trusty-mpm 1.5.2

//! Generator engine for `tm generate capabilities` (issue #2913).
//!
//! Why: the `tm-capabilities` bundled skill (CLI tree, MCP tool catalog,
//! agent roster, skill catalog, doctor checks, framework layout) must never
//! be hand-maintained prose — every one of those six surfaces already exists
//! as machine-extractable, in-process data (clap's `Command` introspection,
//! `mcp::tools::tool_catalog()`, `bundle::ALL` + `agent_metadata`, a
//! maintained-and-cross-checked doctor-check list, the `FrameworkPaths` and
//! tier resolvers the runtime itself resolves against). This module is the
//! single place that walks each surface and turns it into deterministic
//! markdown, so `--check` (the CI drift gate) and the write path share
//! exactly the same generation logic and can never disagree about what
//! "up to date" means.
//! What: [`generate`] builds the full [`GeneratedSet`] (7 files); [`write`](crate::generate::write)
//! writes it to `crates/trusty-mpm/src/assets/skills/`; [`diff`] compares it
//! against the committed copies without writing; [`run_capabilities`] is the
//! `tm generate capabilities[--check]` CLI entry point.
//! Test: `generated_set_has_seven_entries`, `generated_set_is_deterministic`,
//! plus each submodule's own render tests.

mod agents;
mod cli_tree;
mod doctor;
mod entry;
mod framework;
mod mcp_tools;
mod skills;

use std::collections::BTreeMap;
use std::path::{Path, PathBuf};

/// Relative path (under `src/assets/skills/`) -> generated file content.
///
/// Why: `&'static str` keys (string literals fixed at compile time, one per
/// generated file) avoid an owned-`String`-vs-literal mismatch between the
/// build side and the seven fixed call sites in [`generate`]; `BTreeMap` gives
/// deterministic iteration order for free (the write/diff loops don't
/// otherwise care about order, but stable iteration keeps `--check`'s printed
/// drift summary reproducible too).
pub(crate) type GeneratedSet = BTreeMap<&'static str, String>;

/// Build every generated file's content, keyed by its path relative to
/// `src/assets/skills/`.
///
/// Why: a single function is the one place that knows the full generated
/// file set — the entry point plus six references files — so [`write`](crate::generate::write) and
/// [`diff`] share it and can never disagree about which files exist.
/// What: returns 7 entries: `tm-capabilities.md` (the entry file) plus
/// `tm-capabilities/references/{cli,mcp-tools,agents,skills,doctor,framework}.md`.
/// `references/workflows.md` is deliberately absent from this set — it is
/// hand-authored (issue #2913 brief §E) and never regenerated or diffed.
/// Test: `generated_set_has_seven_entries`, `generated_set_is_deterministic`.
pub(crate) fn generate() -> GeneratedSet {
    let mut set = GeneratedSet::new();
    set.insert("tm-capabilities.md", entry::render());
    set.insert("tm-capabilities/references/cli.md", cli_tree::render());
    set.insert(
        "tm-capabilities/references/mcp-tools.md",
        mcp_tools::render(),
    );
    set.insert("tm-capabilities/references/agents.md", agents::render());
    set.insert("tm-capabilities/references/skills.md", skills::render());
    set.insert("tm-capabilities/references/doctor.md", doctor::render());
    set.insert(
        "tm-capabilities/references/framework.md",
        framework::render(),
    );
    set
}

/// The compile-time source asset root: `crates/trusty-mpm/src/assets/skills/`.
///
/// Why: `tm generate capabilities` is a dev-time-only subcommand — it always
/// runs from a checkout of this repo, so anchoring on
/// `CARGO_MANIFEST_DIR` (fixed at compile time to this package's root) is
/// correct and avoids any dependency on the runtime working directory.
fn skills_asset_dir() -> PathBuf {
    Path::new(env!("CARGO_MANIFEST_DIR")).join("src/assets/skills")
}

/// Write every generated file to disk under `root`.
///
/// Why: the non-`--check` path — regenerating and committing the output is
/// how a maintainer picks up a new CLI command, MCP tool, agent, or skill.
/// `root` is injected (rather than hard-coding [`skills_asset_dir`]) so tests
/// can point this at a temp directory instead of mutating the real committed
/// assets on every `cargo test` run.
/// What: creates parent directories as needed (the `references/` subtree
/// does not exist until the first write) and overwrites each file.
/// Test: `write_then_diff_round_trips_clean` (against a temp dir).
pub(crate) fn write(set: &GeneratedSet, root: &Path) -> anyhow::Result<()> {
    for (rel_path, content) in set {
        let target = root.join(rel_path);
        if let Some(parent) = target.parent() {
            std::fs::create_dir_all(parent)?;
        }
        std::fs::write(&target, content)?;
    }
    Ok(())
}

/// Diff every generated file against the committed copy under `root`.
///
/// Why: the `--check` path (the CI drift gate) must never write — it only
/// reports what would change, so a stale committed file fails the build
/// instead of silently self-healing in CI. `root` is injected for the same
/// temp-dir-testability reason as [`write`](crate::generate::write).
/// What: returns the list of mismatched/missing relative paths, each
/// annotated with why it drifted; an empty vec means every generated file
/// matches its committed copy exactly (byte-for-byte).
/// Test: `diff_reports_missing_file_against_empty_dir`,
/// `write_then_diff_round_trips_clean`.
pub(crate) fn diff(set: &GeneratedSet, root: &Path) -> Vec<String> {
    let mut drifted = Vec::new();
    for (rel_path, content) in set {
        let target = root.join(rel_path);
        match std::fs::read_to_string(&target) {
            Ok(existing) if &existing == content => {}
            Ok(_) => drifted.push(format!("{rel_path} (content differs)")),
            Err(_) => drifted.push(format!("{rel_path} (missing)")),
        }
    }
    drifted
}

/// `tm generate capabilities[--check]` — the CLI entry point.
///
/// Why: `commands::generate::generate` (the thin CLI handler) delegates here
/// so the generation engine stays independently unit-testable without
/// clap/anyhow plumbing in every submodule.
/// What: without `check`, writes the freshly generated set and reports the
/// file count. With `check`, diffs instead of writing and returns an error
/// (non-zero exit) listing every drifted file when the set is not clean.
/// Test: exercised end-to-end by `scripts/check_capabilities.sh` against the
/// committed output; unit coverage is per-submodule + [`diff`]/[`write`](crate::generate::write).
pub(crate) fn run_capabilities(check: bool) -> anyhow::Result<()> {
    let set = generate();
    let root = skills_asset_dir();
    if check {
        let drifted = diff(&set, &root);
        if drifted.is_empty() {
            println!(
                "tm-capabilities: up to date ({} generated files).",
                set.len()
            );
            Ok(())
        } else {
            eprintln!(
                "tm-capabilities: drift detected in {} file(s):",
                drifted.len()
            );
            for d in &drifted {
                eprintln!("  - {d}");
            }
            eprintln!(
                "\nRun `tm generate capabilities` (no --check) to regenerate, then commit the diff."
            );
            anyhow::bail!("tm-capabilities drift check failed");
        }
    } else {
        write(&set, &root)?;
        println!(
            "tm-capabilities: wrote {} generated files under crates/trusty-mpm/src/assets/skills/tm-capabilities*",
            set.len()
        );
        Ok(())
    }
}

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

    #[test]
    fn generated_set_has_seven_entries() {
        let set = generate();
        assert_eq!(set.len(), 7);
        assert!(set.contains_key("tm-capabilities.md"));
        assert!(set.contains_key("tm-capabilities/references/cli.md"));
        assert!(set.contains_key("tm-capabilities/references/mcp-tools.md"));
        assert!(set.contains_key("tm-capabilities/references/agents.md"));
        assert!(set.contains_key("tm-capabilities/references/skills.md"));
        assert!(set.contains_key("tm-capabilities/references/doctor.md"));
        assert!(set.contains_key("tm-capabilities/references/framework.md"));
    }

    #[test]
    fn generated_set_is_deterministic() {
        let a = generate();
        let b = generate();
        assert_eq!(a, b);
    }

    #[test]
    fn generated_set_no_content_is_empty() {
        for (path, content) in generate() {
            assert!(!content.trim().is_empty(), "{path} generated empty content");
        }
    }

    #[test]
    fn diff_reports_missing_file_against_empty_dir() {
        // A generated set diffed against a fresh temp dir that certainly
        // doesn't contain it — proves `diff`'s "missing" branch fires. Never
        // touches the real committed assets.
        let tmp = tempfile::tempdir().expect("tempdir");
        let mut set = GeneratedSet::new();
        set.insert("tm-capabilities/whatever.md", "content".to_string());
        let drifted = diff(&set, tmp.path());
        assert_eq!(drifted.len(), 1);
        assert!(drifted[0].contains("missing"), "{drifted:?}");
    }

    #[test]
    fn diff_reports_content_mismatch() {
        let tmp = tempfile::tempdir().expect("tempdir");
        std::fs::write(tmp.path().join("tm-capabilities.md"), "stale content").unwrap();
        let mut set = GeneratedSet::new();
        set.insert("tm-capabilities.md", "fresh content".to_string());
        let drifted = diff(&set, tmp.path());
        assert_eq!(drifted.len(), 1);
        assert!(drifted[0].contains("content differs"), "{drifted:?}");
    }

    #[test]
    fn write_then_diff_round_trips_clean() {
        // `write` + `diff` round-trip against an isolated temp dir: after
        // `write`, a fresh `diff` against the just-written files must report
        // no drift (since `generate()` is deterministic — see
        // `generated_set_is_deterministic`). Never touches the real
        // committed assets — see `scripts/check_capabilities.sh` for the
        // check that DOES compare against the real committed output.
        let tmp = tempfile::tempdir().expect("tempdir");
        let set = generate();
        write(&set, tmp.path()).expect("write succeeds");
        let drifted = diff(&set, tmp.path());
        assert!(
            drifted.is_empty(),
            "unexpected drift after write: {drifted:?}"
        );
    }
}