[Course statistics] Move minimum and maximum attainment date calculation to the backend

services/backend/src/routes/courses.ts

@@ -1,10 +1,10 @@
 import crypto from 'crypto'
 import { Request, Response, Router } from 'express'
+import moment from 'moment'
 
 import { serviceProvider } from '../config'
 import { getCourseYearlyStats } from '../services/courses'
 import { getCoursesByNameAndOrCode, getCoursesByCodes } from '../services/courses/courseFinders'
-import { CourseWithSubsId } from '../types'
 import { getFullStudyProgrammeRights, hasFullAccessToStudentData, validateParamLength } from '../util'
 import logger from '../util/logger'
 
@@ -24,24 +24,45 @@ router.get('/v2/coursesmulti', async (req: GetCoursesRequest, res: Response) =>
     return res.status(400).json({ error: 'Query parameter name or code is invalid' })
   }
 
-  let results: { courses: CourseWithSubsId[] } = { courses: [] }
-  results = await getCoursesByNameAndOrCode(name, code)
+  const courses = await getCoursesByNameAndOrCode(name, code)
 
   if (combineSubstitutions === 'false') {
-    const courseCodes = results.courses.map(course => course.code)
+    const courseCodes = courses.map(course => course.code)
     const substitutions = [
       ...new Set(
-        results.courses
-          .flatMap(course => course.substitutions)
-          .filter(code => code !== null && !courseCodes.includes(code))
+        courses.flatMap(course => course.substitutions).filter(code => code !== null && !courseCodes.includes(code))
       ),
     ]
     const substitutionDetails = await getCoursesByCodes(substitutions)
     for (const substitution of substitutionDetails) {
-      results.courses.push(substitution.dataValues)
+      courses.push(substitution.toJSON())
     }
   }
-  res.json(results)
+
+  const mergedCourses = {}
+
+  for (const course of courses) {
+    const groupId = combineSubstitutions === 'true' ? course.subsId! : course.code
+    if (!(course.max_attainment_date && course.min_attainment_date)) {
+      continue
+    }
+    if (!mergedCourses[groupId]) {
+      mergedCourses[groupId] = {
+        ...course,
+        substitutions: combineSubstitutions === 'true' ? course.substitutions : [],
+      }
+    } else {
+      const mergedCourse = mergedCourses[groupId]
+      if (moment(mergedCourse.max_attainment_date).isBefore(course.max_attainment_date)) {
+        mergedCourse.max_attainment_date = course.max_attainment_date
+      }
+      if (moment(mergedCourse.min_attainment_date).isAfter(course.min_attainment_date)) {
+        mergedCourse.min_attainment_date = course.min_attainment_date
+      }
+    }
+  }
+
+  res.json({ courses: Object.values(mergedCourses) })
 })
 
 interface GetCourseYearlyStatsRequest extends Request {

services/backend/src/services/courses/courseFinders.ts

@@ -1,3 +1,4 @@
+import { orderBy } from 'lodash'
 import { Op } from 'sequelize'
 
 import { Course } from '../../models'
@@ -52,7 +53,17 @@ const getRawCourses = async (name: string, code: string) => {
 const getCourses = async (name: string, code: string) => {
   const rawCourses = await getRawCourses(name, code)
   const courses: CourseWithSubsId[] = rawCourses
-    .map(course => ({ ...course.dataValues }))
+    .map(course => ({
+      ...course.toJSON(),
+      substitutions: orderBy(course.substitutions, [
+        substitution => {
+          if (/^A/.exec(substitution)) return 4 // open university codes come last
+          if (/^\d/.exec(substitution)) return 2 // old numeric codes come second
+          if (/^[A-Za-z]/.exec(substitution)) return 1 // new letter based codes come first
+          return 3 // unknown, comes before open uni?
+        },
+      ]),
+    }))
     .sort((a, b) => getSortRank(b.code) - getSortRank(a.code))
   return courses
 }
@@ -87,7 +98,7 @@ export const getCoursesByNameAndOrCode = async (name: string, code: string) => {
     }
   })
 
-  return { courses }
+  return courses
 }
 
 export const getCoursesByCodes = (codes: string[]) => {

services/frontend/src/selectors/courses.js

@@ -1,66 +0,0 @@
-import { createSelector } from '@reduxjs/toolkit'
-import { orderBy } from 'lodash'
-
-const sortSubstitutions = course => {
-  const result = orderBy(
-    course.substitutions,
-    [
-      a => {
-        if (a.match(/^A/)) return 4 // open university codes come last
-        if (a.match(/^\d/)) return 2 // old numeric codes come second
-        if (a.match(/^[A-Za-z]/)) return 1 // new letter based codes come first
-        return 3 // unknown, comes before open uni?
-      },
-    ],
-    ['asc']
-  )
-  return result
-}
-
-const filterCourseSearchResults = (courses, combineSubstitutions) => {
-  const mergedCourses = {}
-  courses.forEach(course => {
-    // Filter out courses made out of custom attainments (#4624)
-    if (/-\d{9}/.test(course.code)) {
-      return
-    }
-    const groupId = combineSubstitutions ? course.subsId : course.code
-
-    if (!(course.max_attainment_date && course.min_attainment_date)) {
-      return
-    }
-
-    if (!mergedCourses[groupId]) {
-      mergedCourses[groupId] = {
-        ...course,
-        substitutions: combineSubstitutions ? sortSubstitutions(course) : [],
-        min_attainment_date: new Date(course.min_attainment_date),
-        max_attainment_date: new Date(course.max_attainment_date),
-      }
-    } else {
-      const mergedCourse = mergedCourses[groupId]
-      mergedCourse.min_attainment_date = new Date(
-        Math.min(mergedCourse.min_attainment_date, new Date(course.min_attainment_date))
-      )
-      mergedCourse.max_attainment_date = new Date(
-        Math.max(mergedCourse.max_attainment_date, new Date(course.max_attainment_date))
-      )
-    }
-  })
-
-  const result = Object.values(mergedCourses)
-
-  return result
-}
-
-const getCourseSearchSelector = state => state.courseSearch.data.courses
-
-export const getCourseSearchResults = createSelector(
-  [getCourseSearchSelector, (state, combineSubstitutions) => combineSubstitutions],
-  (courses, combineSubstitutions) => {
-    if (!courses) {
-      return []
-    }
-    return filterCourseSearchResults(courses, combineSubstitutions)
-  }
-)