'use client'

import { 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 { Badge } from '@/components/ui/badge'
import { Button } from '@/components/ui/button'
import { Progress } from '@/components/ui/progress'
import { Skeleton } from '@/components/ui/skeleton'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select'
import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs'
import {
  FileSpreadsheet,
  Download,
  BarChart3,
  Users,
  ClipboardList,
  CheckCircle2,
  PieChart,
  TrendingUp,
} from 'lucide-react'
import { formatDateOnly } from '@/lib/utils'
import {
  ScoreDistributionChart,
  EvaluationTimelineChart,
  StatusBreakdownChart,
  JurorWorkloadChart,
  ProjectRankingsChart,
  CriteriaScoresChart,
  GeographicDistribution,
} from '@/components/charts'

function ReportsOverview() {
  const { data: programs, isLoading } = trpc.program.list.useQuery({ includeRounds: true })

  // Flatten rounds from all programs
  const rounds = programs?.flatMap(p => p.rounds.map(r => ({ ...r, programId: p.id, programName: p.name }))) || []

  if (isLoading) {
    return (
      <div className="space-y-6">
        <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-4">
          {[...Array(4)].map((_, i) => (
            <Card key={i}>
              <CardHeader className="space-y-0 pb-2">
                <Skeleton className="h-4 w-20" />
              </CardHeader>
              <CardContent>
                <Skeleton className="h-8 w-16" />
                <Skeleton className="mt-2 h-3 w-24" />
              </CardContent>
            </Card>
          ))}
        </div>
      </div>
    )
  }

  if (!rounds || rounds.length === 0) {
    return (
      <Card>
        <CardContent className="flex flex-col items-center justify-center py-12 text-center">
          <FileSpreadsheet className="h-12 w-12 text-muted-foreground/50" />
          <p className="mt-2 font-medium">No data to report</p>
          <p className="text-sm text-muted-foreground">
            Create rounds and assign jury members to generate reports
          </p>
        </CardContent>
      </Card>
    )
  }

  // Calculate totals
  const totalProjects = programs?.reduce((acc, p) => acc + (p._count?.rounds || 0), 0) || 0
  const totalPrograms = programs?.length || 0
  const activeRounds = rounds.filter((r) => r.status === 'ACTIVE').length

  return (
    <div className="space-y-6">
      {/* Quick Stats */}
      <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-4">
        <Card>
          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
            <CardTitle className="text-sm font-medium">Total Rounds</CardTitle>
            <BarChart3 className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">{rounds.length}</div>
            <p className="text-xs text-muted-foreground">
              {activeRounds} active
            </p>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
            <CardTitle className="text-sm font-medium">Total Projects</CardTitle>
            <ClipboardList className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">{totalProjects}</div>
            <p className="text-xs text-muted-foreground">Across all rounds</p>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
            <CardTitle className="text-sm font-medium">Active Rounds</CardTitle>
            <Users className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">{activeRounds}</div>
            <p className="text-xs text-muted-foreground">Currently active</p>
          </CardContent>
        </Card>

        <Card>
          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
            <CardTitle className="text-sm font-medium">Programs</CardTitle>
            <CheckCircle2 className="h-4 w-4 text-muted-foreground" />
          </CardHeader>
          <CardContent>
            <div className="text-2xl font-bold">{totalPrograms}</div>
            <p className="text-xs text-muted-foreground">Total programs</p>
          </CardContent>
        </Card>
      </div>

      {/* Rounds Table */}
      <Card>
        <CardHeader>
          <CardTitle>Round Reports</CardTitle>
          <CardDescription>
            View progress and export data for each round
          </CardDescription>
        </CardHeader>
        <CardContent>
          <Table>
            <TableHeader>
              <TableRow>
                <TableHead>Round</TableHead>
                <TableHead>Program</TableHead>
                <TableHead>Projects</TableHead>
                <TableHead>Status</TableHead>
                <TableHead className="text-right">Export</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {rounds.map((round) => (
                <TableRow key={round.id}>
                  <TableCell>
                    <div>
                      <p className="font-medium">{round.name}</p>
                      {round.votingEndAt && (
                        <p className="text-sm text-muted-foreground">
                          Ends: {formatDateOnly(round.votingEndAt)}
                        </p>
                      )}
                    </div>
                  </TableCell>
                  <TableCell>{round.programName}</TableCell>
                  <TableCell>-</TableCell>
                  <TableCell>
                    <Badge
                      variant={
                        round.status === 'ACTIVE'
                          ? 'default'
                          : round.status === 'CLOSED'
                            ? 'secondary'
                            : 'outline'
                      }
                    >
                      {round.status}
                    </Badge>
                  </TableCell>
                  <TableCell className="text-right">
                    <div className="flex justify-end gap-2">
                      <Button variant="outline" size="sm" asChild>
                        <a
                          href={`/api/export/evaluations?roundId=${round.id}`}
                          target="_blank"
                          rel="noopener noreferrer"
                        >
                          <Download className="mr-2 h-4 w-4" />
                          Evaluations
                        </a>
                      </Button>
                      <Button variant="outline" size="sm" asChild>
                        <a
                          href={`/api/export/results?roundId=${round.id}`}
                          target="_blank"
                          rel="noopener noreferrer"
                        >
                          <Download className="mr-2 h-4 w-4" />
                          Results
                        </a>
                      </Button>
                    </div>
                  </TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        </CardContent>
      </Card>
    </div>
  )
}

function RoundAnalytics() {
  const [selectedRoundId, setSelectedRoundId] = useState<string | null>(null)

  const { data: programs, isLoading: roundsLoading } = trpc.program.list.useQuery({ includeRounds: true })

  // Flatten rounds from all programs with program name
  const rounds = programs?.flatMap(p => p.rounds.map(r => ({ ...r, programName: p.name }))) || []

  // Set default selected round
  if (rounds.length && !selectedRoundId) {
    setSelectedRoundId(rounds[0].id)
  }

  const { data: scoreDistribution, isLoading: scoreLoading } =
    trpc.analytics.getScoreDistribution.useQuery(
      { roundId: selectedRoundId! },
      { enabled: !!selectedRoundId }
    )

  const { data: timeline, isLoading: timelineLoading } =
    trpc.analytics.getEvaluationTimeline.useQuery(
      { roundId: selectedRoundId! },
      { enabled: !!selectedRoundId }
    )

  const { data: statusBreakdown, isLoading: statusLoading } =
    trpc.analytics.getStatusBreakdown.useQuery(
      { roundId: selectedRoundId! },
      { enabled: !!selectedRoundId }
    )

  const { data: jurorWorkload, isLoading: workloadLoading } =
    trpc.analytics.getJurorWorkload.useQuery(
      { roundId: selectedRoundId! },
      { enabled: !!selectedRoundId }
    )

  const { data: projectRankings, isLoading: rankingsLoading } =
    trpc.analytics.getProjectRankings.useQuery(
      { roundId: selectedRoundId!, limit: 15 },
      { enabled: !!selectedRoundId }
    )

  const { data: criteriaScores, isLoading: criteriaLoading } =
    trpc.analytics.getCriteriaScores.useQuery(
      { roundId: selectedRoundId! },
      { enabled: !!selectedRoundId }
    )

  const selectedRound = rounds.find((r) => r.id === selectedRoundId)
  const { data: geoData, isLoading: geoLoading } =
    trpc.analytics.getGeographicDistribution.useQuery(
      { programId: selectedRound?.programId || '', roundId: selectedRoundId! },
      { enabled: !!selectedRoundId && !!selectedRound?.programId }
    )

  if (roundsLoading) {
    return (
      <div className="space-y-4">
        <Skeleton className="h-10 w-64" />
        <div className="grid gap-6 lg:grid-cols-2">
          <Skeleton className="h-[350px]" />
          <Skeleton className="h-[350px]" />
        </div>
      </div>
    )
  }

  if (!rounds?.length) {
    return (
      <Card>
        <CardContent className="flex flex-col items-center justify-center py-12 text-center">
          <BarChart3 className="h-12 w-12 text-muted-foreground/50" />
          <p className="mt-2 font-medium">No rounds available</p>
          <p className="text-sm text-muted-foreground">
            Create a round to view analytics
          </p>
        </CardContent>
      </Card>
    )
  }

  return (
    <div className="space-y-6">
      {/* Round Selector */}
      <div className="flex items-center gap-4">
        <label className="text-sm font-medium">Select Round:</label>
        <Select value={selectedRoundId || ''} onValueChange={setSelectedRoundId}>
          <SelectTrigger className="w-[300px]">
            <SelectValue placeholder="Select a round" />
          </SelectTrigger>
          <SelectContent>
            {rounds.map((round) => (
              <SelectItem key={round.id} value={round.id}>
                {round.programName} - {round.name}
              </SelectItem>
            ))}
          </SelectContent>
        </Select>
      </div>

      {selectedRoundId && (
        <div className="space-y-6">
          {/* Row 1: Score Distribution & Status Breakdown */}
          <div className="grid gap-6 lg:grid-cols-2">
            {scoreLoading ? (
              <Skeleton className="h-[350px]" />
            ) : scoreDistribution ? (
              <ScoreDistributionChart
                data={scoreDistribution.distribution}
                averageScore={scoreDistribution.averageScore}
                totalScores={scoreDistribution.totalScores}
              />
            ) : null}

            {statusLoading ? (
              <Skeleton className="h-[350px]" />
            ) : statusBreakdown ? (
              <StatusBreakdownChart data={statusBreakdown} />
            ) : null}
          </div>

          {/* Row 2: Evaluation Timeline */}
          {timelineLoading ? (
            <Skeleton className="h-[350px]" />
          ) : timeline?.length ? (
            <EvaluationTimelineChart data={timeline} />
          ) : (
            <Card>
              <CardContent className="flex items-center justify-center py-12">
                <p className="text-muted-foreground">
                  No evaluation data available yet
                </p>
              </CardContent>
            </Card>
          )}

          {/* Row 3: Criteria Scores */}
          {criteriaLoading ? (
            <Skeleton className="h-[350px]" />
          ) : criteriaScores?.length ? (
            <CriteriaScoresChart data={criteriaScores} />
          ) : null}

          {/* Row 4: Juror Workload */}
          {workloadLoading ? (
            <Skeleton className="h-[450px]" />
          ) : jurorWorkload?.length ? (
            <JurorWorkloadChart data={jurorWorkload} />
          ) : (
            <Card>
              <CardContent className="flex items-center justify-center py-12">
                <p className="text-muted-foreground">
                  No juror assignments yet
                </p>
              </CardContent>
            </Card>
          )}

          {/* Row 5: Project Rankings */}
          {rankingsLoading ? (
            <Skeleton className="h-[550px]" />
          ) : projectRankings?.length ? (
            <ProjectRankingsChart data={projectRankings} limit={15} />
          ) : (
            <Card>
              <CardContent className="flex items-center justify-center py-12">
                <p className="text-muted-foreground">
                  No project scores available yet
                </p>
              </CardContent>
            </Card>
          )}

          {/* Row 6: Geographic Distribution */}
          {geoLoading ? (
            <Skeleton className="h-[500px]" />
          ) : geoData?.length ? (
            <GeographicDistribution data={geoData} />
          ) : null}
        </div>
      )}
    </div>
  )
}

export default function ReportsPage() {
  return (
    <div className="space-y-6">
      {/* Header */}
      <div>
        <h1 className="text-2xl font-semibold tracking-tight">Reports</h1>
        <p className="text-muted-foreground">
          View progress, analytics, and export evaluation data
        </p>
      </div>

      {/* Tabs */}
      <Tabs defaultValue="overview" className="space-y-6">
        <TabsList>
          <TabsTrigger value="overview" className="gap-2">
            <FileSpreadsheet className="h-4 w-4" />
            Overview
          </TabsTrigger>
          <TabsTrigger value="analytics" className="gap-2">
            <TrendingUp className="h-4 w-4" />
            Analytics
          </TabsTrigger>
        </TabsList>

        <TabsContent value="overview">
          <ReportsOverview />
        </TabsContent>

        <TabsContent value="analytics">
          <RoundAnalytics />
        </TabsContent>
      </Tabs>
    </div>
  )
}
