'use client'

import { useState, useMemo } from 'react'
import { trpc } from '@/lib/trpc/client'
import { toast } from 'sonner'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Badge } from '@/components/ui/badge'
import { Checkbox } from '@/components/ui/checkbox'
import { Progress } from '@/components/ui/progress'
import { Skeleton } from '@/components/ui/skeleton'
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
  AlertDialogTrigger,
} from '@/components/ui/alert-dialog'
import {
  Collapsible,
  CollapsibleContent,
  CollapsibleTrigger,
} from '@/components/ui/collapsible'
import {
  ChevronDown,
  ChevronUp,
  Loader2,
  CheckCircle2,
  Play,
  Trophy,
  AlertTriangle,
  Search,
} from 'lucide-react'
import { CountryDisplay } from '@/components/shared/country-display'

type AwardShortlistProps = {
  awardId: string
  roundId: string
  awardName: string
  criteriaText?: string | null
  eligibilityMode: string
  shortlistSize: number
  jobStatus?: string | null
  jobTotal?: number | null
  jobDone?: number | null
}

export function AwardShortlist({
  awardId,
  roundId,
  awardName,
  criteriaText,
  eligibilityMode,
  shortlistSize,
  jobStatus,
  jobTotal,
  jobDone,
}: AwardShortlistProps) {
  const [expanded, setExpanded] = useState(false)
  const [eligibilitySearch, setEligibilitySearch] = useState('')
  const utils = trpc.useUtils()

  const isRunning = jobStatus === 'PENDING' || jobStatus === 'PROCESSING'

  const { data: shortlist, isLoading: isLoadingShortlist } = trpc.specialAward.listShortlist.useQuery(
    { awardId, perPage: 100 },
    { enabled: expanded && !isRunning }
  )

  const { data: jobPoll } = trpc.specialAward.getEligibilityJobStatus.useQuery(
    { awardId },
    { enabled: isRunning, refetchInterval: 3000 }
  )

  const runMutation = trpc.specialAward.runEligibilityForRound.useMutation({
    onSuccess: () => {
      toast.success('Eligibility evaluation started')
      utils.specialAward.getEligibilityJobStatus.invalidate({ awardId })
      utils.specialAward.listForRound.invalidate({ roundId })
    },
    onError: (err) => toast.error(`Failed: ${err.message}`),
  })

  const toggleMutation = trpc.specialAward.toggleShortlisted.useMutation({
    onSuccess: (data) => {
      utils.specialAward.listShortlist.invalidate({ awardId })
      utils.specialAward.listForRound.invalidate({ roundId })
      toast.success(data.shortlisted ? 'Added to shortlist' : 'Removed from shortlist')
    },
    onError: (err) => toast.error(`Failed: ${err.message}`),
  })

  const bulkToggleMutation = trpc.specialAward.bulkToggleShortlisted.useMutation({
    onSuccess: (data) => {
      utils.specialAward.listShortlist.invalidate({ awardId })
      utils.specialAward.listForRound.invalidate({ roundId })
      toast.success(`${data.updated} projects ${data.shortlisted ? 'added to' : 'removed from'} shortlist`)
    },
    onError: (err) => toast.error(`Failed: ${err.message}`),
  })

  const { data: awardRounds } = trpc.specialAward.listRounds.useQuery(
    { awardId },
    { enabled: expanded && eligibilityMode === 'SEPARATE_POOL' }
  )
  const hasAwardRounds = (awardRounds?.length ?? 0) > 0

  const confirmMutation = trpc.specialAward.confirmShortlist.useMutation({
    onSuccess: (data) => {
      utils.specialAward.listShortlist.invalidate({ awardId })
      utils.specialAward.listForRound.invalidate({ roundId })
      toast.success(
        `Confirmed ${data.confirmedCount} projects` +
        (data.routedCount > 0 ? ` — ${data.routedCount} routed to award track` : '')
      )
    },
    onError: (err) => toast.error(`Failed: ${err.message}`),
  })

  const currentJobStatus = jobPoll?.eligibilityJobStatus ?? jobStatus
  const currentJobDone = jobPoll?.eligibilityJobDone ?? jobDone
  const currentJobTotal = jobPoll?.eligibilityJobTotal ?? jobTotal
  const jobProgress = currentJobTotal && currentJobTotal > 0
    ? Math.round(((currentJobDone ?? 0) / currentJobTotal) * 100)
    : 0

  const filteredEligibilities = useMemo(() => {
    if (!shortlist) return []
    if (!eligibilitySearch.trim()) return shortlist.eligibilities
    const q = eligibilitySearch.toLowerCase()
    return shortlist.eligibilities.filter((e: any) =>
      (e.project?.title || '').toLowerCase().includes(q) ||
      (e.project?.teamName || '').toLowerCase().includes(q) ||
      (e.project?.country || '').toLowerCase().includes(q) ||
      (e.project?.institution || '').toLowerCase().includes(q) ||
      (e.project?.competitionCategory || '').toLowerCase().includes(q)
    )
  }, [shortlist, eligibilitySearch])

  const shortlistedCount = shortlist?.eligibilities?.filter((e) => e.shortlisted).length ?? 0
  const allShortlisted = shortlist && shortlist.eligibilities.length > 0 && shortlist.eligibilities.every((e) => e.shortlisted)
  const someShortlisted = shortlistedCount > 0 && !allShortlisted


  const handleBulkToggle = () => {
    if (!shortlist) return
    const projectIds = shortlist.eligibilities.map((e) => e.project.id)
    const newValue = !allShortlisted
    bulkToggleMutation.mutate({ awardId, projectIds, shortlisted: newValue })
  }

  return (
    <Collapsible open={expanded} onOpenChange={setExpanded}>
      <div className="border rounded-lg">
        <CollapsibleTrigger asChild>
          <button className="w-full flex items-center justify-between p-4 hover:bg-muted/50 transition-colors text-left">
            <div className="flex items-center gap-3">
              <Trophy className="h-5 w-5 text-amber-600" />
              <div>
                <h4 className="font-semibold text-sm">{awardName}</h4>
                {criteriaText && (
                  <p className="text-xs text-muted-foreground line-clamp-1 max-w-md">
                    {criteriaText}
                  </p>
                )}
              </div>
            </div>
            <div className="flex items-center gap-3">
              <Badge variant="outline" className={eligibilityMode === 'SEPARATE_POOL'
                ? 'bg-purple-50 text-purple-700 border-purple-200'
                : 'bg-blue-50 text-blue-700 border-blue-200'
              }>
                {eligibilityMode === 'SEPARATE_POOL' ? 'Separate Pool' : 'Main Pool'}
              </Badge>
              {currentJobStatus === 'COMPLETED' && (
                <Badge variant="outline" className="bg-green-50 text-green-700 border-green-200">
                  <CheckCircle2 className="h-3 w-3 mr-1" />
                  Evaluated
                </Badge>
              )}
              {expanded ? <ChevronUp className="h-4 w-4" /> : <ChevronDown className="h-4 w-4" />}
            </div>
          </button>
        </CollapsibleTrigger>

        <CollapsibleContent>
          <div className="border-t p-4 space-y-4">
            {/* Job controls */}
            <div className="flex items-center justify-between">
              <div className="text-sm text-muted-foreground">
                Evaluate PASSED projects against this award&apos;s criteria
              </div>
              <Button
                size="sm"
                onClick={() => runMutation.mutate({ awardId, roundId })}
                disabled={runMutation.isPending || isRunning}
              >
                {isRunning ? (
                  <><Loader2 className="h-4 w-4 mr-2 animate-spin" />Processing...</>
                ) : runMutation.isPending ? (
                  <><Loader2 className="h-4 w-4 mr-2 animate-spin" />Starting...</>
                ) : currentJobStatus === 'COMPLETED' ? (
                  <><Play className="h-4 w-4 mr-2" />Re-evaluate</>
                ) : (
                  <><Play className="h-4 w-4 mr-2" />Run Eligibility</>
                )}
              </Button>
            </div>

            {/* Progress bar */}
            {isRunning && currentJobTotal && currentJobTotal > 0 && (
              <div className="space-y-1">
                <Progress value={jobProgress} className="h-2" />
                <p className="text-xs text-muted-foreground text-right">
                  {currentJobDone ?? 0} / {currentJobTotal} projects
                </p>
              </div>
            )}

            {/* Shortlist table */}
            {expanded && currentJobStatus === 'COMPLETED' && (
              <>
                {isLoadingShortlist ? (
                  <div className="space-y-2">
                    {[1, 2, 3].map((i) => <Skeleton key={i} className="h-12 w-full" />)}
                  </div>
                ) : shortlist && shortlist.eligibilities.length > 0 ? (
                  <div className="space-y-3">
                    <div className="flex items-center justify-between">
                      <p className="text-sm font-medium">
                        {shortlist.total} eligible projects
                        {shortlistedCount > 0 && (
                          <span className="text-muted-foreground ml-1">
                            ({shortlistedCount} shortlisted)
                          </span>
                        )}
                      </p>
                      {shortlistedCount > 0 && (
                        <AlertDialog>
                          <AlertDialogTrigger asChild>
                            <Button size="sm" variant="default">
                              <CheckCircle2 className="h-4 w-4 mr-2" />
                              Confirm Shortlist ({shortlistedCount})
                            </Button>
                          </AlertDialogTrigger>
                          <AlertDialogContent>
                            <AlertDialogHeader>
                              <AlertDialogTitle>Confirm Shortlist</AlertDialogTitle>
                              <AlertDialogDescription asChild>
                                <div className="space-y-2">
                                  <p>
                                    {eligibilityMode === 'SEPARATE_POOL'
                                      ? `This will confirm ${shortlistedCount} projects for the "${awardName}" award track. Projects will be routed to the award's rounds for separate evaluation.`
                                      : `This will confirm ${shortlistedCount} projects as eligible for the "${awardName}" award. Projects remain in the main competition pool.`
                                    }
                                  </p>
                                  {eligibilityMode === 'SEPARATE_POOL' && !hasAwardRounds && (
                                    <div className="flex items-start gap-2 rounded-md border border-amber-200 bg-amber-50 p-3 text-amber-800 dark:border-amber-800 dark:bg-amber-950/30 dark:text-amber-300">
                                      <AlertTriangle className="h-4 w-4 mt-0.5 shrink-0" />
                                      <p className="text-sm">
                                        No award rounds have been created yet. Projects will be confirmed but <strong>not routed</strong> to an evaluation track. Create rounds on the award page first.
                                      </p>
                                    </div>
                                  )}
                                </div>
                              </AlertDialogDescription>
                            </AlertDialogHeader>
                            <AlertDialogFooter>
                              <AlertDialogCancel>Cancel</AlertDialogCancel>
                              <AlertDialogAction
                                onClick={() => confirmMutation.mutate({ awardId })}
                                disabled={confirmMutation.isPending}
                              >
                                {confirmMutation.isPending ? 'Confirming...' : 'Confirm'}
                              </AlertDialogAction>
                            </AlertDialogFooter>
                          </AlertDialogContent>
                        </AlertDialog>
                      )}
                    </div>

                    <div className="mb-3">
                      <div className="relative">
                        <Search className="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
                        <Input
                          placeholder="Search projects..."
                          value={eligibilitySearch}
                          onChange={(e) => setEligibilitySearch(e.target.value)}
                          className="pl-9 h-9 max-w-sm"
                        />
                      </div>
                    </div>

                    <div className="border rounded-md overflow-hidden">
                      <table className="w-full text-sm">
                        <thead className="bg-muted/50">
                          <tr>
                            <th className="px-3 py-2 text-left w-8">#</th>
                            <th className="px-3 py-2 text-left">Project</th>
                            <th className="px-3 py-2 text-left w-24">Score</th>
                            <th className="px-3 py-2 text-left min-w-[300px]">Reasoning</th>
                            <th className="px-3 py-2 text-center w-20">
                              <div className="flex items-center justify-center gap-1">
                                <Checkbox
                                  checked={allShortlisted ? true : someShortlisted ? 'indeterminate' : false}
                                  onCheckedChange={handleBulkToggle}
                                  disabled={bulkToggleMutation.isPending}
                                  aria-label="Select all"
                                />
                                <span className="text-xs">All</span>
                              </div>
                            </th>
                          </tr>
                        </thead>
                        <tbody>
                          {filteredEligibilities.map((e, i) => {
                            const reasoning = (e.aiReasoningJson as Record<string, unknown>)?.reasoning as string | undefined
                            const isTop5 = i < shortlistSize
                            return (
                              <tr key={e.id} className={`border-t ${isTop5 ? 'bg-amber-50/50' : ''}`}>
                                <td className="px-3 py-2 text-muted-foreground font-mono">
                                  {isTop5 ? (
                                    <span className="text-amber-600 font-semibold">{i + 1}</span>
                                  ) : (
                                    i + 1
                                  )}
                                </td>
                                <td className="px-3 py-2">
                                  <div>
                                    <p className={`font-medium ${isTop5 ? 'text-amber-900' : ''}`}>
                                      <a
                                        href={`/admin/projects/${e.project.id}`}
                                        target="_blank"
                                        rel="noopener noreferrer"
                                        className="text-primary hover:underline font-medium"
                                        onClick={(ev) => ev.stopPropagation()}
                                      >
                                        {e.project.title}
                                      </a>
                                    </p>
                                    <p className="text-xs text-muted-foreground">
                                      {[e.project.teamName, e.project.competitionCategory].filter(Boolean).length > 0 || e.project.country ? (
                                        <>
                                          {[e.project.teamName, e.project.competitionCategory].filter(Boolean).join(', ')}
                                          {(e.project.teamName || e.project.competitionCategory) && e.project.country ? ', ' : ''}
                                          {e.project.country && <CountryDisplay country={e.project.country} />}
                                        </>
                                      ) : '—'}
                                    </p>
                                  </div>
                                </td>
                                <td className="px-3 py-2">
                                  <div className="flex items-center gap-2">
                                    <Progress
                                      value={e.qualityScore ?? 0}
                                      className="h-2 w-16"
                                    />
                                    <span className="text-xs font-mono font-medium">
                                      {e.qualityScore ?? 0}
                                    </span>
                                  </div>
                                </td>
                                <td className="px-3 py-2">
                                  {reasoning ? (
                                    <p className="text-xs text-muted-foreground whitespace-pre-wrap leading-relaxed">
                                      {reasoning}
                                    </p>
                                  ) : (
                                    <span className="text-xs text-muted-foreground">—</span>
                                  )}
                                </td>
                                <td className="px-3 py-2 text-center">
                                  <Checkbox
                                    checked={e.shortlisted}
                                    onCheckedChange={() =>
                                      toggleMutation.mutate({ awardId, projectId: e.project.id })
                                    }
                                    disabled={toggleMutation.isPending}
                                  />
                                </td>
                              </tr>
                            )
                          })}
                        </tbody>
                      </table>
                    </div>
                  </div>
                ) : (
                  <p className="text-sm text-muted-foreground text-center py-4">
                    No eligible projects found
                  </p>
                )}
              </>
            )}

            {/* Not yet evaluated */}
            {expanded && !currentJobStatus && (
              <p className="text-sm text-muted-foreground text-center py-4">
                Click &quot;Run Eligibility&quot; to evaluate projects against this award&apos;s criteria
              </p>
            )}

            {/* Failed */}
            {currentJobStatus === 'FAILED' && (
              <p className="text-sm text-red-600 text-center py-2">
                Eligibility evaluation failed. Try again.
              </p>
            )}
          </div>
        </CollapsibleContent>
      </div>
    </Collapsible>
  )
}