Merge exams grading into homework

Redirect /teacher/exams/grading* to /teacher/homework/submissions; remove exam grading UI/actions/data-access; add homework student workflow and update design docs.

src/modules/homework/components/homework-assignment-form.tsx

@@ -0,0 +1,138 @@
+"use client"
+
+import { useMemo, useState } from "react"
+import { useFormStatus } from "react-dom"
+import { toast } from "sonner"
+import { useRouter } from "next/navigation"
+
+import { Card, CardContent, CardFooter, CardHeader, CardTitle } from "@/shared/components/ui/card"
+import { Button } from "@/shared/components/ui/button"
+import { Input } from "@/shared/components/ui/input"
+import { Label } from "@/shared/components/ui/label"
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/shared/components/ui/select"
+import { Textarea } from "@/shared/components/ui/textarea"
+
+import { createHomeworkAssignmentAction } from "../actions"
+
+type ExamOption = { id: string; title: string }
+
+function SubmitButton() {
+  const { pending } = useFormStatus()
+  return (
+    <Button type="submit" disabled={pending}>
+      {pending ? "Creating..." : "Create Assignment"}
+    </Button>
+  )
+}
+
+export function HomeworkAssignmentForm({ exams }: { exams: ExamOption[] }) {
+  const router = useRouter()
+
+  const initialExamId = useMemo(() => exams[0]?.id ?? "", [exams])
+  const [examId, setExamId] = useState<string>(initialExamId)
+  const [allowLate, setAllowLate] = useState<boolean>(false)
+
+  const handleSubmit = async (formData: FormData) => {
+    if (!examId) {
+      toast.error("Please select an exam")
+      return
+    }
+    formData.set("sourceExamId", examId)
+    formData.set("allowLate", allowLate ? "true" : "false")
+    formData.set("publish", "true")
+
+    const result = await createHomeworkAssignmentAction(null, formData)
+    if (result.success) {
+      toast.success(result.message)
+      router.push("/teacher/homework/assignments")
+    } else {
+      toast.error(result.message || "Failed to create")
+    }
+  }
+
+  return (
+    <Card>
+      <CardHeader>
+        <CardTitle>Create Assignment</CardTitle>
+      </CardHeader>
+      <CardContent>
+        <form action={handleSubmit} className="space-y-6">
+          <div className="grid grid-cols-1 gap-4 md:grid-cols-2">
+            <div className="grid gap-2 md:col-span-2">
+              <Label>Source Exam</Label>
+              <Select value={examId} onValueChange={setExamId}>
+                <SelectTrigger>
+                  <SelectValue placeholder="Select an exam" />
+                </SelectTrigger>
+                <SelectContent>
+                  {exams.map((e) => (
+                    <SelectItem key={e.id} value={e.id}>
+                      {e.title}
+                    </SelectItem>
+                  ))}
+                </SelectContent>
+              </Select>
+              <input type="hidden" name="sourceExamId" value={examId} />
+            </div>
+
+            <div className="grid gap-2 md:col-span-2">
+              <Label htmlFor="title">Assignment Title (optional)</Label>
+              <Input id="title" name="title" placeholder="Defaults to exam title" />
+            </div>
+
+            <div className="grid gap-2 md:col-span-2">
+              <Label htmlFor="description">Description (optional)</Label>
+              <Textarea id="description" name="description" className="min-h-[80px]" />
+            </div>
+
+            <div className="grid gap-2">
+              <Label htmlFor="availableAt">Available At (optional)</Label>
+              <Input id="availableAt" name="availableAt" type="datetime-local" />
+            </div>
+
+            <div className="grid gap-2">
+              <Label htmlFor="dueAt">Due At (optional)</Label>
+              <Input id="dueAt" name="dueAt" type="datetime-local" />
+            </div>
+
+            <div className="flex items-center gap-2 md:col-span-2">
+              <input
+                id="allowLate"
+                type="checkbox"
+                checked={allowLate}
+                onChange={(e) => setAllowLate(e.target.checked)}
+              />
+              <Label htmlFor="allowLate">Allow late submissions</Label>
+              <input type="hidden" name="allowLate" value={allowLate ? "true" : "false"} />
+            </div>
+
+            <div className="grid gap-2">
+              <Label htmlFor="lateDueAt">Late Due At (optional)</Label>
+              <Input id="lateDueAt" name="lateDueAt" type="datetime-local" />
+            </div>
+
+            <div className="grid gap-2">
+              <Label htmlFor="maxAttempts">Max Attempts</Label>
+              <Input id="maxAttempts" name="maxAttempts" type="number" min={1} max={20} defaultValue={1} />
+            </div>
+
+            <div className="grid gap-2 md:col-span-2">
+              <Label htmlFor="targetStudentIdsText">Target student IDs (optional)</Label>
+              <Textarea
+                id="targetStudentIdsText"
+                name="targetStudentIdsText"
+                placeholder="Leave empty to assign to all students. You can paste IDs separated by comma or newline."
+                className="min-h-[90px]"
+              />
+            </div>
+          </div>
+
+          <CardFooter className="justify-end">
+            <SubmitButton />
+          </CardFooter>
+        </form>
+      </CardContent>
+    </Card>
+  )
+}
+