import Link from "next/link"

import { EmptyState } from "@/shared/components/ui/empty-state"
import { Badge } from "@/shared/components/ui/badge"
import { Button } from "@/shared/components/ui/button"
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/shared/components/ui/table"
import { formatDate } from "@/shared/lib/utils"
import { getDemoStudentUser, getStudentHomeworkAssignments } from "@/modules/homework/data-access"
import { Inbox } from "lucide-react"

export const dynamic = "force-dynamic"

const getStatusVariant = (status: string): "default" | "secondary" | "outline" => {
  if (status === "graded") return "default"
  if (status === "submitted") return "secondary"
  if (status === "in_progress") return "secondary"
  return "outline"
}

const getStatusLabel = (status: string) => {
  if (status === "graded") return "Graded"
  if (status === "submitted") return "Submitted"
  if (status === "in_progress") return "In progress"
  return "Not started"
}

const getActionLabel = (status: string) => {
  if (status === "graded") return "Review"
  if (status === "submitted") return "View"
  if (status === "in_progress") return "Continue"
  return "Start"
}

const getActionVariant = (status: string): "default" | "secondary" | "outline" => {
  if (status === "graded" || status === "submitted") return "outline"
  return "default"
}

export default async function StudentAssignmentsPage() {
  const student = await getDemoStudentUser()

  if (!student) {
    return (
      <div className="h-full flex-1 flex-col space-y-8 p-8 md:flex">
        <div className="flex items-center justify-between space-y-2">
          <div>
            <h2 className="text-2xl font-bold tracking-tight">Assignments</h2>
            <p className="text-muted-foreground">Your homework assignments.</p>
          </div>
        </div>
        <EmptyState title="No user found" description="Create a student user to see assignments." icon={Inbox} />
      </div>
    )
  }

  const assignments = await getStudentHomeworkAssignments(student.id)
  const hasAssignments = assignments.length > 0

  return (
    <div className="h-full flex-1 flex-col space-y-8 p-8 md:flex">
      <div className="flex items-center justify-between space-y-2">
        <div>
          <h2 className="text-2xl font-bold tracking-tight">Assignments</h2>
          <p className="text-muted-foreground">Your homework assignments.</p>
        </div>
        <Button asChild variant="outline">
          <Link href="/student/dashboard">Back</Link>
        </Button>
      </div>

      {!hasAssignments ? (
        <EmptyState title="No assignments" description="You have no assigned homework right now." icon={Inbox} />
      ) : (
        <div className="rounded-md border bg-card">
          <Table>
            <TableHeader>
              <TableRow>
                <TableHead>Title</TableHead>
                <TableHead>Status</TableHead>
                <TableHead>Due</TableHead>
                <TableHead>Attempts</TableHead>
                <TableHead>Score</TableHead>
                <TableHead className="text-right">Action</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {assignments.map((a) => (
                <TableRow key={a.id}>
                  <TableCell className="font-medium">
                    <Link href={`/student/learning/assignments/${a.id}`} className="hover:underline">
                      {a.title}
                    </Link>
                  </TableCell>
                  <TableCell>
                    <Badge variant={getStatusVariant(a.progressStatus)} className="capitalize">
                      {getStatusLabel(a.progressStatus)}
                    </Badge>
                  </TableCell>
                  <TableCell>{a.dueAt ? formatDate(a.dueAt) : "-"}</TableCell>
                  <TableCell className="tabular-nums text-muted-foreground">
                    {a.attemptsUsed}/{a.maxAttempts}
                  </TableCell>
                  <TableCell className="tabular-nums">{a.latestScore ?? "-"}</TableCell>
                  <TableCell className="text-right">
                    <Button asChild size="sm" variant={getActionVariant(a.progressStatus)}>
                      <Link href={`/student/learning/assignments/${a.id}`}>
                        {getActionLabel(a.progressStatus)}
                      </Link>
                    </Button>
                  </TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        </div>
      )}
    </div>
  )
}