// Import service for HomeBox CSV → Moonbase items. Resolves (find-or-creates)
// the nested location path and labels, then creates the items. The parsing is
// pure (src/lib/inventory/homebox-import.ts) and shared with the preview UI.
import { createId } from "@paralleldrive/cuid2";
import { db } from "@/lib/db";
import type { AuthContext } from "@/lib/api/authenticate";
import { recomputeAllPaths } from "@/lib/locations/db";
import { parseHomeBoxCsv, splitLocationPath, type HomeBoxItem } from "@/lib/inventory/homebox-import";

export type ImportSummary = {
  created: number;
  skipped: number;
  locationsCreated: number;
  labelsCreated: number;
};

async function buildLocationCache() {
  const rows = await db.location.findMany({ select: { id: true, name: true, parentId: true } });
  const cache = new Map<string, string>(); // `${parentId||''}:${nameLower}` → id
  for (const r of rows) cache.set(`${r.parentId ?? ""}:${r.name.toLowerCase()}`, r.id);
  return cache;
}

async function resolveLocationPath(
  path: string | null,
  cache: Map<string, string>,
  counter: { n: number },
): Promise<string | null> {
  if (!path) return null;
  const names = splitLocationPath(path);
  let parentId: string | null = null;
  for (const name of names) {
    const key = `${parentId ?? ""}:${name.toLowerCase()}`;
    const existing: string | undefined = cache.get(key);
    let id: string;
    if (existing) {
      id = existing;
    } else {
      const loc = await db.location.create({ data: { name, kind: "OTHER", parentId } });
      id = loc.id;
      cache.set(key, id);
      counter.n++;
    }
    parentId = id;
  }
  return parentId;
}

async function buildLabelCache() {
  const rows = await db.label.findMany({ select: { id: true, name: true } });
  const cache = new Map<string, string>();
  for (const r of rows) cache.set(r.name.toLowerCase(), r.id);
  return cache;
}

async function resolveLabels(
  names: string[],
  cache: Map<string, string>,
  counter: { n: number },
): Promise<string[]> {
  const ids: string[] = [];
  for (const name of names) {
    let id = cache.get(name.toLowerCase());
    if (!id) {
      const label = await db.label.create({ data: { name } });
      id = label.id;
      cache.set(name.toLowerCase(), id);
      counter.n++;
    }
    ids.push(id);
  }
  return ids;
}

function toDate(s: string | null): Date | null {
  return s ? new Date(s) : null;
}

export async function importHomeBoxItems(
  ctx: AuthContext,
  opts: { csv: string; skip?: string[] },
): Promise<ImportSummary> {
  const parsed = parseHomeBoxCsv(opts.csv);
  const skip = new Set((opts.skip ?? []).map((s) => s.trim().toLowerCase()));

  const locCache = await buildLocationCache();
  const labelCache = await buildLabelCache();
  const locCounter = { n: 0 };
  const labelCounter = { n: 0 };
  let created = 0;
  let skipped = 0;

  for (const hb of parsed as HomeBoxItem[]) {
    if (skip.has(hb.name.trim().toLowerCase())) { skipped++; continue; }

    const locationId = await resolveLocationPath(hb.locationPath, locCache, locCounter);
    const labelIds = await resolveLabels(hb.labels, labelCache, labelCounter);

    await db.item.create({
      data: {
        name: hb.name,
        description: hb.description,
        quantity: hb.quantity || 1,
        locationId,
        value: hb.value,
        purchaseDate: toDate(hb.purchaseDate),
        purchaseFrom: hb.purchaseFrom,
        warrantyExpiry: toDate(hb.warrantyExpiry),
        warrantyDetails: hb.warrantyDetails,
        lifetimeWarranty: hb.lifetimeWarranty,
        insured: hb.insured,
        serial: hb.serial,
        modelNumber: hb.modelNumber,
        brand: hb.brand,
        notes: hb.notes,
        soldTo: hb.soldTo,
        soldPrice: hb.soldPrice,
        soldDate: toDate(hb.soldDate),
        soldNotes: hb.soldNotes,
        customFields: Object.keys(hb.customFields).length ? hb.customFields : undefined,
        active: !hb.archived,
        qrSlug: createId().slice(0, 10),
        ...(labelIds.length ? { labels: { create: labelIds.map((labelId) => ({ labelId })) } } : {}),
      },
    });
    created++;
  }

  // New locations were created without paths — recompute breadcrumbs once.
  if (locCounter.n > 0) await recomputeAllPaths();

  await db.auditEvent.create({
    data: {
      action: "item.import",
      actorId: ctx.userId,
      payload: { created, skipped, source: "homebox", via: ctx.via },
    },
  });

  return { created, skipped, locationsCreated: locCounter.n, labelsCreated: labelCounter.n };
}