监听思源退出事件

see https://ld246.com/article/1734263645595

// 调用示例，当callback返回true时退出，返回false时取消退出
function sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}
listenExit(async () => {
    console.log('waiting');
    await sleep(30000);
    return true;
});

// 监听思源退出事件，退出前执行callback，当callback返回true时退出，返回false时取消退出（仅支持electron客户端）
// see https://github.com/siyuan-note/siyuan/blob/5129ad926a21176a352cf5f630e0651011bf9c83/app/src/dialog/processSystem.ts#L287
function listenExit(callback) {
    if(!navigator.userAgent.includes('Electron')) return;
    // 内核是否已退出
    let isKernelExited = false;
    // 是否已取消退出
    let isCancelExited = false;
  
    // 监听内核退出
    const originalFetch = window.fetch;
    window.fetch = async function (url, ...args) {
        try {
            if(url.endsWith('/api/system/exit')) {
                for(;;) {
                    if(await callback()) {
                        isKernelExited = true;
                        break;
                    } else {
                        isCancelExited = true;
                        break;
                    }
                    await sleep(200);
                }
                if(isCancelExited) return new Promise(rs => rs({code:0,msg:'',data:null}));
            }
            const response = await originalFetch(url, ...args);
            return response;
        } catch (error) {
            throw error;
        }
    };

    // 监听客户端退出
    // 保存原始方法
    const ipcRenderer = require('electron').ipcRenderer;
    const originalSend = ipcRenderer.send;
  
    // 重写 ipcRenderer.send 方法
    ipcRenderer.send = async function (...args) {
        if(args[0] === 'siyuan-quit'){
            for(;;) {
                if(isKernelExited) {
                    await sleep(400);
                    break;
                } else if(isCancelExited) {
                    return;
                }
                await sleep(200);
            }
            originalSend.apply(ipcRenderer, args);
        } else {
            originalSend.apply(ipcRenderer, args);
        }
    };

    function sleep(ms) {
        return new Promise(resolve => setTimeout(resolve, ms));
    }
}