'use client'

import { useState } from 'react'
import Link from 'next/link'
import type { Route } from 'next'
import { trpc } from '@/lib/trpc/client'
import { useEdition } from '@/contexts/edition-context'
import { Badge } from '@/components/ui/badge'
import { Button } from '@/components/ui/button'
import {
  Card,
  CardContent,
  CardHeader,
  CardTitle,
  CardDescription,
} from '@/components/ui/card'
import { Skeleton } from '@/components/ui/skeleton'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select'
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog'
import { Textarea } from '@/components/ui/textarea'
import { toast } from 'sonner'
import { cn, formatEnumLabel } from '@/lib/utils'
import { Plus, Scale, Users, Loader2, ArrowRight, CircleDot } from 'lucide-react'

const capModeLabels = {
  HARD: 'Hard Cap',
  SOFT: 'Soft Cap',
  NONE: 'No Cap',
}

const capModeColors = {
  HARD: 'bg-red-100 text-red-700',
  SOFT: 'bg-amber-100 text-amber-700',
  NONE: 'bg-gray-100 text-gray-600',
}

export default function JuriesPage() {
  const { currentEdition } = useEdition()
  const programId = currentEdition?.id
  const utils = trpc.useUtils()

  const [createDialogOpen, setCreateDialogOpen] = useState(false)
  const [formData, setFormData] = useState({
    competitionId: '',
    name: '',
    description: '',
  })

  const { data: competitions, isLoading: loadingCompetitions } = trpc.competition.list.useQuery(
    { programId: programId! },
    { enabled: !!programId }
  )

  const createMutation = trpc.juryGroup.create.useMutation({
    onSuccess: () => {
      utils.juryGroup.list.invalidate()
      toast.success('Jury group created')
      setCreateDialogOpen(false)
      setFormData({ competitionId: '', name: '', description: '' })
    },
    onError: (err) => toast.error(err.message),
  })

  const handleCreate = () => {
    if (!formData.competitionId || !formData.name.trim()) {
      toast.error('Competition and name are required')
      return
    }

    const slug = formData.name
      .toLowerCase()
      .replace(/[^a-z0-9]+/g, '-')
      .replace(/^-|-$/g, '')

    createMutation.mutate({
      competitionId: formData.competitionId,
      name: formData.name.trim(),
      slug,
      description: formData.description || undefined,
    })
  }

  if (!programId) {
    return (
      <div className="space-y-6">
        <h1 className="text-xl font-bold">Juries</h1>
        <Card className="border-dashed">
          <CardContent className="flex flex-col items-center justify-center py-12 text-center">
            <Scale className="h-12 w-12 text-muted-foreground/50" />
            <p className="mt-2 font-medium">No Edition Selected</p>
            <p className="text-sm text-muted-foreground">Select an edition from the sidebar</p>
          </CardContent>
        </Card>
      </div>
    )
  }

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
        <div>
          <h1 className="text-xl font-bold">Juries</h1>
          <p className="text-sm text-muted-foreground">
            Manage jury groups for {currentEdition?.name}
          </p>
        </div>
        <Button size="sm" onClick={() => setCreateDialogOpen(true)}>
          <Plus className="h-4 w-4 mr-1" />
          Create Jury Group
        </Button>
      </div>

      {/* Loading */}
      {loadingCompetitions && (
        <div className="space-y-4">
          {[1, 2].map((i) => (
            <Card key={i}>
              <CardHeader>
                <Skeleton className="h-5 w-48" />
              </CardHeader>
              <CardContent className="space-y-2">
                <Skeleton className="h-20 w-full" />
              </CardContent>
            </Card>
          ))}
        </div>
      )}

      {/* Empty State */}
      {!loadingCompetitions && (!competitions || competitions.length === 0) && (
        <Card className="border-2 border-dashed">
          <CardContent className="flex flex-col items-center justify-center py-16 text-center">
            <div className="rounded-full bg-primary/10 p-4 mb-4">
              <Scale className="h-10 w-10 text-primary" />
            </div>
            <h3 className="text-lg font-semibold mb-2">No Competitions Yet</h3>
            <p className="text-sm text-muted-foreground max-w-md mb-6">
              Create a competition first, then add jury groups.
            </p>
          </CardContent>
        </Card>
      )}

      {/* Competition Groups */}
      {competitions && competitions.length > 0 && (
        <div className="space-y-6">
          {competitions.map((comp) => (
            <CompetitionJuriesSection key={comp.id} competition={comp} />
          ))}
        </div>
      )}

      {/* Create Dialog */}
      <Dialog open={createDialogOpen} onOpenChange={setCreateDialogOpen}>
        <DialogContent>
          <DialogHeader>
            <DialogTitle>Create Jury Group</DialogTitle>
            <DialogDescription>
              Create a new jury panel for a competition.
            </DialogDescription>
          </DialogHeader>
          <div className="space-y-4">
            <div className="space-y-2">
              <Label>Competition *</Label>
              <Select
                value={formData.competitionId}
                onValueChange={(v) => setFormData({ ...formData, competitionId: v })}
              >
                <SelectTrigger>
                  <SelectValue placeholder="Select competition" />
                </SelectTrigger>
                <SelectContent>
                  {competitions?.filter((c) => c.status !== 'ARCHIVED').map((c) => (
                    <SelectItem key={c.id} value={c.id}>
                      {c.name}
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>
            <div className="space-y-2">
              <Label>Name *</Label>
              <Input
                placeholder="e.g. Technical Panel A"
                value={formData.name}
                onChange={(e) => setFormData({ ...formData, name: e.target.value })}
              />
            </div>
            <div className="space-y-2">
              <Label>Description</Label>
              <Textarea
                placeholder="Optional description"
                value={formData.description}
                onChange={(e) => setFormData({ ...formData, description: e.target.value })}
                rows={3}
              />
            </div>
          </div>
          <DialogFooter>
            <Button variant="outline" onClick={() => setCreateDialogOpen(false)}>
              Cancel
            </Button>
            <Button onClick={handleCreate} disabled={createMutation.isPending}>
              {createMutation.isPending ? (
                <>
                  <Loader2 className="h-4 w-4 mr-1 animate-spin" />
                  Creating...
                </>
              ) : (
                'Create'
              )}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </div>
  )
}

// ─── Competition Section ─────────────────────────────────────────────────────

type CompetitionJuriesSectionProps = {
  competition: any
}

function CompetitionJuriesSection({ competition }: CompetitionJuriesSectionProps) {
  const { data: juryGroups, isLoading } = trpc.juryGroup.list.useQuery({
    competitionId: competition.id,
  })

  return (
    <Card>
      <CardHeader>
        <div className="flex items-center justify-between">
          <div>
            <CardTitle className="text-base">{competition.name}</CardTitle>
            <CardDescription>
              {juryGroups?.length || 0} jury group{juryGroups?.length === 1 ? '' : 's'}
            </CardDescription>
          </div>
        </div>
      </CardHeader>
      <CardContent>
        {isLoading ? (
          <div className="space-y-2">
            <Skeleton className="h-20 w-full" />
            <Skeleton className="h-20 w-full" />
          </div>
        ) : !juryGroups || juryGroups.length === 0 ? (
          <p className="text-sm text-muted-foreground text-center py-6">
            No jury groups configured for this competition.
          </p>
        ) : (
          <div className="space-y-3">
            {juryGroups.map((group) => (
              <Link key={group.id} href={`/admin/juries/${group.id}` as Route}>
                <Card className="transition-all duration-200 hover:-translate-y-0.5 hover:shadow-md cursor-pointer group">
                  <CardContent className="p-4">
                    <div className="space-y-3">
                      {/* Header row */}
                      <div className="flex items-start justify-between gap-2">
                        <div className="flex items-center gap-2 min-w-0">
                          <div className="flex h-8 w-8 items-center justify-center rounded-lg bg-brand-blue/10 shrink-0">
                            <Scale className="h-4 w-4 text-brand-blue" />
                          </div>
                          <div className="min-w-0">
                            <h3 className="font-semibold text-sm line-clamp-1 group-hover:text-brand-blue transition-colors">
                              {group.name}
                            </h3>
                            <p className="text-xs text-muted-foreground">
                              {group._count.members} member{group._count.members !== 1 ? 's' : ''}
                              {' · '}
                              {group._count.assignments} assignment{group._count.assignments !== 1 ? 's' : ''}
                            </p>
                          </div>
                        </div>
                        <div className="flex items-center gap-2 shrink-0">
                          <Badge
                            variant="secondary"
                            className={cn('text-[10px]', capModeColors[group.defaultCapMode as keyof typeof capModeColors])}
                          >
                            {capModeLabels[group.defaultCapMode as keyof typeof capModeLabels]}
                          </Badge>
                          <ArrowRight className="h-4 w-4 text-muted-foreground/40 group-hover:text-brand-blue transition-colors" />
                        </div>
                      </div>

                      {/* Round assignments */}
                      {(group as any).rounds?.length > 0 && (
                        <div className="flex flex-wrap gap-1.5">
                          {(group as any).rounds.map((r: any) => (
                            <Badge
                              key={r.id}
                              variant="outline"
                              className={cn(
                                'text-[10px] gap-1',
                                r.status === 'ROUND_ACTIVE' && 'border-blue-300 bg-blue-50 text-blue-700',
                                r.status === 'ROUND_CLOSED' && 'border-emerald-300 bg-emerald-50 text-emerald-700',
                                r.status === 'ROUND_DRAFT' && 'border-slate-200 text-slate-500',
                              )}
                            >
                              <CircleDot className="h-2.5 w-2.5" />
                              {r.name}
                            </Badge>
                          ))}
                        </div>
                      )}

                      {/* Member preview */}
                      {(group as any).members?.length > 0 && (
                        <div className="flex items-center gap-1.5">
                          <div className="flex -space-x-1.5">
                            {(group as any).members.slice(0, 5).map((m: any) => (
                              <div
                                key={m.id}
                                className="h-6 w-6 rounded-full bg-brand-blue/10 border-2 border-white flex items-center justify-center text-[9px] font-semibold text-brand-blue"
                                title={m.user?.name || m.user?.email}
                              >
                                {(m.user?.name || m.user?.email || '?').charAt(0).toUpperCase()}
                              </div>
                            ))}
                          </div>
                          {group._count.members > 5 && (
                            <span className="text-[10px] text-muted-foreground">
                              +{group._count.members - 5} more
                            </span>
                          )}
                        </div>
                      )}
                    </div>
                  </CardContent>
                </Card>
              </Link>
            ))}
          </div>
        )}
      </CardContent>
    </Card>
  )
}