RSSHub/lib/middleware/parameter.js

const he = require('he');

module.exports = async (ctx, next) => {
    await next();

    if (!ctx._matchedRoute) {
        throw Error('wrong path');
    }

    if (ctx.state.data && (!ctx.state.data.item || ctx.state.data.item.length === 0) && !ctx.state.allowEmpty) {
        throw Error('this route is empty, please check the origin site or create an issue to feedback on https://github.com/DIYgod/RSSHub/issues/new/choose');
    }

    // decode HTML entities
    if (ctx.state.data) {
        ctx.state.data.title && (ctx.state.data.title = he.decode(ctx.state.data.title + ''));
        ctx.state.data.description && (ctx.state.data.description = he.decode(ctx.state.data.description + ''));
        ctx.state.data.item &&
            ctx.state.data.item.forEach((item) => {
                item.title && (item.title = he.decode(item.title + ''));
                item.description && (item.description = he.decode(item.description + ''));
            });
    }

    // filter
    if (ctx.state.data && ctx.query && (ctx.query.filter || ctx.query.filter_title || ctx.query.filter_description || ctx.query.filter_author)) {
        ctx.state.data.item = ctx.state.data.item.filter((item) => {
            const title = item.title || '';
            const description = item.description || title;
            const author = item.author || '';
            return !(
                (ctx.query.filter && !title.match(ctx.query.filter) && !description.match(ctx.query.filter)) ||
                (ctx.query.filter_title && !title.match(ctx.query.filter_title)) ||
                (ctx.query.filter_description && !description.match(ctx.query.filter_description)) ||
                (ctx.query.filter_author && !author.match(ctx.query.filter_author))
            );
        });
    }
    if (ctx.state.data && ctx.query && (ctx.query.filterout || ctx.query.filterout_title || ctx.query.filterout_description || ctx.query.filterout_author)) {
        ctx.state.data.item = ctx.state.data.item.filter((item) => {
            const title = item.title;
            const description = item.description || title;
            const author = item.author || '';
            return (
                (ctx.query.filterout && !title.match(ctx.query.filterout) && !description.match(ctx.query.filterout)) ||
                (ctx.query.filterout_title && !title.match(ctx.query.filterout_title)) ||
                (ctx.query.filterout_description && !description.match(ctx.query.filterout_description)) ||
                (ctx.query.filterout_author && !author.match(ctx.query.filterout_author))
            );
        });
    }
    if (ctx.state.data && ctx.query && ctx.query.filter_time) {
        const now = Date.now();
        ctx.state.data.item = ctx.state.data.item.filter(({ pubDate }) => {
            if (!pubDate) {
                return true;
            }

            try {
                return now - new Date(pubDate).getTime() <= parseInt(ctx.query.filter_time) * 1000;
            } catch (err) {
                return true;
            }
        });
    }

    // limit
    if (ctx.state.data && ctx.query && ctx.query.limit) {
        ctx.state.data.item = ctx.state.data.item.slice(0, parseInt(ctx.query.limit));
    }

    // telegram instant view
    if (ctx.state.data && ctx.query && ctx.query.tgiv) {
        ctx.state.data.item.map((item) => {
            const encodedlink = encodeURIComponent(item.link);
            item.link = `https://t.me/iv?url=${encodedlink}&rhash=${ctx.query.tgiv}`;
            return item;
        });
    }
};