recursive-agent 0.6.0

//! `search_files`: substring/regex search across workspace files.

use async_trait::async_trait;
use regex::Regex;
use serde_json::{json, Value};
use std::path::PathBuf;
use walkdir::WalkDir;

use super::{resolve_within, Tool};
use crate::error::{Error, Result};
use crate::llm::ToolSpec;

const DEFAULT_MAX_RESULTS: usize = 50;
const DEFAULT_MAX_LINE_LEN: usize = 240;

#[derive(Debug, Clone)]
pub struct SearchFiles {
    pub root: PathBuf,
    pub max_results: usize,
}

impl SearchFiles {
    pub fn new(root: impl Into<PathBuf>) -> Self {
        Self {
            root: root.into(),
            max_results: DEFAULT_MAX_RESULTS,
        }
    }
}

#[async_trait]
impl Tool for SearchFiles {
    fn spec(&self) -> ToolSpec {
        ToolSpec {
            name: "search_files".into(),
            description:
                "Find lines containing a pattern (literal substring or regex) across files in the workspace. Returns up to N matches as 'path:line: text'."
                    .into(),
            parameters: json!({
                "type": "object",
                "properties": {
                    "pattern":   { "type": "string", "description": "Pattern to search for. Literal substring by default; use `regex: true` for regex mode." },
                    "path":      { "type": "string", "description": "Optional subdirectory (workspace-relative) to scope the search to. Defaults to workspace root." },
                    "max_results": { "type": "integer", "description": "Cap on results (default 50, max 200)." },
                    "regex":     { "type": "boolean", "description": "If true, interpret `pattern` as a regular expression (Rust regex crate syntax). Default false (literal substring)." },
                    "case_insensitive": { "type": "boolean", "description": "If true, matching ignores ASCII case. Works in both literal and regex modes; in regex mode this is equivalent to wrapping the pattern in `(?i:...)`. Default false." }
                },
                "required": ["pattern"]
            }),
        }
    }

    fn side_effect_class(&self) -> crate::tools::ToolSideEffect {
        crate::tools::ToolSideEffect::ReadOnly
    }

    async fn execute(&self, args: Value) -> Result<String> {
        let pattern = args["pattern"].as_str().ok_or_else(|| Error::BadToolArgs {
            name: "search_files".into(),
            message: "missing `pattern`".into(),
        })?;
        if pattern.is_empty() {
            return Err(Error::BadToolArgs {
                name: "search_files".into(),
                message: "`pattern` must not be empty".into(),
            });
        }

        let use_regex = args.get("regex").and_then(|v| v.as_bool()).unwrap_or(false);
        let case_insensitive = args
            .get("case_insensitive")
            .and_then(|v| v.as_bool())
            .unwrap_or(false);
        let re_opt: Option<Regex> = if use_regex {
            let regex = if case_insensitive {
                regex::RegexBuilder::new(pattern)
                    .case_insensitive(true)
                    .build()
            } else {
                Regex::new(pattern)
            };
            Some(regex.map_err(|e| Error::BadToolArgs {
                name: "search_files".into(),
                message: format!("invalid regex: {e}"),
            })?)
        } else {
            None
        };

        let scope = match args.get("path").and_then(|v| v.as_str()) {
            Some(p) => resolve_within(&self.root, p).map_err(|e| Error::BadToolArgs {
                name: "search_files".into(),
                message: format!("path: {e}"),
            })?,
            None => self.root.clone(),
        };

        let cap = args
            .get("max_results")
            .and_then(|v| v.as_u64())
            .map(|n| (n as usize).min(200))
            .unwrap_or(self.max_results);

        let mut hits: Vec<String> = Vec::new();
        'outer: for entry in WalkDir::new(&scope)
            .into_iter()
            .filter_map(|e| e.ok())
            .filter(|e| e.file_type().is_file())
        {
            let path = entry.path();
            // Skip obvious binaries / large files by name. Cheap heuristic.
            if path
                .extension()
                .and_then(|e| e.to_str())
                .map(|e| {
                    matches!(
                        e,
                        "png" | "jpg" | "jpeg" | "gif" | "pdf" | "zip" | "gz" | "tar" | "bin"
                    )
                })
                .unwrap_or(false)
            {
                continue;
            }
            let Ok(contents) = std::fs::read_to_string(path) else {
                continue;
            };
            let rel = path.strip_prefix(&self.root).unwrap_or(path);
            for (line_no, line) in contents.lines().enumerate() {
                let is_match = match &re_opt {
                    Some(re) => re.is_match(line),
                    None => {
                        if case_insensitive {
                            line.to_ascii_lowercase()
                                .contains(&pattern.to_ascii_lowercase())
                        } else {
                            line.contains(pattern)
                        }
                    }
                };
                if is_match {
                    let truncated = if line.len() > DEFAULT_MAX_LINE_LEN {
                        let mut end = DEFAULT_MAX_LINE_LEN;
                        while !line.is_char_boundary(end) {
                            end -= 1;
                        }
                        format!("{}…", &line[..end])
                    } else {
                        line.to_string()
                    };
                    hits.push(format!("{}:{}: {}", rel.display(), line_no + 1, truncated));
                    if hits.len() >= cap {
                        break 'outer;
                    }
                }
            }
        }

        if hits.is_empty() {
            Ok(format!("no matches for `{pattern}`"))
        } else {
            Ok(hits.join("\n"))
        }
    }
}

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

    fn write(dir: &TempDir, name: &str, body: &str) {
        std::fs::write(dir.path().join(name), body).unwrap();
    }

    #[tokio::test]
    async fn finds_matches_with_path_and_line_number() {
        let tmp = TempDir::new().unwrap();
        write(&tmp, "a.txt", "foo\nbar\nbaz");
        write(&tmp, "b.txt", "bar quux");
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "bar"}))
            .await
            .unwrap();
        assert!(out.contains("a.txt:2: bar"));
        assert!(out.contains("b.txt:1: bar quux"));
    }

    #[tokio::test]
    async fn empty_pattern_is_rejected() {
        let tmp = TempDir::new().unwrap();
        let err = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": ""}))
            .await
            .unwrap_err();
        assert!(matches!(err, Error::BadToolArgs { .. }));
    }

    #[tokio::test]
    async fn returns_no_match_message_when_empty() {
        let tmp = TempDir::new().unwrap();
        write(&tmp, "a.txt", "hello world");
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "zzzz"}))
            .await
            .unwrap();
        assert!(out.contains("no matches"));
    }

    #[tokio::test]
    async fn respects_max_results_cap() {
        let tmp = TempDir::new().unwrap();
        let body: String = (0..10).map(|_| "needle\n").collect();
        write(&tmp, "many.txt", &body);
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "needle", "max_results": 3}))
            .await
            .unwrap();
        assert_eq!(out.lines().count(), 3);
    }

    #[tokio::test]
    async fn path_argument_scopes_search() {
        let tmp = TempDir::new().unwrap();
        std::fs::create_dir(tmp.path().join("sub")).unwrap();
        write(&tmp, "outside.txt", "hit");
        std::fs::write(tmp.path().join("sub/inside.txt"), "hit").unwrap();
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "hit", "path": "sub"}))
            .await
            .unwrap();
        assert!(out.contains("inside.txt"));
        assert!(!out.contains("outside.txt"));
    }
    #[tokio::test]
    async fn regex_mode_matches_pattern() {
        let tmp = TempDir::new().unwrap();
        write(&tmp, "lib.rs", "fn foo() {}\nfn bar() {}\nfn foobar() {}");
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "fn f\\w+", "regex": true}))
            .await
            .unwrap();
        assert!(out.contains("foo"));
        assert!(out.contains("foobar"));
        assert!(!out.contains(": fn bar()"));
    }
    #[tokio::test]
    async fn regex_mode_invalid_pattern_is_bad_args() {
        let tmp = TempDir::new().unwrap();
        let err = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "(unclosed", "regex": true}))
            .await
            .unwrap_err();
        assert!(matches!(err, Error::BadToolArgs { .. }));
        assert!(format!("{err}").contains("invalid regex"));
    }
    #[tokio::test]
    async fn literal_mode_treats_pattern_as_substring() {
        let tmp = TempDir::new().unwrap();
        write(&tmp, "data.txt", "abc\nadc");
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "a.c"}))
            .await
            .unwrap();
        assert!(out.contains("no matches"));
    }
    #[tokio::test]
    async fn regex_mode_with_path_scope() {
        let tmp = TempDir::new().unwrap();
        std::fs::create_dir(tmp.path().join("src")).unwrap();
        write(&tmp, "outside.txt", "fn main()");
        std::fs::write(tmp.path().join("src/lib.rs"), "fn helper()\nfn main()").unwrap();
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "fn \\w+", "regex": true, "path": "src"}))
            .await
            .unwrap();
        assert!(out.contains("helper"));
        assert!(out.contains("main"));
        assert!(!out.contains("outside.txt"));
    }

    // Tests for case_insensitive flag (goal-29)
    #[tokio::test]
    async fn literal_mode_case_insensitive_finds_match() {
        let tmp = TempDir::new().unwrap();
        write(
            &tmp,
            "todo.txt",
            "TODO: fix this
todo: done",
        );
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "TODO", "case_insensitive": true}))
            .await
            .unwrap();
        assert!(out.contains("TODO: fix this"));
        assert!(out.contains("todo: done"));
    }

    #[tokio::test]
    async fn regex_mode_case_insensitive_finds_match() {
        let tmp = TempDir::new().unwrap();
        write(
            &tmp,
            "test.txt",
            "foo123
bar456",
        );
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": r"FOO\d+", "regex": true, "case_insensitive": true}))
            .await
            .unwrap();
        assert!(out.contains("foo123"));
        assert!(!out.contains("bar456"));
    }

    #[tokio::test]
    async fn case_sensitive_by_default() {
        let tmp = TempDir::new().unwrap();
        write(
            &tmp,
            "mixed.txt",
            "TODO
todo
Todo",
        );
        // Without case_insensitive, should only find exact match
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "TODO"}))
            .await
            .unwrap();
        assert!(out.contains("TODO"));
        assert!(!out.contains("todo"));
        assert!(!out.contains("Todo"));
    }

    /// Regression test: long lines containing multi-byte Unicode characters (like the
    /// box-drawing `─` U+2500, encoded as 3 UTF-8 bytes E2 94 80) must not panic
    /// when the truncation boundary lands in the middle of a multi-byte sequence.
    #[tokio::test]
    async fn long_line_with_multibyte_unicode_does_not_panic() {
        let tmp = TempDir::new().unwrap();

        // Build a line where the 240-byte boundary lands inside `─` (U+2500, 3 bytes).
        // "search_target " is 14 ASCII bytes. Then append `─` chars until line > 240 bytes.
        // `─` takes 3 bytes, so we need (240 - 14) / 3 ≈ 75 chars to land near boundary.
        let mut long_line = String::from("search_target ");
        while long_line.len() <= 240 {
            long_line.push('─');
        }
        // Append a suffix so the file has another match-less line too.
        let body = format!("{long_line}\nno match here\n");
        write(&tmp, "unicode.txt", &body);

        // Must not panic.
        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "search_target"}))
            .await
            .unwrap();
        assert!(out.contains("unicode.txt:1:"));
        assert!(out.contains("search_target"));
    }

    /// Regression test: JSONL files with multi-byte Unicode inside a long JSON line
    /// (mimicking a session transcript that contains box-drawing characters) must not panic.
    #[tokio::test]
    async fn jsonl_line_with_unicode_box_drawing_does_not_panic() {
        let tmp = TempDir::new().unwrap();
        // Construct a long JSONL-like line that contains the target pattern AND box-drawing chars.
        let separator = "─".repeat(60); // 60 × 3 bytes = 180 bytes
        let content_field =
            format!("pub struct AgentRuntime{{}}\\n// {separator}─────────────────────────");
        let line = format!(
            "{{\"role\":\"tool\",\"content\":\"# range: lines 1-50 of 200\\\\n{content_field}\"}}"
        );
        assert!(
            line.len() > 240,
            "test line must exceed truncation limit; got {}",
            line.len()
        );
        write(&tmp, "transcript.jsonl", &line);

        let out = SearchFiles::new(tmp.path())
            .execute(json!({"pattern": "pub struct AgentRuntime"}))
            .await
            .unwrap();
        assert!(out.contains("transcript.jsonl:1:"));
    }
}