fix: parse Cub AUR responses with serde

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

local/recipes/system/cub/source/cub-lib/src/aur.rs

@@ -1,27 +1,61 @@
-use std::collections::BTreeMap;
+use serde::Deserialize;
 
 use crate::error::CubError;
 
 const DEFAULT_AUR_BASE_URL: &str = "https://aur.archlinux.org";
 
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Deserialize)]
 pub struct AurPackage {
+    #[serde(rename = "Name")]
     pub name: String,
+    #[serde(rename = "Version")]
     pub version: String,
+    #[serde(rename = "Description")]
+    #[serde(default)]
     pub description: String,
+    #[serde(rename = "URL")]
+    #[serde(default)]
     pub url: String,
+    #[serde(rename = "License")]
+    #[serde(default)]
     pub license: Vec<String>,
+    #[serde(rename = "Depends")]
+    #[serde(default)]
     pub depends: Vec<String>,
+    #[serde(rename = "MakeDepends")]
+    #[serde(default)]
     pub makedepends: Vec<String>,
+    #[serde(rename = "OptDepends")]
+    #[serde(default)]
     pub optdepends: Vec<String>,
+    #[serde(rename = "Provides")]
+    #[serde(default)]
     pub provides: Vec<String>,
+    #[serde(rename = "Conflicts")]
+    #[serde(default)]
     pub conflicts: Vec<String>,
+    #[serde(rename = "NumVotes")]
     pub num_votes: u64,
+    #[serde(rename = "Popularity")]
     pub popularity: f64,
+    #[serde(rename = "LastModified")]
     pub last_modified: i64,
+    #[serde(rename = "OutOfDate")]
+    #[serde(default)]
     pub out_of_date: Option<bool>,
 }
 
+#[derive(Debug, Deserialize)]
+struct AurRpcResponse {
+    version: i64,
+    #[serde(rename = "type")]
+    response_type: String,
+    resultcount: i64,
+    results: Vec<AurPackage>,
+    #[serde(default)]
+    error: Option<String>,
+}
+
 #[cfg(feature = "full")]
 pub struct AurClient {
     pub base_url: String,
@@ -153,526 +187,39 @@ fn non_empty_trimmed(value: &str) -> Option<&str> {
 }
 
 fn aur_error(message: impl Into<String>) -> CubError {
-    CubError::Conversion(format!("AUR: {}", message.into()))
+    CubError::Aur(message.into())
 }
 
 #[cfg(not(feature = "full"))]
 fn feature_not_enabled_error() -> CubError {
-    CubError::Conversion("reqwest feature not enabled".into())
+    CubError::Aur("reqwest feature not enabled".into())
 }
 
 fn parse_rpc_response(body: &str, empty_message: &str) -> Result<Vec<AurPackage>, CubError> {
-    let root = JsonParser::new(body)
-        .parse()
+    let rpc: AurRpcResponse = serde_json::from_str(body)
         .map_err(|err| aur_error(format!("failed to parse JSON response: {err}")))?;
 
-    let object = match root {
-        JsonValue::Object(object) => object,
-        _ => {
-            return Err(aur_error(
-                "invalid JSON response: expected top-level object",
-            ))
-        }
-    };
-
-    let version = require_i64(&object, "version")?;
-    if version != 5 {
-        return Err(aur_error(format!("unexpected RPC version: {version}")));
+    if rpc.version != 5 {
+        return Err(aur_error(format!("unexpected RPC version: {}", rpc.version)));
     }
 
-    let response_type = require_string(&object, "type")?;
-    if response_type == "error" {
-        let message =
-            optional_string(&object, "error")?.unwrap_or_else(|| "unknown AUR error".to_string());
+    if rpc.response_type == "error" {
+        let message = rpc.error.unwrap_or_else(|| "unknown AUR error".to_string());
         return Err(aur_error(message));
     }
 
-    if response_type != "search" && response_type != "multiinfo" && response_type != "info" {
+    if rpc.response_type != "search" && rpc.response_type != "multiinfo" && rpc.response_type != "info" {
         return Err(aur_error(format!(
-            "unexpected RPC response type: {response_type}"
+            "unexpected RPC response type: {}",
+            rpc.response_type
         )));
     }
 
-    let resultcount = require_i64(&object, "resultcount")?;
-    let results = require_array(&object, "results")?;
-
-    if resultcount <= 0 || results.is_empty() {
+    if rpc.resultcount <= 0 || rpc.results.is_empty() {
         return Err(aur_error(empty_message.to_string()));
     }
 
-    let mut packages = Vec::with_capacity(results.len());
-    for value in results {
-        packages.push(AurPackage::from_json_value(value)?);
-    }
-
-    if packages.is_empty() {
-        return Err(aur_error(empty_message.to_string()));
-    }
-
-    Ok(packages)
-}
-
-impl AurPackage {
-    fn from_json_value(value: &JsonValue) -> Result<Self, CubError> {
-        let object = match value {
-            JsonValue::Object(object) => object,
-            _ => return Err(aur_error("invalid package entry: expected object")),
-        };
-
-        Ok(Self {
-            name: require_string(object, "Name")?,
-            version: require_string(object, "Version")?,
-            description: optional_string(object, "Description")?.unwrap_or_default(),
-            url: optional_string(object, "URL")?.unwrap_or_default(),
-            license: optional_string_list(object, "License")?,
-            depends: optional_string_list(object, "Depends")?,
-            makedepends: optional_string_list(object, "MakeDepends")?,
-            optdepends: optional_string_list(object, "OptDepends")?,
-            provides: optional_string_list(object, "Provides")?,
-            conflicts: optional_string_list(object, "Conflicts")?,
-            num_votes: optional_u64(object, "NumVotes")?.unwrap_or(0),
-            popularity: optional_f64(object, "Popularity")?.unwrap_or(0.0),
-            last_modified: optional_i64(object, "LastModified")?.unwrap_or(0),
-            out_of_date: optional_out_of_date(object, "OutOfDate")?,
-        })
-    }
-}
-
-fn require_string(object: &BTreeMap<String, JsonValue>, key: &str) -> Result<String, CubError> {
-    optional_string(object, key)?.ok_or_else(|| aur_error(format!("missing field '{key}'")))
-}
-
-fn optional_string(
-    object: &BTreeMap<String, JsonValue>,
-    key: &str,
-) -> Result<Option<String>, CubError> {
-    match object.get(key) {
-        None | Some(JsonValue::Null) => Ok(None),
-        Some(JsonValue::String(value)) => Ok(Some(value.clone())),
-        Some(_) => Err(aur_error(format!("invalid field '{key}': expected string"))),
-    }
-}
-
-fn require_array<'a>(
-    object: &'a BTreeMap<String, JsonValue>,
-    key: &str,
-) -> Result<&'a [JsonValue], CubError> {
-    match object.get(key) {
-        Some(JsonValue::Array(values)) => Ok(values.as_slice()),
-        Some(_) => Err(aur_error(format!("invalid field '{key}': expected array"))),
-        None => Err(aur_error(format!("missing field '{key}'"))),
-    }
-}
-
-fn optional_string_list(
-    object: &BTreeMap<String, JsonValue>,
-    key: &str,
-) -> Result<Vec<String>, CubError> {
-    match object.get(key) {
-        None | Some(JsonValue::Null) => Ok(Vec::new()),
-        Some(JsonValue::String(value)) => Ok(vec![value.clone()]),
-        Some(JsonValue::Array(values)) => {
-            let mut items = Vec::with_capacity(values.len());
-            for value in values {
-                match value {
-                    JsonValue::String(item) => items.push(item.clone()),
-                    JsonValue::Null => {}
-                    _ => {
-                        return Err(aur_error(format!(
-                            "invalid field '{key}': expected string array"
-                        )))
-                    }
-                }
-            }
-            Ok(items)
-        }
-        Some(_) => Err(aur_error(format!(
-            "invalid field '{key}': expected string array"
-        ))),
-    }
-}
-
-fn require_i64(object: &BTreeMap<String, JsonValue>, key: &str) -> Result<i64, CubError> {
-    optional_i64(object, key)?.ok_or_else(|| aur_error(format!("missing field '{key}'")))
-}
-
-fn optional_i64(object: &BTreeMap<String, JsonValue>, key: &str) -> Result<Option<i64>, CubError> {
-    match object.get(key) {
-        None | Some(JsonValue::Null) => Ok(None),
-        Some(JsonValue::Integer(value)) => Ok(Some(*value)),
-        Some(_) => Err(aur_error(format!(
-            "invalid field '{key}': expected integer"
-        ))),
-    }
-}
-
-fn optional_u64(object: &BTreeMap<String, JsonValue>, key: &str) -> Result<Option<u64>, CubError> {
-    match object.get(key) {
-        None | Some(JsonValue::Null) => Ok(None),
-        Some(JsonValue::Integer(value)) if *value >= 0 => Ok(Some(*value as u64)),
-        Some(_) => Err(aur_error(format!(
-            "invalid field '{key}': expected unsigned integer"
-        ))),
-    }
-}
-
-fn optional_f64(object: &BTreeMap<String, JsonValue>, key: &str) -> Result<Option<f64>, CubError> {
-    match object.get(key) {
-        None | Some(JsonValue::Null) => Ok(None),
-        Some(JsonValue::Integer(value)) => Ok(Some(*value as f64)),
-        Some(JsonValue::Float(value)) => Ok(Some(*value)),
-        Some(_) => Err(aur_error(format!("invalid field '{key}': expected number"))),
-    }
-}
-
-fn optional_out_of_date(
-    object: &BTreeMap<String, JsonValue>,
-    key: &str,
-) -> Result<Option<bool>, CubError> {
-    match object.get(key) {
-        None | Some(JsonValue::Null) => Ok(None),
-        Some(JsonValue::Bool(value)) => Ok(Some(*value)),
-        Some(JsonValue::Integer(value)) => Ok(Some(*value != 0)),
-        Some(JsonValue::Float(value)) => Ok(Some(*value != 0.0)),
-        Some(_) => Err(aur_error(format!(
-            "invalid field '{key}': expected bool or number"
-        ))),
-    }
-}
-
-#[derive(Debug, Clone, PartialEq)]
-enum JsonValue {
-    Null,
-    Bool(bool),
-    Integer(i64),
-    Float(f64),
-    String(String),
-    Array(Vec<JsonValue>),
-    Object(BTreeMap<String, JsonValue>),
-}
-
-struct JsonParser<'a> {
-    input: &'a [u8],
-    position: usize,
-}
-
-impl<'a> JsonParser<'a> {
-    fn new(input: &'a str) -> Self {
-        Self {
-            input: input.as_bytes(),
-            position: 0,
-        }
-    }
-
-    fn parse(mut self) -> Result<JsonValue, String> {
-        let value = self.parse_value()?;
-        self.skip_whitespace();
-        if self.position != self.input.len() {
-            return Err(format!(
-                "unexpected trailing content at byte {}",
-                self.position
-            ));
-        }
-        Ok(value)
-    }
-
-    fn parse_value(&mut self) -> Result<JsonValue, String> {
-        self.skip_whitespace();
-        match self.peek_byte() {
-            Some(b'{') => self.parse_object(),
-            Some(b'[') => self.parse_array(),
-            Some(b'"') => self.parse_string().map(JsonValue::String),
-            Some(b't') => self.parse_true(),
-            Some(b'f') => self.parse_false(),
-            Some(b'n') => self.parse_null(),
-            Some(b'-' | b'0'..=b'9') => self.parse_number(),
-            Some(byte) => Err(format!(
-                "unexpected byte '{}' at {}",
-                byte as char, self.position
-            )),
-            None => Err("unexpected end of input".to_string()),
-        }
-    }
-
-    fn parse_object(&mut self) -> Result<JsonValue, String> {
-        self.expect_byte(b'{')?;
-        self.skip_whitespace();
-
-        let mut object = BTreeMap::new();
-        if self.peek_byte() == Some(b'}') {
-            self.position += 1;
-            return Ok(JsonValue::Object(object));
-        }
-
-        loop {
-            self.skip_whitespace();
-            let key = self.parse_string()?;
-            self.skip_whitespace();
-            self.expect_byte(b':')?;
-            let value = self.parse_value()?;
-            object.insert(key, value);
-            self.skip_whitespace();
-
-            match self.peek_byte() {
-                Some(b',') => {
-                    self.position += 1;
-                }
-                Some(b'}') => {
-                    self.position += 1;
-                    break;
-                }
-                Some(byte) => {
-                    return Err(format!(
-                        "unexpected byte '{}' in object at {}",
-                        byte as char, self.position
-                    ))
-                }
-                None => return Err("unexpected end of input while parsing object".to_string()),
-            }
-        }
-
-        Ok(JsonValue::Object(object))
-    }
-
-    fn parse_array(&mut self) -> Result<JsonValue, String> {
-        self.expect_byte(b'[')?;
-        self.skip_whitespace();
-
-        let mut values = Vec::new();
-        if self.peek_byte() == Some(b']') {
-            self.position += 1;
-            return Ok(JsonValue::Array(values));
-        }
-
-        loop {
-            values.push(self.parse_value()?);
-            self.skip_whitespace();
-            match self.peek_byte() {
-                Some(b',') => {
-                    self.position += 1;
-                }
-                Some(b']') => {
-                    self.position += 1;
-                    break;
-                }
-                Some(byte) => {
-                    return Err(format!(
-                        "unexpected byte '{}' in array at {}",
-                        byte as char, self.position
-                    ))
-                }
-                None => return Err("unexpected end of input while parsing array".to_string()),
-            }
-        }
-
-        Ok(JsonValue::Array(values))
-    }
-
-    fn parse_string(&mut self) -> Result<String, String> {
-        self.expect_byte(b'"')?;
-        let mut value = String::new();
-
-        loop {
-            match self.peek_byte() {
-                Some(b'"') => {
-                    self.position += 1;
-                    return Ok(value);
-                }
-                Some(b'\\') => {
-                    self.position += 1;
-                    value.push(self.parse_escape_sequence()?);
-                }
-                Some(0x00..=0x1F) => {
-                    return Err(format!(
-                        "invalid control character in string at {}",
-                        self.position
-                    ))
-                }
-                Some(_) => value.push_str(&self.parse_raw_string_segment()?),
-                None => break,
-            }
-        }
-
-        Err("unexpected end of input while parsing string".to_string())
-    }
-
-    fn parse_raw_string_segment(&mut self) -> Result<String, String> {
-        let start = self.position;
-        while let Some(byte) = self.peek_byte() {
-            if matches!(byte, b'"' | b'\\' | 0x00..=0x1F) {
-                break;
-            }
-            self.position += 1;
-        }
-
-        let segment = std::str::from_utf8(&self.input[start..self.position])
-            .map_err(|err| format!("invalid UTF-8 in string: {err}"))?;
-        Ok(segment.to_string())
-    }
-
-    fn parse_escape_sequence(&mut self) -> Result<char, String> {
-        match self.next_byte() {
-            Some(b'"') => Ok('"'),
-            Some(b'\\') => Ok('\\'),
-            Some(b'/') => Ok('/'),
-            Some(b'b') => Ok('\u{0008}'),
-            Some(b'f') => Ok('\u{000C}'),
-            Some(b'n') => Ok('\n'),
-            Some(b'r') => Ok('\r'),
-            Some(b't') => Ok('\t'),
-            Some(b'u') => self.parse_unicode_escape(),
-            Some(byte) => Err(format!(
-                "invalid escape byte '{}' at {}",
-                byte as char,
-                self.position.saturating_sub(1)
-            )),
-            None => Err("unexpected end of input while parsing escape sequence".to_string()),
-        }
-    }
-
-    fn parse_unicode_escape(&mut self) -> Result<char, String> {
-        let start = self.position;
-        let mut value = 0u32;
-
-        for _ in 0..4 {
-            let byte = self.next_byte().ok_or_else(|| {
-                "unexpected end of input while parsing unicode escape".to_string()
-            })?;
-            value = (value << 4)
-                | match byte {
-                    b'0'..=b'9' => (byte - b'0') as u32,
-                    b'a'..=b'f' => (byte - b'a' + 10) as u32,
-                    b'A'..=b'F' => (byte - b'A' + 10) as u32,
-                    _ => {
-                        return Err(format!(
-                            "invalid unicode escape at byte {}",
-                            start.saturating_sub(2)
-                        ))
-                    }
-                };
-        }
-
-        char::from_u32(value).ok_or_else(|| format!("invalid unicode scalar value: {value:#X}"))
-    }
-
-    fn parse_true(&mut self) -> Result<JsonValue, String> {
-        self.expect_keyword(b"true")?;
-        Ok(JsonValue::Bool(true))
-    }
-
-    fn parse_false(&mut self) -> Result<JsonValue, String> {
-        self.expect_keyword(b"false")?;
-        Ok(JsonValue::Bool(false))
-    }
-
-    fn parse_null(&mut self) -> Result<JsonValue, String> {
-        self.expect_keyword(b"null")?;
-        Ok(JsonValue::Null)
-    }
-
-    fn parse_number(&mut self) -> Result<JsonValue, String> {
-        let start = self.position;
-
-        if self.peek_byte() == Some(b'-') {
-            self.position += 1;
-        }
-
-        self.parse_digits()?;
-
-        if self.peek_byte() == Some(b'.') {
-            self.position += 1;
-            self.parse_digits()?;
-        }
-
-        if matches!(self.peek_byte(), Some(b'e' | b'E')) {
-            self.position += 1;
-            if matches!(self.peek_byte(), Some(b'+' | b'-')) {
-                self.position += 1;
-            }
-            self.parse_digits()?;
-        }
-
-        let slice = std::str::from_utf8(&self.input[start..self.position])
-            .map_err(|err| format!("invalid UTF-8 in number: {err}"))?;
-
-        if slice
-            .as_bytes()
-            .iter()
-            .any(|byte| matches!(byte, b'.' | b'e' | b'E'))
-        {
-            slice
-                .parse::<f64>()
-                .map(JsonValue::Float)
-                .map_err(|err| format!("invalid number '{slice}': {err}"))
-        } else {
-            slice
-                .parse::<i64>()
-                .map(JsonValue::Integer)
-                .map_err(|err| format!("invalid number '{slice}': {err}"))
-        }
-    }
-
-    fn parse_digits(&mut self) -> Result<(), String> {
-        let start = self.position;
-        while matches!(self.peek_byte(), Some(b'0'..=b'9')) {
-            self.position += 1;
-        }
-
-        if self.position == start {
-            Err(format!("expected digit at byte {}", self.position))
-        } else {
-            Ok(())
-        }
-    }
-
-    fn expect_keyword(&mut self, keyword: &[u8]) -> Result<(), String> {
-        for expected in keyword {
-            match self.next_byte() {
-                Some(byte) if byte == *expected => {}
-                Some(byte) => {
-                    return Err(format!(
-                        "unexpected byte '{}' while parsing keyword at {}",
-                        byte as char,
-                        self.position.saturating_sub(1)
-                    ))
-                }
-                None => return Err("unexpected end of input while parsing keyword".to_string()),
-            }
-        }
-        Ok(())
-    }
-
-    fn skip_whitespace(&mut self) {
-        while matches!(self.peek_byte(), Some(b' ' | b'\n' | b'\r' | b'\t')) {
-            self.position += 1;
-        }
-    }
-
-    fn expect_byte(&mut self, expected: u8) -> Result<(), String> {
-        match self.next_byte() {
-            Some(byte) if byte == expected => Ok(()),
-            Some(byte) => Err(format!(
-                "expected '{}' but found '{}' at {}",
-                expected as char,
-                byte as char,
-                self.position.saturating_sub(1)
-            )),
-            None => Err(format!(
-                "expected '{}' but reached end of input",
-                expected as char
-            )),
-        }
-    }
-
-    fn peek_byte(&self) -> Option<u8> {
-        self.input.get(self.position).copied()
-    }
-
-    fn next_byte(&mut self) -> Option<u8> {
-        let byte = self.peek_byte()?;
-        self.position += 1;
-        Some(byte)
-    }
+    Ok(rpc.results)
 }
 
 #[cfg(test)]