indra 0.8.0

//! `indra skills`: keep the skill mirrors in step with the canonical skills,
//! and install them where other agents look for skills.
//!
//! The canonical copy is `plugins/indra/skills/` (fixed by the Claude Code
//! plugin format). `skills/` at the repository root is a generated mirror:
//! Gemini CLI loads an extension's skills from `<extension root>/skills`, and
//! the extension root is the repository root.

use clap::{Args, Subcommand, ValueEnum};
use std::path::{Path, PathBuf};
use std::process::ExitCode;

#[derive(Args)]
pub struct SkillsArgs {
    /// The repository (default: found from this folder up)
    #[arg(long, global = true)]
    repo: Option<PathBuf>,
    #[command(subcommand)]
    cmd: SkillsCmd,
}

#[derive(Clone, Copy, ValueEnum)]
enum Agent {
    /// ~/.agents/skills: the agentskills.io path (opencode, Gemini CLI, Codex)
    Agents,
    /// ~/.claude/skills: Claude Code user skills
    Claude,
    /// ~/.config/opencode/skills
    Opencode,
}

#[derive(Clone, Copy, ValueEnum, PartialEq, Eq)]
enum Scope {
    User,
    Workspace,
}

#[derive(Subcommand)]
enum SkillsCmd {
    /// Refresh the skills/ mirror from plugins/indra/skills/ (or --check it)
    Sync {
        /// Exit non-zero if the mirror is stale (for CI)
        #[arg(long)]
        check: bool,
    },
    /// Copy the skills into a folder an agent discovers
    Install {
        #[arg(long, value_enum)]
        to: Agent,
        /// Into your home folder, or this workspace
        #[arg(long, value_enum, default_value = "user")]
        scope: Scope,
    },
}

/// The indra repository at or above `start`.
pub fn find_repo(start: &Path) -> Option<PathBuf> {
    let mut d = Some(start.to_path_buf());
    while let Some(x) = d {
        if x.join("plugins").join("indra").join("skills").is_dir() {
            return Some(x);
        }
        d = x.parent().map(Path::to_path_buf);
    }
    None
}

/// What differs between the canonical skills and the mirror (empty: in step),
/// and how many files the canonical copy has.
pub fn check(repo: &Path) -> (usize, Vec<String>) {
    let (source, mirror) = (
        repo.join("plugins").join("indra").join("skills"),
        repo.join("skills"),
    );
    let src = tree_files(&source);
    let mut problems = Vec::new();
    if !mirror.is_dir() {
        problems.push(format!("mirror does not exist: {}", mirror.display()));
    } else {
        let dst = tree_files(&mirror);
        for m in src.iter().filter(|f| !dst.contains(f)) {
            problems.push(format!("missing from mirror: {}", m.display()));
        }
        for x in dst.iter().filter(|f| !src.contains(f)) {
            problems.push(format!("stale in mirror: {}", x.display()));
        }
        for f in src.iter().filter(|f| dst.contains(f)) {
            if !same(&source.join(f), &mirror.join(f)) {
                problems.push(format!("differs: {}", f.display()));
            }
        }
    }
    (src.len(), problems)
}

/// Refresh the mirror; the number of files copied.
pub fn sync(repo: &Path) -> Result<usize, String> {
    copy_tree(
        &repo.join("plugins").join("indra").join("skills"),
        &repo.join("skills"),
    )
}

/// Where `install` puts skills for `to` (agents, claude, opencode): under
/// home, or under `workspace` when given.
pub fn install_dir(to: &str, workspace: Option<&Path>) -> Result<PathBuf, String> {
    let home = crate::paths::home().ok_or("no home folder")?;
    Ok(match (to, workspace) {
        ("agents", None) => home.join(".agents").join("skills"),
        ("agents", Some(w)) => w.join(".agents").join("skills"),
        ("claude", None) => home.join(".claude").join("skills"),
        ("claude", Some(w)) => w.join(".claude").join("skills"),
        ("opencode", None) => home.join(".config").join("opencode").join("skills"),
        ("opencode", Some(w)) => w.join(".opencode").join("skills"),
        _ => return Err("install to agents, claude or opencode".into()),
    })
}

/// Copy every skill into `dest`; how many.
pub fn install(repo: &Path, dest: &Path) -> Result<usize, String> {
    let source = repo.join("plugins").join("indra").join("skills");
    std::fs::create_dir_all(dest).map_err(|e| e.to_string())?;
    let mut names: Vec<_> = std::fs::read_dir(&source)
        .map_err(|e| e.to_string())?
        .flatten()
        .filter(|e| e.path().is_dir())
        .map(|e| e.file_name())
        .collect();
    names.sort();
    for n in &names {
        copy_tree(&source.join(n), &dest.join(n))?;
    }
    Ok(names.len())
}

fn repo_root(given: &Option<PathBuf>) -> Result<PathBuf, String> {
    if let Some(r) = given {
        return Ok(r.clone());
    }
    let mut d = std::env::current_dir().ok();
    while let Some(x) = d {
        if x.join("plugins").join("indra").join("skills").is_dir() {
            return Ok(x);
        }
        d = x.parent().map(Path::to_path_buf);
    }
    Err(
        "no plugins/indra/skills here or above; run inside the indra repository or pass --repo"
            .into(),
    )
}

/// Every file under `root`, relative and sorted.
fn tree_files(root: &Path) -> Vec<PathBuf> {
    fn walk(root: &Path, d: &Path, out: &mut Vec<PathBuf>) {
        let Ok(rd) = std::fs::read_dir(d) else { return };
        for e in rd.flatten() {
            let p = e.path();
            if p.is_dir() {
                if e.file_name() != "__pycache__" {
                    walk(root, &p, out);
                }
            } else if let Ok(r) = p.strip_prefix(root) {
                out.push(r.to_path_buf());
            }
        }
    }
    let mut out = Vec::new();
    walk(root, root, &mut out);
    out.sort();
    out
}

fn copy_tree(src: &Path, dst: &Path) -> Result<usize, String> {
    if dst.exists() {
        std::fs::remove_dir_all(dst).map_err(|e| format!("{}: {}", dst.display(), e))?;
    }
    let files = tree_files(src);
    for rel in &files {
        let to = dst.join(rel);
        if let Some(p) = to.parent() {
            std::fs::create_dir_all(p).map_err(|e| e.to_string())?;
        }
        std::fs::copy(src.join(rel), &to).map_err(|e| format!("{}: {}", to.display(), e))?;
        // Bundled scripts keep their exec bit whoever regenerates the mirror.
        #[cfg(unix)]
        if rel.extension().map(|x| x == "sh").unwrap_or(false) {
            use std::os::unix::fs::PermissionsExt;
            let _ = std::fs::set_permissions(&to, std::fs::Permissions::from_mode(0o755));
        }
    }
    Ok(files.len())
}

fn same(a: &Path, b: &Path) -> bool {
    matches!((std::fs::read(a), std::fs::read(b)), (Ok(x), Ok(y)) if x == y)
}

pub fn run(a: SkillsArgs) -> Result<ExitCode, String> {
    let repo = repo_root(&a.repo)?;
    let source = repo.join("plugins").join("indra").join("skills");
    if !source.is_dir() {
        eprintln!("error: canonical skills not found at {}", source.display());
        return Ok(ExitCode::from(2));
    }
    match a.cmd {
        SkillsCmd::Sync { check: true } => {
            let (n, problems) = check(&repo);
            if problems.is_empty() {
                println!("skills/ mirror is up to date ({} files).", n);
                return Ok(ExitCode::SUCCESS);
            }
            eprintln!("skills/ mirror is STALE. Run: indra skills sync");
            for p in problems {
                eprintln!("  {}", p);
            }
            Ok(ExitCode::from(1))
        }
        SkillsCmd::Sync { check: false } => {
            println!("Synced {} files -> skills", sync(&repo)?);
            Ok(ExitCode::SUCCESS)
        }
        SkillsCmd::Install { to, scope } => {
            let here = std::env::current_dir().map_err(|e| e.to_string())?;
            let name = match to {
                Agent::Agents => "agents",
                Agent::Claude => "claude",
                Agent::Opencode => "opencode",
            };
            let dest = install_dir(name, (scope == Scope::Workspace).then_some(here.as_path()))?;
            let n = install(&repo, &dest)?;
            println!("Installed {} skills -> {}", n, dest.display());
            Ok(ExitCode::SUCCESS)
        }
    }
}