From 9a66ddada369d8c272279f430343629a76dc59f3 Mon Sep 17 00:00:00 2001
From: Eden Xu <130119691+FlyingPufferFish@users.noreply.github.com>
Date: Mon, 7 Oct 2024 12:15:01 +1100
Subject: [PATCH] feat(timetables): modify update endpoint to receive list of
 unit updates

---
 .vscode/settings.json                         |  6 +-
 .../main/java/org/acme/TimetableResource.java | 84 ++++++++++++++++++-
 2 files changed, 85 insertions(+), 5 deletions(-)

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 8a4aef0..5a04e02 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,3 +1,7 @@
 {
-  "conventionalCommits.scopes": ["database", "display ganttchart"]
+  "conventionalCommits.scopes": [
+    "database",
+    "display ganttchart",
+    "timetables"
+  ]
 }
diff --git a/backend/src/main/java/org/acme/TimetableResource.java b/backend/src/main/java/org/acme/TimetableResource.java
index 1256789..2d73625 100644
--- a/backend/src/main/java/org/acme/TimetableResource.java
+++ b/backend/src/main/java/org/acme/TimetableResource.java
@@ -1,14 +1,19 @@
 package org.acme;
 
 import ai.timefold.solver.core.api.solver.SolverManager;
+import io.smallrye.mutiny.Uni;
 import jakarta.inject.Inject;
 import jakarta.transaction.Transactional;
 import jakarta.ws.rs.Consumes;
 import jakarta.ws.rs.GET;
 import jakarta.ws.rs.POST;
+import jakarta.ws.rs.PUT;
 import jakarta.ws.rs.Path;
 import jakarta.ws.rs.Produces;
+import jakarta.ws.rs.WebApplicationException;
 import jakarta.ws.rs.core.MediaType;
+import jakarta.ws.rs.core.Response;
+
 import org.acme.domain.Room;
 import org.acme.domain.Student;
 import org.acme.domain.Timetable;
@@ -62,11 +67,82 @@ public List<Timetable> view() {
         return Timetable.listAll();
     }
 
-    @Path("/unit")
-    @POST
+
+    /**
+     * Takes a list of Units as input to updates exisiting timetable once users 
+     * make drag-and-drop modifications in frontend
+     * 
+     * @param updatedUnits  List of all Unit updates
+     * @return              A Response object indicating status
+     */
+    @Path("/update")
+    @PUT
+    @Transactional
     @Consumes(MediaType.APPLICATION_JSON)
-    public Unit handleUnit(Unit unit) {
-        return unit;
+    public Response timetableUpdate(List<Unit> updatedUnits) {
+        List<Unit> dbUnits = Unit.listAll();
+        for (Unit updatedUnit : updatedUnits) {
+            if (unitUpdate(updatedUnit, dbUnits) == null) {
+                return Response.serverError().build();
+            }
+        }
+        return Response.ok().build();
+    }
+
+
+    /**
+     * Update the time/location of a unit
+     * 
+     * @param updatedUnit   Unit object with updated time/location
+     * @param dbUnits       List of all Unit objects in the database
+     * @return              The updated Unit, null otherwise
+     */
+    @PUT
+    @Transactional
+    @Consumes(MediaType.APPLICATION_JSON)
+    public Unit unitUpdate(Unit updatedUnit, List<Unit> dbUnits) {
+
+        // find existing Unit obj in db by unitId
+        for (Unit unit : dbUnits) {
+            if (updatedUnit.unitId == unit.unitId) {
+                assert(unit.isPersistent());
+                // update day of week
+                unit.dayOfWeek = updatedUnit.dayOfWeek;
+                // update startTime
+                unit.startTime = updatedUnit.startTime;
+                // if room is different
+                if (unit.room.roomCode != updatedUnit.room.roomCode 
+                || !unit.room.buildingId.equals(updatedUnit.room.buildingId)) {
+                    // update room
+                    Room newRoom;
+                    if ((newRoom = findRoom(updatedUnit.room)) == null) {
+                        throw new WebApplicationException("Room with building ID " + updatedUnit.room.buildingId + ", and room code " + updatedUnit.room.roomCode + " not found", 404);
+                    }
+                    unit.room = newRoom;
+                }
+                return unit;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Find existing Room object inside the database with 
+     * desired buildingId and roomCode
+     * 
+     * @param inputRoom     Room object with buildingId and roomCode of desired Room
+     * @return              Room object meeting the input criteria, null otherwise
+     */
+    public Room findRoom(Room inputRoom) {
+        List<Room> rooms = Room.listAll();
+        for (Room room : rooms) {
+            if (room.roomCode.equals(inputRoom.roomCode) 
+            && room.buildingId.equals(inputRoom.buildingId)) {
+                assert(room.isPersistent());
+                return room;
+            }
+        }
+        return null;
     }
 
     public void findByCampusAndDelete(String campusName) {