repotoire 0.8.0

//! Shared helpers for Claude Code settings.json: path resolution, read/validate, atomic write.

use anyhow::{anyhow, Context, Result};
use std::path::PathBuf;

/// Resolve the path to Claude Code's `settings.json`.
///
/// Order:
///   1. `$CLAUDE_CONFIG_DIR/settings.json` — Claude Code's documented override (anthropics/claude-code#3833).
///   2. `home::home_dir()/.claude/settings.json` — default. Uses the `home` crate (NOT `dirs::home_dir()`)
///      so we honor `USERPROFILE` on Windows the way Claude Code does (via Node's `os.homedir`).
///
/// Returns `Err` only when both `CLAUDE_CONFIG_DIR` is unset AND `home::home_dir()` returns `None`
/// (rare: daemons, some CI, broken envs).
pub(super) fn settings_path() -> Result<PathBuf> {
    if let Ok(dir) = std::env::var("CLAUDE_CONFIG_DIR") {
        if !dir.is_empty() {
            return Ok(PathBuf::from(dir).join("settings.json"));
        }
    }
    let home = home::home_dir().ok_or_else(|| {
        anyhow!("could not determine home directory (set CLAUDE_CONFIG_DIR or HOME)")
    })?;
    Ok(home.join(".claude").join("settings.json"))
}

/// Maximum settings.json size we will read. Anything larger is suspicious; refuse.
const MAX_SETTINGS_BYTES: u64 = 10 * 1024 * 1024;

/// Read and parse settings.json.
///
/// Returns:
///   - `Ok(serde_json::Value::Object(_))` on success (or `{}` if the file does not exist).
///   - `Err` if the file is not a regular file, larger than 10 MiB, or not valid JSON.
pub(super) fn read_settings_or_empty(path: &std::path::Path) -> Result<serde_json::Value> {
    use std::fs;
    use std::io::Read;

    let meta = match fs::symlink_metadata(path) {
        Ok(m) => m,
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
            return Ok(serde_json::json!({}));
        }
        Err(e) => return Err(anyhow::Error::from(e).context(format!("stat {}", path.display()))),
    };

    // If this is a symlink, follow it and re-stat to validate the target.
    let target_meta = if meta.file_type().is_symlink() {
        fs::metadata(path)
            .with_context(|| format!("symlink target unreachable: {}", path.display()))?
    } else {
        meta
    };

    if target_meta.is_dir() {
        anyhow::bail!(
            "{} is not a regular file (it is a directory).",
            path.display()
        );
    }
    if !target_meta.is_file() {
        anyhow::bail!(
            "{} is not a regular file (FIFO, device, or socket).",
            path.display()
        );
    }
    if target_meta.len() > MAX_SETTINGS_BYTES {
        anyhow::bail!(
            "{} is suspiciously large (>{} MiB); refusing to parse.",
            path.display(),
            MAX_SETTINGS_BYTES / (1024 * 1024)
        );
    }

    let mut buf = String::new();
    fs::File::open(path)
        .with_context(|| format!("open {}", path.display()))?
        .take(MAX_SETTINGS_BYTES + 1)
        .read_to_string(&mut buf)
        .with_context(|| format!("read {}", path.display()))?;

    let parsed: serde_json::Value = serde_json::from_str(&buf).with_context(|| {
        format!(
            "{} is not valid JSON. Fix or remove it before re-running.",
            path.display()
        )
    })?;

    if !parsed.is_object() {
        anyhow::bail!("{} top-level value is not a JSON object.", path.display());
    }

    Ok(parsed)
}

/// Generate a backup file path: `<settings.json>.bak.<UTC-yyyymmdd-hhmmss>.<random-4>`.
/// The random suffix avoids collisions on rapid re-installs within the same second.
pub(super) fn backup_path(settings: &std::path::Path) -> std::path::PathBuf {
    use rand::Rng;
    let now = chrono::Utc::now().format("%Y%m%d-%H%M%S");
    let rand: String = (0..4)
        .map(|_| {
            let n: u8 = rand::rng().random_range(0..16);
            std::char::from_digit(n as u32, 16).expect("0..16 always valid hex digit")
        })
        .collect();
    let mut buf = settings.as_os_str().to_owned();
    buf.push(format!(".bak.{now}.{rand}"));
    buf.into()
}

/// Atomically write `contents` to `target`.
///
/// On Unix: atomic via tempfile-in-same-dir + rename. Preserves the existing file's
/// mode (so `chmod 600` survives). If `target` is a symlink, writes to the resolved
/// target so the link itself is not replaced.
///
/// On Windows: best-effort atomic. `std::fs::rename` first attempts a non-atomic
/// `FileRenameInfo` and falls back to atomic API on conflict. This is the closest
/// we get without a third-party Windows-specific crate.
pub(super) fn atomic_write(target: &std::path::Path, contents: &[u8]) -> Result<()> {
    use std::fs;

    // Resolve symlink so rename doesn't replace the link itself.
    let resolved: std::path::PathBuf = match fs::symlink_metadata(target) {
        Ok(m) if m.file_type().is_symlink() => fs::canonicalize(target)
            .with_context(|| format!("canonicalize symlink target {}", target.display()))?,
        _ => target.to_path_buf(),
    };

    let parent = resolved
        .parent()
        .ok_or_else(|| anyhow!("settings path has no parent: {}", resolved.display()))?;
    fs::create_dir_all(parent)
        .with_context(|| format!("create parent dir {}", parent.display()))?;

    // Snapshot the existing file's mode (Unix only) before writing.
    #[cfg(unix)]
    let prev_mode: Option<u32> = match fs::metadata(&resolved) {
        Ok(m) => {
            use std::os::unix::fs::PermissionsExt;
            Some(m.permissions().mode())
        }
        Err(_) => None,
    };

    let mut tmp = tempfile::NamedTempFile::new_in(parent)
        .with_context(|| format!("create temp file in {}", parent.display()))?;
    {
        use std::io::Write;
        tmp.write_all(contents)
            .with_context(|| format!("write temp for {}", resolved.display()))?;
        tmp.as_file()
            .sync_all()
            .with_context(|| format!("fsync temp for {}", resolved.display()))?;
    }

    // Apply previous mode to the tempfile before rename so chmod 600 survives.
    #[cfg(unix)]
    if let Some(mode) = prev_mode {
        use std::os::unix::fs::PermissionsExt;
        let perms = std::fs::Permissions::from_mode(mode);
        std::fs::set_permissions(tmp.path(), perms)
            .with_context(|| format!("preserve mode {:o} on temp file", mode))?;
    }

    tmp.persist(&resolved)
        .map_err(|e| anyhow!("persist {}: {}", resolved.display(), e.error))?;

    Ok(())
}

/// True if `cmd` is one of our `claude-hook run` invocations.
///
/// Splits on whitespace and checks: tokens[0] ends with `repotoire` (or `repotoire.exe`),
/// tokens[1] == `claude-hook`, tokens[2] == `run`. Allows future flags after `run`.
/// Suffix-match on the binary path filename means a stale install at a moved binary
/// is still detected.
pub(super) fn is_repotoire_hook_command(cmd: &str) -> bool {
    let mut parts = cmd.split_whitespace();
    let bin = match parts.next() {
        Some(s) => s,
        None => return false,
    };
    let leaf = std::path::Path::new(bin)
        .file_name()
        .and_then(|n| n.to_str())
        .unwrap_or("");
    let is_our_bin = if cfg!(target_os = "windows") {
        leaf.eq_ignore_ascii_case("repotoire") || leaf.eq_ignore_ascii_case("repotoire.exe")
    } else {
        leaf == "repotoire"
    };
    if !is_our_bin {
        return false;
    }
    if parts.next() != Some("claude-hook") {
        return false;
    }
    if parts.next() != Some("run") {
        return false;
    }
    true
}

/// True if `cmd` matches an old-style hook (a script path under `~/.repotoire/hooks/`).
pub(super) fn is_old_style_hook_command(cmd: &str, home: &std::path::Path) -> bool {
    let needle = home.join(".repotoire").join("hooks");
    cmd.contains(needle.to_string_lossy().as_ref())
}

/// Insert our hook entry into `root`, preserving all other keys.
///
/// Ensures `hooks` (object) and `hooks.PreToolUse` (array) exist; appends a new
/// `{matcher: "Bash", hooks: [{type: "command", command: <our_command>}]}` entry.
pub(super) fn insert_hook_entry(root: &mut serde_json::Value, our_command: &str) {
    let obj = root.as_object_mut().expect("settings root must be object");
    let hooks = obj
        .entry("hooks".to_string())
        .or_insert_with(|| serde_json::json!({}));
    let hooks_obj = hooks
        .as_object_mut()
        .expect("hooks must be an object if present");
    let pre = hooks_obj
        .entry("PreToolUse".to_string())
        .or_insert_with(|| serde_json::json!([]));
    let pre_arr = pre
        .as_array_mut()
        .expect("PreToolUse must be an array if present");
    pre_arr.push(serde_json::json!({
        "matcher": "Bash",
        "hooks": [
            {"type": "command", "command": our_command}
        ]
    }));
}

/// Walk `hooks.PreToolUse[]` and look for a hook whose inner command field
/// matches `pred`. Returns the index of the first matching outer entry.
pub(super) fn find_pretool_entry_by_command<F>(
    root: &serde_json::Value,
    mut pred: F,
) -> Option<usize>
where
    F: FnMut(&str) -> bool,
{
    let arr = root.get("hooks")?.get("PreToolUse")?.as_array()?;
    for (i, entry) in arr.iter().enumerate() {
        if let Some(inner) = entry.get("hooks").and_then(|h| h.as_array()) {
            for h in inner {
                if let Some(cmd) = h.get("command").and_then(|c| c.as_str()) {
                    if pred(cmd) {
                        return Some(i);
                    }
                }
            }
        }
    }
    None
}

/// Remove every `hooks.PreToolUse[]` entry containing a command matching `pred`.
/// Returns the number of outer entries removed.
pub(super) fn filter_pretool_entries<F>(root: &mut serde_json::Value, mut pred: F) -> usize
where
    F: FnMut(&str) -> bool,
{
    let arr = match root
        .get_mut("hooks")
        .and_then(|h| h.get_mut("PreToolUse"))
        .and_then(|p| p.as_array_mut())
    {
        Some(a) => a,
        None => return 0,
    };
    let before = arr.len();
    arr.retain(|entry| {
        let inner = match entry.get("hooks").and_then(|h| h.as_array()) {
            Some(a) => a,
            None => return true,
        };
        let any_match = inner.iter().any(|h| {
            h.get("command")
                .and_then(|c| c.as_str())
                .map(&mut pred)
                .unwrap_or(false)
        });
        !any_match
    });
    before - arr.len()
}

/// After mutating, remove `hooks.PreToolUse` if empty, then `hooks` if empty.
/// Avoids leaving `{"hooks":{}}` or `{"hooks":{"PreToolUse":[]}}` clutter.
pub(super) fn cleanup_empty_containers(root: &mut serde_json::Value) {
    let obj = match root.as_object_mut() {
        Some(o) => o,
        None => return,
    };
    let hooks = match obj.get_mut("hooks").and_then(|v| v.as_object_mut()) {
        Some(h) => h,
        None => return,
    };
    if let Some(arr) = hooks.get("PreToolUse").and_then(|v| v.as_array()) {
        if arr.is_empty() {
            hooks.remove("PreToolUse");
        }
    }
    if hooks.is_empty() {
        obj.remove("hooks");
    }
}

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

    /// Helper: run `f` with a single env var set, restore previous state after.
    /// Note: env vars are process-global; these tests run serial via `--test-threads=1`
    /// in the e2e suite. For unit tests in this module we use unique var names where possible.
    fn with_env<R>(key: &str, val: Option<&str>, f: impl FnOnce() -> R) -> R {
        let prev = std::env::var(key).ok();
        match val {
            Some(v) => std::env::set_var(key, v),
            None => std::env::remove_var(key),
        }
        let result = f();
        match prev {
            Some(v) => std::env::set_var(key, v),
            None => std::env::remove_var(key),
        }
        result
    }

    #[test]
    fn settings_path_uses_claude_config_dir_when_set() {
        with_env("CLAUDE_CONFIG_DIR", Some("/tmp/fake-claude-config"), || {
            let p = settings_path().expect("path resolves");
            assert_eq!(p, PathBuf::from("/tmp/fake-claude-config/settings.json"));
        });
    }

    #[test]
    fn settings_path_falls_back_to_home_when_claude_config_dir_empty() {
        with_env("CLAUDE_CONFIG_DIR", Some(""), || {
            let p = settings_path().expect("path resolves");
            // Should end with .claude/settings.json — exact prefix depends on home::home_dir.
            assert!(p.ends_with(".claude/settings.json"), "got {}", p.display());
        });
    }

    #[test]
    fn settings_path_falls_back_to_home_when_claude_config_dir_unset() {
        with_env("CLAUDE_CONFIG_DIR", None, || {
            let p = settings_path().expect("path resolves");
            assert!(p.ends_with(".claude/settings.json"), "got {}", p.display());
        });
    }

    #[test]
    fn read_returns_empty_object_when_file_missing() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("does-not-exist.json");
        let val = read_settings_or_empty(&path).unwrap();
        assert_eq!(val, serde_json::json!({}));
    }

    #[test]
    fn read_returns_parsed_object_when_file_exists() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("settings.json");
        std::fs::write(&path, r#"{"theme":"dark"}"#).unwrap();
        let val = read_settings_or_empty(&path).unwrap();
        assert_eq!(val["theme"], "dark");
    }

    #[test]
    fn read_errors_on_malformed_json() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("settings.json");
        std::fs::write(&path, "{ broken json").unwrap();
        let err = read_settings_or_empty(&path).unwrap_err();
        assert!(format!("{err:#}").contains("is not valid JSON"));
    }

    #[test]
    fn read_errors_when_path_is_directory() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("settings.json");
        std::fs::create_dir(&path).unwrap();
        let err = read_settings_or_empty(&path).unwrap_err();
        assert!(format!("{err:#}").contains("not a regular file"));
    }

    #[test]
    fn read_errors_on_non_object_top_level() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("settings.json");
        std::fs::write(&path, "[]").unwrap();
        let err = read_settings_or_empty(&path).unwrap_err();
        assert!(format!("{err:#}").contains("top-level value is not a JSON object"));
    }

    #[test]
    fn atomic_write_creates_file() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("settings.json");
        atomic_write(&path, b"{\"theme\":\"dark\"}").unwrap();
        let read = std::fs::read_to_string(&path).unwrap();
        assert_eq!(read, "{\"theme\":\"dark\"}");
    }

    #[test]
    fn atomic_write_overwrites_existing() {
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("settings.json");
        std::fs::write(&path, "old").unwrap();
        atomic_write(&path, b"new").unwrap();
        assert_eq!(std::fs::read_to_string(&path).unwrap(), "new");
    }

    #[cfg(unix)]
    #[test]
    fn atomic_write_preserves_mode() {
        use std::os::unix::fs::PermissionsExt;
        let dir = tempfile::tempdir().unwrap();
        let path = dir.path().join("settings.json");
        std::fs::write(&path, "old").unwrap();
        std::fs::set_permissions(&path, std::fs::Permissions::from_mode(0o600)).unwrap();

        atomic_write(&path, b"new").unwrap();

        let mode = std::fs::metadata(&path).unwrap().permissions().mode();
        assert_eq!(mode & 0o777, 0o600);
    }

    #[cfg(unix)]
    #[test]
    fn atomic_write_preserves_symlink() {
        use std::os::unix::fs::symlink;
        let dir = tempfile::tempdir().unwrap();
        let real = dir.path().join("real.json");
        let link = dir.path().join("link.json");
        std::fs::write(&real, "old").unwrap();
        symlink(&real, &link).unwrap();

        atomic_write(&link, b"new").unwrap();

        // link is still a symlink
        assert!(std::fs::symlink_metadata(&link)
            .unwrap()
            .file_type()
            .is_symlink());
        // and the target was written
        assert_eq!(std::fs::read_to_string(&real).unwrap(), "new");
    }

    #[test]
    fn backup_path_appends_suffix() {
        let p = std::path::Path::new("/tmp/settings.json");
        let b = backup_path(p);
        let s = b.to_string_lossy();
        assert!(s.starts_with("/tmp/settings.json.bak."), "got {s}");
        // bak.<14-digit-timestamp>.<4-hex>
        assert!(
            s.len() >= "/tmp/settings.json.bak.".len() + 14 + 1 + 4,
            "got {s}"
        );
    }

    #[test]
    fn is_repotoire_hook_command_matches_canonical_form() {
        assert!(is_repotoire_hook_command(
            "/usr/local/bin/repotoire claude-hook run"
        ));
        assert!(is_repotoire_hook_command(
            "/opt/homebrew/bin/repotoire claude-hook run"
        ));
        assert!(is_repotoire_hook_command(
            "/usr/local/bin/repotoire claude-hook run --debug"
        ));
    }

    #[test]
    fn is_repotoire_hook_command_rejects_unrelated() {
        assert!(!is_repotoire_hook_command("/usr/bin/git commit"));
        assert!(!is_repotoire_hook_command(
            "/usr/local/bin/repotoire-test claude-hook run"
        ));
        assert!(!is_repotoire_hook_command(
            "/usr/local/bin/repotoire analyze"
        ));
        assert!(!is_repotoire_hook_command(
            "/usr/local/bin/repotoire claude-hook install"
        ));
        assert!(!is_repotoire_hook_command(""));
    }

    // Old-style hooks only ever lived under ~/.repotoire/hooks/pre-commit.sh on
    // Unix (install.sh is bash-only). On Windows there's no path to detect.
    #[cfg(not(target_os = "windows"))]
    #[test]
    fn is_old_style_hook_command_matches_legacy_path() {
        let home = std::path::Path::new("/home/user");
        assert!(is_old_style_hook_command(
            "/home/user/.repotoire/hooks/pre-commit.sh",
            home
        ));
        assert!(!is_old_style_hook_command(
            "/usr/local/bin/repotoire claude-hook run",
            home
        ));
    }

    #[test]
    fn insert_hook_entry_into_empty_root() {
        let mut root = serde_json::json!({});
        insert_hook_entry(&mut root, "/bin/repotoire claude-hook run");
        assert_eq!(root["hooks"]["PreToolUse"][0]["matcher"], "Bash");
        assert_eq!(
            root["hooks"]["PreToolUse"][0]["hooks"][0]["command"],
            "/bin/repotoire claude-hook run"
        );
    }

    #[test]
    fn insert_hook_entry_preserves_other_keys() {
        let mut root = serde_json::json!({"theme": "dark", "enabledPlugins": {"foo": true}});
        insert_hook_entry(&mut root, "/bin/repotoire claude-hook run");
        assert_eq!(root["theme"], "dark");
        assert_eq!(root["enabledPlugins"]["foo"], true);
        assert_eq!(root["hooks"]["PreToolUse"].as_array().unwrap().len(), 1);
    }

    #[test]
    fn insert_hook_entry_appends_to_existing_array() {
        let mut root = serde_json::json!({
            "hooks": {
                "PreToolUse": [
                    {"matcher": "Bash", "hooks": [{"type": "command", "command": "/bin/foo"}]}
                ]
            }
        });
        insert_hook_entry(&mut root, "/bin/repotoire claude-hook run");
        assert_eq!(root["hooks"]["PreToolUse"].as_array().unwrap().len(), 2);
        assert_eq!(
            root["hooks"]["PreToolUse"][1]["hooks"][0]["command"],
            "/bin/repotoire claude-hook run"
        );
    }

    #[test]
    fn filter_pretool_entries_preserves_unrelated() {
        let mut root = serde_json::json!({
            "hooks": {
                "PreToolUse": [
                    {"matcher": "Bash", "hooks": [{"type": "command", "command": "/bin/foo"}]},
                    {"matcher": "Bash", "hooks": [{"type": "command", "command": "/bin/repotoire claude-hook run"}]}
                ]
            }
        });
        let removed = filter_pretool_entries(&mut root, is_repotoire_hook_command);
        assert_eq!(removed, 1);
        assert_eq!(root["hooks"]["PreToolUse"].as_array().unwrap().len(), 1);
        assert_eq!(
            root["hooks"]["PreToolUse"][0]["hooks"][0]["command"],
            "/bin/foo"
        );
    }

    #[test]
    fn cleanup_empty_containers_removes_empty_pretooluse_and_hooks() {
        let mut root = serde_json::json!({
            "theme": "dark",
            "hooks": {"PreToolUse": []}
        });
        cleanup_empty_containers(&mut root);
        assert!(root.get("hooks").is_none());
        assert_eq!(root["theme"], "dark");
    }

    #[test]
    fn cleanup_empty_containers_keeps_hooks_when_other_event_present() {
        let mut root = serde_json::json!({
            "hooks": {
                "PreToolUse": [],
                "PostToolUse": [{"matcher": "Bash", "hooks": [{"type":"command","command":"/bin/foo"}]}]
            }
        });
        cleanup_empty_containers(&mut root);
        assert!(root.get("hooks").is_some());
        assert!(root["hooks"].get("PreToolUse").is_none());
        assert!(root["hooks"].get("PostToolUse").is_some());
    }
}