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lean_ctx/server/
helpers.rs

1use serde_json::Value;
2
3pub fn get_str_array(
4    args: Option<&serde_json::Map<String, Value>>,
5    key: &str,
6) -> Option<Vec<String>> {
7    let val = args?.get(key)?;
8
9    // Normal path: native JSON array.
10    if let Some(arr) = val.as_array() {
11        let mut out = Vec::with_capacity(arr.len());
12        for v in arr {
13            out.push(v.as_str()?.to_string());
14        }
15        return Some(out);
16    }
17
18    // Fallback: some MCP bridges serialize arrays as JSON-encoded strings.
19    // Example: { "paths": "[\"src/main.rs\",\"src/lib.rs\"]" }
20    if let Some(s) = val.as_str()
21        && let Ok(Value::Array(arr)) = serde_json::from_str::<Value>(s)
22    {
23        let mut out = Vec::with_capacity(arr.len());
24        for v in &arr {
25            out.push(v.as_str()?.to_string());
26        }
27        return Some(out);
28    }
29
30    None
31}
32
33pub fn get_str(args: Option<&serde_json::Map<String, Value>>, key: &str) -> Option<String> {
34    args?
35        .get(key)?
36        .as_str()
37        .map(std::string::ToString::to_string)
38}
39
40pub fn get_int(args: Option<&serde_json::Map<String, Value>>, key: &str) -> Option<i64> {
41    args?.get(key)?.as_i64()
42}
43
44pub fn get_bool(args: Option<&serde_json::Map<String, Value>>, key: &str) -> Option<bool> {
45    args?.get(key)?.as_bool()
46}
47
48pub fn hash_fast(s: &str) -> String {
49    const THRESHOLD: usize = 16 * 1024;
50    if s.len() <= THRESHOLD {
51        crate::core::hasher::hash_str(s)
52    } else {
53        let prefix = &s[..s.floor_char_boundary(4096)];
54        let suffix = &s[s.ceil_char_boundary(s.len().saturating_sub(4096))..];
55        let mut hasher = blake3::Hasher::new();
56        hasher.update(prefix.as_bytes());
57        hasher.update(s.len().to_string().as_bytes());
58        hasher.update(suffix.as_bytes());
59        hasher.finalize().to_hex().to_string()
60    }
61}
62
63pub fn canonicalize_json(v: &Value) -> Value {
64    match v {
65        Value::Object(map) => {
66            let mut keys: Vec<&String> = map.keys().collect();
67            keys.sort();
68            let mut out = serde_json::Map::new();
69            for k in keys {
70                if let Some(val) = map.get(k) {
71                    out.insert(k.clone(), canonicalize_json(val));
72                }
73            }
74            Value::Object(out)
75        }
76        Value::Array(arr) => Value::Array(arr.iter().map(canonicalize_json).collect()),
77        other => other.clone(),
78    }
79}
80
81pub fn canonical_args_string(args: Option<&serde_json::Map<String, Value>>) -> String {
82    let v = args.map_or(Value::Null, |m| Value::Object(m.clone()));
83    let canon = canonicalize_json(&v);
84    serde_json::to_string(&canon).unwrap_or_default()
85}
86
87pub fn extract_search_pattern_from_command(command: &str) -> Option<String> {
88    let parts: Vec<&str> = command.split_whitespace().collect();
89    if parts.len() < 2 {
90        return None;
91    }
92    let cmd = parts[0];
93    if cmd == "grep" || cmd == "rg" || cmd == "ag" || cmd == "ack" {
94        for (i, part) in parts.iter().enumerate().skip(1) {
95            if !part.starts_with('-') {
96                return Some(part.to_string());
97            }
98            if (*part == "-e" || *part == "--regexp" || *part == "-m") && i + 1 < parts.len() {
99                return Some(parts[i + 1].to_string());
100            }
101        }
102    }
103    if cmd == "find" || cmd == "fd" {
104        for (i, part) in parts.iter().enumerate() {
105            if (*part == "-name" || *part == "-iname") && i + 1 < parts.len() {
106                return Some(
107                    parts[i + 1]
108                        .trim_matches('\'')
109                        .trim_matches('"')
110                        .to_string(),
111                );
112            }
113        }
114        if cmd == "fd" && parts.len() >= 2 && !parts[1].starts_with('-') {
115            return Some(parts[1].to_string());
116        }
117    }
118    None
119}