import React from 'react';
import { createClient } from '@/lib/supabase/server';
import { redirect } from 'next/navigation';
import MetricsDashboard from '@/components/MetricsDashboard';
import { resolveActiveTenant, restGet } from '@/lib/tenant-context';
import {
  AdDailyRow,
  CrmLeadRow,
  DealWonRow,
  KpiWeeklyRow,
  buildChannelSeries,
  buildComparisons,
  mergeDealsIntoWeekly,
  resolveWeeklyRows,
  resolveWonCohort,
  sumDaily,
  sumWeekly,
} from '@/lib/metrics';
import { isAgencyRole, serviceHeaders, supabaseUrl, userRole } from '@/lib/agency';

export const dynamic = 'force-dynamic';

/** Enough history for YoY on ad-level Meta rows (can be dense). */
const AD_DAILY_LOOKBACK_DAYS = 420;
const AD_DAILY_PAGE = 1000;

async function fetchAdDaily(
  tenantId: string | null,
  useServiceRole: boolean
): Promise<AdDailyRow[]> {
  const since = new Date();
  since.setUTCDate(since.getUTCDate() - AD_DAILY_LOOKBACK_DAYS);
  const sinceStr = since.toISOString().slice(0, 10);
  const out: AdDailyRow[] = [];

  if (useServiceRole) {
    const headers = serviceHeaders();
    const base = supabaseUrl();
    if (!headers || !base) return [];
    const tidFilter = tenantId
      ? `&tenant_id=eq.${encodeURIComponent(tenantId)}`
      : '';
    for (let offset = 0; offset < 200000; offset += AD_DAILY_PAGE) {
      const r = await fetch(
        `${base}/rest/v1/ad_daily?select=*&date=gte.${sinceStr}${tidFilter}&order=date.desc&limit=${AD_DAILY_PAGE}&offset=${offset}`,
        { headers, cache: 'no-store' }
      );
      if (!r.ok) break;
      const chunk = (await r.json()) as AdDailyRow[];
      out.push(...chunk);
      if (chunk.length < AD_DAILY_PAGE) break;
    }
    return out;
  }

  const supabase = await createClient();
  for (let offset = 0; offset < 200000; offset += AD_DAILY_PAGE) {
    const { data, error } = await supabase
      .from('ad_daily')
      .select('*')
      .gte('date', sinceStr)
      .order('date', { ascending: false })
      .range(offset, offset + AD_DAILY_PAGE - 1);
    if (error) break;
    const chunk = (data as AdDailyRow[]) || [];
    out.push(...chunk);
    if (chunk.length < AD_DAILY_PAGE) break;
  }
  return out;
}

/** Paginate CRM leads (source + created_at + status) for attribution + cohort. */
async function fetchCrmLeads(
  tenantId: string | null,
  useServiceRole: boolean
): Promise<CrmLeadRow[]> {
  const select = 'source,created_at,status,tenant_id,updated_at,status_changed_at';
  const selectFallback = 'source,created_at,status,tenant_id';
  const pageSize = 1000;
  const out: CrmLeadRow[] = [];

  if (useServiceRole) {
    const headers = serviceHeaders();
    const base = supabaseUrl();
    if (!headers || !base) return [];
    const tidFilter = tenantId
      ? `&tenant_id=eq.${encodeURIComponent(tenantId)}`
      : '';
    let useSelect = select;
    for (let offset = 0; offset < 50000; offset += pageSize) {
      const r = await fetch(
        `${base}/rest/v1/leads?select=${useSelect}${tidFilter}&crm=eq.clientify&order=created_at.desc&limit=${pageSize}&offset=${offset}`,
        { headers, cache: 'no-store' }
      );
      if (!r.ok) {
        if (useSelect !== selectFallback && offset === 0) {
          useSelect = selectFallback;
          offset = -pageSize;
          continue;
        }
        break;
      }
      const chunk = (await r.json()) as CrmLeadRow[];
      out.push(...chunk);
      if (chunk.length < pageSize) break;
    }
    return out;
  }

  const supabase = await createClient();
  for (let offset = 0; offset < 50000; offset += pageSize) {
    let { data, error } = await supabase
      .from('leads')
      .select(select)
      .eq('crm', 'clientify')
      .order('created_at', { ascending: false })
      .range(offset, offset + pageSize - 1);
    if (error && offset === 0) {
      const retry = await supabase
        .from('leads')
        .select(selectFallback)
        .eq('crm', 'clientify')
        .order('created_at', { ascending: false })
        .range(offset, offset + pageSize - 1);
      data = retry.data as typeof data;
      error = retry.error;
    }
    if (error) break;
    const chunk = (data as CrmLeadRow[]) || [];
    out.push(...chunk);
    if (chunk.length < pageSize) break;
  }
  return out;
}

/** Won deals for cohort CAC / revenue / ROAS. */
async function fetchWonDeals(
  tenantId: string | null,
  useServiceRole: boolean
): Promise<DealWonRow[]> {
  const select = 'amount,won_at,stage,tenant_id,pipeline_id,pipeline_name';
  const pageSize = 1000;
  const out: DealWonRow[] = [];

  if (useServiceRole) {
    const headers = serviceHeaders();
    const base = supabaseUrl();
    if (!headers || !base) return [];
    const tidFilter = tenantId
      ? `&tenant_id=eq.${encodeURIComponent(tenantId)}`
      : '';
    for (let offset = 0; offset < 50000; offset += pageSize) {
      const r = await fetch(
        `${base}/rest/v1/deals?select=${select}${tidFilter}&stage=eq.won&order=won_at.desc.nullslast&limit=${pageSize}&offset=${offset}`,
        { headers, cache: 'no-store' }
      );
      if (!r.ok) break;
      const chunk = (await r.json()) as DealWonRow[];
      out.push(...chunk);
      if (chunk.length < pageSize) break;
    }
    return out;
  }

  const supabase = await createClient();
  for (let offset = 0; offset < 50000; offset += pageSize) {
    const { data } = await supabase
      .from('deals')
      .select(select)
      .eq('stage', 'won')
      .order('won_at', { ascending: false, nullsFirst: false })
      .range(offset, offset + pageSize - 1);
    const chunk = (data as DealWonRow[]) || [];
    out.push(...chunk);
    if (chunk.length < pageSize) break;
  }
  return out;
}

export default async function KpisPage() {
  const supabase = await createClient();
  const {
    data: { user },
  } = await supabase.auth.getUser();
  if (!user) redirect('/login');

  const ctx = await resolveActiveTenant(user);
  const agency = isAgencyRole(userRole(user));

  let weekly: KpiWeeklyRow[] = [];
  let daily: AdDailyRow[] = [];
  let crmLeads: CrmLeadRow[] = [];
  let wonDeals: DealWonRow[] = [];

  if (agency && (ctx.portfolioWide || ctx.viaView)) {
    if (ctx.portfolioWide) {
      const w = await restGet<KpiWeeklyRow[]>(
        '/rest/v1/kpi_weekly?select=*&order=week.desc'
      );
      weekly = w.data || [];
      daily = await fetchAdDaily(null, true);
      crmLeads = [];
      wonDeals = await fetchWonDeals(null, true);
    } else if (ctx.tenantId) {
      const tid = encodeURIComponent(ctx.tenantId);
      const w = await restGet<KpiWeeklyRow[]>(
        `/rest/v1/kpi_weekly?tenant_id=eq.${tid}&select=*&order=week.desc`
      );
      weekly = w.data || [];
      daily = await fetchAdDaily(ctx.tenantId, true);
      crmLeads = await fetchCrmLeads(ctx.tenantId, true);
      wonDeals = await fetchWonDeals(ctx.tenantId, true);
    }
  } else {
    const { data: w } = await supabase
      .from('kpi_weekly')
      .select('*')
      .order('week', { ascending: false });
    weekly = (w as KpiWeeklyRow[]) || [];
    daily = await fetchAdDaily(ctx.tenantId, false);
    crmLeads = await fetchCrmLeads(ctx.tenantId, false);
    wonDeals = await fetchWonDeals(ctx.tenantId, false);
  }

  const cohort = resolveWonCohort(wonDeals, crmLeads);
  wonDeals = cohort.deals;

  weekly = mergeDealsIntoWeekly(resolveWeeklyRows(weekly, daily), wonDeals);

  const comparisons = buildComparisons(weekly);
  const month =
    comparisons.currentMonth.spend > 0 || comparisons.currentMonth.leads > 0
      ? comparisons.currentMonth
      : sumWeekly(weekly);
  const dailyTotals = sumDaily(daily);
  const sparse = weekly.length < 4;
  const channelSeries = buildChannelSeries(weekly);

  return (
    <MetricsDashboard
      label={ctx.label}
      portfolioWide={ctx.portfolioWide}
      month={month}
      week={comparisons.currentWeek}
      deltas={comparisons.deltas}
      daily={dailyTotals}
      sparse={sparse}
      weeklyRows={weekly}
      channelPoints={channelSeries.points}
      dailyRows={daily}
      crmLeads={crmLeads}
      wonDeals={wonDeals}
      cohortSource={cohort.source}
    />
  );
}