✨ feat(engine): provide startpage search engine (#314)

src/engines/mod.rs

@@ -7,3 +7,4 @@ pub mod brave;
 pub mod duckduckgo;
 pub mod search_result_parser;
 pub mod searx;
+pub mod startpage;

src/engines/startpage.rs

@@ -0,0 +1,96 @@
+//! The `duckduckgo` module handles the scraping of results from the duckduckgo search engine
+//! by querying the upstream duckduckgo search engine with user provided query and with a page
+//! number if provided.
+
+use std::collections::HashMap;
+
+use reqwest::header::HeaderMap;
+use reqwest::Client;
+use scraper::Html;
+
+use crate::models::aggregation_models::SearchResult;
+
+use crate::models::engine_models::{EngineError, SearchEngine};
+
+use error_stack::{Report, Result, ResultExt};
+
+use super::search_result_parser::SearchResultParser;
+
+/// A new Startpage engine type defined in-order to implement the `SearchEngine` trait which allows to
+/// reduce code duplication as well as allows to create vector of different search engines easily.
+pub struct Startpage {
+    /// The parser, used to interpret the search result.
+    parser: SearchResultParser,
+}
+
+impl Startpage {
+    /// Creates the Startpage parser.
+    pub fn new() -> Result<Self, EngineError> {
+        Ok(Self {
+            parser: SearchResultParser::new(
+                ".no-results",
+                ".w-gl__result__main",
+                ".w-gl__result-second-line-container>.w-gl__result-title>h3",
+                ".w-gl__result-url",
+                ".w-gl__description",
+            )?,
+        })
+    }
+}
+
+#[async_trait::async_trait]
+impl SearchEngine for Startpage {
+    async fn results(
+        &self,
+        query: &str,
+        page: u32,
+        user_agent: &str,
+        client: &Client,
+        _safe_search: u8,
+    ) -> Result<HashMap<String, SearchResult>, EngineError> {
+        // Page number can be missing or empty string and so appropriate handling is required
+        // so that upstream server recieves valid page number.
+        let url: String = match page {
+            1 | 0 => {
+                format!("https://startpage.com/do/dsearch?q={query}&num=10&start=0")
+            }
+            _ => {
+                format!(
+                    "https://startpage.com/do/dsearch?q={query}&num=10&start={}",
+                    page * 10,
+                )
+            }
+        };
+
+        // initializing HeaderMap and adding appropriate headers.
+        let header_map = HeaderMap::try_from(&HashMap::from([
+            ("USER_AGENT".to_string(), user_agent.to_string()),
+            ("REFERER".to_string(), "https://google.com/".to_string()),
+            (
+                "CONTENT_TYPE".to_string(),
+                "application/x-www-form-urlencoded".to_string(),
+            ),
+            ("COOKIE".to_string(), "preferences=connect_to_serverEEE0N1Ndate_timeEEEworldN1Ndisable_family_filterEEE0N1Ndisable_open_in_new_windowEEE0N1Nenable_post_methodEEE1N1Nenable_proxy_safety_suggestEEE1N1Nenable_stay_controlEEE0N1Ninstant_answersEEE1N1Nlang_homepageEEEs%2Fnight%2FenN1NlanguageEEEenglishN1Nlanguage_uiEEEenglishN1Nnum_of_resultsEEE10N1Nsearch_results_regionEEEallN1NsuggestionsEEE1N1Nwt_unitEEEcelsius".to_string()),
+        ]))
+        .change_context(EngineError::UnexpectedError)?;
+
+        let document: Html = Html::parse_document(
+            &Startpage::fetch_html_from_upstream(self, &url, header_map, client).await?,
+        );
+
+        if self.parser.parse_for_no_results(&document).next().is_some() {
+            return Err(Report::new(EngineError::EmptyResultSet));
+        }
+
+        // scrape all the results from the html
+        self.parser
+            .parse_for_results(&document, |title, url, desc| {
+                Some(SearchResult::new(
+                    title.inner_html().trim(),
+                    &format!("{}", url.inner_html().trim()),
+                    desc.inner_html().trim(),
+                    &["startpage"],
+                ))
+            })
+    }
+}

src/models/engine_models.rs

@@ -154,6 +154,10 @@ impl EngineHandler {
                     let engine = crate::engines::brave::Brave::new()?;
                     ("brave", Box::new(engine))
                 }
+                "startpage" => {
+                    let engine = crate::engines::startpage::Startpage::new()?;
+                    ("startpage", Box::new(engine))
+                }
                 _ => {
                     return Err(Report::from(EngineError::NoSuchEngineFound(
                         engine_name.to_string(),