import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { eq, ledgerEvents, users, type Db } from "@parking/db";
import { createTestDb } from "@parking/db/testing";
import type { FastifyInstance } from "fastify";
import { buildServer } from "../server.js";
import { login, makeLog, minutesAgo, seedTariff, seedUser } from "../test-helpers.js";
import type { EventLog } from "../event-log.js";

// Merchant validations (bar/lavazh): the merchant user scans a ticket and applies
// their program (a SIGNED, attributed ledger event); the booth settlement quotes NET
// and the payment CONSUMES the validation ids. These tests pin the route guards
// (binding, caps, session state), the signed apply/void events, and the money cycle
// through /api/pay/quote + /api/pay. See wiki/concepts/validation-discounts.md.

let db: Db;
let close: () => void;
let app: FastifyInstance;

beforeEach(async () => {
  const t = createTestDb();
  db = t.db;
  close = t.close;
  app = await buildServer({ db });
  await app.ready();
});
afterEach(async () => {
  await app.close();
  close();
});

type Auth = { cookie: string; csrf: string };
const hdrs = (a: Auth) => ({ cookie: a.cookie, "x-csrf-token": a.csrf });

async function seedMerchant(username = "bari"): Promise<{ auth: Auth; userId: string }> {
  await seedUser(db, { username, password: "pw123456", roleId: "validues", permissions: ["validation:create"] });
  const auth = await login(app, username, "pw123456");
  const row = db.select().from(users).where(eq(users.username, username)).get()!;
  return { auth, userId: row.id };
}

async function seedAdmin(): Promise<Auth> {
  await seedUser(db, { username: "admin", password: "pw123456" });
  return login(app, "admin", "pw123456");
}

/** Admin-upserts the "bar" program bound to the given user. */
async function putProgram(auth: Auth, body: Record<string, unknown>, id = "bar") {
  return app.inject({ method: "PUT", url: `/api/validation/programs/${id}`, headers: hdrs(auth), payload: body });
}

const fixedProgram = (userId: string, over: Record<string, unknown> = {}) => ({
  name: "Bar",
  mode: "fixed",
  maxAmountMinor: 100000,
  active: true,
  userIds: [userId],
  ...over,
});

describe("merchant validations", () => {
  let log: EventLog;
  beforeEach(() => {
    log = makeLog(db);
  });

  const mint = (identity: string, minAgo: number, payload: Record<string, unknown> | null = null) =>
    log.append({ type: "vehicle_entry", direction: "entry", identity, occurredAt: minutesAgo(minAgo), payload });

  it("program upsert is admin-gated and signs a config_change; a no-op save signs nothing", async () => {
    const admin = await seedAdmin();
    const { auth: merchant, userId } = await seedMerchant();

    expect((await putProgram(merchant, fixedProgram(userId))).statusCode).toBe(403);

    const res = await putProgram(admin, fixedProgram(userId));
    expect(res.statusCode).toBe(200);
    expect(res.json()).toMatchObject({ id: "bar", mode: "fixed", active: true, userIds: [userId] });

    const changes = () => db.select().from(ledgerEvents).all().filter((r) => r.type === "config_change");
    expect(changes()).toHaveLength(1);
    expect(changes()[0].payload).toMatchObject({ setting: "validationProgram.bar", operator: "admin" });

    // Identical second save → no second config_change.
    await putProgram(admin, fixedProgram(userId));
    expect(changes()).toHaveLength(1);
  });

  it("per-mode validation: timeCredit needs minutes, percent needs percent, fixed needs a cap", async () => {
    const admin = await seedAdmin();
    expect((await putProgram(admin, { name: "X", mode: "timeCredit", active: true })).statusCode).toBe(400);
    expect((await putProgram(admin, { name: "X", mode: "percent", active: true })).statusCode).toBe(400);
    expect((await putProgram(admin, { name: "X", mode: "fixed", active: true })).statusCode).toBe(400);
    expect((await putProgram(admin, { name: "X", mode: "timeCredit", minutes: 60, active: true })).statusCode).toBe(200);
  });

  it("GET /mine returns only MY bound, active programs", async () => {
    const admin = await seedAdmin();
    const { auth: merchant, userId } = await seedMerchant();
    await putProgram(admin, fixedProgram(userId));
    await putProgram(admin, { name: "Lavazh", mode: "comp", active: true, userIds: [] }, "lavazh");

    const res = await app.inject({ method: "GET", url: "/api/validation/mine", headers: hdrs(merchant) });
    expect(res.statusCode).toBe(200);
    const programs = res.json().programs as { id: string }[];
    expect(programs.map((p) => p.id)).toEqual(["bar"]);
  });

  it("apply: binding, session-state, duplicate and amount guards", async () => {
    const admin = await seedAdmin();
    const { auth: merchant, userId } = await seedMerchant();
    const { auth: other } = await seedMerchant("tjetri");
    await putProgram(admin, fixedProgram(userId));
    seedTariff(db);
    await mint("T1", 120);

    const apply = (auth: Auth, payload: Record<string, unknown>) =>
      app.inject({ method: "POST", url: "/api/validation/apply", headers: hdrs(auth), payload });

    // Unbound merchant → 403; unknown ticket → 404; missing amount (fixed) → 400;
    // amount above the cap → 400.
    expect((await apply(other, { identity: "T1", programId: "bar", amountMinor: 5000 })).statusCode).toBe(403);
    expect((await apply(merchant, { identity: "NOPE", programId: "bar", amountMinor: 5000 })).statusCode).toBe(404);
    expect((await apply(merchant, { identity: "T1", programId: "bar" })).statusCode).toBe(400);
    expect((await apply(merchant, { identity: "T1", programId: "bar", amountMinor: 999999 })).statusCode).toBe(400);

    // Subscriber sessions are never validated (prepaid).
    await mint("SUB1", 60, { permit: true, permitId: "s-1" });
    expect((await apply(merchant, { identity: "SUB1", programId: "bar", amountMinor: 5000 })).statusCode).toBe(409);

    // Success → a SIGNED validation event with resolved values + the merchant username.
    const ok = await apply(merchant, { identity: "T1", programId: "bar", amountMinor: 5000 });
    expect(ok.statusCode).toBe(201);
    const ev = db.select().from(ledgerEvents).all().find((r) => r.type === "validation")!;
    expect(ev.payload).toMatchObject({
      programId: "bar",
      programLabel: "Bar",
      mode: "fixed",
      amountMinor: 5000,
      operator: "bari",
    });

    // Same program twice on one ticket → 409.
    expect((await apply(merchant, { identity: "T1", programId: "bar", amountMinor: 1000 })).statusCode).toBe(409);
  });

  it("the money cycle: quote nets the validation, pay records gross/discount and CONSUMES it", async () => {
    const admin = await seedAdmin();
    const { auth: merchant, userId } = await seedMerchant();
    await putProgram(admin, fixedProgram(userId));
    // 100/h flat; 2h → gross 20000.
    seedTariff(db, { pricePerIncrementMinor: 10000, incrementMin: 60 });
    await mint("T1", 119);

    await app.inject({
      method: "POST",
      url: "/api/validation/apply",
      headers: hdrs(merchant),
      payload: { identity: "T1", programId: "bar", amountMinor: 5000 },
    });

    const q1 = await app.inject({ method: "GET", url: "/api/pay/quote?identity=T1", headers: hdrs(admin) });
    expect(q1.json()).toMatchObject({
      grossMinor: 20000,
      discountMinor: 5000,
      amountMinor: 15000,
    });
    expect(q1.json().validationLines).toEqual([
      { programId: "bar", label: "Bar", mode: "fixed", discountMinor: 5000 },
    ]);

    // Pay (needs an open shift) → the payment carries the split + consumed ids.
    await app.inject({ method: "POST", url: "/api/shift/open", headers: hdrs(admin) });
    const pay = await app.inject({ method: "POST", url: "/api/pay", headers: hdrs(admin), payload: { identity: "T1", tender: "cash" } });
    expect(pay.statusCode).toBe(201);
    expect(pay.json().amountMinor).toBe(15000);

    const payment = db.select().from(ledgerEvents).all().find((r) => r.type === "payment")!;
    expect(payment.payload).toMatchObject({ amountMinor: 15000, grossMinor: 20000, discountMinor: 5000 });
    expect((payment.payload as { validationIds?: string[] }).validationIds).toHaveLength(1);

    // Settled: the follow-up quote owes 0 and applies nothing further.
    const q2 = await app.inject({ method: "GET", url: "/api/pay/quote?identity=T1", headers: hdrs(admin) });
    expect(q2.json().amountMinor).toBe(0);
    expect(q2.json().validationLines).toEqual([]);
  });

  it("a full comp settles at 0 through the normal pay path (grace starts, chain verifies)", async () => {
    const admin = await seedAdmin();
    const { auth: merchant, userId } = await seedMerchant();
    await putProgram(admin, { name: "Lavazh falas", mode: "comp", active: true, userIds: [userId] }, "lavazh");
    seedTariff(db, { pricePerIncrementMinor: 10000 });
    await mint("T1", 90);

    await app.inject({
      method: "POST",
      url: "/api/validation/apply",
      headers: hdrs(merchant),
      payload: { identity: "T1", programId: "lavazh" },
    });

    const q = await app.inject({ method: "GET", url: "/api/pay/quote?identity=T1", headers: hdrs(admin) });
    expect(q.json().amountMinor).toBe(0);
    expect(q.json().grossMinor).toBeGreaterThan(0);

    await app.inject({ method: "POST", url: "/api/shift/open", headers: hdrs(admin) });
    const pay = await app.inject({ method: "POST", url: "/api/pay", headers: hdrs(admin), payload: { identity: "T1", tender: "cash" } });
    expect(pay.statusCode).toBe(201);
    expect(pay.json().amountMinor).toBe(0);

    // The 0-net settlement still grants walk-back grace (the session reads settled).
    const view = await app.inject({ method: "GET", url: "/api/session/T1", headers: hdrs(admin) });
    expect(view.json()).toMatchObject({ withinGrace: true, amountMinor: 0 });
  });

  it("void: own unused only; a consumed validation is locked", async () => {
    const admin = await seedAdmin();
    const { auth: merchant, userId } = await seedMerchant();
    const { auth: other, userId: otherId } = await seedMerchant("tjetri");
    await putProgram(admin, fixedProgram(userId, { userIds: [userId, otherId] }));
    seedTariff(db, { pricePerIncrementMinor: 10000 });
    await mint("T1", 90);

    const applied = await app.inject({
      method: "POST",
      url: "/api/validation/apply",
      headers: hdrs(merchant),
      payload: { identity: "T1", programId: "bar", amountMinor: 5000 },
    });
    const eventId = applied.json().eventId as string;

    const voidReq = (auth: Auth) =>
      app.inject({ method: "POST", url: "/api/validation/void", headers: hdrs(auth), payload: { eventId, identity: "T1" } });

    // Someone else's validation → 403. Own → ok, and the quote returns to gross.
    expect((await voidReq(other)).statusCode).toBe(403);
    expect((await voidReq(merchant)).statusCode).toBe(200);
    const q = await app.inject({ method: "GET", url: "/api/pay/quote?identity=T1", headers: hdrs(admin) });
    expect(q.json().discountMinor).toBe(0);

    // Re-apply (the void freed the per-session slot), consume it with a payment, then
    // a void must refuse — the settlement already happened.
    const re = await app.inject({
      method: "POST",
      url: "/api/validation/apply",
      headers: hdrs(merchant),
      payload: { identity: "T1", programId: "bar", amountMinor: 5000 },
    });
    await app.inject({ method: "POST", url: "/api/shift/open", headers: hdrs(admin) });
    await app.inject({ method: "POST", url: "/api/pay", headers: hdrs(admin), payload: { identity: "T1", tender: "cash" } });
    const locked = await app.inject({
      method: "POST",
      url: "/api/validation/void",
      headers: hdrs(merchant),
      payload: { eventId: re.json().eventId, identity: "T1" },
    });
    expect(locked.statusCode).toBe(409);
  });

  it("maxPerDay caps applications across tickets", async () => {
    const admin = await seedAdmin();
    const { auth: merchant, userId } = await seedMerchant();
    await putProgram(admin, { name: "Lavazh", mode: "comp", maxPerDay: 1, active: true, userIds: [userId] }, "lavazh");
    seedTariff(db);
    await mint("T1", 60);
    await mint("T2", 30);

    const apply = (identity: string) =>
      app.inject({ method: "POST", url: "/api/validation/apply", headers: hdrs(merchant), payload: { identity, programId: "lavazh" } });
    expect((await apply("T1")).statusCode).toBe(201);
    expect((await apply("T2")).statusCode).toBe(409);
  });
});