import type { Asset, BookedLine, Invoice, Site } from "./data";

// Sites are DERIVED from the invoices: each distinct invoice site becomes a site.
// They are not typed in by hand, so this is the only place that creates them.
//
// Existing records are never deleted and never overwritten — a site may carry notes
// and may have lines booked to it, so removing one would orphan that history. An
// invoice site that disappears simply stops appearing in new invoices.
export async function syncSitesFromInvoices(pb: any, invoices: Invoice[]): Promise<Site[]> {
  const existing = (await pb.collection("sites").getFullList()) as Site[];
  const byName = new Map(existing.map((s: Site) => [(s.name || "").toLowerCase(), s]));

  const wanted = [...new Set(invoices.map((i) => (i.site || "").trim()).filter(Boolean))];
  for (const name of wanted) {
    if (byName.has(name.toLowerCase())) continue;
    try {
      const created = await pb.collection("sites").create({ name, is_active: true });
      byName.set(name.toLowerCase(), created as Site);
    } catch {
      // A concurrent upload may have created it first; the catch is a no-op.
    }
  }
  return byName.size ? Array.from(byName.values()) : existing;
}

export type SiteSummary = {
  id: string;
  name: string;
  /** Income, ex VAT — what actually lands in the P&L. */
  revenueExcl: number;
  vat: number;
  /** What the debtors were billed in total. */
  revenueIncl: number;
  invoices: { id: string; invoiceNo: string; invoiceDate: string; totalIncl: number }[];
  machineCount: number;
  lineCount: number;
  /** Lines with neither a plant item nor a site — the work still outstanding. */
  unbookedCount: number;
  unbookedAmount: number;
};

// Per-site revenue and VAT, derived by walking invoice lines through their invoice.
export function buildSiteSummaries(
  sites: Site[],
  invoices: Invoice[],
  lines: BookedLine[],
  assets: Asset[],
): SiteSummary[] {
  const invById = new Map(invoices.map((i) => [i.id, i]));
  const assetById = new Map(assets.map((a) => [a.id, a]));

  return sites
    .map((site) => {
      const siteLines = lines.filter((l) => invById.get(l.invoice)?.site === site.name);
      const revExcl = siteLines.reduce((s, l) => s + (l.amount_excl || 0), 0);
      const vat = siteLines.reduce((s, l) => s + (l.vat || 0), 0);
      const incl = siteLines.reduce((s, l) => s + (l.total_incl || 0), 0);

      const invMap = new Map<string, { id: string; invoiceNo: string; invoiceDate: string; totalIncl: number }>();
      for (const l of siteLines) {
        const inv = invById.get(l.invoice);
        if (inv) invMap.set(inv.id, { id: inv.id, invoiceNo: inv.invoice_no, invoiceDate: inv.invoice_date, totalIncl: inv.total_incl });
      }

      const unbooked = siteLines.filter((l) => !l.isBooked && !l.booked_site);
      return {
        id: site.id,
        name: site.name,
        revenueExcl: revExcl,
        vat,
        revenueIncl: incl,
        invoices: Array.from(invMap.values()).sort((a, b) => b.invoiceDate.localeCompare(a.invoiceDate)),
        machineCount: new Set(siteLines.map((l) => l.booked_asset).filter(Boolean)).size,
        lineCount: siteLines.length,
        unbookedCount: unbooked.length,
        unbookedAmount: unbooked.reduce((s, l) => s + (l.total_incl || 0), 0),
      };
    })
    .filter((s) => s.invoices.length > 0 || s.lineCount > 0)
    .sort((a, b) => b.revenueIncl - a.revenueIncl);
}

// Sites already taken by another line that has no plant item.
// One container per site: once a site holds a container, the next container's
// picker must not offer it, so the outstanding containers spread across sites
// instead of piling onto the first one.
export function takenSiteIdsFor(lines: BookedLine[], exceptLineId: string): Set<string> {
  const taken = new Set<string>();
  for (const l of lines) {
    if (l.id === exceptLineId) continue;
    if (l.booked_site && !l.booked_asset) taken.add(l.booked_site);
  }
  return taken;
}

// Auto-allocation for a line that matches no plant item.
//
// The invoices print a generic code for hire containers ("MPLANT05 Storage Container")
// that the plant register does not carry. Each site records the container it hires, and
// the code the invoice uses for it. So a container line arriving on an invoice for a site
// that has a matching container is booked to that container rather than left stuck.
//
// The lookup is against THIS invoice's site only — two sites can both hire
// "MPLANT05" units, and each line must go to the unit actually on its own site.
export function findSiteContainer(
  sites: Site[],
  siteName: string,
  machineCode: string,
): Site | null {
  const wanted = (machineCode || "").trim().toLowerCase();
  if (!wanted || !siteName) return null;
  return (
    sites.find(
      (s) =>
        (s.name || "").toLowerCase() === (siteName || "").toLowerCase() &&
        (s.container_code || "").trim().toLowerCase() === wanted &&
        Boolean(s.container_asset),
    ) ?? null
  );
}