CoursesSchema.ts

import computedField from 'sanity-plugin-computed-field'
import createSchema from 'part:@sanity/base/schema-creator'
import schemaTypes from 'all:part:@sanity/base/schema-type'

const Course = {
  name: 'course',
  title: 'Title for Course',
  description: 'Represents a given course taught at Sanity U',
  type: 'document',
  fields: [
    {
      name: 'title',
      title: 'Title',
      description: 'Please give this course a title',
      type: 'string',
    },
    {
      title: 'Is Active',
      name: 'courseActive',
      description: 'Whether this course has scheduled items remaining this quarter.',
      type: 'boolean',
      inputComponent: computedField,
      options: {
        documentQuerySelection: `
      "numScheduled": count(*[_type == "scheduledCourse" && references(^._id) && startTime > ${new Date().toISOString()}])
      `,
        reduceQueryResult: (queryResult: {numScheduled: number}) => {
          return queryResult.numScheduled > 0
        },
      },
    },
    {
      title: 'Description',
      description: 'Generated by what instructors are teaching this class on the schedule.',
      type: 'text',
      name: 'description',
      inputComponent: computedField,
      options: {
        editable: true,
        documentQuerySelection: `
          title,
          "courses": *[_type == "scheduledCourse" && references(^._id)] {
            instructor {
              name
            }
          }`,
        reduceQueryResult: (queryResult: {
          title: string
          courses: {instructor: {name: string}}[]
        }) => {
          // Sets a preview of the instructors that are currently scheduled to teach this course
          if (queryResult.courses && queryResult.courses.length > 0) {
            const instructorSet = queryResult.courses.reduce((prev, current) => {
              prev.add(current.instructor.name)
              return prev
            }, new Set<string>())
            return `${queryResult.title} is taught by ${Array.from(instructorSet.values()).join(
              ', '
            )}`
          }
          return 'No instructors scheduled'
        },
      },
    },
    {
      title: 'Days of the week occuring',
      name: 'daysOfWeek',
      description:
        "Given the classes occurring after today, computes what day of the week they're on. Click 'Regenerate' to update",
      type: 'string',
      inputComponent: computedField,
      options: {
        documentQuerySelection: `
        "itemsScheduled": *[_type == "scheduledCourse" && references(^._id) && startTime > ${new Date().toISOString()}] {
          startTime
        }`,
        // Sets a preview of the days of the week that this course takes place
        reduceQueryResult: (queryResult: {itemsScheduled?: {startTime: string}[]}) => {
          const dateFormat = new Intl.DateTimeFormat('en-US', {
            weekday: 'long',
          })
          if (!queryResult.itemsScheduled || queryResult.itemsScheduled.length > 0) {
            return 'No Classes Scheduled'
          }
          const daySet = queryResult.itemsScheduled.reduce((prev, current) => {
            prev.add(dateFormat.format(new Date(current.startTime)))
            return prev
          }, new Set<string>())

          // Returns the days of the week, separated by a comma. "Sunday, Monday, Thursday" for example
          return Array.from(daySet.values()).join(', ')
        },
      },
    },
    {
      title: 'Number of classes',
      name: 'numClasses',
      description: 'Computed by number of classes on the schedule',
      type: 'string',
      inputComponent: computedField,
      options: {
        documentQuerySelection: `
        "numScheduled": count(*[_type == "scheduledCourse" && references(^._id)])`,
        
        // Sets the number of scheduled classes available for this course
        reduceQueryResult: (queryResult: {numScheduled: number}) => {
          return queryResult.numScheduled
        },
      },
    },
  ],
}

// Represents a course that is scheduled for a time.
const ScheduledCourse = {
  name: 'scheduledCourse',
  title: 'Scheduled Course',
  type: 'document',
  fields: [
    {
      name: 'course',
      type: 'reference',
      to: [{type: 'course', title: 'Taught Course'}],
    },
    {
      name: 'startTime',
      description: 'Please choose the day and time this course is taught',
      type: 'datetime',
    },
    {
      name: 'instructor',
      type: 'reference',
      to: [{type: 'instructor', title: 'Instructor'}],
    },
  ],
}

// Represents a course that is scheduled for a time.
const Instructor = {
  name: 'instructor',
  title: 'Instructor',
  type: 'document',
  fields: [
    {
      title: 'Name',
      name: 'name',
      description: 'Name of instructor',
      type: 'string',
    },
  ],
}

export const schema = createSchema({
  // We name our schema
  name: 'default',
  // Then proceed to concatenate our document type
  // to the ones provided by any plugins that are installed
  types: schemaTypes.concat([
    //Documents:
    Course,
    ScheduledCourse,
    Instructor,
  ]),
})