import { NextRequest, NextResponse } from 'next/server';
import { createClient } from '@/lib/supabase/server';
import { resolveActiveTenant, restGet } from '@/lib/tenant-context';
import { isAgencyRole, userRole } from '@/lib/agency';
import { AdDailyRow, KpiWeeklyRow } from '@/lib/metrics';
import {
  SimChannel,
  simulateFromTenantMetrics,
} from '@/lib/simulate';

export const dynamic = 'force-dynamic';

async function loadTenantMetrics(tenantId: string, agencyView: boolean) {
  let daily: AdDailyRow[] = [];
  let weekly: KpiWeeklyRow[] = [];

  if (agencyView) {
    const tid = encodeURIComponent(tenantId);
    const [d, w] = await Promise.all([
      restGet<AdDailyRow[]>(
        `/rest/v1/ad_daily?tenant_id=eq.${tid}&select=*&order=date.desc&limit=400`
      ),
      restGet<KpiWeeklyRow[]>(
        `/rest/v1/kpi_weekly?tenant_id=eq.${tid}&select=*&order=week.desc&limit=52`
      ),
    ]);
    daily = d.data || [];
    weekly = w.data || [];
  } else {
    const supabase = await createClient();
    const [{ data: d }, { data: w }] = await Promise.all([
      supabase
        .from('ad_daily')
        .select('*')
        .order('date', { ascending: false })
        .limit(400),
      supabase
        .from('kpi_weekly')
        .select('*')
        .order('week', { ascending: false })
        .limit(52),
    ]);
    daily = (d as AdDailyRow[]) || [];
    weekly = (w as KpiWeeklyRow[]) || [];
  }
  return { daily, weekly };
}

export async function POST(req: NextRequest) {
  const supabase = await createClient();
  const {
    data: { user },
  } = await supabase.auth.getUser();
  if (!user) {
    return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
  }

  const ctx = await resolveActiveTenant(user);
  if (!ctx.tenantId || ctx.portfolioWide) {
    return NextResponse.json(
      { error: 'Selecciona un cliente en Contexto para simular.' },
      { status: 400 }
    );
  }

  try {
    const body = await req.json();
    const spend = parseFloat(body.spend || 1000);
    let channel = String(body.channel || 'blended').toLowerCase();

    if (channel === 'tiktok') {
      return NextResponse.json(
        {
          error:
            'TikTok no está activo aún en este portafolio. Usa Meta, Google o blended.',
        },
        { status: 400 }
      );
    }
    if (!['meta', 'google', 'blended'].includes(channel)) {
      channel = 'blended';
    }

    const agency = isAgencyRole(userRole(user));
    const { daily, weekly } = await loadTenantMetrics(
      ctx.tenantId,
      agency && ctx.viaView
    );

    const sim = simulateFromTenantMetrics({
      spend: Number.isFinite(spend) && spend > 0 ? spend : 1000,
      channel: channel as SimChannel,
      daily,
      weekly,
    });

    return NextResponse.json({
      ...sim,
      tenant_label: ctx.label,
      hint: 'Estimación con CPL, cierre y ticket del cliente en contexto (ad_daily + kpi_weekly).',
    });
  } catch (e: unknown) {
    const message = e instanceof Error ? e.message : 'Error';
    return NextResponse.json({ error: message }, { status: 500 });
  }
}