/**
 * @file Fails when an Express route under /api has no operation in the OpenAPI
 * document. Builds the app with `createApp()`, walks every router layer with
 * its mount prefix (recorded by wrapping `express.application.use` before the
 * server loads), and checks each method + path against `createOpenApiSpec()`.
 * Path parameters are compared by position only (`:token` and `{ref}` match),
 * and the two alias mounts that the spec documents by their tag description
 * (`/api/workspaces` = `/api/lanes`, `/api/ai-routers` = `/api/ai-proxies`)
 * are allowlisted. It also fails on a spec operation no route answers.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { describe, it, before } = require("node:test");
const assert = require("node:assert/strict");
const path = require("path");
const os = require("os");
const fs = require("fs");

const TEST_DB = path.join(os.tmpdir(), `dashboard-openapi-cov-${Date.now()}-${process.pid}.db`);
process.env.DASHBOARD_DB_PATH = TEST_DB;
process.env.DASHBOARD_LIVENESS_PROBE = "0";

// Record each app.use mount path on the layer it creates — Express keeps only
// a compiled matcher, which cannot be turned back into the prefix.
const express = require("express");
const originalUse = express.application.use;
express.application.use = function (mount, ...rest) {
  const out = originalUse.call(this, mount, ...rest);
  if (typeof mount === "string" || Array.isArray(mount)) {
    const stack = (this.router || this._router).stack;
    stack[stack.length - 1].__mount = mount;
  }
  return out;
};

const { createApp } = require("../index");
const { createOpenApiSpec } = require("../openapi");

/** Mounts that repeat another, documented mount by design (see the tags). */
const ALIAS_PREFIXES = ["/api/workspaces", "/api/ai-routers"];
/** Spec paths served by middleware rather than a route (Swagger UI). */
const MIDDLEWARE_PATHS = ["get /api/docs"];
const METHODS = new Set(["get", "post", "put", "patch", "delete"]);

/** `:id`, `:id(\\d+)`, `{id}` all become `{}`; a trailing slash is dropped. */
function normalize(p) {
  return (
    p
      .replace(/:[A-Za-z_]\w*(\([^)]*\))?\??/g, "{}")
      .replace(/\{[^}]+\}/g, "{}")
      .replace(/\/$/, "") || "/"
  );
}

function collectRoutes(app) {
  const out = new Set();
  const walk = (stack, prefixes) => {
    for (const layer of stack) {
      if (layer.route) {
        const routePaths = [].concat(layer.route.path);
        for (const prefix of prefixes) {
          for (const rp of routePaths) {
            for (const m of Object.keys(layer.route.methods)) {
              if (METHODS.has(m)) out.add(`${m} ${normalize(prefix + rp)}`);
            }
          }
        }
      } else if (layer.handle && Array.isArray(layer.handle.stack)) {
        const mounts = layer.__mount === undefined ? [""] : [].concat(layer.__mount);
        walk(
          layer.handle.stack,
          prefixes.flatMap((a) => mounts.map((b) => a + b))
        );
      }
    }
  };
  walk((app.router || app._router).stack, [""]);
  return [...out].filter((k) => k.split(" ")[1].startsWith("/api"));
}

describe("OpenAPI coverage", () => {
  let routes;
  let documented;

  before(() => {
    routes = collectRoutes(createApp());
    documented = new Set();
    for (const [p, ops] of Object.entries(createOpenApiSpec().paths)) {
      for (const m of Object.keys(ops)) if (METHODS.has(m)) documented.add(`${m} ${normalize(p)}`);
    }
  });

  it("finds the routes it is meant to check", () => {
    assert.ok(routes.length > 300, `only ${routes.length} routes found — the walk is broken`);
    assert.ok(routes.includes("get /api/lanes/{}"));
  });

  it("documents every registered /api route", () => {
    const missing = routes.filter(
      (k) =>
        !documented.has(k) &&
        !ALIAS_PREFIXES.some((a) => {
          const p = k.split(" ")[1];
          return p === a || p.startsWith(a + "/");
        })
    );
    assert.deepEqual(missing, [], `routes missing from the OpenAPI spec:\n${missing.join("\n")}`);
  });

  it("documents no operation that no route answers", () => {
    const have = new Set(routes);
    const stale = [...documented].filter((k) => !have.has(k) && !MIDDLEWARE_PATHS.includes(k));
    assert.deepEqual(stale, [], `spec operations with no route:\n${stale.join("\n")}`);
  });
});

process.on("exit", () => {
  for (const f of [TEST_DB, `${TEST_DB}-wal`, `${TEST_DB}-shm`]) {
    try {
      fs.unlinkSync(f);
    } catch {
      /* already gone */
    }
  }
});