import {
  ActiveProposalsSection,
  ImpactMetricsSection,
  MyOrganizationsSection,
  PlatformHealthSection,
  PlatformOverviewSection,
  QuickActionsSection,
  RecentActivitySection,
  YourContributionSection,
} from '@/components/dashboard';
import { MainLayout } from '@/components/layout/MainLayout.tsx';
import PageHeader from '@/components/layout/PageHeader.tsx';
import DateRangePicker, { type DateRange } from '@/components/ui/DateRangePicker.tsx';
import { Container, Flex, Grid, Stack } from '@/components/ui/layout';
import { useAuth } from '@/contexts/AuthContext.tsx';
import {
  useDashboardStatistics,
  useImpactMetrics,
  useMatchingStatistics,
  usePlatformStatistics,
} from '@/hooks/api/useAnalyticsAPI.ts';
import { useUserOrganizations } from '@/hooks/api/useOrganizationsAPI.ts';
import { useProposals } from '@/hooks/api/useProposalsAPI.ts';
import { useTranslation } from '@/hooks/useI18n.tsx';
import { useNavigation } from '@/hooks/useNavigation.tsx';
import { useOrganizations } from '@/hooks/useOrganizations.ts';
import type { Proposal } from '@/types.ts';
import { useMemo, useState } from 'react';
import { useNavigate } from 'react-router-dom';

type ActivityFilter = 'all' | 'match' | 'proposal' | 'organization';

const DashboardPage = () => {
  const { t } = useTranslation();
  const navigate = useNavigate();
  const { handleBackNavigation, handleFooterNavigate } = useNavigation();
  const { user } = useAuth();
  const [activityFilter, setActivityFilter] = useState<ActivityFilter>('all');
  const [dateRange, setDateRange] = useState<DateRange>({
    startDate: null,
    endDate: null,
    preset: '30d',
  });

  // Analytics data - Zod validates these, so if data exists, it's guaranteed to be valid
  const {
    data: dashboardStats,
    isLoading: isLoadingDashboard,
    error: dashboardError,
  } = useDashboardStatistics();
  const {
    data: platformStats,
    isLoading: isLoadingPlatform,
    error: platformError,
  } = usePlatformStatistics();
  const {
    data: matchingStats,
    isLoading: isLoadingMatching,
    error: matchingError,
  } = useMatchingStatistics();
  const {
    data: impactMetrics,
    isLoading: isLoadingImpact,
    error: impactError,
  } = useImpactMetrics();

  // User-specific data
  const { data: proposalsData } = useProposals();
  const { organizations } = useOrganizations();
  const { data: userOrganizations } = useUserOrganizations();

  // Proposals data - validated by API
  const proposals: Proposal[] = proposalsData?.proposals ?? [];
  const pendingProposals = proposals.filter((p: Proposal) => p.status === 'pending');

  // Calculate derived statistics - data is validated by Zod, so we can trust it
  const stats = useMemo(() => {
    // If data exists, it's validated by Zod - use it directly
    const dashboard = dashboardStats;
    const platform = platformStats;
    const matching = matchingStats;
    const impact = impactMetrics;

    // User-specific metrics
    const myOrganizationsCount = Array.isArray(userOrganizations) ? userOrganizations.length : 0;
    const myProposalsCount = proposals.length;
    const myPendingProposalsCount = pendingProposals.length;

    return {
      // Platform-wide metrics - prefer dashboard stats, fallback to platform stats
      totalOrganizations: dashboard?.total_organizations ?? platform?.total_organizations ?? 0,
      totalSites: dashboard?.total_sites ?? platform?.total_sites ?? 0,
      totalResourceFlows: dashboard?.total_resource_flows ?? platform?.total_resource_flows ?? 0,
      totalMatches: dashboard?.total_matches ?? platform?.total_matches ?? 0,
      activeProposals: pendingProposals.length,
      recentActivity: dashboard?.recent_activity ?? [],

      // User-specific metrics
      myOrganizations: myOrganizationsCount,
      myProposals: myProposalsCount,
      myPendingProposals: myPendingProposalsCount,

      // Matching statistics - optional fields use nullish coalescing
      matchSuccessRate: matching?.match_success_rate ?? 0,
      avgMatchTime: matching?.avg_match_time_days ?? 0,
      topResourceTypes: matching?.top_resource_types ?? [],

      // Impact metrics
      totalCo2Saved: impact?.total_co2_saved_tonnes ?? impact?.total_co2_savings_tonnes ?? 0,
      totalEconomicValue: impact?.total_economic_value ?? impact?.total_economic_value_eur ?? 0,
      activeMatches: impact?.active_matches_count ?? 0,
    };
  }, [
    dashboardStats,
    platformStats,
    matchingStats,
    impactMetrics,
    proposalsData,
    userOrganizations,
    pendingProposals,
  ]);

  // Filter activities based on selected filter
  // Activity type is validated by Zod, so it's guaranteed to be a string
  const filteredActivities = useMemo(() => {
    if (activityFilter === 'all') {
      return stats.recentActivity;
    }
    return stats.recentActivity.filter((activity) => {
      const activityType = activity.type.toLowerCase();
      switch (activityFilter) {
        case 'match':
          return activityType.includes('match');
        case 'proposal':
          return activityType.includes('proposal');
        case 'organization':
          return activityType.includes('organization') || activityType.includes('org');
        default:
          return true;
      }
    });
  }, [stats.recentActivity, activityFilter]);

  // Number formatting handled by shared utilities inside components

  const isLoading = isLoadingDashboard || isLoadingPlatform || isLoadingMatching || isLoadingImpact;
  const hasError = dashboardError || platformError || matchingError || impactError;

  return (
    <MainLayout onNavigate={handleFooterNavigate} className="bg-muted/30">
      <Container size="2xl" className="py-8 sm:py-12">
        <Flex align="center" justify="between" className="mb-6">
          <PageHeader
            title={t('dashboard.title')}
            subtitle={t('dashboard.subtitle', { name: user?.name || user?.email || 'User' })}
            onBack={handleBackNavigation}
          />
          <DateRangePicker value={dateRange} onChange={setDateRange} />
        </Flex>

        <Stack spacing="2xl">
          <YourContributionSection
            myOrganizations={stats.myOrganizations}
            myProposals={stats.myProposals}
            myPendingProposals={stats.myPendingProposals}
            t={t}
          />

          <PlatformOverviewSection
            totalOrganizations={stats.totalOrganizations}
            totalSites={stats.totalSites}
            totalResourceFlows={stats.totalResourceFlows}
            totalMatches={stats.totalMatches}
            t={t}
          />

          <ImpactMetricsSection
            totalCo2Saved={stats.totalCo2Saved}
            totalEconomicValue={stats.totalEconomicValue}
            activeMatches={stats.activeMatches}
            t={t}
          />

          <QuickActionsSection onNavigate={(path) => navigate(path)} t={t} />

          {/* Recent Activity & Proposals */}
          <Grid cols={{ md: 2 }} gap="lg">
            <RecentActivitySection
              filteredActivities={filteredActivities}
              activityFilter={activityFilter}
              setActivityFilter={setActivityFilter}
              isLoading={isLoading}
              t={t}
            />

            <ActiveProposalsSection
              pendingProposals={pendingProposals}
              onNavigate={(path) => navigate(path)}
              t={t}
            />
          </Grid>

          <MyOrganizationsSection
            organizations={organizations}
            onNavigate={(path) => navigate(path)}
            t={t}
          />

          <PlatformHealthSection
            matchSuccessRate={stats.matchSuccessRate}
            avgMatchTime={stats.avgMatchTime}
            topResourceTypes={stats.topResourceTypes}
            t={t}
          />
        </Stack>
      </Container>
    </MainLayout>
  );
};

export default DashboardPage;