zshrs 0.10.9

//! Apply daemon canonical state to a freshly-built ShellExecutor —
//! by reading the daemon's rkyv shard directly from disk. No IPC.
//!
//! **zshrs-original infrastructure — no C source counterpart.** C
//! zsh always runs `Src/init.c::source_startup_files()` to set up
//! a fresh shell from the user's dotfiles. zshrs adds a fast path:
//! if `zshrs-daemon` has a canonical-state shard on disk
//! (`~/.zshrs/images/*-recorder.rkyv`), we mmap and apply it
//! directly into the executor's `pub` HashMaps, skipping the
//! `.zshenv`/`.zprofile`/`.zshrc`/`.zlogin` source pass entirely.
//! The shard format is rkyv (zero-copy archived structs) so the
//! cold-start cost is ~1ms instead of ~150ms.
//!
//! **Why direct shard read, not IPC.** The original spec
//! (`docs/DAEMON.md` "NO WALKING IN CLIENTS" + cache-architecture
//! memory) calls for thin clients that mmap the daemon's pre-built
//! shards as a zero-copy data plane. The earlier IPC version of this
//! file did 1+ `definitions_query` round-trips per cold-start, which
//! at ~600μs per round-trip put us 5-10ms over the spec target. The
//! mmap path is the real architecture: kernel page-cache after first
//! launch + rkyv check_archived + struct copy = sub-millisecond.
//!
//! IPC stays intact for `zd` / editor plugins / dashboards (see
//! `daemon/definitions.rs`). It's the right interface for "give me
//! the current catalog snapshot" from external tools. It's the wrong
//! interface for the shell's own cold-start hot path.
//!
//! The recorder writes one `*-recorder.rkyv` shard per ingest into
//! `~/.zshrs/images/`. We pick the latest by mtime, deserialize,
//! and copy fields straight into the executor's pub HashMaps.
//!
//! Failure mode: any I/O error → return 0; caller falls back to
//! vanilla `source_startup_files()`. Logged so the user can see why.

#![cfg(feature = "daemon")]

use std::path::PathBuf;

use crate::daemon::paths::CachePaths;
use crate::daemon::shard::{list_shards, read_canonical_shard, CanonicalShard};
use crate::exec::{AutoloadFlags, ShellExecutor, ZStyle};

/// Read the latest recorder shard and apply its canonical state to
/// the executor. Returns total rows applied (`0` if no shard or
/// read failure → caller falls back to vanilla dotfile source).
/// zshrs-original — no C counterpart. C zsh's
/// `source_startup_files()` (Src/init.c) is the only path; this is
/// a faster alternative built on top of the daemon shard.
pub fn apply_all(executor: &mut ShellExecutor) -> usize {
    let t0 = std::time::Instant::now();

    let paths = match CachePaths::resolve() {
        Ok(p) => p,
        Err(e) => {
            tracing::warn!(error = %e, "canonical_apply: cache paths unresolved");
            return 0;
        }
    };

    let shard_path = match latest_recorder_shard(&paths) {
        Some(p) => p,
        None => {
            tracing::info!(
                "canonical_apply: no recorder shard found in {} — vanilla fallback",
                paths.images.display()
            );
            return 0;
        }
    };

    let shard = match read_canonical_shard(&shard_path) {
        Ok(s) => s,
        Err(e) => {
            tracing::warn!(error = %e, path = %shard_path.display(), "canonical_apply: shard read failed");
            return 0;
        }
    };

    let total = apply_shard(executor, shard);
    let elapsed_us = t0.elapsed().as_micros();
    tracing::info!(
        rows = total,
        elapsed_us,
        path = %shard_path.display(),
        "canonical state applied from rkyv shard (no IPC)"
    );
    total
}

/// Walk `~/.zshrs/images/` and return the newest
/// `*-recorder.rkyv` shard by mtime.
/// zshrs-original — no C counterpart.
fn latest_recorder_shard(paths: &CachePaths) -> Option<PathBuf> {
    let entries = list_shards(paths).ok()?;
    entries
        .into_iter()
        .filter(|p| {
            p.file_name()
                .and_then(|s| s.to_str())
                .map(|s| s.ends_with("-recorder.rkyv"))
                .unwrap_or(false)
        })
        .max_by_key(|p| {
            std::fs::metadata(p)
                .and_then(|m| m.modified())
                .ok()
        })
}

/// Bulk-copy every subsystem from a deserialized canonical shard
/// into the executor's mutable tables.
/// zshrs-original — no C counterpart. The closest C analog is the
/// per-subsystem builtin dispatch each dotfile triggers
/// (`alias`/`bindkey`/`zstyle`/`compdef`/etc.) but compressed into
/// a single in-memory copy.
fn apply_shard(executor: &mut ShellExecutor, shard: CanonicalShard) -> usize {
    let mut total = 0;

    // Aliases (3 flavors).
    for (n, v) in shard.aliases {
        executor.aliases.insert(n, v);
        total += 1;
    }
    for (n, v) in shard.global_aliases {
        executor.global_aliases.insert(n, v);
        total += 1;
    }
    for (n, v) in shard.suffix_aliases {
        executor.suffix_aliases.insert(n, v);
        total += 1;
    }

    // Exported env: mirror to process env so child commands inherit.
    for (n, v) in shard.env_exports {
        std::env::set_var(&n, &v);
        executor.variables.insert(n, v);
        total += 1;
    }

    // Non-exported shell params.
    for (n, v) in shard.params {
        executor.variables.insert(n, v);
        total += 1;
    }

    // setopt / unsetopt.
    for opt in shard.setopts {
        executor.options.insert(opt, true);
        total += 1;
    }
    for opt in shard.unsetopts {
        executor.options.insert(opt, false);
        total += 1;
    }

    // path + fpath: ordered Vec<String> in the shard.
    if !shard.path.is_empty() {
        let joined = shard.path.join(":");
        std::env::set_var("PATH", &joined);
        executor.variables.insert("PATH".to_string(), joined);
        total += shard.path.len();
        executor.arrays.insert("path".to_string(), shard.path);
    }
    if !shard.fpath.is_empty() {
        let joined = shard.fpath.join(":");
        std::env::set_var("FPATH", &joined);
        executor.variables.insert("FPATH".to_string(), joined);
        total += shard.fpath.len();
        executor.fpath = shard.fpath.iter().map(PathBuf::from).collect();
        executor.arrays.insert("fpath".to_string(), shard.fpath);
    }

    // named_dir (hash -d): direct insert into executor.named_dirs.
    // After this, `~name` expansion is a HashMap lookup on first
    // access, no parsing of `hash -d` lines.
    for (name, path) in shard.named_dirs {
        executor.named_dirs.insert(name, PathBuf::from(path));
        total += 1;
    }

    // autoload_functions: register every name as autoload-pending
    // with the standard `-Uz` flag set (NO_ALIAS + ZSH_STYLE), what
    // every modern compsys / plugin does. The body lookup happens on
    // first call via the autoload resolver; we don't pre-compile.
    let auto_flags = AutoloadFlags::NO_ALIAS | AutoloadFlags::ZSH_STYLE;
    for name in shard.autoload_functions.keys() {
        executor
            .autoload_pending
            .insert(name.clone(), auto_flags);
        total += 1;
    }

    // zstyle: shard stores `Vec<(pattern, "style val val ...")>` —
    // split the joined-rest back into (style, values) so the exec
    // side has the same `ZStyle { pattern, style, values: Vec<_> }`
    // shape it would build by sourcing `zstyle :ctx style val val …`
    // statements.
    for (pattern, rest) in shard.zstyle {
        let mut parts = rest.split_whitespace();
        let style = match parts.next() {
            Some(s) => s.to_string(),
            None => continue,
        };
        let values: Vec<String> = parts.map(str::to_string).collect();
        executor.zstyles.push(ZStyle {
            pattern,
            style,
            values,
        });
        total += 1;
    }

    // bindkey: install each captured (keyseq, widget) into the global
    // KeymapManager. Recorder encodes the keymap-target by prefixing
    // the value with `[KEYMAP] ` (per `builtin_bindkey` in
    // src/exec.rs); strip that prefix and dispatch to the right
    // keymap. Default = Main.
    {
        use crate::zle::{zle, KeymapName};
        let mut zle_state = zle();
        for (keyseq, value) in shard.bindkeys {
            let (keymap, widget) = parse_bindkey_value(&value);
            zle_state.bind_key(keymap, &keyseq, widget);
            total += 1;
        }
    }

    // compdef: each (function, "cmd1 cmd2 ...") row replays through
    // the same compdef builtin install path
    // (compsys::compdef::compdef_execute) that runtime `compdef _git
    // git` would have used. Recorder captures with format
    // `name=function value="cmd1 cmd2 …"` (per `builtin_compdef` in
    // src/exec.rs).
    if !shard.compdef.is_empty() {
        // Executor's constructor only opens compsys_cache if the
        // .db file already exists (cold start = None). Open it
        // lazily here so the apply path is self-sufficient: first
        // recorder ingest creates the cache; subsequent shells see
        // it and apply normally.
        if executor.compsys_cache.is_none() {
            let cache_path = compsys::cache::default_cache_path();
            if let Some(parent) = cache_path.parent() {
                let _ = std::fs::create_dir_all(parent);
            }
            match compsys::cache::CompsysCache::open(&cache_path) {
                Ok(c) => {
                    tracing::info!(
                        path = %cache_path.display(),
                        "compsys cache lazily created for canonical compdef apply"
                    );
                    executor.compsys_cache = Some(c);
                }
                Err(e) => {
                    tracing::warn!(error = %e, "compsys cache open failed; compdef rows skipped");
                }
            }
        }
        if let Some(cache) = executor.compsys_cache.as_mut() {
            for (function, cmds_joined) in shard.compdef {
                let mut args: Vec<String> = Vec::with_capacity(8);
                args.push(function);
                for cmd in cmds_joined.split_whitespace() {
                    args.push(cmd.to_string());
                }
                if args.len() < 2 {
                    continue; // recorder dropped the cmd list — can't replay
                }
                let _rc = compsys::compdef::compdef_execute(cache, &args);
                total += 1;
            }
        }
    }

    // zle widgets: recorder routes them into shard.extras["zle"]
    // (one per `zle -N name [body]` capture). Reinstall via
    // ZleManager.user_widgets. Body string is whatever the user
    // gave; the widget invocation path looks it up at execution
    // time so re-installing the name+body string is enough.
    if let Some(zle_widgets) = shard.extras.get("zle") {
        use crate::zle::zle;
        let mut zle_state = zle();
        for (name, body) in zle_widgets {
            zle_state.user_widgets.insert(name.clone(), body.clone());
            total += 1;
        }
    }

    // inline-defined functions: captured in shard but not yet wired.
    // Two paths to install:
    //   (a) parse body string + fusevm-compile here on cold-start.
    //       ~50ms for 1k functions on M-series — defeats the
    //       zero-cost goal.
    //   (b) recorder ships pre-compiled bytecode in the shard;
    //       shell installs the chunk directly.
    // Path (b) is the right one (needs recorder-side change to
    // capture body bytecode at definition time + a new
    // `functions_compiled: HashMap<String, Vec<u8>>` shard field).
    // Until then, autoload-pending fallback covers the case: when
    // the user calls a function that wasn't pre-installed, the
    // autoload resolver fires + parses the body lazily.
    let _ = shard.functions;

    // zmodload / manpath / plugins / sourced_files / extras: no
    // executor surface today (modules call `zmodload` builtin
    // directly at use time; manpath is read from $MANPATH env;
    // plugins/sourced_files are diagnostic-only; extras is a
    // catch-all).
    let _ = shard.zmodload;
    let _ = shard.manpath;
    let _ = shard.plugins;
    let _ = shard.sourced_files;
    let _ = shard.extras;

    total
}

/// Decode a recorder-emitted bindkey value into (keymap, widget).
///
/// Format from `src/exec.rs:builtin_bindkey`:
///   `widget_name`               → KeymapName::Main
///   `[keymap_name] widget_name` → KeymapName::from_str("keymap_name")
///
/// Unknown keymap names fall back to `Main` (matches what zsh's
/// `bindkey` does for unrecognized -M targets — a safer default than
/// silently dropping the binding).
/// Parse a `bindkey` shard value into `(keymap, sequence)`.
/// zshrs-original — splits the canonical form `"keymap:sequence"`
/// the recorder writes back into the two arguments
/// `bindkey` (Src/Zle/zle_keymap.c) takes at the C builtin layer.
fn parse_bindkey_value(value: &str) -> (crate::zle::KeymapName, &str) {
    use crate::zle::KeymapName;
    if let Some(rest) = value.strip_prefix('[') {
        if let Some(close_idx) = rest.find(']') {
            let keymap_str = &rest[..close_idx];
            let widget = rest[close_idx + 1..].trim_start();
            let keymap = KeymapName::from_str(keymap_str).unwrap_or(KeymapName::Main);
            return (keymap, widget);
        }
    }
    (KeymapName::Main, value)
}

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

    #[test]
    fn bindkey_value_parses_main_keymap_default() {
        let (km, w) = parse_bindkey_value("history-search-backward");
        assert_eq!(km, KeymapName::Main);
        assert_eq!(w, "history-search-backward");
    }

    #[test]
    fn bindkey_value_parses_explicit_keymap() {
        let (km, w) = parse_bindkey_value("[viins] backward-delete-char");
        assert_eq!(km, KeymapName::ViInsert);
        assert_eq!(w, "backward-delete-char");
    }

    #[test]
    fn bindkey_value_unknown_keymap_falls_back_to_main() {
        let (km, w) = parse_bindkey_value("[totally-not-real] do-thing");
        assert_eq!(km, KeymapName::Main);
        assert_eq!(w, "do-thing");
    }

    #[test]
    fn bindkey_value_handles_extra_whitespace_after_close_bracket() {
        let (km, w) = parse_bindkey_value("[vicmd]   forward-word");
        assert_eq!(km, KeymapName::ViCommand);
        assert_eq!(w, "forward-word");
    }
}