'use client'

import { useState, useEffect, useCallback } from 'react'
import Link from 'next/link'
import { useSearchParams, usePathname } from 'next/navigation'
import { trpc } from '@/lib/trpc/client'
import { toast } from 'sonner'
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from '@/components/ui/card'
import { Badge } from '@/components/ui/badge'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Skeleton } from '@/components/ui/skeleton'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuSeparator,
  DropdownMenuTrigger,
} from '@/components/ui/dropdown-menu'
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from '@/components/ui/alert-dialog'
import {
  Plus,
  MoreHorizontal,
  ClipboardList,
  Eye,
  Pencil,
  FileUp,
  Users,
  Search,
  Trash2,
  Loader2,
  Sparkles,
} from 'lucide-react'
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select'
import { Label } from '@/components/ui/label'
import { truncate } from '@/lib/utils'
import { ProjectLogo } from '@/components/shared/project-logo'
import { Pagination } from '@/components/shared/pagination'
import {
  ProjectFiltersBar,
  type ProjectFilters,
} from './project-filters'

const statusColors: Record<
  string,
  'default' | 'success' | 'secondary' | 'destructive' | 'warning'
> = {
  SUBMITTED: 'secondary',
  ELIGIBLE: 'default',
  ASSIGNED: 'default',
  SEMIFINALIST: 'success',
  FINALIST: 'success',
  WINNER: 'success',
  REJECTED: 'destructive',
  WITHDRAWN: 'secondary',
}

function parseFiltersFromParams(
  searchParams: URLSearchParams
): ProjectFilters & { page: number } {
  return {
    search: searchParams.get('q') || '',
    statuses: searchParams.get('status')
      ? searchParams.get('status')!.split(',')
      : [],
    roundId: searchParams.get('round') || '',
    competitionCategory: searchParams.get('category') || '',
    oceanIssue: searchParams.get('issue') || '',
    country: searchParams.get('country') || '',
    wantsMentorship:
      searchParams.get('mentorship') === 'true'
        ? true
        : searchParams.get('mentorship') === 'false'
          ? false
          : undefined,
    hasFiles:
      searchParams.get('hasFiles') === 'true'
        ? true
        : searchParams.get('hasFiles') === 'false'
          ? false
          : undefined,
    hasAssignments:
      searchParams.get('hasAssign') === 'true'
        ? true
        : searchParams.get('hasAssign') === 'false'
          ? false
          : undefined,
    page: parseInt(searchParams.get('page') || '1', 10),
  }
}

function filtersToParams(
  filters: ProjectFilters & { page: number }
): URLSearchParams {
  const params = new URLSearchParams()
  if (filters.search) params.set('q', filters.search)
  if (filters.statuses.length > 0)
    params.set('status', filters.statuses.join(','))
  if (filters.roundId) params.set('round', filters.roundId)
  if (filters.competitionCategory)
    params.set('category', filters.competitionCategory)
  if (filters.oceanIssue) params.set('issue', filters.oceanIssue)
  if (filters.country) params.set('country', filters.country)
  if (filters.wantsMentorship !== undefined)
    params.set('mentorship', String(filters.wantsMentorship))
  if (filters.hasFiles !== undefined)
    params.set('hasFiles', String(filters.hasFiles))
  if (filters.hasAssignments !== undefined)
    params.set('hasAssign', String(filters.hasAssignments))
  if (filters.page > 1) params.set('page', String(filters.page))
  return params
}

const PER_PAGE = 20

export default function ProjectsPage() {

  const pathname = usePathname()
  const searchParams = useSearchParams()

  const parsed = parseFiltersFromParams(searchParams)
  const [filters, setFilters] = useState<ProjectFilters>({
    search: parsed.search,
    statuses: parsed.statuses,
    roundId: parsed.roundId,
    competitionCategory: parsed.competitionCategory,
    oceanIssue: parsed.oceanIssue,
    country: parsed.country,
    wantsMentorship: parsed.wantsMentorship,
    hasFiles: parsed.hasFiles,
    hasAssignments: parsed.hasAssignments,
  })
  const [page, setPage] = useState(parsed.page)
  const [searchInput, setSearchInput] = useState(parsed.search)

  // Debounced search
  useEffect(() => {
    const timer = setTimeout(() => {
      if (searchInput !== filters.search) {
        setFilters((f) => ({ ...f, search: searchInput }))
        setPage(1)
      }
    }, 300)
    return () => clearTimeout(timer)
  }, [searchInput, filters.search])

  // Sync URL
  const syncUrl = useCallback(
    (f: ProjectFilters, p: number) => {
      const params = filtersToParams({ ...f, page: p })
      const qs = params.toString()
      window.history.replaceState(null, '', qs ? `${pathname}?${qs}` : pathname)
    },
    [pathname]
  )

  useEffect(() => {
    syncUrl(filters, page)
  }, [filters, page, syncUrl])

  // Reset page when filters change
  const handleFiltersChange = (newFilters: ProjectFilters) => {
    setFilters(newFilters)
    setPage(1)
  }

  // Build tRPC query input
  const queryInput = {
    search: filters.search || undefined,
    statuses:
      filters.statuses.length > 0
        ? (filters.statuses as Array<
            | 'SUBMITTED'
            | 'ELIGIBLE'
            | 'ASSIGNED'
            | 'SEMIFINALIST'
            | 'FINALIST'
            | 'REJECTED'
          >)
        : undefined,
    roundId: filters.roundId || undefined,
    competitionCategory:
      (filters.competitionCategory as 'STARTUP' | 'BUSINESS_CONCEPT') ||
      undefined,
    oceanIssue: filters.oceanIssue
      ? (filters.oceanIssue as
          | 'POLLUTION_REDUCTION'
          | 'CLIMATE_MITIGATION'
          | 'TECHNOLOGY_INNOVATION'
          | 'SUSTAINABLE_SHIPPING'
          | 'BLUE_CARBON'
          | 'HABITAT_RESTORATION'
          | 'COMMUNITY_CAPACITY'
          | 'SUSTAINABLE_FISHING'
          | 'CONSUMER_AWARENESS'
          | 'OCEAN_ACIDIFICATION'
          | 'OTHER')
      : undefined,
    country: filters.country || undefined,
    wantsMentorship: filters.wantsMentorship,
    hasFiles: filters.hasFiles,
    hasAssignments: filters.hasAssignments,
    page,
    perPage: PER_PAGE,
  }

  const utils = trpc.useUtils()
  const { data, isLoading } = trpc.project.list.useQuery(queryInput)
  const { data: filterOptions } = trpc.project.getFilterOptions.useQuery()

  const [deleteDialogOpen, setDeleteDialogOpen] = useState(false)
  const [projectToDelete, setProjectToDelete] = useState<{ id: string; title: string } | null>(null)
  const [aiTagDialogOpen, setAiTagDialogOpen] = useState(false)
  const [selectedRoundForTagging, setSelectedRoundForTagging] = useState<string>('')

  // Fetch rounds for the AI tagging dialog
  const { data: programs } = trpc.program.list.useQuery()
  const { data: allRounds } = trpc.round.list.useQuery(
    { programId: programs?.[0]?.id ?? '' },
    { enabled: !!programs?.[0]?.id }
  )

  // AI batch tagging mutation
  const batchTagProjects = trpc.tag.batchTagProjects.useMutation({
    onSuccess: (result) => {
      if (result.errors && result.errors.length > 0) {
        // Show first error if there are any
        toast.error(`AI Tagging issue: ${result.errors[0]}`)
      } else if (result.processed === 0 && result.skipped === 0 && result.failed === 0) {
        toast.info('No projects to tag - all projects in this round already have tags')
      } else {
        toast.success(
          `AI Tagging complete: ${result.processed} tagged, ${result.skipped} skipped, ${result.failed} failed`
        )
      }
      setAiTagDialogOpen(false)
      setSelectedRoundForTagging('')
      utils.project.list.invalidate()
    },
    onError: (error) => {
      toast.error(error.message || 'Failed to generate AI tags')
    },
  })

  const deleteProject = trpc.project.delete.useMutation({
    onSuccess: () => {
      toast.success('Project deleted successfully')
      utils.project.list.invalidate()
      setDeleteDialogOpen(false)
      setProjectToDelete(null)
    },
    onError: (error) => {
      toast.error(error.message || 'Failed to delete project')
    },
  })

  const handleDeleteClick = (project: { id: string; title: string }) => {
    setProjectToDelete(project)
    setDeleteDialogOpen(true)
  }

  return (
    <div className="space-y-6">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-semibold tracking-tight">Projects</h1>
          <p className="text-muted-foreground">
            Manage submitted projects across all rounds
          </p>
        </div>
        <div className="flex gap-2">
          <Button variant="outline" onClick={() => setAiTagDialogOpen(true)}>
            <Sparkles className="mr-2 h-4 w-4" />
            AI Tags
          </Button>
          <Button variant="outline" asChild>
            <Link href="/admin/projects/import">
              <FileUp className="mr-2 h-4 w-4" />
              Import
            </Link>
          </Button>
          <Button asChild>
            <Link href="/admin/projects/new">
              <Plus className="mr-2 h-4 w-4" />
              Add Project
            </Link>
          </Button>
        </div>
      </div>

      {/* Search */}
      <div className="relative">
        <Search className="absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-muted-foreground" />
        <Input
          value={searchInput}
          onChange={(e) => setSearchInput(e.target.value)}
          placeholder="Search projects by title, team, or description..."
          className="pl-10"
        />
      </div>

      {/* Filters */}
      <ProjectFiltersBar
        filters={filters}
        filterOptions={filterOptions}
        onChange={handleFiltersChange}
      />

      {/* Content */}
      {isLoading ? (
        <Card>
          <CardContent className="p-6">
            <div className="space-y-4">
              {[...Array(5)].map((_, i) => (
                <div key={i} className="flex items-center justify-between">
                  <div className="space-y-2">
                    <Skeleton className="h-5 w-64" />
                    <Skeleton className="h-4 w-32" />
                  </div>
                  <Skeleton className="h-9 w-9" />
                </div>
              ))}
            </div>
          </CardContent>
        </Card>
      ) : data && data.projects.length === 0 ? (
        <Card>
          <CardContent className="flex flex-col items-center justify-center py-12 text-center">
            <ClipboardList className="h-12 w-12 text-muted-foreground/50" />
            <p className="mt-2 font-medium">No projects found</p>
            <p className="text-sm text-muted-foreground">
              {filters.search ||
              filters.statuses.length > 0 ||
              filters.roundId ||
              filters.competitionCategory ||
              filters.oceanIssue ||
              filters.country
                ? 'Try adjusting your filters'
                : 'Import projects via CSV or create them manually'}
            </p>
            {!filters.search && filters.statuses.length === 0 && (
              <div className="mt-4 flex gap-2">
                <Button asChild>
                  <Link href="/admin/projects/import">
                    <FileUp className="mr-2 h-4 w-4" />
                    Import CSV
                  </Link>
                </Button>
                <Button variant="outline" asChild>
                  <Link href="/admin/projects/new">
                    <Plus className="mr-2 h-4 w-4" />
                    Add Project
                  </Link>
                </Button>
              </div>
            )}
          </CardContent>
        </Card>
      ) : data ? (
        <>
          {/* Desktop table */}
          <Card className="hidden md:block">
            <Table>
              <TableHeader>
                <TableRow>
                  <TableHead>Project</TableHead>
                  <TableHead>Round</TableHead>
                  <TableHead>Files</TableHead>
                  <TableHead>Assignments</TableHead>
                  <TableHead>Status</TableHead>
                  <TableHead className="text-right">Actions</TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {data.projects.map((project) => {
                  const isEliminated = project.status === 'REJECTED'
                  return (
                  <TableRow
                    key={project.id}
                    className={`group relative cursor-pointer hover:bg-muted/50 ${isEliminated ? 'opacity-60 bg-destructive/5' : ''}`}
                  >
                    <TableCell>
                      <Link
                        href={`/admin/projects/${project.id}`}
                        className="flex items-center gap-3 after:absolute after:inset-0 after:content-['']"
                      >
                        <ProjectLogo
                          project={project}
                          size="sm"
                          fallback="initials"
                        />
                        <div>
                          <p className="font-medium hover:text-primary">
                            {truncate(project.title, 40)}
                          </p>
                          <p className="text-sm text-muted-foreground">
                            {project.teamName}
                          </p>
                        </div>
                      </Link>
                    </TableCell>
                    <TableCell>
                      <div>
                        <div className="flex items-center gap-2">
                          <p>{project.round?.name ?? '-'}</p>
                          {project.status === 'REJECTED' && (
                            <Badge variant="destructive" className="text-xs">
                              Eliminated
                            </Badge>
                          )}
                        </div>
                        <p className="text-sm text-muted-foreground">
                          {project.round?.program?.name}
                        </p>
                      </div>
                    </TableCell>
                    <TableCell>{project.files?.length ?? 0}</TableCell>
                    <TableCell>
                      <div className="flex items-center gap-1">
                        <Users className="h-4 w-4 text-muted-foreground" />
                        {project._count.assignments}
                      </div>
                    </TableCell>
                    <TableCell>
                      <Badge
                        variant={statusColors[project.status ?? 'SUBMITTED'] || 'secondary'}
                      >
                        {(project.status ?? 'SUBMITTED').replace('_', ' ')}
                      </Badge>
                    </TableCell>
                    <TableCell className="relative z-10 text-right">
                      <DropdownMenu>
                        <DropdownMenuTrigger asChild>
                          <Button variant="ghost" size="icon">
                            <MoreHorizontal className="h-4 w-4" />
                            <span className="sr-only">Actions</span>
                          </Button>
                        </DropdownMenuTrigger>
                        <DropdownMenuContent align="end">
                          <DropdownMenuItem asChild>
                            <Link href={`/admin/projects/${project.id}`}>
                              <Eye className="mr-2 h-4 w-4" />
                              View Details
                            </Link>
                          </DropdownMenuItem>
                          <DropdownMenuItem asChild>
                            <Link href={`/admin/projects/${project.id}/edit`}>
                              <Pencil className="mr-2 h-4 w-4" />
                              Edit
                            </Link>
                          </DropdownMenuItem>
                          <DropdownMenuSeparator />
                          <DropdownMenuItem
                            className="text-destructive focus:text-destructive"
                            onClick={(e) => {
                              e.stopPropagation()
                              handleDeleteClick({ id: project.id, title: project.title })
                            }}
                          >
                            <Trash2 className="mr-2 h-4 w-4" />
                            Delete
                          </DropdownMenuItem>
                        </DropdownMenuContent>
                      </DropdownMenu>
                    </TableCell>
                  </TableRow>
                )})}
              </TableBody>
            </Table>
          </Card>

          {/* Mobile card view */}
          <div className="space-y-4 md:hidden">
            {data.projects.map((project) => (
              <Link
                key={project.id}
                href={`/admin/projects/${project.id}`}
                className="block"
              >
                <Card className="transition-colors hover:bg-muted/50">
                  <CardHeader className="pb-3">
                    <div className="flex items-start gap-3">
                      <ProjectLogo
                        project={project}
                        size="md"
                        fallback="initials"
                      />
                      <div className="flex-1 min-w-0">
                        <div className="flex items-start justify-between gap-2">
                          <CardTitle className="text-base line-clamp-2">
                            {project.title}
                          </CardTitle>
                          <Badge
                            variant={
                              statusColors[project.status ?? 'SUBMITTED'] || 'secondary'
                            }
                            className="shrink-0"
                          >
                            {(project.status ?? 'SUBMITTED').replace('_', ' ')}
                          </Badge>
                        </div>
                        <CardDescription>{project.teamName}</CardDescription>
                      </div>
                    </div>
                  </CardHeader>
                  <CardContent className="space-y-3">
                    <div className="flex items-center justify-between text-sm">
                      <span className="text-muted-foreground">Round</span>
                      <div className="flex items-center gap-2">
                        <span>{project.round?.name ?? '-'}</span>
                        {project.status === 'REJECTED' && (
                          <Badge variant="destructive" className="text-xs">
                            Eliminated
                          </Badge>
                        )}
                      </div>
                    </div>
                    <div className="flex items-center justify-between text-sm">
                      <span className="text-muted-foreground">Assignments</span>
                      <span>{project._count.assignments} jurors</span>
                    </div>
                  </CardContent>
                </Card>
              </Link>
            ))}
          </div>

          {/* Pagination */}
          <Pagination
            page={data.page}
            totalPages={data.totalPages}
            total={data.total}
            perPage={PER_PAGE}
            onPageChange={setPage}
          />
        </>
      ) : null}

      {/* Delete Confirmation Dialog */}
      <AlertDialog open={deleteDialogOpen} onOpenChange={setDeleteDialogOpen}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>Delete Project</AlertDialogTitle>
            <AlertDialogDescription>
              Are you sure you want to delete &quot;{projectToDelete?.title}&quot;? This will
              permanently remove the project, all its files, assignments, and evaluations.
              This action cannot be undone.
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel>Cancel</AlertDialogCancel>
            <AlertDialogAction
              onClick={() => projectToDelete && deleteProject.mutate({ id: projectToDelete.id })}
              className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
            >
              {deleteProject.isPending ? (
                <Loader2 className="mr-2 h-4 w-4 animate-spin" />
              ) : null}
              Delete
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>

      {/* AI Tagging Dialog */}
      <AlertDialog open={aiTagDialogOpen} onOpenChange={setAiTagDialogOpen}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle className="flex items-center gap-2">
              <Sparkles className="h-5 w-5" />
              Generate AI Tags
            </AlertDialogTitle>
            <AlertDialogDescription>
              Use AI to automatically generate expertise tags for all projects in a round
              that don&apos;t have tags yet. This helps with jury matching and filtering.
            </AlertDialogDescription>
          </AlertDialogHeader>
          <div className="space-y-4 py-4">
            <div className="space-y-2">
              <Label htmlFor="round-select">Select Round</Label>
              <Select
                value={selectedRoundForTagging}
                onValueChange={setSelectedRoundForTagging}
              >
                <SelectTrigger id="round-select">
                  <SelectValue placeholder="Choose a round..." />
                </SelectTrigger>
                <SelectContent>
                  {filterOptions?.rounds?.map((round) => (
                    <SelectItem key={round.id} value={round.id}>
                      {round.name} ({round.program?.name})
                    </SelectItem>
                  ))}
                </SelectContent>
              </Select>
            </div>
            <p className="text-sm text-muted-foreground">
              Only projects without existing tags will be processed. Existing tags are preserved.
            </p>
          </div>
          <AlertDialogFooter>
            <AlertDialogCancel>Cancel</AlertDialogCancel>
            <AlertDialogAction
              onClick={() => {
                if (selectedRoundForTagging) {
                  batchTagProjects.mutate({ roundId: selectedRoundForTagging })
                }
              }}
              disabled={!selectedRoundForTagging || batchTagProjects.isPending}
            >
              {batchTagProjects.isPending ? (
                <Loader2 className="mr-2 h-4 w-4 animate-spin" />
              ) : (
                <Sparkles className="mr-2 h-4 w-4" />
              )}
              {batchTagProjects.isPending ? 'Processing...' : 'Generate Tags'}
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </div>
  )
}