import { db } from "@/db";
import { clients, projects, payments } from "@/db/schema";
import { eq, sum, count, sql } from "drizzle-orm";

export type KpiStats = {
  clientiAttivi: number;
  clientiNuoviMese: number;    // clients created in the current calendar month
  revenueTotale: string;       // sum of projects.accepted_total (non-archived)
  pagamentiInSospeso: string;  // sum of payments.amount where status = 'da_saldare' or 'inviata'
  progettiInCorso: number;     // projects not archived
};

export type DashboardStats = {
  kpi: KpiStats;
};

export async function getDashboardStats(): Promise<DashboardStats> {
  // ── KPIs ─────────────────────────────────────────────────────────────────────
  const [clientiAttiviRow] = await db
    .select({ count: count() })
    .from(clients)
    .where(eq(clients.archived, false));

  const [clientiNuoviMeseRow] = await db
    .select({ count: count() })
    .from(clients)
    .where(
      sql`date_trunc('month', ${clients.created_at}) = date_trunc('month', now())`
    );

  const [revenueRow] = await db
    .select({ total: sum(projects.accepted_total) })
    .from(projects)
    .where(eq(projects.archived, false));

  const [pagamentiDaSaldareRow] = await db
    .select({ total: sum(payments.amount) })
    .from(payments)
    .where(eq(payments.status, "da_saldare"));

  const [pagamentiInviataRow] = await db
    .select({ total: sum(payments.amount) })
    .from(payments)
    .where(eq(payments.status, "inviata"));

  const [progettiRow] = await db
    .select({ count: count() })
    .from(projects)
    .where(eq(projects.archived, false));

  const pagamentiSospeso =
    (parseFloat(pagamentiDaSaldareRow?.total ?? "0") || 0) +
    (parseFloat(pagamentiInviataRow?.total ?? "0") || 0);

  const kpi: KpiStats = {
    clientiAttivi: clientiAttiviRow?.count ?? 0,
    clientiNuoviMese: clientiNuoviMeseRow?.count ?? 0,
    revenueTotale: revenueRow?.total ?? "0",
    pagamentiInSospeso: pagamentiSospeso.toFixed(2),
    progettiInCorso: progettiRow?.count ?? 0,
  };

  return { kpi };
}