'use strict';

const test = require('node:test');
const assert = require('node:assert/strict');

const { fetchReleases, truncateString } = require('../releases');

// 以可控的假回應替換全域 fetch，並於結束後還原
function withFetch(handler, run) {
    const original = globalThis.fetch;
    globalThis.fetch = handler;
    return Promise.resolve()
        .then(run)
        .finally(() => {
            globalThis.fetch = original;
        });
}

// 建立模擬 Response 物件
const jsonResponse = (body, ok = true) => ({
    ok,
    text: async () => (typeof body === 'string' ? body : JSON.stringify(body)),
});

test('fetchReleases 單頁（不足一頁即停止）', async () => {
    await withFetch(
        async () => jsonResponse([{ tag_name: 'v1.0.0' }]),
        async () => {
            const releases = await fetchReleases('https://gitea.example.com/api');
            assert.deepEqual(releases, [{ tag_name: 'v1.0.0' }]);
        },
    );
});

test('fetchReleases 跨頁合併直到不足一頁', async () => {
    const pages = {
        1: Array.from({ length: 10 }, (_, i) => ({ tag_name: `v1.0.${i}` })),
        2: [{ tag_name: 'v1.1.0' }],
    };
    const seen = [];

    await withFetch(
        async (url) => {
            const page = Number(new URL(url).searchParams.get('page'));
            seen.push(page);
            return jsonResponse(pages[page]);
        },
        async () => {
            const releases = await fetchReleases('https://gitea.example.com/api');
            assert.equal(releases.length, 11);
            assert.deepEqual(seen, [1, 2]);
        },
    );
});

test('fetchReleases 對非 2xx 回應拋錯', async () => {
    await withFetch(
        async () => jsonResponse('Not Found', false),
        async () => {
            await assert.rejects(
                () => fetchReleases('https://gitea.example.com/api'),
                /release API 請求失敗/,
            );
        },
    );
});

test('fetchReleases 對無法解析的 JSON 回應拋錯', async () => {
    await withFetch(
        async () => jsonResponse('{ this is not valid json', true),
        async () => {
            await assert.rejects(
                () => fetchReleases('https://gitea.example.com/api'),
                /回傳資料無法解析/,
            );
        },
    );
});

test('truncateString 以字元截斷且不拆分多位元組字元（emoji 代理對）', () => {
    const emojis = '😀'.repeat(25);
    const result = truncateString(emojis, 10);
    // 應得到完整 10 個 emoji（以 code point 計），不殘留落單的代理碼元
    assert.equal(Array.from(result).length, 10);
    assert.equal(result, '😀'.repeat(10));
    assert.ok(!/[\uD800-\uDBFF](?![\uDC00-\uDFFF])/.test(result), '不應殘留落單的高代理碼元');
});

test('fetchReleases 解析失敗時截斷過長的回應片段', async () => {
    const huge = `{${'x'.repeat(5000)}`;
    await withFetch(
        async () => jsonResponse(huge, true),
        async () => {
            await assert.rejects(
                () => fetchReleases('https://gitea.example.com/api'),
                (err) => {
                    const match = err.message.match(/片段：「([\s\S]*)」$/);
                    assert.ok(match, '錯誤訊息應包含回應內容片段');
                    assert.ok(Array.from(match[1]).length <= 200, '片段應截斷至 200 字元內');
                    return true;
                },
            );
        },
    );
});

test('fetchReleases 對非陣列回應拋錯', async () => {
    await withFetch(
        async () => jsonResponse({ message: 'oops' }),
        async () => {
            await assert.rejects(
                () => fetchReleases('https://gitea.example.com/api'),
                /回傳非陣列資料/,
            );
        },
    );
});

test('fetchReleases 有 token 時帶入授權標頭', async () => {
    let captured;

    await withFetch(
        async (url, options) => {
            captured = options;
            return jsonResponse([]);
        },
        async () => {
            await fetchReleases('https://gitea.example.com/api', { token: 'secret' });
            assert.equal(captured.headers.Authorization, 'token secret');
        },
    );
});