zdbk课表爬虫 (x6eull#2)

Co-authored-by: x6eull <[email protected]>

Author: zjukunk

src/interop/env.ts

@@ -1,9 +1,12 @@
+import '../utils'
+
 export const isNode = !import.meta.env
 if (isNode)
   // 当且仅当node环境下，手动加载环境变量
   await import('dotenv').then(({ config }) => {
-    ;([] as string[])
-      .concat(...['.env', '.env.development'].map((f) => [f, f + '.local']))
+    ;['.env', '.env.development']
+      .map((f) => [f, f + '.local'])
+      .flat(1)
       .forEach((file) => {
         const err = config({ path: file }).error as
           | (Error & { code?: string })

src/interop/fetch.ts

@@ -1,7 +1,6 @@
 import { CapacitorCookies, CapacitorHttp } from '@capacitor/core'
 import { appPlatform } from '.'
 import { isNode } from './env'
-import '../utils/extendHeaders'
 
 let cookieJar: import('tough-cookie').CookieJar | null = null
 // node环境不会自动保存cookie，手动跟踪

src/models/Course.ts

@@ -1,4 +1,4 @@
-import { DayOfWeek, Semester, WeekOfSemester } from './shared'
+import { DayOfWeek, Semester, WeekType } from './shared'
 
 /**课程信息，对于同一课程代码，多次选课（弃修、重修）为不同的实例。 */
 export interface Course {
@@ -20,9 +20,8 @@ export interface Course {
 
 /**相对于学期的上课时间、地点 */
 export interface ClassArrangement {
-  /**单双周，或表示学期中第n周 */
-  weekType: 'odd' | 'even' | 'every' | WeekOfSemester
-  /**星期几 */
+  /**上课周次 */
+  weekType: WeekType
   dayOfWeek: DayOfWeek
   /**从第几节开始 =djj */
   startSection: number

src/models/shared.ts

@@ -4,6 +4,10 @@ export type DayOfWeek = 1 | 2 | 3 | 4 | 5 | 6 | 7
 export type WeekOfSemester =
   | (1 | 2 | 3 | 4 | 5 | 6 | 7 | 8)
   | (9 | 10 | 11 | 12 | 13 | 14 | 15 | 16)
+/**使用位域表示长学期中的多个周，第n周为2^n，最低位保留。如1、4周表示为0b10010 */
+export type MultipleWeeksOfSemester = number
+/**表示单双周/每周/学期中特定的几周。 */
+export type WeekType = 'odd' | 'even' | 'every' | MultipleWeeksOfSemester
 
 /**学期，支持：春/夏/秋/冬/短/春夏/秋冬 */
 export enum Term {

src/spiders/CourseSpider.ts

@@ -0,0 +1,166 @@
+import { DayOfWeek, Term } from '../models/shared'
+import { Course, ClassArrangement } from '../models/Course'
+import { WeekType } from '@/models/shared'
+import { ZjuamService } from '../interop/zjuam'
+import { requestCredential } from '@/interop/credential'
+
+/**课程表中的课程信息，无学分、考试 */
+type CourseInSchedule = Omit<Course, 'credit' | 'exams'>
+type RawCourseResp = {
+  kbList: {
+    kcb: string
+    dsz: string
+    djj: string
+    xqj: number
+    xxq: string
+    xkkh: string
+    skcd: string
+  }[]
+  xnm: string
+}
+
+export class CourseSpider {
+  private zjuamService = new ZjuamService(
+    { service: 'http://zdbk.zju.edu.cn/jwglxt/xtgl/login_ssologin.html' },
+    60 * 30,
+  )
+  constructor() {}
+
+  /**查询指定年份区间的课表。未查短学期的课，未查实践课。 */
+  public async getCourses(
+    /** 起始学年（靠前的，如2024 - 2025请传2024） */
+    xnmStart: number,
+    /** 结束学年（靠前的，如2024 - 2025请传2024）*/
+    xnmEnd: number,
+  ): Promise<CourseInSchedule[]> {
+    const { username: zjuId } = await requestCredential(this.zjuamService)
+    const cMap = new Map<string, CourseInSchedule[]>()
+    for (let curYear = xnmStart; curYear <= xnmEnd; curYear++) {
+      const semesters = [
+        { xqm: '1|秋', xqmmc: '秋' },
+        { xqm: '1|冬', xqmmc: '冬' },
+        { xqm: '2|春', xqmmc: '春' },
+        { xqm: '2|夏', xqmmc: '夏' },
+      ]
+      for (const { xqm, xqmmc } of semesters) {
+        const params = new URLSearchParams({
+          xnm: `${curYear}-${curYear + 1}`,
+          xqm,
+          xqmmc,
+          xxqf: '0',
+          xxfs: '0',
+        })
+        const response = await this.zjuamService.nxFetch.postUrlEncoded(
+          `http://zdbk.zju.edu.cn/jwglxt/kbcx/xskbcx_cxXsKb.html?gnmkdm=N253508&su=${zjuId}`,
+          { body: params },
+        )
+
+        const { xnm: respXnm, kbList } =
+          (await response.json()) as RawCourseResp
+        for (const { kcb, dsz, djj, xqj, xxq, xkkh, skcd } of kbList) {
+          const kcbItem = kcb.split('<br>')
+          const name = kcbItem[0]
+          const teacher = kcbItem[2]
+          const location = kcbItem[3].replace(/zwf.*/, '').trim()
+
+          const termIdMap = {
+            春: Term.Spring,
+            夏: Term.Summer,
+            秋: Term.Autumn,
+            冬: Term.Winter,
+            短: Term.Short,
+          }
+          let termId = 0
+          for (const xxqChar of xxq)
+            if (xxqChar in termIdMap)
+              termId |= termIdMap[xxqChar as keyof typeof termIdMap]
+            else throw new Error('学期匹配失败')
+
+          cMap.pushValue(xkkh, {
+            semester: {
+              year: Number(respXnm.split('-')[0]),
+              term: termId,
+            },
+            id: xkkh,
+            name: name,
+            teacherName: teacher,
+            classes: [
+              {
+                weekType: dsz === '0' ? 'odd' : dsz === '1' ? 'even' : 'every',
+                dayOfWeek: xqj as DayOfWeek,
+                startSection: Number(djj),
+                sectionCount: Number(skcd),
+                location: location,
+              },
+            ],
+          })
+        }
+      }
+    }
+    return [...cMap.values()].map((courses) => ({
+      ...courses[0], // 首项必定存在，课程名称、教师等均取自首项
+      classes: this.mergeClasses(courses.map((c) => c.classes).flat(1)),
+    }))
+  }
+
+  /**
+   * 合并课程安排。
+   * 对于地点、周数完全相同的，合并至上课节数不相交，连续的节数也合并为一项；
+   * 地点/周数不一样的不合并。
+   */
+  private mergeClasses(classes: ClassArrangement[]): ClassArrangement[] {
+    const weekMap = new Map<WeekType, Map<DayOfWeek, Map<string, number>>>()
+    classes.forEach((c) => {
+      const { weekType, dayOfWeek, location, startSection, sectionCount } = c
+      const dayMap = weekMap.ensure(weekType, () => new Map())
+      const locMap = dayMap.ensure(dayOfWeek, () => new Map())
+      /**把已有的位域（默认0）和当前的startSection、sectionCount段进行合并 */
+      function mergeSection(prevSections = 0) {
+        for (let sec = startSection; sec < startSection + sectionCount; sec++)
+          prevSections |= 0b1 << sec
+        //示例：第1、2、4节有课，位域应为0b10110（最低位保留）
+        return prevSections
+      }
+      locMap.ensure(location, mergeSection, mergeSection)
+    })
+    return [...weekMap]
+      .map(([week, dayMap]) =>
+        [...dayMap].map(([day, locMap]) =>
+          [...locMap].map(([loc, secFlags]) => {
+            const sections = [] as ClassArrangement[]
+            secFlags >>= 1 //最低位保留，右移掉以减少一次循环
+            let curSec = 1,
+              startSec = 0,
+              secCount = 0
+            /**把当前的startSec、secCount以及其它变量合成为ClassArrangement并加到数组中 */
+            function finishCurSection() {
+              sections.push({
+                weekType: week,
+                dayOfWeek: day,
+                location: loc,
+                startSection: startSec,
+                sectionCount: secCount,
+              })
+            }
+            while (secFlags != 0) {
+              const curSecValid = Boolean(secFlags & 0b1)
+              if (curSecValid) {
+                //当前sec有课
+                if (startSec === 0) startSec = curSec
+                secCount++
+              } else if (startSec !== 0) {
+                finishCurSection()
+                startSec = 0
+                secCount = 0
+              }
+              secFlags >>= 1
+              curSec++
+            }
+            if (startSec != 0) finishCurSection()
+            return sections
+          }),
+        ),
+      )
+      .flat(3)
+  }
+}

src/utils/extendMap.ts

@@ -0,0 +1,31 @@
+type ElementType<A> = A extends (infer E)[] ? E : never
+
+interface Map<K, V> {
+  /**如果指定的键存在，向对应的值push一个元素；否则新建一个仅有该元素的数组，并插入Map。 */
+  pushValue(key: K, element: ElementType<V>): void
+  /**如果指定的键存在，则获取该值，并尝试调用onExists；否则，调用valueInit，插入新的值并返回该新值。 */
+  ensure(key: K, valueInit: () => V, onExists?: (v: V) => void): V
+}
+
+Object.defineProperty(Map.prototype, 'pushValue', {
+  value(key, element) {
+    if (this.has(key)) this.get(key)!.push(element)
+    else this.set(key, [element])
+  },
+} satisfies ThisType<Map<unknown, unknown[]>> & {
+  value: Map<unknown, unknown[]>['pushValue']
+})
+Object.defineProperty(Map.prototype, 'ensure', {
+  value(key, value, onExists) {
+    if (this.has(key)) {
+      const prevValue = this.get(key)!
+      onExists?.(prevValue)
+      return prevValue
+    }
+    const v = value()
+    this.set(key, v)
+    return v
+  },
+} satisfies ThisType<Map<unknown, unknown>> & {
+  value: Map<unknown, unknown>['ensure']
+})

src/utils/functions.ts

@@ -16,3 +16,8 @@ export function afterDone<T>(
   // eslint-disable-next-line @typescript-eslint/no-unsafe-argument, @typescript-eslint/no-explicit-any
   else f(result as any)
 }
+
+/**新建一个函数，该函数始终返回调用ret时的参数 */
+export function constF<R>(arg: R): () => R {
+  return () => arg
+}

src/utils/index.ts

@@ -0,0 +1,4 @@
+/**utils初始化文件，主要用于加载扩展原型方法 */
+
+import './extendHeaders'
+import './extendMap'