import test from "node:test";
import assert from "node:assert/strict";
import { readFile } from "node:fs/promises";
import { registerHooks } from "node:module";

const functionUrl = new URL("../functions/abConfigAdmin.ts", import.meta.url);
const state = {
  configs: [],
  nextId: 1,
};

function clone(value) {
  return value == null ? value : JSON.parse(JSON.stringify(value));
}

function matches(document, query) {
  return Object.keys(query).every(key => document[key] === query[key]);
}

function collection(name) {
  assert.equal(name, "ab_config");
  return {
    async get() {
      return { data: clone(state.configs) };
    },
    where(query) {
      return {
        async getOne() {
          return { data: clone(state.configs.find(item => matches(item, query)) || null) };
        },
        async update(payload) {
          const matched = state.configs.filter(item => matches(item, query));
          matched.forEach(item => Object.assign(item, clone(payload)));
          return { updated: matched.length };
        },
        async remove() {
          const oldLength = state.configs.length;
          state.configs = state.configs.filter(item => !matches(item, query));
          return { deleted: oldLength - state.configs.length };
        },
      };
    },
    async add(payload) {
      const document = { _id: `config-${state.nextId++}`, ...clone(payload) };
      state.configs.push(document);
      return { id: document._id };
    },
  };
}

globalThis.__abConfigAdminCloudMock = {
  database() {
    return { collection };
  },
};

registerHooks({
  resolve(specifier, context, nextResolve) {
    if (specifier === "@lafjs/cloud") {
      return {
        url: "data:text/javascript,export default globalThis.__abConfigAdminCloudMock",
        shortCircuit: true,
      };
    }
    return nextResolve(specifier, context);
  },
});

const { default: abConfigAdmin } = await import(functionUrl);

function reset() {
  state.configs = [];
  state.nextId = 1;
}

function config(extra = {}) {
  return {
    experimentId: "exp_layer_1_001",
    layer: "1",
    name: "Layer 1",
    enabled: true,
    resetAssignments: false,
    variants: [{ group: "A", ratio: 50 }, { group: "B", ratio: 50 }],
    ...extra,
  };
}

async function save(items) {
  return await abConfigAdmin({
    body: {
      action: "save",
      adminToken: "abtest-admin-token",
      config: items,
    },
  });
}

test("resetVersion changes only on an enabled false-to-true transition", async () => {
  reset();

  await save([config()]);
  assert.equal(state.configs[0].resetVersion, 0);

  await save([config({ resetAssignments: true })]);
  const firstVersion = state.configs[0].resetVersion;
  assert.ok(firstVersion > 0);

  await save([config({
    experimentId: "exp_layer_1_002",
    resetAssignments: true,
    variants: [{ group: "A", ratio: 80 }, { group: "B", ratio: 20 }],
  })]);
  assert.equal(state.configs.length, 1);
  assert.equal(state.configs[0].experimentId, "exp_layer_1_002");
  assert.equal(state.configs[0].resetVersion, firstVersion);

  await save([config({ experimentId: "exp_layer_1_002", resetAssignments: false })]);
  assert.equal(state.configs[0].resetVersion, firstVersion);

  await save([config({ experimentId: "exp_layer_1_002", resetAssignments: true })]);
  assert.ok(state.configs[0].resetVersion > firstVersion);
});

test("a disabled layer does not create a reset version", async () => {
  reset();

  await save([config({ enabled: false })]);
  await save([config({ enabled: false, resetAssignments: true })]);
  assert.equal(state.configs[0].resetVersion, 0);

  await save([config({ enabled: true, resetAssignments: true })]);
  assert.equal(state.configs[0].resetVersion, 0);

  await save([config({ enabled: true, resetAssignments: false })]);
  await save([config({ enabled: true, resetAssignments: true })]);
  assert.ok(state.configs[0].resetVersion > 0);

  await save([config({ enabled: false, resetAssignments: true })]);
  assert.equal(state.configs[0].resetVersion, 0);

  await save([config({ enabled: true, resetAssignments: true })]);
  assert.equal(state.configs[0].resetVersion, 0);
});

test("an existing enabled reset without a version is initialized on publish", async () => {
  reset();
  state.configs.push({ _id: "legacy", ...config({ resetAssignments: true }) });

  const result = await save([config({ resetAssignments: true })]);

  assert.equal(result.code, 1);
  assert.ok(state.configs[0].resetVersion > 0);
});

test("Default is a case-insensitive reserved group name", async () => {
  reset();

  const result = await save([config({
    variants: [{ group: "DEFAULT", ratio: 50 }, { group: "B", ratio: 50 }],
  })]);

  assert.equal(result.code, 0);
  assert.match(result.msg, /Default.*reserved/i);
  assert.equal(state.configs.length, 0);
});

test("the admin page explains edge-triggered reset behavior", async () => {
  const ui = await readFile(new URL("../../xxwz.html", import.meta.url), "utf8");

  assert.match(ui, /关闭→开启并发布/);
  assert.match(ui, /关闭后未登录用户不补做/);
  assert.match(ui, /Default.*系统保留/);
});