a3s-search 0.8.0

//! Bing China search engine implementation using headless browser.
//!
//! This engine requires the `headless` feature because Bing China's search results
//! page relies on JavaScript rendering that plain HTTP requests cannot handle.

use crate::html_engine::{selector, HtmlEngine, HtmlParser};
use crate::{EngineCategory, EngineConfig, Result, SearchQuery, SearchResult};
use scraper::Html;

/// Bing China HTML parser.
pub struct BingChinaParser;

/// Bing China search engine (必应中国).
pub type BingChina = HtmlEngine<BingChinaParser>;

impl BingChina {
    /// Creates a new Bing China engine with the given page fetcher.
    pub fn new(fetcher: std::sync::Arc<dyn crate::PageFetcher>) -> Self {
        HtmlEngine::with_fetcher(BingChinaParser, fetcher)
    }
}

impl HtmlParser for BingChinaParser {
    fn default_config() -> EngineConfig {
        EngineConfig {
            name: "Bing China".to_string(),
            shortcut: "bing_cn".to_string(),
            categories: vec![EngineCategory::General],
            weight: 1.0,
            timeout: 10,
            enabled: true,
            paging: true,
            safesearch: true,
        }
    }

    fn build_url(&self, query: &SearchQuery) -> String {
        let mut url = format!(
            "https://cn.bing.com/search?q={}",
            urlencoding::encode(&query.query)
        );
        if query.page > 1 {
            url.push_str(&format!("&first={}", (query.page - 1) * 10 + 1));
        }
        url
    }

    fn parse(&self, html: &str) -> Result<Vec<SearchResult>> {
        let document = Html::parse_document(html);
        let result_sel = selector("li.b_algo")?;
        let title_sel = selector("h2 a")?;
        let snippet_sel = selector(".b_caption p, .b_algoSlug")?;

        let mut results = Vec::new();

        for element in document.select(&result_sel) {
            let title_elem = match element.select(&title_sel).next() {
                Some(el) => el,
                None => continue,
            };

            let title = title_elem.text().collect::<String>().trim().to_string();
            let url = title_elem
                .value()
                .attr("href")
                .unwrap_or_default()
                .to_string();

            let content = element
                .select(&snippet_sel)
                .next()
                .map(|e| e.text().collect::<String>().trim().to_string())
                .unwrap_or_default();

            if !url.is_empty() && !title.is_empty() && url.starts_with("http") {
                results.push(SearchResult::new(url, title, content));
            }
        }

        Ok(results)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::fetcher_http::HttpFetcher;
    use crate::Engine;
    use std::sync::Arc;

    fn make_bing_china() -> BingChina {
        BingChina::new(Arc::new(HttpFetcher::new()))
    }

    #[test]
    fn test_bing_china_new() {
        let engine = make_bing_china();
        assert_eq!(engine.config().name, "Bing China");
        assert_eq!(engine.config().shortcut, "bing_cn");
        assert_eq!(engine.config().categories, vec![EngineCategory::General]);
        assert_eq!(engine.config().weight, 1.0);
        assert_eq!(engine.config().timeout, 10);
        assert!(engine.config().enabled);
        assert!(engine.config().paging);
        assert!(engine.config().safesearch);
    }

    #[test]
    fn test_bing_china_with_config() {
        let custom_config = EngineConfig {
            name: "Custom Bing".to_string(),
            shortcut: "cbing".to_string(),
            weight: 1.5,
            ..Default::default()
        };
        let engine = make_bing_china().with_config(custom_config);
        assert_eq!(engine.config().name, "Custom Bing");
        assert_eq!(engine.config().shortcut, "cbing");
        assert_eq!(engine.config().weight, 1.5);
    }

    #[test]
    fn test_bing_china_engine_trait() {
        let engine = make_bing_china();
        assert_eq!(engine.name(), "Bing China");
        assert_eq!(engine.shortcut(), "bing_cn");
        assert_eq!(engine.weight(), 1.0);
        assert!(engine.is_enabled());
    }

    #[test]
    fn test_parse_results_empty_html() {
        let parser = BingChinaParser;
        let results = parser.parse("<html><body></body></html>").unwrap();
        assert!(results.is_empty());
    }

    #[test]
    fn test_parse_results_with_results() {
        let parser = BingChinaParser;
        let html = r#"
            <html>
            <body>
                <ol id="b_results">
                    <li class="b_algo">
                        <h2><a href="https://www.rust-lang.org/">Rust Programming Language</a></h2>
                        <div class="b_caption"><p>A language empowering everyone.</p></div>
                    </li>
                    <li class="b_algo">
                        <h2><a href="https://doc.rust-lang.org/book/">The Rust Book</a></h2>
                        <div class="b_caption"><p>The official Rust book.</p></div>
                    </li>
                </ol>
            </body>
            </html>
        "#;
        let results = parser.parse(html).unwrap();
        assert_eq!(results.len(), 2);
        assert_eq!(results[0].title, "Rust Programming Language");
        assert_eq!(results[0].url, "https://www.rust-lang.org/");
        assert_eq!(results[0].content, "A language empowering everyone.");
        assert_eq!(results[1].title, "The Rust Book");
    }

    #[test]
    fn test_parse_results_skips_non_http_urls() {
        let parser = BingChinaParser;
        let html = r#"
            <html>
            <body>
                <li class="b_algo">
                    <h2><a href="javascript:void(0)">Bad Link</a></h2>
                </li>
            </body>
            </html>
        "#;
        let results = parser.parse(html).unwrap();
        assert!(results.is_empty());
    }

    #[test]
    fn test_parse_results_skips_missing_title() {
        let parser = BingChinaParser;
        let html = r#"
            <html>
            <body>
                <li class="b_algo">
                    <div class="b_caption"><p>No title element</p></div>
                </li>
            </body>
            </html>
        "#;
        let results = parser.parse(html).unwrap();
        assert!(results.is_empty());
    }

    #[test]
    fn test_parse_results_with_algo_slug() {
        let parser = BingChinaParser;
        let html = r#"
            <html>
            <body>
                <li class="b_algo">
                    <h2><a href="https://example.com">Example</a></h2>
                    <div class="b_algoSlug">Snippet from algo slug.</div>
                </li>
            </body>
            </html>
        "#;
        let results = parser.parse(html).unwrap();
        assert_eq!(results.len(), 1);
        assert_eq!(results[0].content, "Snippet from algo slug.");
    }
}