import { describe, expect, it } from "vitest";
import { Transaction } from "@/lib/server/models/Transaction";
import { Product, BranchPricing } from "@/lib/server/models/Product";
import { stockOf } from "@/lib/server/stock";
import * as cash from "@/app/api/transactions/cash/route";
import type { SaleResult } from "@/lib/syncProtocol";
import { json, makeTenant, req, uuid, type Actor, type Tenant, db } from "./helpers";

function sale(t: Tenant, cashier: Actor, lines: { productId: string; quantity: number; unitPrice?: number }[], extra = {}) {
  return {
    clientUuid: uuid(),
    staffId: cashier.id,
    branchId: cashier.branchId!,
    clientSubmittedAt: new Date().toISOString(),
    lines,
    ...extra,
  };
}

async function post(as: Actor, sales: unknown[]) {
  return json<{ results: SaleResult[] }>(await cash.POST(req("POST", "/api/transactions/cash", { as, body: { sales } })));
}

describe("offline sale sync", () => {
  it("records a multi-item sale as one line per product and deducts each from stock", async () => {
    const t = await makeTenant();
    const s = sale(t, t.cashierA, [
      { productId: t.water20, quantity: 2, unitPrice: 200 },
      { productId: t.water5, quantity: 3, unitPrice: 60 },
    ]);
    const { status, body } = await post(t.cashierA, [s]);
    expect(status).toBe(200);
    expect(body.results).toEqual([{ clientUuid: s.clientUuid, status: "saved", amountTotal: 580, priceMismatch: false }]);
    expect(await db(() => Transaction.countDocuments({ saleId: s.clientUuid }))).toBe(2);
    expect(await stockOf(t.businessId, t.branchA, t.water20)).toBe(-2);
    expect(await stockOf(t.businessId, t.branchA, t.water5)).toBe(-3);
  });

  it("reports a replayed sale as duplicate, so the device can stop resending it", async () => {
    const t = await makeTenant();
    const s = sale(t, t.cashierA, [{ productId: t.water20, quantity: 1 }]);
    await post(t.cashierA, [s]);
    const replay = await post(t.cashierA, [s]);
    expect(replay.body.results[0]).toMatchObject({ clientUuid: s.clientUuid, status: "duplicate" });
    expect(await db(() => Transaction.countDocuments({ saleId: s.clientUuid }))).toBe(1);
    expect(await stockOf(t.businessId, t.branchA, t.water20)).toBe(-1);
  });

  it("syncs a 120-sale backlog in chunks with no duplicates (the old 100-row dead end)", async () => {
    const t = await makeTenant();
    const backlog = Array.from({ length: 120 }, () => sale(t, t.cashierA, [{ productId: t.water20, quantity: 1 }]));
    // An over-sized batch is refused outright...
    const tooBig = await cash.POST(req("POST", "/x", { as: t.cashierA, body: { sales: backlog } }));
    expect(tooBig.status).toBe(400);
    // ...and the device sends it in chunks of 50, twice over (a full replay).
    for (let pass = 0; pass < 2; pass++) {
      for (let i = 0; i < backlog.length; i += 50) {
        const { status } = await post(t.cashierA, backlog.slice(i, i + 50));
        expect(status).toBe(200);
      }
    }
    expect(await Transaction.countDocuments({ businessId: t.businessId })).toBe(120);
    expect(await stockOf(t.businessId, t.branchA, t.water20)).toBe(-120);
  });

  it("rejects one bad sale without blocking the rest of the batch", async () => {
    const t = await makeTenant();
    const good = sale(t, t.cashierA, [{ productId: t.water20, quantity: 1 }]);
    const malformed = { clientUuid: uuid(), lines: [] };
    const { body } = await post(t.cashierA, [malformed, good]);
    const byId = Object.fromEntries(body.results.map((r) => [r.clientUuid, r.status]));
    expect(byId[malformed.clientUuid]).toBe("rejected");
    expect(byId[good.clientUuid]).toBe("saved");
  });

  it("refuses to credit a queued sale to whoever happens to be signed in", async () => {
    const t = await makeTenant();
    const otherCashiersSale = sale(t, t.cashierB, [{ productId: t.water20, quantity: 1 }]);
    const { body } = await post(t.cashierA, [otherCashiersSale]);
    expect(body.results[0].status).toBe("rejected");
    expect(await db(() => Transaction.countDocuments({}))).toBe(0);
  });

  it("keeps a sale at the branch where it happened after the cashier is moved", async () => {
    const t = await makeTenant();
    const s = sale(t, t.cashierA, [{ productId: t.water20, quantity: 1 }]); // recorded at branch A
    const moved = { ...t.cashierA, branchId: t.branchB };
    await post(moved, [s]);
    const txn = await db(() => Transaction.findOne({ saleId: s.clientUuid }));
    expect(txn!.branchId.toString()).toBe(t.branchA);
  });

  it("rejects a sale naming another tenant's product or branch", async () => {
    const t = await makeTenant("Alpha");
    const other = await makeTenant("Beta");
    const foreignProduct = sale(t, t.cashierA, [{ productId: other.water20, quantity: 1 }]);
    const foreignBranch = sale(t, t.cashierA, [{ productId: t.water20, quantity: 1 }], { branchId: other.branchA });
    const { body } = await post(t.cashierA, [foreignProduct, foreignBranch]);
    expect(body.results.map((r) => r.status)).toEqual(["rejected", "rejected"]);
    expect(await db(() => Transaction.countDocuments({}))).toBe(0);
  });

  it("uses the branch price, flags a price the device showed differently, and keeps deactivated products sellable", async () => {
    const t = await makeTenant();
    await BranchPricing.create({ businessId: t.businessId, branchId: t.branchA, productId: t.water20, unitPrice: 180 });
    await db(() => Product.updateOne({ _id: t.water5 }, { isActive: false }));
    const s = sale(t, t.cashierA, [
      { productId: t.water20, quantity: 1, unitPrice: 200 }, // stale price on the device
      { productId: t.water5, quantity: 1, unitPrice: 60 },
    ]);
    const { body } = await post(t.cashierA, [s]);
    expect(body.results[0]).toMatchObject({ status: "saved", amountTotal: 240, priceMismatch: true });
  });

  it("accepts a cash sale with no customer phone, and keeps one with a bad phone", async () => {
    const t = await makeTenant();
    const noPhone = sale(t, t.cashierA, [{ productId: t.water20, quantity: 1 }]);
    const badPhone = sale(t, t.cashierA, [{ productId: t.water20, quantity: 1 }], { customerPhone: "12" });
    const { body } = await post(t.cashierA, [noPhone, badPhone]);
    expect(body.results.map((r) => r.status)).toEqual(["saved", "saved"]);
  });

  it("still accepts the old single-product payload", async () => {
    const t = await makeTenant();
    const legacy = { clientUuid: uuid(), customerPhone: "0712345678", productId: t.water20, quantity: 2 };
    const { body } = await post(t.cashierA, [legacy]);
    expect(body.results[0]).toMatchObject({ status: "saved", amountTotal: 400 });
  });
});