'use client'

import { Suspense, use, useState } from 'react'
import Link from 'next/link'
import { trpc } from '@/lib/trpc/client'
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from '@/components/ui/card'
import { Button } from '@/components/ui/button'
import { Badge } from '@/components/ui/badge'
import { Skeleton } from '@/components/ui/skeleton'
import { Switch } from '@/components/ui/switch'
import { Label } from '@/components/ui/label'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from '@/components/ui/dropdown-menu'
import {
  ArrowLeft,
  ShieldAlert,
  CheckCircle2,
  AlertCircle,
  MoreHorizontal,
  ShieldCheck,
  UserX,
  StickyNote,
  Loader2,
} from 'lucide-react'
import { toast } from 'sonner'
import { formatDistanceToNow } from 'date-fns'

interface PageProps {
  params: Promise<{ id: string }>
}

function COIManagementContent({ roundId }: { roundId: string }) {
  const [conflictsOnly, setConflictsOnly] = useState(false)

  const { data: round, isLoading: loadingRound } = trpc.round.get.useQuery({ id: roundId })
  const { data: coiList, isLoading: loadingCOI } = trpc.evaluation.listCOIByRound.useQuery({
    roundId,
    hasConflictOnly: conflictsOnly || undefined,
  })

  const utils = trpc.useUtils()
  const reviewCOI = trpc.evaluation.reviewCOI.useMutation({
    onSuccess: (data) => {
      utils.evaluation.listCOIByRound.invalidate({ roundId })
      toast.success(`COI marked as "${data.reviewAction}"`)
    },
    onError: (error) => {
      toast.error(error.message || 'Failed to review COI')
    },
  })

  if (loadingRound || loadingCOI) {
    return <COISkeleton />
  }

  if (!round) {
    return (
      <Card>
        <CardContent className="flex flex-col items-center justify-center py-12 text-center">
          <AlertCircle className="h-12 w-12 text-destructive/50" />
          <p className="mt-2 font-medium">Round Not Found</p>
          <Button asChild className="mt-4">
            <Link href="/admin/rounds">Back to Rounds</Link>
          </Button>
        </CardContent>
      </Card>
    )
  }

  const conflictCount = coiList?.filter((c) => c.hasConflict).length ?? 0
  const totalCount = coiList?.length ?? 0
  const reviewedCount = coiList?.filter((c) => c.reviewAction).length ?? 0

  const getReviewBadge = (reviewAction: string | null) => {
    switch (reviewAction) {
      case 'cleared':
        return (
          <Badge variant="default" className="bg-green-600">
            <ShieldCheck className="mr-1 h-3 w-3" />
            Cleared
          </Badge>
        )
      case 'reassigned':
        return (
          <Badge variant="default" className="bg-blue-600">
            <UserX className="mr-1 h-3 w-3" />
            Reassigned
          </Badge>
        )
      case 'noted':
        return (
          <Badge variant="secondary">
            <StickyNote className="mr-1 h-3 w-3" />
            Noted
          </Badge>
        )
      default:
        return (
          <Badge variant="outline" className="text-amber-600 border-amber-300">
            Pending Review
          </Badge>
        )
    }
  }

  const getConflictTypeBadge = (type: string | null) => {
    switch (type) {
      case 'financial':
        return <Badge variant="destructive">Financial</Badge>
      case 'personal':
        return <Badge variant="secondary">Personal</Badge>
      case 'organizational':
        return <Badge variant="outline">Organizational</Badge>
      case 'other':
        return <Badge variant="outline">Other</Badge>
      default:
        return null
    }
  }

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-center gap-4">
        <Button variant="ghost" asChild className="-ml-4">
          <Link href={`/admin/rounds/${roundId}`}>
            <ArrowLeft className="mr-2 h-4 w-4" />
            Back to Round
          </Link>
        </Button>
      </div>

      <div className="space-y-1">
        <div className="flex items-center gap-2 text-sm text-muted-foreground">
          <Link href={`/admin/programs/${round.program.id}`} className="hover:underline">
            {round.program.name}
          </Link>
          <span>/</span>
          <Link href={`/admin/rounds/${roundId}`} className="hover:underline">
            {round.name}
          </Link>
        </div>
        <h1 className="text-2xl font-semibold tracking-tight flex items-center gap-2">
          <ShieldAlert className="h-6 w-6" />
          Conflict of Interest Declarations
        </h1>
      </div>

      {/* Stats */}
      <div className="grid gap-4 sm:grid-cols-3">
        <Card>
          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
            <CardTitle className="text-sm font-medium">Total Declarations</CardTitle>
            <ShieldAlert className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">{totalCount}</div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
            <CardTitle className="text-sm font-medium">Conflicts Declared</CardTitle>
            <AlertCircle className="h-4 w-4 text-amber-500" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold text-amber-600">{conflictCount}</div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
            <CardTitle className="text-sm font-medium">Reviewed</CardTitle>
            <CheckCircle2 className="h-4 w-4 text-green-600" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">{reviewedCount}</div>
          </CardContent>
        </Card>
      </div>

      {/* COI Table */}
      <Card>
        <CardHeader>
          <div className="flex items-center justify-between">
            <div>
              <CardTitle className="text-lg">Declarations</CardTitle>
              <CardDescription>
                Review and manage conflict of interest declarations from jury members
              </CardDescription>
            </div>
            <div className="flex items-center gap-2">
              <Switch
                id="conflicts-only"
                checked={conflictsOnly}
                onCheckedChange={setConflictsOnly}
              />
              <Label htmlFor="conflicts-only" className="text-sm">
                Conflicts only
              </Label>
            </div>
          </div>
        </CardHeader>
        <CardContent>
          {coiList && coiList.length > 0 ? (
            <div className="rounded-lg border">
              <Table>
                <TableHeader>
                  <TableRow>
                    <TableHead>Project</TableHead>
                    <TableHead>Juror</TableHead>
                    <TableHead>Conflict</TableHead>
                    <TableHead>Type</TableHead>
                    <TableHead>Description</TableHead>
                    <TableHead>Status</TableHead>
                    <TableHead className="w-12">Actions</TableHead>
                  </TableRow>
                </TableHeader>
                <TableBody>
                  {coiList.map((coi) => (
                    <TableRow key={coi.id}>
                      <TableCell className="font-medium max-w-[200px] truncate">
                        {coi.assignment.project.title}
                      </TableCell>
                      <TableCell>
                        {coi.user.name || coi.user.email}
                      </TableCell>
                      <TableCell>
                        {coi.hasConflict ? (
                          <Badge variant="destructive">Yes</Badge>
                        ) : (
                          <Badge variant="outline" className="text-green-600 border-green-300">
                            No
                          </Badge>
                        )}
                      </TableCell>
                      <TableCell>
                        {coi.hasConflict ? getConflictTypeBadge(coi.conflictType) : '-'}
                      </TableCell>
                      <TableCell className="max-w-[200px]">
                        {coi.description ? (
                          <span className="text-sm text-muted-foreground truncate block">
                            {coi.description}
                          </span>
                        ) : (
                          <span className="text-sm text-muted-foreground">-</span>
                        )}
                      </TableCell>
                      <TableCell>
                        {coi.hasConflict ? (
                          <div className="space-y-1">
                            {getReviewBadge(coi.reviewAction)}
                            {coi.reviewedBy && (
                              <p className="text-xs text-muted-foreground">
                                by {coi.reviewedBy.name || coi.reviewedBy.email}
                                {coi.reviewedAt && (
                                  <> {formatDistanceToNow(new Date(coi.reviewedAt), { addSuffix: true })}</>
                                )}
                              </p>
                            )}
                          </div>
                        ) : (
                          <span className="text-sm text-muted-foreground">N/A</span>
                        )}
                      </TableCell>
                      <TableCell>
                        {coi.hasConflict && (
                          <DropdownMenu>
                            <DropdownMenuTrigger asChild>
                              <Button
                                variant="ghost"
                                size="sm"
                                disabled={reviewCOI.isPending}
                              >
                                {reviewCOI.isPending ? (
                                  <Loader2 className="h-4 w-4 animate-spin" />
                                ) : (
                                  <MoreHorizontal className="h-4 w-4" />
                                )}
                              </Button>
                            </DropdownMenuTrigger>
                            <DropdownMenuContent align="end">
                              <DropdownMenuItem
                                onClick={() =>
                                  reviewCOI.mutate({
                                    id: coi.id,
                                    reviewAction: 'cleared',
                                  })
                                }
                              >
                                <ShieldCheck className="mr-2 h-4 w-4" />
                                Clear
                              </DropdownMenuItem>
                              <DropdownMenuItem
                                onClick={() =>
                                  reviewCOI.mutate({
                                    id: coi.id,
                                    reviewAction: 'reassigned',
                                  })
                                }
                              >
                                <UserX className="mr-2 h-4 w-4" />
                                Reassign
                              </DropdownMenuItem>
                              <DropdownMenuItem
                                onClick={() =>
                                  reviewCOI.mutate({
                                    id: coi.id,
                                    reviewAction: 'noted',
                                  })
                                }
                              >
                                <StickyNote className="mr-2 h-4 w-4" />
                                Note
                              </DropdownMenuItem>
                            </DropdownMenuContent>
                          </DropdownMenu>
                        )}
                      </TableCell>
                    </TableRow>
                  ))}
                </TableBody>
              </Table>
            </div>
          ) : (
            <div className="flex flex-col items-center justify-center py-12 text-center">
              <ShieldAlert className="h-12 w-12 text-muted-foreground/50" />
              <p className="mt-2 font-medium">No Declarations Yet</p>
              <p className="text-sm text-muted-foreground">
                {conflictsOnly
                  ? 'No conflicts of interest have been declared for this round'
                  : 'No jury members have submitted COI declarations for this round yet'}
              </p>
            </div>
          )}
        </CardContent>
      </Card>
    </div>
  )
}

function COISkeleton() {
  return (
    <div className="space-y-6">
      <Skeleton className="h-9 w-36" />

      <div className="space-y-1">
        <Skeleton className="h-4 w-48" />
        <Skeleton className="h-8 w-80" />
      </div>

      <div className="grid gap-4 sm:grid-cols-3">
        {[1, 2, 3].map((i) => (
          <Card key={i}>
            <CardHeader className="pb-2">
              <Skeleton className="h-4 w-32" />
            </CardHeader>
            <CardContent>
              <Skeleton className="h-8 w-16" />
            </CardContent>
          </Card>
        ))}
      </div>

      <Card>
        <CardHeader>
          <Skeleton className="h-5 w-48" />
          <Skeleton className="h-4 w-64" />
        </CardHeader>
        <CardContent>
          <Skeleton className="h-48 w-full" />
        </CardContent>
      </Card>
    </div>
  )
}

export default function COIManagementPage({ params }: PageProps) {
  const { id } = use(params)

  return (
    <Suspense fallback={<COISkeleton />}>
      <COIManagementContent roundId={id} />
    </Suspense>
  )
}