lucida-queue/backend/services/lucida.ts

import {DownloadResult, LucidaOptions} from "../types/queue";
import {Browser, BrowserContext, Download, firefox, Locator, Page, Response as PResponse} from "playwright";
import path from "node:path";
import {fetchBooklet} from "./booklet";
import * as fs from "node:fs";

class Lucida {
    private browser: Browser | null;
    private context: BrowserContext | null;
    private options: LucidaOptions;

    public constructor(lucidaOptions: LucidaOptions) {
        this.browser = null;
        this.context = null;
        this.options = lucidaOptions
    }

    public async construct(): Promise<void> {
        console.log('Lucida: Launching browser');

        const proxy: {server: string} | undefined = this.options.proxy ? {server: this.options.proxy} : undefined;
        this.browser = await firefox.launch({
            headless: this.options.headless,
            proxy: proxy,
            args: ['--no-sandbox', '--no-gpu']
        });
        this.context = await this.browser.newContext({
            acceptDownloads: true,
            baseURL: this.options.baseUrl
        });
    }

    public async destruct(reason: string | undefined = undefined): Promise<void> {
        if (this.browser === null) {
            return;
        }

        console.log('Lucida: Closing browser');
        if (this.context !== null) {
            await this.context.close({reason: reason});
        }

        await this.browser.close();
    }

    private async getError(page: Page): Promise<string | undefined> {
        const errorElement: Locator = page.locator('div[class="error svelte-40348f"]');
        const hasError: boolean = !page.isClosed() && await errorElement.count() !== 0 && await errorElement.isVisible();

        if (!hasError) {
            return undefined;
        }

        let errorText: string = (await errorElement.innerText()).trim();
        errorText += (await errorElement.locator('details').locator('p').allTextContents()).map(e => e.trim());
        return errorText;
    }

    /**
     * Check the 'Hide my download from recently downloaded' checkbox
     * @param page The page to check
     * @private
     */
    private async hideDownload(page: Page): Promise<void> {
        const hideCheckbox: Locator = page.locator('input[id="hide-from-ticker"]');
        if (await hideCheckbox.count() === 0 || !await hideCheckbox.isVisible()) {
            console.error('Lucida: No hide checkbox found!');
            return;
        }

        try {
            await hideCheckbox.setChecked(true, {force: true});
        } catch (err) {
            console.error('Lucida: Could not check hide checkbox:', err instanceof Error ? err.message : 'Unknown error');
        }
    }

    private async saveDownload(download: Download, downloadPath: string): Promise<string> {
        const pathName: string = path.join(downloadPath, download.suggestedFilename());
        // await download.saveAs(pathName);
        // return pathName;

        const stream = fs.createWriteStream(pathName);
        const response = await download.createReadStream();
        if (response) {
            response.pipe(stream);
            await new Promise((resolve, reject) => {
                stream.on('finish', resolve);
                stream.on('error', reject);
            });
        }

        return pathName;
    }

    public async download(url: string, downloadPath: string, timeout: number, status: {
        status: string
    }): Promise<DownloadResult> {
        let finished: boolean = false;

        let close: boolean = false;
        if (this.context === null) {
            await this.construct();
            close = true;
        }

        if (this.context === null) {
            return {
                success: false,
                error: 'Could not create browser context'
            };
        }
        const downloadPage: Page = await this.context.newPage();

        const downloadPageUrl: string = this.options.baseUrl + '?url=' + encodeURIComponent(url);
        const downloadPageResp: PResponse | null = await downloadPage.goto(downloadPageUrl);
        if (downloadPageResp === null || !downloadPageResp.ok()) {
            return {
                success: false,
                error: 'Could not load page'
            };
        }

        // Check for errors
        const error: string | undefined = await this.getError(downloadPage);
        if (error) {
            await downloadPage.close();
            return {
                success: false,
                error: error
            };
        }

        await this.hideDownload(downloadPage);

        const start: number = Date.now();
        let retryCount: number = 0;

        // Listen for download
        downloadPage.once('download', async (download) => {
            await this.saveDownload(download, downloadPath);
            finished = true;
            await fetchBooklet(url, downloadPath, this.context);

            await downloadPage.close();
            if (close) {
                await this.destruct();
            }

            process.stdout.clearLine(0);
            return {success: true};
        });
        // Start download
        await downloadPage.getByText('download full album').click();

        // Retry file download if it fails
        const progressElement: Locator = downloadPage.locator('div[class="loader svelte-1ipdo3f"]');
        while (!finished && retryCount < 10 && (Date.now() - start) < timeout) {
            const retry: Locator = downloadPage.getByText('Retry');
            const error: string | undefined = finished ? undefined : await this.getError(downloadPage);

            if (error !== undefined) {
                console.log('Retrying download because of error:', error);
                await retry.click();
                retryCount++;
            } else if (!finished && await progressElement.count() !== 0 && await progressElement.isVisible()) {
                const progress: string = (await progressElement.locator('p').innerText()).trim();
                status.status = progress;
                process.stdout.clearLine(0);
                process.stdout.write(`\r${progress}`);
            }
        }

        process.stdout.clearLine(0);

        if (!finished) {
            // Cleanup
            await downloadPage.close();
            if (close) {
                await this.destruct();
            }

            let errorMessage: string;
            if (timeout <= (Date.now() - start)) {
                errorMessage = 'Download timed out';
            } else if (retryCount >= 10) {
                errorMessage = 'Download failed after 10 retries';
            } else {
                errorMessage = 'Unknown error';
            }
            return {
                success: false,
                error: errorMessage
            };
        }

        return {success: true};
    }
}

export default Lucida;