import { describe, it, expect, vi, beforeEach } from "vitest";
import { Hono } from "hono";

// ─── Mock db module ───────────────────────────────────────────────────────────

let selectImpl: () => Promise<unknown>;

vi.mock("@groombook/db", () => {
  const staff = new Proxy(
    { _name: "staff" },
    {
      get(_target, prop) {
        if (prop === "_name") return "staff";
        return { table: "staff", column: prop };
      },
    }
  );

  return {
    getDb: () => ({
      select: (_fields: unknown) => ({
        from: (_table: unknown) => ({
          limit: (_n: number) => selectImpl(),
        }),
      }),
    }),
    staff,
  };
});

// ─── Build test app ───────────────────────────────────────────────────────────

async function makeApp() {
  const { getDb, staff } = await import("@groombook/db");

  const app = new Hono();
  app.get("/health/ready", async (c) => {
    try {
      await getDb().select({ id: staff.id }).from(staff).limit(1);
      return c.json({ status: "ready" }, 200);
    } catch (err) {
      const pgCode = (err as Record<string, unknown>).code ?? "unknown";
      console.error("[health/ready] DB check failed:", pgCode);
      return c.json({ status: "degraded" }, 503);
    }
  });
  return app;
}

// ─── Tests ────────────────────────────────────────────────────────────────────

describe("GET /health/ready", () => {
  beforeEach(() => {
    vi.restoreAllMocks();
  });

  it("returns 200 {status:'ready'} when DB query succeeds", async () => {
    selectImpl = () => Promise.resolve([{ id: "staff-1" }]);

    const app = await makeApp();
    const res = await app.request("/health/ready", { method: "GET" });
    const body = (await res.json()) as Record<string, unknown>;

    expect(res.status).toBe(200);
    expect(body.status).toBe("ready");
  });

  it("returns 503 {status:'degraded'} when DB query throws (schema dropped)", async () => {
    const schemaErr = Object.assign(new Error("relation \"staff\" does not exist"), { code: "42P01" });
    selectImpl = () => Promise.reject(schemaErr);

    const consoleSpy = vi.spyOn(console, "error").mockImplementation(() => {});

    const app = await makeApp();
    const res = await app.request("/health/ready", { method: "GET" });
    const body = (await res.json()) as Record<string, unknown>;

    expect(res.status).toBe(503);
    expect(body.status).toBe("degraded");

    // Must not leak SQL error details in the response body
    expect(JSON.stringify(body)).not.toContain("42P01");
    expect(JSON.stringify(body)).not.toContain("relation");

    consoleSpy.mockRestore();
  });

  it("returns 503 {status:'degraded'} on any DB connection error", async () => {
    selectImpl = () => Promise.reject(new Error("ECONNREFUSED"));

    const consoleSpy = vi.spyOn(console, "error").mockImplementation(() => {});

    const app = await makeApp();
    const res = await app.request("/health/ready", { method: "GET" });
    const body = (await res.json()) as Record<string, unknown>;

    expect(res.status).toBe(503);
    expect(body.status).toBe("degraded");

    consoleSpy.mockRestore();
  });
});