/**
 * Stock Quick-Draft service — backs the /stock-orders modal that lets
 * a buyer add items to draft stock_purchases in an item-first rhythm.
 *
 * Reuses `generateStockPurchaseNumber` from `stock-purchases-service.ts`
 * for the find-or-create open-draft step; no schema changes, no new
 * statuses. Admin PB only (consistent with the other service modules).
 */
import type PocketBase from "pocketbase";
import { getAdminPocketBase } from "./pocketbase-admin";
import { generateStockPurchaseNumber } from "./stock-purchases-service";

const STOCK_ITEMS = "stock_items";
const STOCK_PURCHASES = "stock_purchases";
const STOCK_PURCHASE_ITEMS = "stock_purchase_items";

const SEARCH_LIMIT_MAX = 25;
const SEARCH_LIMIT_DEFAULT = 10;

/* ============================================================================
 * Minimal PB client shape this module needs.
 *
 * The route passes in the real `getAdminPocketBase()`; the unit test
 * passes in a tiny mock. Only the methods we actually call are typed.
 * ========================================================================== */

export interface StockQuickDraftPb {
  collection: (name: string) => {
    getList: (
      page?: number,
      perPage?: number,
      opts?: { filter?: string; sort?: string; expand?: string }
    ) => Promise<{
      items: Array<Record<string, unknown>>;
      totalItems: number;
      page: number;
      perPage: number;
      totalPages: number;
    }>;
    getFullList: (opts?: { filter?: string }) => Promise<Array<Record<string, unknown>>>;
    getOne: (id: string, opts?: { expand?: string }) => Promise<Record<string, unknown>>;
    create: (data: Record<string, unknown>) => Promise<Record<string, unknown>>;
    update: (id: string, data: Record<string, unknown>) => Promise<Record<string, unknown>>;
    delete: (id: string) => Promise<Record<string, unknown>>;
  };
}

/* ============================================================================
 * Public types
 * ========================================================================== */

export interface StockItemSearchResult {
  id: string;
  sku: string;
  name: string;
  description: string;
  unit?: string;
}

export interface SupplierHistoryEntry {
  supplierId: string;
  supplierName: string;
  lastCost: number;
  lastDate: string;
  timesBought: number;
}

export interface AddQuickDraftLineNewStockItem {
  name: string;
  sku: string;
  description?: string;
  unit?: string;
}

export interface AddQuickDraftLineInput {
  supplierId: string;
  stockItemId?: string;
  quantity: number;
  costPrice: number;
  newStockItem?: AddQuickDraftLineNewStockItem;
}

export type AddQuickDraftLineResult =
  | { ok: true; purchaseId: string; purchaseNumber: string; lineId: string; createdDraft: boolean }
  | { ok: false; reason: string; message: string };

export type RemoveQuickDraftLineResult =
  | { ok: true }
  | { ok: false; reason: string; message: string };

/* ============================================================================
 * Helpers
 * ========================================================================== */

async function resolvePb(pb?: StockQuickDraftPb): Promise<StockQuickDraftPb> {
  if (pb) return pb;
  return (await getAdminPocketBase()) as unknown as StockQuickDraftPb;
}

/* ============================================================================
 * searchStockItemsForQuickDraft
 * ========================================================================== */

/**
 * Typeahead search over `stock_items`. Matches `sku` OR `name` with
 * PocketBase's `~` (contains, case-insensitive). Excludes inactive
 * items. Limit defaults to 10, clamped to a max of 25.
 *
 * Returns a narrow projection — only the fields the modal needs.
 */
export async function searchStockItemsForQuickDraft(
  pb: StockQuickDraftPb,
  q: string,
  limit?: number,
): Promise<StockItemSearchResult[]> {
  const safeLimit = Math.min(Math.max(limit ?? SEARCH_LIMIT_DEFAULT, 1), SEARCH_LIMIT_MAX);
  const escaped = q.replace(/"/g, '\\"');
  const filter = `is_active=true && (sku ~ "${escaped}" || name ~ "${escaped}")`;

  const result = await pb.collection(STOCK_ITEMS).getList(1, safeLimit, {
    filter,
    sort: "name",
  });

  return result.items.map((row) => ({
    id: String(row.id),
    sku: String(row.sku ?? ""),
    name: String(row.name ?? ""),
    description: String(row.description ?? ""),
    unit: row.unit ? String(row.unit) : undefined,
  }));
}