/**
 * 回報 PR 現況，並在它結束時清掉工作樹。
 *
 * 這一支的價值在**四種 PR 狀態各自的處置**：merged 與 closed 是終止狀態，工作樹清掉；
 * open 繼續監看；draft 尤其要盯住——被退回草稿代表還要繼續改，這時候那棵工作樹更需要
 * 留著，清掉它等於把人做到一半的環境收走。
 *
 * 另外兩件事各有測試：建議動作是**列舉值**（呼叫端要程式化判斷，不是去讀一段文字），
 * 以及清理的守門（有未提交變更就擋下，絕不 `--force`）。
 *
 * 一次性、無狀態：不與上次的結果比較，也不讀寫任何游標或狀態檔——「已處理」的判定
 * 基準是 Gitea 上的 `+1` 與 resolve，現況快照本身就足以回答「還有沒有事要做」。
 */
import test from 'node:test';
import assert from 'node:assert/strict';
import { existsSync, mkdirSync, mkdtempSync, readdirSync, rmSync, writeFileSync } from 'node:fs';
import { join } from 'node:path';
import { runScript, tmpRoot } from './helpers/run-script.js';
import { makeTempRepoWithRemote } from './helpers/temp-repo.js';
import { healthyRoutes, stubEnv, withStubGitea } from './helpers/stub-gitea.js';

const REPO = 'plugins/tea-sdlc';
const INDEX = 46;
const SLUG = 'pr-watch-and-cleanup';
const BRANCH = `feat/${SLUG}/main`;

/**
 * 一顆 PR 的現場：狀態由 options 決定，留言預設沒有。
 * 一般留言只有在沒有自己打的 `+1` 時才算未處理。
 */
function routes({ state = 'open', merged = false, draft = false, general = [], head } = {}) {
  const base = healthyRoutes(REPO, {
    [`GET /api/v1/repos/${REPO}/pulls/${INDEX}`]: {
      status: 200,
      body: {
        number: INDEX,
        title: BRANCH,
        html_url: `https://gitea.jsc.idv.tw/${REPO}/pulls/${INDEX}`,
        state,
        merged,
        draft,
        // 預設是「PR 還開著」的樣子：head.ref 就是分支名。合併之後 Gitea 會換一種樣子，
        // 那一種由測試自己指定。
        head: head ?? { ref: BRANCH, label: BRANCH },
      },
    },
    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/comments`]: {
      status: 200,
      body: general.map((c, i) => ({ id: 100 + i, body: c.body, user: { login: 'reviewer' } })),
    },
    [`GET /api/v1/repos/${REPO}/pulls/${INDEX}/reviews`]: { status: 200, body: [] },
    [`GET /api/v1/repos/${REPO}/issues/${INDEX}/timeline`]: { status: 200, body: [] },
  });
  general.forEach((c, i) => {
    base[`GET /api/v1/repos/${REPO}/issues/comments/${100 + i}/reactions`] = {
      status: 200,
      body: (c.reactions ?? []).map((content) => ({
        content,
        user: { login: c.reactedBy ?? 'tester' },
      })),
    };
  });
  return base;
}

/** 備好一棵真的工作樹（由 branch-prep 建）與一台假 Gitea */
async function withScene(t, pr = {}) {
  const repo = makeTempRepoWithRemote();
  t.after(() => repo.cleanup());
  mkdirSync(tmpRoot, { recursive: true });
  const home = mkdtempSync(join(tmpRoot, 'home-'));
  t.after(() => rmSync(home, { recursive: true, force: true }));

  const prep = await runScript(
    'branch-prep.js',
    ['--repo', REPO, '--path', repo.dir, '--source', 'master', '--type', 'feat', '--slug', SLUG],
    { env: { TEA_SDLC_HOME: home } },
  );
  assert.equal(prep.json.ok, true, prep.json.error?.message);

  const stub = await withStubGitea(t, routes(pr));
  const run = (args = []) =>
    runScript('pr-watch.js', ['--repo', REPO, '--index', String(INDEX), ...args], {
      env: { ...stubEnv(stub), TEA_SDLC_HOME: home },
    });

  return { repo, home, stub, run, worktree: prep.json.data.worktree };
}

// ── PR 狀態到處置的對照表 ─────────────────────────────────────────

const DISPOSITION = [
  {
    name: 'open：繼續監看，工作樹留著',
    pr: { state: 'open' },
    expected: { state: 'open', terminal: false, cleaned: false, suggestedAction: 'nothing-to-do' },
    工作樹還在: true,
  },
  {
    name: 'merged：終止，工作樹清掉',
    pr: { state: 'closed', merged: true },
    expected: { state: 'merged', terminal: true, cleaned: true, suggestedAction: 'nothing-to-do' },
    工作樹還在: false,
  },
  {
    name: 'closed：同樣終止，工作樹清掉',
    pr: { state: 'closed', merged: false },
    expected: { state: 'closed', terminal: true, cleaned: true, suggestedAction: 'nothing-to-do' },
    工作樹還在: false,
  },
  {
    name: 'draft：不終止也不清理——退回草稿代表還要繼續改',
    pr: { state: 'open', draft: true },
    expected: { state: 'draft', terminal: false, cleaned: false, suggestedAction: 'nothing-to-do' },
    工作樹還在: true,
  },
];

for (const { name, pr, expected, 工作樹還在 } of DISPOSITION) {
  test(`狀態：${name}`, async (t) => {
    const { run, worktree } = await withScene(t, pr);

    const { code, json } = await run();

    assert.equal(code, 0, json.error?.message);
    assert.equal(json.data.state, expected.state);
    assert.equal(json.data.terminal, expected.terminal);
    assert.equal(json.data.cleaned, expected.cleaned);
    assert.equal(json.data.suggestedAction, expected.suggestedAction);
    assert.equal(existsSync(worktree), 工作樹還在);
  });
}

test('清理只移除工作樹，本機分支留著', async (t) => {
  const { repo, run, worktree } = await withScene(t, { state: 'closed', merged: true });

  await run();

  assert.equal(existsSync(worktree), false);
  assert.equal(
    repo.git('branch', '--list', BRANCH).trim().replace(/^\*?\s*/, ''),
    BRANCH,
    '本機分支要留著，之後還能回頭看那段歷史',
  );
});

// ── 未處理留言 ─────────────────────────────────────────────────────

test('有未處理留言時建議去跑 sdlc-fix，但不自己執行', async (t) => {
  const { run, stub } = await withScene(t, { general: [{ body: '這裡少了錯誤處理' }] });

  const { json } = await run();

  assert.equal(json.data.未處理留言數, 1);
  assert.equal(json.data.suggestedAction, 'run-sdlc-fix');
  assert.deepEqual(
    stub.requests.filter((r) => r.method !== 'GET' && !r.path.endsWith('/issues/0')),
    [],
    '只通知不動手：監看不該替使用者回覆或標記任何東西',
  );
});

test('自己打過 +1 的留言算已處理，不再催', async (t) => {
  const { run } = await withScene(t, {
    general: [{ body: '這裡少了錯誤處理', reactions: ['+1'], reactedBy: 'tester' }],
  });

  const { json } = await run();

  assert.equal(json.data.未處理留言數, 0);
  assert.equal(json.data.suggestedAction, 'nothing-to-do');
});

test('別人打的 +1 不算已處理：那是「我同意」，不是「我處理過了」', async (t) => {
  const { run } = await withScene(t, {
    general: [{ body: '這裡少了錯誤處理', reactions: ['+1'], reactedBy: 'reviewer' }],
  });

  const { json } = await run();

  assert.equal(json.data.未處理留言數, 1);
});

test('draft 上也照樣數留言，繼續監看', async (t) => {
  const { run, worktree } = await withScene(t, {
    state: 'open',
    draft: true,
    general: [{ body: '這段先別急著合併' }],
  });

  const { json } = await run();

  assert.equal(json.data.state, 'draft');
  assert.equal(json.data.suggestedAction, 'run-sdlc-fix');
  assert.equal(json.data.terminal, false);
  assert.equal(existsSync(worktree), true, '被退回草稿時更需要那棵工作樹');
});

// ── 清理的守門 ─────────────────────────────────────────────────────

test('工作樹裡有未提交變更時擋下清理，並報出路徑', async (t) => {
  const { run, worktree } = await withScene(t, { state: 'closed', merged: true });
  writeFileSync(join(worktree, 'wip.txt'), '做到一半\n');

  const { code, json } = await run();

  assert.equal(code, 0, '這是一份現況回報，擋下清理不等於整件事失敗');
  assert.equal(json.data.terminal, true);
  assert.equal(json.data.cleaned, false);
  assert.equal(json.data.suggestedAction, 'blocked-dirty');
  assert.equal(json.data.工作樹.有未提交變更, true);
  assert.deepEqual(json.data.工作樹.檔案, ['wip.txt']);
  assert.equal(existsSync(join(worktree, 'wip.txt')), true, '絕不 --force：沒提交的東西救不回來');
});

test('工作樹早就不在時不當成失敗，也不說自己清了', async (t) => {
  const { repo, run, worktree } = await withScene(t, { state: 'closed', merged: true });
  repo.git('worktree', 'remove', worktree);

  const { code, json } = await run();

  assert.equal(code, 0);
  assert.equal(json.data.工作樹.存在, false);
  assert.equal(json.data.cleaned, false);
  assert.equal(json.data.suggestedAction, 'nothing-to-do');
});

test('路徑上是別的 clone 留下的東西時，說出來而不是靜靜跳過', async (t) => {
  const { repo, run, worktree } = await withScene(t, { state: 'closed', merged: true });
  repo.git('worktree', 'remove', worktree);
  mkdirSync(join(worktree, '.git'), { recursive: true });

  const { code, json } = await run();

  assert.equal(code, 0);
  assert.equal(json.data.工作樹.是工作樹, false, '.git 是目錄的是獨立 clone，不是工作樹');
  assert.equal(json.data.cleaned, false);
  assert.equal(json.data.suggestedAction, 'cleanup', '要人動手，而手動出口會說出確切的原因');
  assert.equal(existsSync(join(worktree, '.git')), true, '不是我們建的東西就不碰');
});

test('清不掉的路徑，--dry-run 不會預告一行實跑會拒絕的指令', async (t) => {
  // 試跑印得出漂亮的計畫、實跑卻被擋下來，是最難查的那種落差
  const { repo, run, worktree } = await withScene(t, { state: 'closed', merged: true });
  repo.git('worktree', 'remove', worktree);
  mkdirSync(worktree, { recursive: true });
  writeFileSync(join(worktree, '別人的東西.txt'), 'x\n');

  const { json } = await run(['--dry-run']);

  assert.deepEqual(json.data.commands, []);
  assert.equal(json.data.工作樹.是工作樹, false);
});

// ── 合併之後的 head ───────────────────────────────────────────────

test('來源分支在合併時被刪掉，仍要推導出正確的工作樹並清掉它', async (t) => {
  // Gitea 在這種情況下把 head.ref 換成 refs/pull/{編號}/head，分支名退到 head.label。
  // 拿 ref 去推導會算出一條不存在的路徑，然後靜靜回報「沒事要做」——而合併正是唯一
  // 該動手清理的時機，等於自動清理在真實情況下從來不會成立。
  const { run, worktree } = await withScene(t, {
    state: 'closed',
    merged: true,
    head: { ref: `refs/pull/${INDEX}/head`, label: BRANCH },
  });

  const { code, json } = await run();

  assert.equal(code, 0, json.error?.message);
  assert.equal(json.data.branch, BRANCH, '分支名要取自 head.label');
  assert.equal(json.data.工作樹.路徑, worktree);
  assert.equal(json.data.cleaned, true);
  assert.equal(existsSync(worktree), false);
});

test('fork 來的 PR：head.label 是 owner:branch，只取分支那一段', async (t) => {
  const { run, worktree } = await withScene(t, {
    state: 'closed',
    merged: true,
    head: { ref: `refs/pull/${INDEX}/head`, label: `someone:${BRANCH}` },
  });

  const { json } = await run();

  assert.equal(json.data.branch, BRANCH);
  assert.equal(existsSync(worktree), false, '推導出來的仍是同一條路徑');
});

test('分支名兩邊都取不到時明確中止，不拿空字串去推導路徑', async (t) => {
  const { run } = await withScene(t, {
    state: 'closed',
    merged: true,
    head: { ref: `refs/pull/${INDEX}/head` },
  });

  const { code, json } = await run();

  assert.equal(code, 1);
  assert.equal(json.error.code, 'PULL_HEAD_MISSING');
  assert.match(json.error.message, /worktree-remove/, '要指出手動出口怎麼指名那一棵');
});

// ── 回報內容 ───────────────────────────────────────────────────────

test('回報內容含 PR 狀態、未處理留言數與工作樹現況', async (t) => {
  const { run, worktree } = await withScene(t, { general: [{ body: '一則意見' }] });

  const { json } = await run();

  assert.equal(json.data.index, INDEX);
  assert.equal(json.data.url, `https://gitea.jsc.idv.tw/${REPO}/pulls/${INDEX}`);
  assert.equal(json.data.branch, BRANCH, '工作樹是從 PR 的 head 分支推導的，要說出用的是哪一支');
  assert.equal(json.data.未處理留言數, 1);
  assert.deepEqual(json.data.工作樹, {
    路徑: worktree,
    存在: true,
    是工作樹: true,
    有未提交變更: false,
    檔案: [],
  });
});

test('建議動作是固定的列舉值，呼叫端才能程式化判斷', async (t) => {
  const 列舉 = ['run-sdlc-fix', 'cleanup', 'nothing-to-do', 'blocked-dirty'];
  const { run } = await withScene(t);

  const { json } = await run();

  assert.ok(列舉.includes(json.data.suggestedAction), `不在列舉裡：${json.data.suggestedAction}`);
});

// ── 無狀態 ─────────────────────────────────────────────────────────

test('跑兩次結果一樣，而且不留下任何游標或狀態檔', async (t) => {
  const { repo, home, run } = await withScene(t, { general: [{ body: '一則意見' }] });

  const first = await run();
  const second = await run();

  assert.deepEqual(second.json, first.json, '不與上次比較，同樣的現況就該得到同樣的答案');
  assert.deepEqual(readdirSync(home), ['worktrees'], '家目錄底下只該有工作樹本身');
  assert.equal(repo.git('status', '--porcelain'), '', '目標專案裡不留任何東西');
});

// ── --dry-run ─────────────────────────────────────────────────────

test('--dry-run 印出將執行的 git 指令與將發出的請求，且不清理', async (t) => {
  const { run, worktree } = await withScene(t, { state: 'closed', merged: true });

  const { code, json } = await run(['--dry-run']);

  assert.equal(code, 0);
  assert.equal(json.data.dryRun, true);
  assert.deepEqual(json.data.commands, [`git worktree remove ${worktree}`]);
  assert.ok(json.data.requests.some((r) => r.path.endsWith(`/pulls/${INDEX}`)));
  assert.equal(json.data.cleaned, false);
  assert.equal(json.data.suggestedAction, 'cleanup', '試跑不動手，該做的事要說出來');
  assert.equal(existsSync(worktree), true);
});

test('--dry-run 在還不該清理的狀態下不印 git 指令', async (t) => {
  const { run } = await withScene(t, { state: 'open' });

  const { json } = await run(['--dry-run']);

  assert.deepEqual(json.data.commands, []);
});

// ── 錯誤 ───────────────────────────────────────────────────────────

test('PR 不存在時回可區分的錯誤碼', async (t) => {
  const { stub, run } = await withScene(t);
  stub.requests.length = 0;

  const { json } = await runScript(
    'pr-watch.js',
    ['--repo', REPO, '--index', '999'],
    { env: stubEnv(stub) },
  );

  assert.equal(json.error.code, 'PULL_NOT_FOUND');
});

test('--index 不是正整數時擋在打 Gitea 之前', async (t) => {
  const { stub } = await withScene(t);
  const before = stub.requests.length;

  const { json } = await runScript('pr-watch.js', ['--repo', REPO, '--index', '0'], {
    env: stubEnv(stub),
  });

  assert.equal(json.error.code, 'BAD_INDEX');
  assert.equal(stub.requests.length, before);
});