import { useMemo, useState } from 'react';
import { useNavigate } from 'react-router-dom';
import { Briefcase, Filter, Grid3X3, List, Plus } from 'lucide-react';
import { MainLayout } from '@/components/layout/MainLayout.tsx';
import PageHeader from '@/components/layout/PageHeader.tsx';
import OrganizationCard from '@/components/organization/OrganizationCard.tsx';
import Badge from '@/components/ui/Badge.tsx';
import Button from '@/components/ui/Button.tsx';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/Card.tsx';
import { Container, Flex, Grid, Stack } from '@/components/ui/layout';
import SearchInput from '@/components/ui/SearchInput.tsx';
import Select from '@/components/ui/Select.tsx';
import Spinner from '@/components/ui/Spinner.tsx';
import { useOrganizations } from '@/hooks/api/useOrganizationsAPI.ts';
import { useTranslation } from '@/hooks/useI18n.tsx';
import { useNavigation } from '@/hooks/useNavigation.tsx';
import { getTranslatedSectorName } from '@/lib/sector-mapper.ts';
import { getOrganizationSubtypeLabel } from '@/schemas/organizationSubtype.ts';
import type { Organization } from '@/types.ts';

const OrganizationsListPage = () => {
  const { t } = useTranslation();
  const navigate = useNavigate();
  const { handleBackNavigation, handleFooterNavigate } = useNavigation();

  const { data: organizations, isLoading, error } = useOrganizations();

  // Filter and search state
  const [searchQuery, setSearchQuery] = useState('');
  const [selectedSector, setSelectedSector] = useState<string>('all');
  const [selectedSubtype, setSelectedSubtype] = useState<string>('all');
  const [sortBy, setSortBy] = useState<string>('name');
  const [viewMode, setViewMode] = useState<'grid' | 'list'>('grid');
  const [showVerifiedOnly, setShowVerifiedOnly] = useState(false);

  // Process organizations data
  const processedOrganizations = useMemo(() => {
    if (!organizations) return [];

    const filtered = organizations.filter((org: Organization) => {
      // Search filter
      const matchesSearch =
        !searchQuery ||
        org.Name?.toLowerCase().includes(searchQuery.toLowerCase()) ||
        org.Description?.toLowerCase().includes(searchQuery.toLowerCase()) ||
        org.Address?.toLowerCase().includes(searchQuery.toLowerCase());

      // Sector filter
      const matchesSector = selectedSector === 'all' || org.Sector === selectedSector;

      // Subtype filter
      const matchesSubtype = selectedSubtype === 'all' || org.Subtype === selectedSubtype;

      // Verified filter
      const matchesVerified = !showVerifiedOnly || org.Verified;

      return matchesSearch && matchesSector && matchesSubtype && matchesVerified;
    });

    // Sort
    filtered.sort((a: Organization, b: Organization) => {
      switch (sortBy) {
        case 'name':
          return a.Name?.localeCompare(b.Name || '') || 0;
        case 'sector':
          return (a.Sector || '').localeCompare(b.Sector || '');
        case 'verified':
          return (b.Verified ? 1 : 0) - (a.Verified ? 1 : 0);
        case 'activity':
          // Sort by number of resource flows + matches
          const aActivity = (a.ResourceFlows?.length || 0) + (a.Matches?.length || 0);
          const bActivity = (b.ResourceFlows?.length || 0) + (b.Matches?.length || 0);
          return bActivity - aActivity;
        default:
          return 0;
      }
    });

    return filtered;
  }, [organizations, searchQuery, selectedSector, selectedSubtype, sortBy, showVerifiedOnly]);

  // Get unique sectors and subtypes for filters
  const filterOptions = useMemo(() => {
    if (!organizations) return { sectors: [], subtypes: [] };

    const sectors = Array.from(
      new Set(organizations.map((org: Organization) => org.Sector).filter(Boolean))
    );
    const subtypes = Array.from(
      new Set(organizations.map((org: Organization) => org.Subtype).filter(Boolean))
    );

    return { sectors, subtypes };
  }, [organizations]);

  // Sector options for dropdown
  const sectorOptions = [
    { value: 'all', label: t('organizationsList.allSectors') },
    ...filterOptions.sectors.map((sector) => ({
      value: sector,
      label: getTranslatedSectorName(sector),
    })),
  ];

  // Subtype options for dropdown
  const subtypeOptions = [
    { value: 'all', label: t('organizationsList.allSubtypes') },
    ...filterOptions.subtypes.map((subtype) => ({
      value: subtype,
      label: getOrganizationSubtypeLabel(subtype),
    })),
  ];

  // Sort options
  const sortOptions = [
    { value: 'name', label: t('organizationsList.sortByName') },
    { value: 'sector', label: t('organizationsList.sortBySector') },
    { value: 'verified', label: t('organizationsList.sortByVerified') },
    { value: 'activity', label: t('organizationsList.sortByActivity') },
  ];

  const handleCreateOrganization = () => {
    navigate('/organizations/new');
  };

  const handleOrganizationClick = (organization: Organization) => {
    navigate(`/organization/${organization.ID}`);
  };

  const clearFilters = () => {
    setSearchQuery('');
    setSelectedSector('all');
    setSelectedSubtype('all');
    setShowVerifiedOnly(false);
    setSortBy('name');
  };

  const activeFiltersCount = [
    searchQuery,
    selectedSector !== 'all',
    selectedSubtype !== 'all',
    showVerifiedOnly,
  ].filter(Boolean).length;

  if (isLoading) {
    return (
      <MainLayout onNavigate={handleFooterNavigate} className="bg-muted/30">
        <Container size="2xl" className="py-8 sm:py-12">
          <div className="flex items-center justify-center min-h-96">
            <div className="text-center">
              <Spinner className="h-8 w-8 mx-auto mb-4" />
              <p className="text-muted-foreground">{t('organizationsList.loading')}</p>
            </div>
          </div>
        </Container>
      </MainLayout>
    );
  }

  if (error) {
    return (
      <MainLayout onNavigate={handleFooterNavigate} className="bg-muted/30">
        <Container size="2xl" className="py-8 sm:py-12">
          <PageHeader
            title={t('organizationsList.errorTitle')}
            subtitle={t('organizationsList.errorSubtitle')}
            onBack={handleBackNavigation}
          />
          <Card>
            <CardContent className="py-12">
              <div className="text-center">
                <p className="text-destructive mb-4">{error.message}</p>
                <Button onClick={() => window.location.reload()}>{t('common.retry')}</Button>
              </div>
            </CardContent>
          </Card>
        </Container>
      </MainLayout>
    );
  }

  return (
    <MainLayout onNavigate={handleFooterNavigate} className="bg-muted/30">
      <Container size="2xl" className="py-8 sm:py-12">
        <PageHeader
          title={t('organizationsList.title')}
          subtitle={t('organizationsList.subtitle')}
          onBack={handleBackNavigation}
        />

        <Stack spacing="2xl">
          {/* Header Actions */}
          <Flex align="center" justify="between" className="flex-wrap gap-4">
            <div className="flex items-center gap-4">
              <Button onClick={handleCreateOrganization}>
                <Plus className="h-4 mr-2 text-current w-4" />
                {t('organizationsList.createOrganization')}
              </Button>

              {activeFiltersCount > 0 && (
                <Button variant="outline" onClick={clearFilters}>
                  {t('organizationsList.clearFilters')} ({activeFiltersCount})
                </Button>
              )}
            </div>

            <Flex gap="sm">
              <Button
                variant={viewMode === 'grid' ? 'default' : 'outline'}
                size="sm"
                onClick={() => setViewMode('grid')}
              >
                <Grid3X3 className="h-4 text-current w-4" />
              </Button>
              <Button
                variant={viewMode === 'list' ? 'default' : 'outline'}
                size="sm"
                onClick={() => setViewMode('list')}
              >
                <List className="h-4 text-current w-4" />
              </Button>
            </Flex>
          </Flex>

          {/* Search and Filters */}
          <Card>
            <CardHeader>
              <CardTitle className="flex items-center gap-2">
                <Filter className="h-4 h-5 text-current w-4 w-5" />
                {t('organizationsList.searchAndFilters')}
              </CardTitle>
            </CardHeader>
            <CardContent>
              <Grid cols={{ md: 2, lg: 4 }} gap="md">
                <div>
                  <label className="block text-sm font-medium mb-2">
                    {t('organizationsList.search')}
                  </label>
                  <SearchInput
                    value={searchQuery}
                    onChange={setSearchQuery}
                    placeholder={t('organizationsList.searchPlaceholder')}
                  />
                </div>

                <div>
                  <label className="block text-sm font-medium mb-2">
                    {t('organizationsList.sector')}
                  </label>
                  <Select
                    value={selectedSector}
                    onValueChange={setSelectedSector}
                    options={sectorOptions}
                  />
                </div>

                <div>
                  <label className="block text-sm font-medium mb-2">
                    {t('organizationsList.subtype')}
                  </label>
                  <Select
                    value={selectedSubtype}
                    onValueChange={setSelectedSubtype}
                    options={subtypeOptions}
                  />
                </div>

                <div>
                  <label className="block text-sm font-medium mb-2">
                    {t('organizationsList.sortBy')}
                  </label>
                  <Select value={sortBy} onValueChange={setSortBy} options={sortOptions} />
                </div>
              </Grid>

              {/* Additional filters */}
              <div className="flex items-center gap-4 mt-4">
                <label className="flex items-center gap-2">
                  <input
                    type="checkbox"
                    checked={showVerifiedOnly}
                    onChange={(e) => setShowVerifiedOnly(e.target.checked)}
                    className="rounded"
                  />
                  <span className="text-sm">{t('organizationsList.verifiedOnly')}</span>
                </label>
              </div>
            </CardContent>
          </Card>

          {/* Results Summary */}
          <div className="flex items-center justify-between">
            <p className="text-muted-foreground">
              {t('organizationsList.showingResults', {
                shown: processedOrganizations.length,
                total: organizations?.length || 0,
              })}
            </p>
            {activeFiltersCount > 0 && (
              <Badge variant="secondary">
                {activeFiltersCount} {t('organizationsList.filtersActive')}
              </Badge>
            )}
          </div>

          {/* Organizations Grid/List */}
          {processedOrganizations.length > 0 ? (
            <Grid cols={viewMode === 'grid' ? { sm: 1, md: 2, lg: 3 } : { cols: 1 }} gap="md">
              {processedOrganizations.map((organization: Organization) => (
                <OrganizationCard
                  key={organization.ID}
                  organization={organization}
                  showDetails={viewMode === 'grid'}
                  onClick={handleOrganizationClick}
                />
              ))}
            </Grid>
          ) : (
            <Card>
              <CardContent className="py-12">
                <div className="text-center">
                  <Briefcase className="h-12 h-4 mb-4 mx-auto text-current text-muted-foreground w-12 w-4" />
                  <h3 className="text-lg font-semibold mb-2">
                    {t('organizationsList.noOrganizations')}
                  </h3>
                  <p className="text-muted-foreground mb-4">
                    {searchQuery ||
                    selectedSector !== 'all' ||
                    selectedSubtype !== 'all' ||
                    showVerifiedOnly
                      ? t('organizationsList.noOrganizationsMatchFilters')
                      : t('organizationsList.noOrganizationsYet')}
                  </p>
                  {(searchQuery ||
                    selectedSector !== 'all' ||
                    selectedSubtype !== 'all' ||
                    showVerifiedOnly) && (
                    <Button onClick={clearFilters}>{t('organizationsList.clearFilters')}</Button>
                  )}
                  {!searchQuery &&
                    selectedSector === 'all' &&
                    selectedSubtype === 'all' &&
                    !showVerifiedOnly && (
                      <Button onClick={handleCreateOrganization}>
                        <Plus className="h-4 mr-2 text-current w-4" />
                        {t('organizationsList.createFirstOrganization')}
                      </Button>
                    )}
                </div>
              </CardContent>
            </Card>
          )}
        </Stack>
      </Container>
    </MainLayout>
  );
};

export default OrganizationsListPage;