 +++++++++++++--
 4 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/src/core-ownership.js b/src/core-ownership.js
index 96d5011c..5d74432c 100644
--- a/src/core-ownership.js
+++ b/src/core-ownership.js
@@ -3,12 +3,18 @@ import { parseVersionId } from '@mapeo/schema'
 import { defaultGetWinner } from '@mapeo/sqlite-indexer'
 import assert from 'node:assert/strict'
 import sodium from 'sodium-universal'
-import { kTable, kSelect, kCreateWithDocId } from './datatype/index.js'
+import {
+  kTable,
+  kSelect,
+  kCreateWithDocId,
+  kDataStore,
+} from './datatype/index.js'
 import { eq, or } from 'drizzle-orm'
 import mapObject from 'map-obj'
 import { discoveryKey } from 'hypercore-crypto'
 import pDefer from 'p-defer'
 import { NAMESPACES } from './constants.js'
+import { TypedEmitter } from 'tiny-typed-emitter'
 /**
  * @import {
  *   CoreOwnershipWithSignatures,
@@ -18,7 +24,15 @@ import { NAMESPACES } from './constants.js'
  * } from './types.js'
  */
 
-export class CoreOwnership {
+/**
+ * @typedef {object} CoreOwnershipEvents
+ * @property {(docIds: Set<string>) => void} update Emitted when new coreOwnership records are indexed
+ */
+
+/**
+ * @extends {TypedEmitter<CoreOwnershipEvents>}
+ */
+export class CoreOwnership extends TypedEmitter {
   #dataType
   #ownershipWriteDone
   /**
@@ -35,8 +49,9 @@ export class CoreOwnership {
    * @param {KeyPair} opts.identityKeypair
    */
   constructor({ dataType, coreKeypairs, identityKeypair }) {
+    super()
     this.#dataType = dataType
-    const authWriterCore = dataType.writerCore
+    const authWriterCore = dataType[kDataStore].writerCore
     const deferred = pDefer()
     this.#ownershipWriteDone = deferred.promise
 
@@ -55,6 +70,8 @@ export class CoreOwnership {
     } else {
       authWriterCore.once('ready', writeOwnership)
     }
+
+    dataType[kDataStore].on('coreOwnership', this.emit.bind(this, 'update'))
   }
 
   /**
@@ -85,11 +102,20 @@ export class CoreOwnership {
    * @returns {Promise<string>} coreId of core belonging to `deviceId` for `namespace`
    */
   async getCoreId(deviceId, namespace) {
-    await this.#ownershipWriteDone
-    const result = await this.#dataType.getByDocId(deviceId)
+    const result = await this.get(deviceId)
     return result[`${namespace}CoreId`]
   }
 
+  /**
+   * Get capabilities for a given deviceId
+   *
+   * @param {string} deviceId
+   */
+  async get(deviceId) {
+    await this.#ownershipWriteDone
+    return this.#dataType.getByDocId(deviceId)
+  }
+
   /**
    *
    * @param {KeyPair} identityKeypair
diff --git a/src/datatype/index.d.ts b/src/datatype/index.d.ts
index 0239185d..e2966854 100644
--- a/src/datatype/index.d.ts
+++ b/src/datatype/index.d.ts
@@ -34,6 +34,7 @@ export interface DataTypeEvents<TDoc extends MapeoDoc> {
 export const kCreateWithDocId: unique symbol
 export const kSelect: unique symbol
 export const kTable: unique symbol
+export const kDataStore: unique symbol
 
 type OmitUnion<T, K extends keyof any> = T extends any ? Omit<T, K> : never
 type ExcludeSchema<
@@ -62,12 +63,12 @@ export class DataType<
 
   get [kTable](): TTable
 
+  get [kDataStore](): TDataStore
+
   get schemaName(): TSchemaName
 
   get namespace(): TDataStore.namespace
 
-  get writerCore(): Hypercore<'binary', Buffer>
-
   [kCreateWithDocId](
     docId: string,
     value:
diff --git a/src/datatype/index.js b/src/datatype/index.js
index 5def0fef..94b5042f 100644
--- a/src/datatype/index.js
+++ b/src/datatype/index.js
@@ -45,6 +45,7 @@ function generateDate() {
 export const kCreateWithDocId = Symbol('kCreateWithDocId')
 export const kSelect = Symbol('select')
 export const kTable = Symbol('table')
+export const kDataStore = Symbol('dataStore')
 
 /**
  * @template {import('../datastore/index.js').DataStore} TDataStore
@@ -117,8 +118,8 @@ export class DataType extends TypedEmitter {
     return this.#dataStore.namespace
   }
 
-  get writerCore() {
-    return this.#dataStore.writerCore
+  get [kDataStore]() {
+    return this.#dataStore
   }
 
   /**
diff --git a/src/roles.js b/src/roles.js
index 6a6fcd33..b2304eb4 100644
--- a/src/roles.js
+++ b/src/roles.js
@@ -1,7 +1,8 @@
 import { currentSchemaVersions } from '@mapeo/schema'
 import mapObject from 'map-obj'
-import { kCreateWithDocId } from './datatype/index.js'
+import { kCreateWithDocId, kDataStore } from './datatype/index.js'
 import { assert, setHas } from './utils.js'
+import { TypedEmitter } from 'tiny-typed-emitter'
 /** @import { Namespace } from './types.js' */
 
 // Randomly generated 8-byte encoded as hex
@@ -214,7 +215,15 @@ export const ROLES = {
   [NO_ROLE_ID]: NO_ROLE,
 }
 
-export class Roles {
+/**
+ * @typedef {object} RolesEvents
+ * @property {(docIds: Set<string>) => void} update Emitted when new role records are indexed
+ */
+
+/**
+ * @extends {TypedEmitter<RolesEvents>}
+ */
+export class Roles extends TypedEmitter {
   #dataType
   #coreOwnership
   #coreManager
@@ -239,11 +248,13 @@ export class Roles {
    * @param {Buffer} opts.deviceKey public key of this device
    */
   constructor({ dataType, coreOwnership, coreManager, projectKey, deviceKey }) {
+    super()
     this.#dataType = dataType
     this.#coreOwnership = coreOwnership
     this.#coreManager = coreManager
     this.#projectCreatorAuthCoreId = projectKey.toString('hex')
     this.#ownDeviceId = deviceKey.toString('hex')
+    dataType[kDataStore].on('role', this.emit.bind(this, 'update'))
   }
 
   /**