phrona 0.1.0

High-performance metasearch engine library for Rust and Python
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140

use async_trait::async_trait;

use crate::engine::{Engine, EngineContext};
use crate::engines::util;
use crate::error::{Error, Result};
use crate::models::{Category, RawResult};
use crate::parse;

/// Wikipedia opensearch API: returns the best single match with a summary.
pub struct Wikipedia;

#[async_trait]
impl Engine for Wikipedia {
    fn name(&self) -> &'static str {
        "wikipedia"
    }

    fn category(&self) -> Category {
        Category::Web
    }

    async fn search(&self, ctx: &EngineContext<'_>) -> Result<Vec<RawResult>> {
        let (lang, _) = ctx.opts.lang_country();
        let lang = lang_clean(&lang);
        let url = parse::with_query(
            &format!("https://{lang}.wikipedia.org/w/api.php"),
            [
                ("action", "opensearch"),
                ("profile", "fuzzy"),
                ("limit", "1"),
                ("search", ctx.opts.query.as_str()),
            ],
        );
        let resp = ctx.client.get(&url).await?;
        util::check_response(self.name(), &resp, util::MediaType::Json)?;
        let body = util::read_body(resp, self.name()).await?;
        let json: serde_json::Value = serde_json::from_slice(&body)
            .map_err(|_| Error::schema("wikipedia", "invalid JSON response"))?;
        let Some((title, url)) = parse_opensearch(&json) else {
            return Ok(Vec::new());
        };
        let mut description = String::new();
        let extract_url = parse::with_query(
            &format!("https://{lang}.wikipedia.org/w/api.php"),
            [
                ("action", "query"),
                ("format", "json"),
                ("prop", "extracts"),
                ("explaintext", "1"),
                ("exintro", "1"),
                ("redirects", "1"),
                ("titles", title.as_str()),
            ],
        );
        if let Ok(resp) = ctx.client.get(&extract_url).await {
            if let Ok(bytes) = util::read_body(resp, self.name()).await {
                if let Ok(ext) = serde_json::from_slice::<serde_json::Value>(&bytes) {
                    if let Some(page) = ext
                        .pointer("/query/pages")
                        .and_then(|v| v.as_object())
                        .and_then(|m| m.values().next())
                    {
                        if let Some(e) = page.get("extract").and_then(|v| v.as_str()) {
                            if !e.contains("may refer to:") {
                                description = e.to_string();
                            }
                        }
                    }
                }
            }
        }
        Ok(vec![RawResult {
            title,
            url,
            description,
            engine: self.name().into(),
            position: 1,
            ..Default::default()
        }])
    }
}

/// Extract (title, url) from an opensearch response.
pub fn parse_opensearch(json: &serde_json::Value) -> Option<(String, String)> {
    let title = json
        .get(1)
        .and_then(|v| v.as_array())
        .and_then(|a| a.first())
        .and_then(|v| v.as_str())
        .map(|s| s.to_string());
    let url = json
        .get(3)
        .and_then(|v| v.as_array())
        .and_then(|a| a.first())
        .and_then(|v| v.as_str())
        .map(|s| s.to_string());
    Some((title?, url?))
}

fn lang_clean(lang: &str) -> String {
    if lang.is_empty() || lang == "all" || lang == "us" || lang == "gb" {
        "en".to_string()
    } else {
        lang.to_string()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn parse_fixture() {
        if !crate::engines::util::fixture_parses("wikipedia_opensearch.json") {
            return;
        }
        let json: serde_json::Value = serde_json::from_str(include_str!(
            "../../tests/fixtures/wikipedia_opensearch.json"
        ))
        .unwrap();
        let (title, url) = parse_opensearch(&json).expect("fixture must parse");
        assert_eq!(title, "Rust (programming language)");
        assert!(url.contains("wikipedia.org"));
    }

    #[test]
    fn parse_handles_missing_sections() {
        assert!(parse_opensearch(&serde_json::json!({})).is_none());
        assert!(parse_opensearch(&serde_json::json!([null, [], [], []])).is_none());
    }

    #[test]
    fn lang_clean_falls_back_to_english() {
        assert_eq!(lang_clean(""), "en");
        assert_eq!(lang_clean("all"), "en");
        assert_eq!(lang_clean("us"), "en");
        assert_eq!(lang_clean("gb"), "en");
        assert_eq!(lang_clean("de"), "de");
    }
}