From 868aa018a4653c2aac1ba816ce141809c4998007 Mon Sep 17 00:00:00 2001
From: Tanner Collin <git@tannercollin.com>
Date: Tue, 10 May 2022 01:07:32 +0000
Subject: [PATCH] Add ability to change class instructor

---
 apiserver/apiserver/api/serializers.py | 14 ++++++++-
 webclient/src/InstructorClasses.js     | 39 ++++++++++++++++++++++++--
 2 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/apiserver/apiserver/api/serializers.py b/apiserver/apiserver/api/serializers.py
index f777107..f896cec 100644
--- a/apiserver/apiserver/api/serializers.py
+++ b/apiserver/apiserver/api/serializers.py
@@ -15,6 +15,7 @@ import datetime, time
 
 from . import models, fields, utils, utils_ldap, utils_auth, utils_stats
 from .. import settings, secrets
+from .permissions import is_admin_director
 
 class UsageSerializer(serializers.ModelSerializer):
     first_name = serializers.SerializerMethodField()
@@ -482,7 +483,7 @@ class SessionSerializer(serializers.ModelSerializer):
     class Meta:
         model = models.Session
         fields = '__all__'
-        read_only_fields = ['old_instructor', 'instructor']
+        read_only_fields = ['old_instructor']
 
     def get_student_count(self, obj):
         return len([x for x in obj.students.all() if x.attendance_status != 'Withdrawn'])
@@ -503,6 +504,17 @@ class SessionSerializer(serializers.ModelSerializer):
         else:
             return None
 
+    def update(self, instance, validated_data):
+        if not self.initial_data.get('instructor_id', None):
+            raise ValidationError(dict(instructor_id='This field is required.'))
+
+        member = get_object_or_404(models.Member, id=self.initial_data['instructor_id'])
+        if not (is_admin_director(member.user) or member.is_instructor):
+            raise ValidationError(dict(instructor_id='Member is not an instructor.'))
+
+        validated_data['instructor'] = member.user
+        return super().update(instance, validated_data)
+
 class SessionListSerializer(SessionSerializer):
     students = None
 
diff --git a/webclient/src/InstructorClasses.js b/webclient/src/InstructorClasses.js
index ad660e0..2754029 100644
--- a/webclient/src/InstructorClasses.js
+++ b/webclient/src/InstructorClasses.js
@@ -228,7 +228,8 @@ export function InstructorClassAttendance(props) {
 };
 
 function InstructorClassEditor(props) {
-	const { input, setInput, error, editing } = props;
+	const { input, setInput, error, editing, token } = props;
+	const [editInstructor, setEditInstructor] = useState(false);
 
 	const handleValues = (e, v) => setInput({ ...input, [v.name]: v.value });
 	const handleUpload = (e, v) => setInput({ ...input, [v.name]: e.target.files[0] });
@@ -245,6 +246,38 @@ function InstructorClassEditor(props) {
 
 	return (
 		<div className='class-editor'>
+			{editing &&
+				(editInstructor ?
+					<>
+						<Form.Field error={error.instructor_id}>
+							<label>Instructor (search)</label>
+							<MembersDropdown
+								token={token}
+								{...makeProps('instructor_id')}
+								onChange={handleValues}
+								initial={input.instructor_name}
+							/>
+							{error.instructor_id && <Label pointing prompt>
+								{error.instructor_id}
+							</Label>}
+						</Form.Field>
+
+						<Message info>
+							<Message.Header>Are you sure?</Message.Header>
+							<p>Only the new instructor will be able to edit this class.</p>
+						</Message>
+					</>
+				:
+					<Button
+						onClick={() => setEditInstructor(true)}
+					>
+						Change instructor
+					</Button>
+				)
+			}
+
+			<p/>
+
 			<Form.Input
 				label='Cost ($) — 0 for free'
 				{...makeProps('cost')}
@@ -326,7 +359,7 @@ export function InstructorClassDetail(props) {
 				<Form onSubmit={handleSubmit}>
 					<Header size='small'>Edit Class</Header>
 
-					<InstructorClassEditor editing input={input} setInput={setInput} error={error} />
+					<InstructorClassEditor editing input={input} setInput={setInput} error={error} token={token} />
 
 					<Form.Button loading={loading} error={error.non_field_errors}>
 						Submit
@@ -402,7 +435,7 @@ export function InstructorClassList(props) {
 
 							<p>Documentation: <a href='https://wiki.protospace.ca/Be_a_Course_Instructor' target='_blank' rel='noopener noreferrer'>https://wiki.protospace.ca/Be_a_Course_Instructor</a></p>
 
-							<InstructorClassEditor input={input} setInput={setInput} error={error} />
+							<InstructorClassEditor input={input} setInput={setInput} error={error} token={token} />
 
 							<Form.Button loading={loading} error={error.non_field_errors}>
 								Submit