add fsrs-browser

src/controller/fsrs-browser/index.ts

@@ -0,0 +1,24 @@
+import type { Context } from 'koa'
+import { project } from '../../services/optimizer/fsrs-browser/constrant'
+import { FSRSBrowserService } from '../../services/optimizer/fsrs-browser'
+import { INextRequest } from '../../services/optimizer/fsrs-browser/types'
+
+class FSRSBrowserController {
+  intro = async (ctx: Context) => {
+    ctx.body = project
+  }
+
+  scheduler = async (ctx: Context) => {
+    const { d, s, r, ivl } = ctx.request.body as Omit<
+      INextRequest,
+      'card_id' | 'now' | 'timezone'
+    >
+    const svc = await new FSRSBrowserService().init()
+    const scheduler = svc.state(d, s, r, ivl)
+    ctx.body = scheduler
+  }
+}
+
+const controller = new FSRSBrowserController()
+
+export default controller

src/controller/fsrs-browser/router.ts

@@ -0,0 +1,18 @@
+import { TRouter } from '../../bootstrap/types'
+import fsrsBrowserController from './index'
+
+const routers: TRouter = {
+  ['browser/intro']: {
+    method: 'get',
+    path: '/intro',
+    endpoint: fsrsBrowserController.intro
+  },
+  ['browser/scheduler']: {
+    method: 'post',
+    path: '/scheduler',
+    endpoint: fsrsBrowserController.scheduler
+  },
+
+}
+
+export default routers

src/controller/router.ts

@@ -1,8 +1,10 @@
 import { TRouter } from '../bootstrap/types'
 import tsfsrsRouters from '../controller/ts-fsrs/router'
+import browserRouters from '../controller/fsrs-browser/router'
 
 const root = {
-  ...tsfsrsRouters
+  ...tsfsrsRouters,
+  ...browserRouters
 } satisfies TRouter
 
 export default root

src/services/optimizer/fsrs-browser/constrant.ts

@@ -0,0 +1,6 @@
+export const project = {
+  name: 'fsrs-browser',
+  version: 'v1.4.3',
+  repo: 'https://github.com/open-spaced-repetition/fsrs-browser',
+  npm: 'https://www.npmjs.com/package/fsrs-browser'
+} as const

src/services/optimizer/fsrs-browser/index.ts

@@ -0,0 +1,48 @@
+import { readFileSync } from 'fs'
+import init, { Fsrs, InitOutput, ItemState } from 'fsrs-browser/fsrs_browser'
+let initOutput: InitOutput | null = null
+
+export class FSRSBrowserService {
+  constructor() {}
+
+  async init() {
+    if (!initOutput) {
+      const wasmBuffer = readFileSync(
+        new URL('fsrs_browser_bg.wasm', import.meta.url)
+      )
+      initOutput = await init(wasmBuffer.buffer)
+    }
+    return this
+  }
+
+  next(d: number, s: number, r: number) {
+    const fsrs = new Fsrs()
+    const result = fsrs.nextInterval(s, d, r)
+    fsrs.free()
+    return +result.toFixed(4)
+  }
+
+  state(d: number, s: number, r: number, interval: number) {
+    const fsrs = new Fsrs()
+    const result = fsrs.nextStates(s || undefined, d || undefined, r, interval)
+
+    const dataset = {
+      again: this._getState(result.again),
+      hard: this._getState(result.hard),
+      good: this._getState(result.good),
+      easy: this._getState(result.easy)
+    }
+
+    fsrs.free()
+    return dataset
+  }
+
+  _getState(info: ItemState) {
+    return {
+      memoryState: {
+        stability: +info.memory.stability.toFixed(4),
+        difficulty: +info.memory.difficulty.toFixed(4)
+      }
+    }
+  }
+}

src/services/optimizer/fsrs-browser/types.ts

@@ -0,0 +1,8 @@
+import { IRequest } from '../../scheduler/ts-fsrs/types'
+
+export interface INextRequest<T = string | number> extends IRequest<T> {
+  s: number
+  d: number
+  r: number
+  ivl: number
+}