prevent lectures from dropping on each other

nextjs/src/app/course/[courseName]/calendar/day/Day.tsx

@@ -1,20 +1,14 @@
 "use client";
 import {
-  dateToMarkdownString,
   getDateFromStringOrThrow,
   getDateOnlyMarkdownString,
 } from "@/models/local/timeUtils";
 import { useDraggingContext } from "../../context/draggingContext";
-import { useCourseContext } from "../../context/courseContext";
-import Link from "next/link";
 import { useLocalCourseSettingsQuery } from "@/hooks/localCourse/localCoursesHooks";
 import { getDayOfWeek } from "@/models/local/localCourse";
-import { getLectureUrl } from "@/services/urlUtils";
 import { ItemInDay } from "./ItemInDay";
 import { useTodaysItems } from "./useTodaysItems";
-import Modal from "@/components/Modal";
-import NewItemForm from "../../modules/NewItemForm";
-import { useLecturesByWeekQuery } from "@/hooks/localCourse/lectureHooks";
+import { DayTitle } from "./DayTitle";
 
 export default function Day({ day, month }: { day: string; month: number }) {
   const dayAsDate = getDateFromStringOrThrow(
@@ -130,33 +124,3 @@ export default function Day({ day, month }: { day: string; month: number }) {
     </div>
   );
 }
-
-function DayTitle({ day, dayAsDate }: { day: string; dayAsDate: Date }) {
-  const { courseName } = useCourseContext();
-  const { data: weeks } = useLecturesByWeekQuery();
-  const todaysLecture = weeks
-    .flatMap((w) => w.lectures)
-    .find((l) => l.date == getDateOnlyMarkdownString(dayAsDate));
-  return (
-    <div className="flex justify-between">
-      <Link
-        className="ms-1 me-1 truncate text-nowrap transition-all hover:font-bold hover:text-slate-300"
-        href={getLectureUrl(courseName, day)}
-      >
-        {dayAsDate.getDate()} {todaysLecture?.name}
-      </Link>
-      <Modal
-        buttonText="+"
-        buttonClass="unstyled hover:font-bold hover:scale-125 px-1 mb-auto mt-0 pt-0"
-      >
-        {({ closeModal }) => (
-          <div>
-            <NewItemForm creationDate={day} onCreate={closeModal} />
-            <br />
-            <button onClick={closeModal}>close</button>
-          </div>
-        )}
-      </Modal>
-    </div>
-  );
-}

nextjs/src/app/course/[courseName]/calendar/day/DayTitle.tsx

@@ -0,0 +1,53 @@
+import Modal from "@/components/Modal";
+import { useLecturesByWeekQuery } from "@/hooks/localCourse/lectureHooks";
+import { getLectureUrl } from "@/services/urlUtils";
+import Link from "next/link";
+import { useCourseContext } from "../../context/courseContext";
+import NewItemForm from "../../modules/NewItemForm";
+import { DraggableItem } from "../../context/draggingContext";
+import { useDragStyleContext } from "../../context/dragStyleContext";
+import { getLectureForDay } from "@/models/local/lectureUtils";
+
+export function DayTitle({ day, dayAsDate }: { day: string; dayAsDate: Date }) {
+  const { courseName } = useCourseContext();
+  const { data: weeks } = useLecturesByWeekQuery();
+  const { setIsDragging } = useDragStyleContext();
+  const todaysLecture = getLectureForDay(weeks, dayAsDate);
+  return (
+    <div className="flex justify-between">
+      <Link
+        className="ms-1 me-1 truncate text-nowrap transition-all hover:font-bold hover:text-slate-300"
+        href={getLectureUrl(courseName, day)}
+        draggable={true}
+        onDragStart={(e) => {
+          if (todaysLecture) {
+            const draggableItem: DraggableItem = {
+              type: "lecture",
+              item: { ...todaysLecture, dueAt: todaysLecture.date },
+              sourceModuleName: undefined,
+            };
+            e.dataTransfer.setData(
+              "draggableItem",
+              JSON.stringify(draggableItem)
+            );
+            setIsDragging(true);
+          }
+        }}
+      >
+        {dayAsDate.getDate()} {todaysLecture?.name}
+      </Link>
+      <Modal
+        buttonText="+"
+        buttonClass="unstyled hover:font-bold hover:scale-125 px-1 mb-auto mt-0 pt-0"
+      >
+        {({ closeModal }) => (
+          <div>
+            <NewItemForm creationDate={day} onCreate={closeModal} />
+            <br />
+            <button onClick={closeModal}>close</button>
+          </div>
+        )}
+      </Modal>
+    </div>
+  );
+}

nextjs/src/app/course/[courseName]/context/DraggingContextProvider.tsx

@@ -7,12 +7,19 @@ import { LocalQuiz } from "@/models/local/quiz/localQuiz";
 import {
   getDateFromStringOrThrow,
   dateToMarkdownString,
+  getDateOnlyMarkdownString,
 } from "@/models/local/timeUtils";
 import { LocalAssignment } from "@/models/local/assignment/localAssignment";
 import { useUpdateAssignmentMutation } from "@/hooks/localCourse/assignmentHooks";
 import { useUpdatePageMutation } from "@/hooks/localCourse/pageHooks";
 import { LocalCoursePage } from "@/models/local/page/localCoursePage";
 import { useDragStyleContext } from "./dragStyleContext";
+import { Lecture } from "@/models/local/lecture";
+import {
+  useLecturesByWeekQuery,
+  useLectureUpdateMutation,
+} from "@/hooks/localCourse/lectureHooks";
+import { getLectureForDay } from "@/models/local/lectureUtils";
 
 export default function DraggingContextProvider({
   children,
@@ -21,9 +28,11 @@ export default function DraggingContextProvider({
 }) {
   const { setIsDragging } = useDragStyleContext();
   const updateQuizMutation = useUpdateQuizMutation();
+  const updateLectureMutation = useLectureUpdateMutation();
   const updateAssignmentMutation = useUpdateAssignmentMutation();
   const updatePageMutation = useUpdatePageMutation();
   const { data: settings } = useLocalCourseSettingsQuery();
+  const { data: weeks } = useLecturesByWeekQuery();
 
   useEffect(() => {
     const handleDrop = () => {
@@ -55,13 +64,16 @@ export default function DraggingContextProvider({
           updateAssignment();
         } else if (itemBeingDragged.type === "page") {
           updatePage();
+        } else if (itemBeingDragged.type === "lecture") {
+          // const lecture = itemBeingDragged.item as Lecture & { dueAt: string };
+          console.log("cannot drop lecture on module, only on days");
         }
       }
       setIsDragging(false);
 
       function updateQuiz() {
         const quiz = itemBeingDragged.item as LocalQuiz;
-
+        if (itemBeingDragged.sourceModuleName) {
           updateQuizMutation.mutate({
             item: quiz,
             itemName: quiz.name,
@@ -69,9 +81,16 @@ export default function DraggingContextProvider({
             previousModuleName: itemBeingDragged.sourceModuleName,
             previousItemName: quiz.name,
           });
+        } else {
+          console.error(
+            `error dropping quiz, sourceModuleName is undefined `,
+            quiz
+          );
+        }
       }
       function updateAssignment() {
         const assignment = itemBeingDragged.item as LocalAssignment;
+        if (itemBeingDragged.sourceModuleName) {
           updateAssignmentMutation.mutate({
             item: assignment,
             previousModuleName: itemBeingDragged.sourceModuleName,
@@ -79,9 +98,16 @@ export default function DraggingContextProvider({
             itemName: assignment.name,
             previousItemName: assignment.name,
           });
+        } else {
+          console.error(
+            `error dropping assignment, sourceModuleName is undefined `,
+            assignment
+          );
+        }
       }
       function updatePage() {
         const page = itemBeingDragged.item as LocalCoursePage;
+        if (itemBeingDragged.sourceModuleName) {
           updatePageMutation.mutate({
             item: page,
             moduleName: dropModuleName,
@@ -89,6 +115,12 @@ export default function DraggingContextProvider({
             previousItemName: page.name,
             previousModuleName: itemBeingDragged.sourceModuleName,
           });
+        } else {
+          console.error(
+            `error dropping page, sourceModuleName is undefined `,
+            page
+          );
+        }
       }
     },
     [
@@ -113,6 +145,8 @@ export default function DraggingContextProvider({
           updateAssignment(dayAsDate);
         } else if (itemBeingDragged.type === "page") {
           updatePage(dayAsDate);
+        } else if (itemBeingDragged.type === "lecture") {
+          updateLecture(dayAsDate);
         }
       }
       setIsDragging(false);
@@ -124,8 +158,32 @@ export default function DraggingContextProvider({
         dayAsDate.setSeconds(0);
         return dayAsDate;
       }
+      function updateLecture(dayAsDate: Date) {
+        const { dueAt, ...lecture } = itemBeingDragged.item as Lecture & {
+          dueAt: string;
+        };
+        console.log("dropped lecture on day");
+        const existingLecture = getLectureForDay(weeks, dayAsDate);
+        if (existingLecture) {
+          console.log("attempting to drop on existing lecture");
+        } else {
+          updateLectureMutation.mutate({
+            previousDay: lecture.date,
+            lecture: {
+              ...lecture,
+              date: getDateOnlyMarkdownString(dayAsDate),
+            },
+          });
+        }
+      }
       function updateQuiz(dayAsDate: Date) {
         const previousQuiz = itemBeingDragged.item as LocalQuiz;
+        if (!itemBeingDragged.sourceModuleName) {
+          console.error(
+            "error dropping quiz on day, sourceModuleName is undefined"
+          );
+          return;
+        }
 
         const quiz: LocalQuiz = {
           ...previousQuiz,
@@ -146,6 +204,12 @@ export default function DraggingContextProvider({
       }
       function updatePage(dayAsDate: Date) {
         const previousPage = itemBeingDragged.item as LocalCoursePage;
+        if (!itemBeingDragged.sourceModuleName) {
+          console.error(
+            "error dropping page on day, sourceModuleName is undefined"
+          );
+          return;
+        }
         const page: LocalCoursePage = {
           ...previousPage,
           dueAt: dateToMarkdownString(dayAsDate),
@@ -159,6 +223,12 @@ export default function DraggingContextProvider({
         });
       }
       function updateAssignment(dayAsDate: Date) {
+        if (!itemBeingDragged.sourceModuleName) {
+          console.error(
+            "error dropping assignment on day, sourceModuleName is undefined"
+          );
+          return;
+        }
         const previousAssignment = itemBeingDragged.item as LocalAssignment;
         const assignment: LocalAssignment = {
           ...previousAssignment,
@@ -199,6 +269,7 @@ export default function DraggingContextProvider({
     </DraggingContext.Provider>
   );
 }
+
 function getNewLockDate(
   originalDueDate: string,
   originalLockDate: string | undefined,

nextjs/src/app/course/[courseName]/context/draggingContext.tsx

@@ -4,8 +4,8 @@ import { createContext, useContext, DragEvent } from "react";
 
 export interface DraggableItem {
   item: IModuleItem;
-  sourceModuleName: string;
-  type: "quiz" | "assignment" | "page";
+  sourceModuleName: string | undefined; // undefined for lectures
+  type: "quiz" | "assignment" | "page" | "lecture";
 }
 
 export interface DraggingContextInterface {

nextjs/src/app/course/[courseName]/lecture/[lectureDay]/EditLecture.tsx

@@ -38,7 +38,7 @@ Date: ${lectureDay}
         const parsed = parseLecture(text);
         if (!lecture || lectureToString(parsed) !== lectureToString(lecture)) {
           console.log("updating lecture");
-          updateLecture.mutate(parsed);
+          updateLecture.mutate({ lecture: parsed });
         }
         setError("");
       } catch (e: any) {

nextjs/src/app/todaysLectures/OneCourseLectures.tsx

@@ -5,6 +5,7 @@ import { getDateOnlyMarkdownString } from "@/models/local/timeUtils";
 import { getLecturePreviewUrl } from "@/services/urlUtils";
 import Link from "next/link";
 import { useCourseContext } from "../course/[courseName]/context/courseContext";
+import { getLectureForDay } from "@/models/local/lectureUtils";
 
 export default function OneCourseLectures() {
   const { courseName } = useCourseContext();
@@ -12,9 +13,7 @@ export default function OneCourseLectures() {
 
   const dayAsDate = new Date();
   const dayAsString = getDateOnlyMarkdownString(dayAsDate);
-  const todaysLecture = weeks
-    .flatMap((w) => w.lectures)
-    .find((l) => l.date == dayAsString);
+  const todaysLecture = getLectureForDay(weeks, dayAsDate);
   if (!todaysLecture) return <></>;
   return (
     <Link

nextjs/src/hooks/localCourse/lectureHooks.ts

@@ -6,6 +6,7 @@ import {
 import { lectureKeys } from "./lectureKeys";
 import { useCourseContext } from "@/app/course/[courseName]/context/courseContext";
 import {
+  deleteLecture,
   getLectures,
   updateLecture,
 } from "@/services/fileStorage/lectureFileStorageService";
@@ -28,8 +29,18 @@ export const useLectureUpdateMutation = () => {
   const { data: settings } = useLocalCourseSettingsQuery();
   const queryClient = useQueryClient();
   return useMutation({
-    mutationFn: async (lecture: Lecture) => {
+    mutationFn: async ({
+      lecture,
+      previousDay,
+    }: {
+      lecture: Lecture;
+      previousDay?: string;
+    }) => {
       await updateLecture(courseName, settings, lecture);
+
+      if (previousDay && previousDay !== lecture.date) {
+        await deleteLecture(courseName, settings, previousDay);
+      }
     },
     onSuccess: () => {
       queryClient.invalidateQueries({

nextjs/src/models/local/lectureUtils.ts

@@ -0,0 +1,9 @@
+import { Lecture } from "./lecture";
+import { getDateOnlyMarkdownString } from "./timeUtils";
+
+export function getLectureForDay(weeks: { weekName: string; lectures: Lecture[]; }[], dayAsDate: Date) {
+  return weeks
+    .flatMap((w) => w.lectures)
+    .find((l) => l.date == getDateOnlyMarkdownString(dayAsDate));
+}
+

nextjs/src/services/fileStorage/lectureFileStorageService.ts

@@ -57,7 +57,10 @@ export async function updateLecture(
     "lecture start date in update lecture"
   );
 
-  const weekFolderName = getLectureWeekName(courseSettings.startDate, lecture.date);
+  const weekFolderName = getLectureWeekName(
+    courseSettings.startDate,
+    lecture.date
+  );
   const weekPath = path.join(courseLectureRoot, weekFolderName);
   if (!(await directoryExists(weekPath))) {
     await fs.mkdir(weekPath, { recursive: true });
@@ -71,6 +74,41 @@ export async function updateLecture(
   await fs.writeFile(lecturePath, lectureContents);
 }
 
+export async function deleteLecture(
+  courseName: string,
+  courseSettings: LocalCourseSettings,
+  dayAsString: string
+) {
+  console.log("deleting lecture", courseName, dayAsString);
+  const lectureDate = getDateFromStringOrThrow(
+    dayAsString,
+    "lecture start date in update lecture"
+  );
+
+  const weekFolderName = getLectureWeekName(
+    courseSettings.startDate,
+    dayAsString
+  );
+
+  const courseLectureRoot = path.join(basePath, courseName, lectureFolderName);
+  const weekPath = path.join(courseLectureRoot, weekFolderName);
+  const lecturePath = path.join(
+    weekPath,
+    `${lectureDate.getDay()}-${getDayOfWeek(lectureDate)}.md`
+  );
+  try {
+    await fs.access(lecturePath); // throws error if no file
+    await fs.unlink(lecturePath);
+    console.log(`File deleted: ${lecturePath}`);
+  } catch (error: any) {
+    if (error?.code === "ENOENT") {
+      console.log(`Cannot delete lecture, file does not exist: ${lecturePath}`);
+    } else {
+      throw error;
+    }
+  }
+}
+
 const directoryExists = async (path: string): Promise<boolean> => {
   try {
     const stat = await fs.stat(path);