truth_mirror/

hooks.rs

//! Hook installation, uninstallation, and dry-run planning.

use std::{
    fs,
    io::{self, Read},
    path::{Component, Path, PathBuf},
    process::{Command, ExitCode},
};

use anyhow::{Context, Result, bail};

use crate::{
    claim,
    cli::{self, Agent, HookName},
    gate,
    reviewer::ReviewQueue,
    surface::{self, SurfacePlan},
};

const INSTALLED_HOOKS: &[HookName] =
    &[HookName::CommitMsg, HookName::PostCommit, HookName::PrePush];
pub(crate) const MANAGED_MARKER: &str = "# truth-mirror managed hook";
const MANAGED_END_MARKER: &str = "# truth-mirror hook end";
pub(crate) const FORWARDER_NAME: &str = "_forward-local.sh";
const OUTER_HOOK_MARKERS: &[&str] = &[
    "# Entire CLI hooks",
    "# truth-mirror managed hook",
    "entire hooks git",
];
const STATE_GITIGNORE_HEADER: &str = "# truth-mirror runtime state - machine-generated";
const STATE_GITIGNORE_LINES: &[&str] = &[
    "*",
    "!.gitignore",
    "!config.toml",
    "runs/",
    "review-queue.jsonl",
    "ledger.jsonl",
    "ledger.md",
    "tmp/",
    "logs/",
    "*.local.*",
];
pub(crate) const FORWARDER_SOURCE: &str = r#"#!/bin/sh
# _forward-local.sh - delegate to .git/hooks from a committed core.hooksPath.
# Uses --git-common-dir (resolves to .git/) not core.hooksPath to prevent an infinite loop.
name="$1"; shift
git_dir="$(git rev-parse --git-common-dir 2>/dev/null)"
[ -n "$git_dir" ] || exit 0
local_hook="$git_dir/hooks/$name"
if [ -x "$local_hook" ]; then exec "$local_hook" "$@"; fi
exit 0
"#;

/// Printed after `--pi` install: Pi only executes project extensions once the
/// folder is trusted (verified against Pi 0.80.3 `core/project-trust.js`).
const PI_TRUST_NOTE: &str = "pi: installed .pi/extensions/truth-mirror.js — Pi loads it once you trust this project folder in Pi.";

/// Printed after `--grok` install: skill-based reinjection (Grok ignores passive hook stdout).
const GROK_SKILL_NOTE: &str = "grok: installed .grok/skills/truth-mirror/SKILL.md — Grok does not inject passive hook stdout; run `truth-mirror reinject --agent grok` (skill reminds the agent). Project hooks need `/hooks-trust` if enforcement hooks are installed.";

pub fn run(
    args: cli::InstallHooksArgs,
    state_dir: &Path,
    config_path: Option<&Path>,
    config: &crate::config::TruthMirrorConfig,
) -> Result<ExitCode> {
    let repo_root = git_root()?;
    let hooks_path = repo_root.join(state_dir).join("hooks");
    let plan = HookInstallPlan::new(&repo_root, &hooks_path, args.uninstall);
    // Preserve non-default global flags so the INSTALLED hooks use the same config
    // and state dir at runtime instead of silently reloading defaults.
    let global_args = hook_global_args(config_path, &repo_root, state_dir);
    let plan = HookInstallPlan {
        global_args,
        mode: detect_hook_mode(&repo_root, state_dir)?,
        ..plan
    };
    let agents = file_surface_agents(&args);
    let pi = pi_targeted(&args);
    let grok = grok_targeted(&args);

    if args.dry_run {
        println!("{}", plan.render());
        for agent in &agents {
            println!(
                "surface: {} -> {}",
                surface::agent_slug(*agent),
                surface::surface_relative_path(*agent)
            );
        }
        if pi {
            println!("surface: pi -> {}", surface::PI_EXTENSION_RELATIVE);
        }
        if grok {
            println!("surface: grok -> {}", surface::GROK_SKILL_RELATIVE);
            if config.enforcement.is_enabled() {
                println!(
                    "surface: grok-enforcement -> {}",
                    surface::surface_relative_path(Agent::Grok)
                );
            }
        }
        return Ok(ExitCode::SUCCESS);
    }

    let enforcement_enabled = config.enforcement.is_enabled();

    if args.uninstall {
        uninstall(&plan)?;
        for agent in &agents {
            surface::uninstall_enforcement(&repo_root, *agent)?;
            SurfacePlan::for_agent(&repo_root, *agent).uninstall()?;
        }
        if pi {
            surface::uninstall_pi_extension(&repo_root)?;
            remove_legacy_pi_hooks(&repo_root)?;
        }
        if grok {
            // Best-effort enforcement uninstall first so a corrupt hooks JSON cannot
            // block skill removal (full uninstall is also resilient elsewhere).
            if let Err(error) = surface::uninstall_enforcement(&repo_root, Agent::Grok) {
                eprintln!(
                    "{} grok enforcement uninstall failed (continuing skill cleanup): {error}",
                    crate::messages::diagnostic_prefix()
                );
            }
            surface::uninstall_grok_skill(&repo_root)?;
            surface::cleanup_empty_grok_dirs(&repo_root);
        }
        uninstall_legacy_hook_references(&repo_root)?;
    } else {
        install(&plan, args.inject_forwarder)?;
        print_async_review_guidance(&plan.global_args);
        for agent in &agents {
            SurfacePlan::for_agent(&repo_root, *agent).install()?;
            // Enforcement is opt-in: only install the tool-blocking hook when the
            // repo config enables it. Preserve global flags so it uses this config.
            if enforcement_enabled {
                surface::install_enforcement(&repo_root, *agent, &plan.global_args)?;
            }
        }
        if args.pi {
            // Clean any bogus .pi/hooks.json a prior truth-mirror wrote, install the
            // real project-local extension, and note the one-time trust step.
            remove_legacy_pi_hooks(&repo_root)?;
            surface::install_pi_extension(&repo_root)?;
            println!("{PI_TRUST_NOTE}");
        }
        if args.grok {
            // Grok cannot reinject via UserPromptSubmit stdout (passive hooks).
            // Install a project skill; optional PreToolUse enforcement uses hooks JSON.
            surface::install_grok_skill(&repo_root)?;
            if enforcement_enabled {
                surface::install_enforcement(&repo_root, Agent::Grok, &plan.global_args)?;
            }
            println!("{GROK_SKILL_NOTE}");
        }
    }

    Ok(ExitCode::SUCCESS)
}

fn print_async_review_guidance(global_args: &str) {
    eprintln!(
        "{} post-commit hooks queue async reviews; {}.",
        crate::messages::diagnostic_prefix(),
        crate::messages::async_review_drain_hint(global_args)
    );
}

/// Standalone `uninstall` subcommand: full teardown of all truth-mirror hooks,
/// surfaces, legacy artefacts, and (with `--purge`) state directories.
///
/// Factoring note: the shared hook-uninstall logic reused here lives in
/// [`uninstall`] (hook-mode dispatch) and the per-surface helpers in
/// [`crate::surface`]. Agent-surface resilience (A7) means a malformed
/// `settings.json` must not abort the remaining surfaces; errors are collected
/// and reported together.
pub fn run_uninstall(
    args: cli::UninstallArgs,
    state_dir: &Path,
    config_path: Option<&Path>,
) -> Result<std::process::ExitCode> {
    let repo_root = git_root()?;
    let hooks_path = repo_root.join(state_dir).join("hooks");
    let global_args = hook_global_args(config_path, &repo_root, state_dir);
    let plan = HookInstallPlan {
        repo_root: repo_root.clone(),
        hooks_path: hooks_path.clone(),
        uninstall: true,
        mode: detect_hook_mode(&repo_root, state_dir)?,
        global_args,
    };

    if args.dry_run {
        println!("{}", plan.render());
        let agent_list = surface::FILE_SURFACE_AGENTS
            .iter()
            .map(|agent| surface::agent_slug(*agent))
            .chain(["pi", "grok"])
            .collect::<Vec<_>>()
            .join(", ");
        println!("uninstall: would remove all agent surfaces ({agent_list})");
        println!(
            "uninstall: would clean .pre-entire bridges and orphaned .pre-truth-mirror backups"
        );
        println!("uninstall: would remove legacy .truth-mirror/hooks/ install artifacts");
        println!(
            "uninstall: would scrub legacy truth-mirror hook references without managed markers"
        );
        if args.purge {
            println!(
                "uninstall: --purge: would delete {} and .truth-mirror/ entirely",
                state_dir.display()
            );
        } else {
            println!(
                "uninstall: ledger data in {} is preserved (use --purge to delete)",
                state_dir.display()
            );
        }
        return Ok(std::process::ExitCode::SUCCESS);
    }

    // ── Step 1: uninstall git hooks (mode-specific) ─────────────────────────
    uninstall(&plan)?;
    // R1: Also clean up stale .git/hooks managed shims from a prior plain-mode
    // install, regardless of the current hook mode (e.g. a Husky-mode repo that
    // previously had a plain install). uninstall_plain is guarded by
    // is_truth_mirror_managed so double-running it in Plain mode is a no-op.
    if !matches!(plan.mode, HookInstallMode::Plain) {
        uninstall_plain(&plan)?;
    }

    // ── Step 2: remove all agent surfaces (full teardown, resilient) ─────────
    let mut surface_errors: Vec<String> = Vec::new();
    for &agent in surface::FILE_SURFACE_AGENTS.iter() {
        if let Err(error) = surface::uninstall_enforcement(&repo_root, agent) {
            surface_errors.push(format!(
                "enforcement/{}: {error}",
                surface::agent_slug(agent)
            ));
        }
        if let Err(error) = surface::SurfacePlan::for_agent(&repo_root, agent).uninstall() {
            surface_errors.push(format!("surface/{}: {error}", surface::agent_slug(agent)));
        }
    }
    // Pi extension
    if let Err(error) = surface::uninstall_pi_extension(&repo_root) {
        surface_errors.push(format!("surface/pi-extension: {error}"));
    } else {
        // A6: attempt non-recursive rmdir on .pi/extensions/ then .pi/
        let pi_extensions = repo_root.join(".pi/extensions");
        let pi_dir = repo_root.join(".pi");
        // Ignore ENOTEMPTY (still has other files) — only remove if empty
        let _ = fs::remove_dir(&pi_extensions);
        let _ = fs::remove_dir(&pi_dir);
    }
    // Grok skill + enforcement hook (not in FILE_SURFACE_AGENTS)
    if let Err(error) = surface::uninstall_enforcement(&repo_root, Agent::Grok) {
        surface_errors.push(format!("enforcement/grok: {error}"));
    }
    if let Err(error) = surface::uninstall_grok_skill(&repo_root) {
        surface_errors.push(format!("surface/grok-skill: {error}"));
    } else {
        surface::cleanup_empty_grok_dirs(&repo_root);
    }
    // Legacy .pi/hooks.json
    if let Err(error) = remove_legacy_pi_hooks(&repo_root) {
        surface_errors.push(format!("surface/pi-legacy: {error}"));
    }

    // ── Step 3: .pre-entire bridge cleanup (A2) ───────────────────────────────
    // When Entire takes ownership of a hook it saves the previous hook
    // (truth-mirror's managed shim) as `<hook>.pre-entire`. Remove those when
    // they are still truth-mirror-managed so truth-mirror is fully gone.
    if let Err(e) = uninstall_pre_entire_bridges(&plan) {
        surface_errors.push(format!("bridges: {e}"));
    }

    // ── Step 4: orphaned .pre-truth-mirror backup cleanup (A3) ───────────────
    let git_hooks = repo_root.join(".git/hooks");
    if let Err(e) = cleanup_orphaned_backups(&git_hooks) {
        surface_errors.push(format!("backups/.git/hooks: {e}"));
    }
    if let HookInstallMode::CustomCommitted { ref hooks_path } = plan.mode.clone()
        && let Err(e) = cleanup_orphaned_backups(hooks_path)
    {
        surface_errors.push(format!("backups/{}: {e}", hooks_path.display()));
    }

    // ── Step 5: legacy .truth-mirror/hooks/ install artifact cleanup (A4) ───
    let legacy_state = repo_root.join(crate::config::LEGACY_STATE_DIR);
    let legacy_hooks_dir = legacy_state.join("hooks");
    if legacy_hooks_dir.is_dir()
        && let Err(e) = fs::remove_dir_all(&legacy_hooks_dir)
    {
        surface_errors.push(format!("legacy-hooks-dir: {e}"));
    }

    // ── Step 6: state .gitignore removal (A5) ────────────────────────────────
    let real_state_dir = absolutize(&repo_root, state_dir);
    remove_state_gitignore_if_pristine(&real_state_dir);

    // ── Step 7: purge state directories (A4 --purge) ─────────────────────────
    if args.purge {
        if real_state_dir.is_dir()
            && let Err(e) = fs::remove_dir_all(&real_state_dir)
        {
            surface_errors.push(format!("purge {}: {e}", real_state_dir.display()));
        }
        if legacy_state.is_dir()
            && let Err(e) = fs::remove_dir_all(&legacy_state)
        {
            surface_errors.push(format!("purge {}: {e}", legacy_state.display()));
        }
    }

    // ── Step 8: legacy truth-mirror references without managed markers ───────
    // Older installs and hand-rolled husky/Entire bridges may invoke truth-mirror
    // without the current `# truth-mirror managed hook` / `# truth-mirror hook end`
    // delimiters. Strip or remove those references so the uninstall is complete.
    if let Err(e) = uninstall_legacy_hook_references(&repo_root) {
        surface_errors.push(format!("legacy-hook-refs: {e}"));
    }

    // ── Report all collected errors (A7 + R3) ────────────────────────────────
    // surface_errors accumulates both surface/agent failures (Step 2) and
    // hook-cleanup failures (Steps 3-7) so that a failure in any later step
    // never silently drops earlier diagnostics.
    if !surface_errors.is_empty() {
        for error in &surface_errors {
            eprintln!(
                "{} uninstall error: {error}",
                crate::messages::diagnostic_prefix()
            );
        }
        return Ok(std::process::ExitCode::FAILURE);
    }

    Ok(std::process::ExitCode::SUCCESS)
}

/// Remove `.pre-entire` bridge files from a hooks directory when their content
/// is truth-mirror-managed (A2). These are created when Entire takes ownership
/// of a hook that truth-mirror previously managed.
fn uninstall_pre_entire_bridges(plan: &HookInstallPlan) -> Result<()> {
    let dirs: Vec<PathBuf> = match &plan.mode {
        HookInstallMode::Husky { content_dir } => {
            vec![plan.repo_root.join(".git/hooks"), content_dir.clone()]
        }
        _ => vec![plan.repo_root.join(".git/hooks")],
    };
    for dir in dirs {
        for hook in INSTALLED_HOOKS {
            let bridge = dir.join(format!("{}.pre-entire", hook.as_str()));
            if read_to_string_if_file(&bridge)?
                .as_deref()
                .is_some_and(is_truth_mirror_managed)
            {
                remove_file_if_exists(&bridge)?;
            }
        }
    }
    Ok(())
}

/// Clean up orphaned `.pre-truth-mirror` backup files in `hooks_dir` (A3).
///
/// Safe rules:
/// - Active hook absent → restore backup to active, remove backup.
/// - Active exists and backup bytes == backup bytes → redundant copy, remove.
/// - Active is a directory, or either read fails (non-UTF-8, permissions) →
///   preserve the backup and warn; continue to the next hook.
/// - Otherwise → content differs; preserve the backup and warn.
///
/// Only called when the active hook is NOT truth-mirror-managed (the case where
/// truth-mirror-managed active hooks restoring the backup is already handled by
/// [`uninstall_plain`]).
///
/// Uses raw byte comparison (R4) so non-UTF-8 hook content never aborts the run.
fn cleanup_orphaned_backups(hooks_dir: &Path) -> Result<()> {
    if !hooks_dir.is_dir() {
        return Ok(());
    }
    for hook in INSTALLED_HOOKS {
        let active = hooks_dir.join(hook.as_str());
        let backup = backup_path(&active, "pre-truth-mirror");
        if !backup.is_file() {
            continue;
        }

        // Read backup bytes; a read failure is unexpected — skip and warn.
        let backup_bytes = match fs::read(&backup) {
            Ok(b) => b,
            Err(e) => {
                eprintln!(
                    "{} warning: could not read backup {}; leaving it in place: {e}",
                    crate::messages::diagnostic_prefix(),
                    backup.display(),
                );
                continue;
            }
        };

        // If the active path is a directory we cannot safely proceed.
        if active.is_dir() {
            eprintln!(
                "{} warning: active hook path {} is a directory, not a file; \
                 leaving backup {} in place.",
                crate::messages::diagnostic_prefix(),
                active.display(),
                backup.display(),
            );
            continue;
        }

        // Read the active hook as raw bytes; treat missing as None.
        let active_bytes = match read_bytes_if_file(&active) {
            Ok(b) => b,
            Err(e) => {
                eprintln!(
                    "{} warning: could not read active hook {}; leaving backup {} in place: {e}",
                    crate::messages::diagnostic_prefix(),
                    active.display(),
                    backup.display(),
                );
                continue;
            }
        };

        // Only process backups when the active hook is NOT truth-mirror-managed.
        // (truth-mirror-managed active hook + backup is already handled in uninstall_plain.)
        // Convert to str for the marker check; non-UTF-8 → treat as not managed.
        let active_str = active_bytes
            .as_deref()
            .and_then(|b| std::str::from_utf8(b).ok());
        if active_str.is_some_and(is_truth_mirror_managed) {
            continue;
        }

        match active_bytes {
            None => {
                // Active absent — restore backup (recovery path).
                fs::write(&active, &backup_bytes)?;
                make_executable(&active)?;
                fs::remove_file(&backup)?;
            }
            Some(ref ab) if ab == &backup_bytes => {
                // Backup is a redundant copy — remove it.
                fs::remove_file(&backup)?;
            }
            Some(_) => {
                // Content differs — preserve the backup and warn.
                eprintln!(
                    "{} warning: preserved {} because its content differs from the active \
                     hook {}; inspect and remove manually.",
                    crate::messages::diagnostic_prefix(),
                    backup.display(),
                    active.display(),
                );
            }
        }
    }
    Ok(())
}

/// Remove the machine-generated state `.gitignore` iff its content starts with
/// the managed header. If the file has been user-modified, leave it and warn (A5).
fn remove_state_gitignore_if_pristine(state_dir: &Path) {
    let gitignore = state_dir.join(".gitignore");
    match read_to_string_if_file(&gitignore) {
        Ok(Some(content)) if content.starts_with(STATE_GITIGNORE_HEADER) => {
            if let Err(error) = remove_file_if_exists(&gitignore) {
                eprintln!(
                    "{} warning: could not remove state .gitignore {}: {error}",
                    crate::messages::diagnostic_prefix(),
                    gitignore.display(),
                );
            }
        }
        Ok(Some(_)) => {
            eprintln!(
                "{} hint: {} appears user-modified; leaving it in place.",
                crate::messages::diagnostic_prefix(),
                gitignore.display(),
            );
        }
        _ => {}
    }
}

/// File-surface agents (Claude, Codex) touched by this invocation. Install acts
/// only on explicitly selected agents; a bare `install-hooks --uninstall` clears
/// all file surfaces so it fully reverses a prior per-agent install.
fn file_surface_agents(args: &cli::InstallHooksArgs) -> Vec<Agent> {
    let mut agents = Vec::new();
    if args.claude {
        agents.push(Agent::Claude);
    }
    if args.codex {
        agents.push(Agent::Codex);
    }

    if agents.is_empty() && args.uninstall && !args.pi && !args.grok {
        return surface::FILE_SURFACE_AGENTS.to_vec();
    }
    agents
}

/// Whether this invocation should act on Pi: explicit `--pi`, or a bare
/// `--uninstall` (no agent flags) that clears everything including legacy Pi files.
fn pi_targeted(args: &cli::InstallHooksArgs) -> bool {
    args.pi || (args.uninstall && !args.claude && !args.codex && !args.grok)
}

/// Whether this invocation should act on Grok: explicit `--grok`, or bare uninstall.
fn grok_targeted(args: &cli::InstallHooksArgs) -> bool {
    args.grok || (args.uninstall && !args.claude && !args.codex && !args.pi)
}

/// Remove a `.pi/hooks.json` left by an earlier (incorrect) truth-mirror version.
fn remove_legacy_pi_hooks(repo_root: &Path) -> Result<()> {
    let path = repo_root.join(".pi/hooks.json");
    if path.is_file() {
        fs::remove_file(&path)?;
    }
    Ok(())
}

pub fn dispatch(
    args: cli::HookDispatchArgs,
    state_dir: &Path,
    config_path: Option<&Path>,
    config: &crate::config::TruthMirrorConfig,
) -> Result<ExitCode> {
    run_chained_hook(state_dir, args.hook, &args.args)?;

    match args.hook {
        HookName::CommitMsg => dispatch_commit_msg(state_dir, &args.args, config)?,
        HookName::PostCommit => dispatch_post_commit(state_dir)?,
        HookName::PrePush => dispatch_pre_push(state_dir, config_path, config, &args.args)?,
    }

    Ok(ExitCode::SUCCESS)
}

#[derive(Clone, Debug, Default, Eq, PartialEq)]
pub struct HookInstallPlan {
    pub repo_root: PathBuf,
    pub hooks_path: PathBuf,
    pub uninstall: bool,
    pub mode: HookInstallMode,
    /// Global CLI flags (`--config`, `--state-dir`) preserved into the shims so a
    /// custom-config install keeps using that config at hook runtime. Empty for a
    /// default install (the trailing space is included when non-empty).
    pub global_args: String,
}

#[derive(Clone, Debug, Default, Eq, PartialEq)]
pub enum HookInstallMode {
    #[default]
    Plain,
    LegacyTruthMirrorHooksPath {
        configured_path: String,
    },
    Husky {
        content_dir: PathBuf,
    },
    CustomCommitted {
        hooks_path: PathBuf,
    },
}

impl HookInstallPlan {
    pub fn new(repo_root: &Path, hooks_path: &Path, uninstall: bool) -> Self {
        Self {
            repo_root: repo_root.to_path_buf(),
            hooks_path: hooks_path.to_path_buf(),
            uninstall,
            mode: HookInstallMode::Plain,
            global_args: String::new(),
        }
    }

    pub fn render(&self) -> String {
        let action = if self.uninstall {
            "uninstall"
        } else {
            "install"
        };
        let mut output = format!(
            "truth-mirror hook plan\nrepo={}\naction={action}\nmode={}\nstateHooks={}\n",
            self.repo_root.display(),
            self.mode.as_str(),
            self.hooks_path.display()
        );
        for hook in INSTALLED_HOOKS {
            output.push_str(&format!(
                "\nhook={}\npath={}\nbody:\n{}",
                hook.as_str(),
                self.active_hook_path(*hook).display(),
                self.render_hook_body(*hook)
            ));
        }
        output
    }

    fn active_hook_path(&self, hook: HookName) -> PathBuf {
        match &self.mode {
            HookInstallMode::Husky { content_dir } => content_dir.join(hook.as_str()),
            HookInstallMode::Plain | HookInstallMode::LegacyTruthMirrorHooksPath { .. } => {
                self.repo_root.join(".git/hooks").join(hook.as_str())
            }
            HookInstallMode::CustomCommitted { hooks_path } => hooks_path.join(hook.as_str()),
        }
    }

    fn render_hook_body(&self, hook: HookName) -> String {
        match self.mode {
            HookInstallMode::Husky { .. } => render_husky_block(hook, &self.global_args),
            HookInstallMode::CustomCommitted { .. } => render_custom_forwarder_stub(hook),
            HookInstallMode::Plain | HookInstallMode::LegacyTruthMirrorHooksPath { .. } => {
                render_shim(hook, &self.global_args)
            }
        }
    }
}

impl HookInstallMode {
    fn as_str(&self) -> &'static str {
        match self {
            HookInstallMode::Plain => "plain",
            HookInstallMode::LegacyTruthMirrorHooksPath { .. } => "plain-legacy-truth-mirror",
            HookInstallMode::Husky { .. } => "husky",
            HookInstallMode::CustomCommitted { .. } => "custom-committed",
        }
    }
}

/// Build the preserved global-flag prefix (with a trailing space when non-empty).
fn hook_global_args(config_path: Option<&Path>, repo_root: &Path, state_dir: &Path) -> String {
    let mut parts = Vec::new();
    if let Some(config) = config_path {
        parts.push(format!(
            "--config {}",
            quote_git_arg(&absolutize(repo_root, config))
        ));
    }
    if state_dir != Path::new(crate::config::DEFAULT_STATE_DIR) {
        parts.push(format!(
            "--state-dir {}",
            quote_git_arg(&absolutize(repo_root, state_dir))
        ));
    }
    if parts.is_empty() {
        String::new()
    } else {
        format!("{} ", parts.join(" "))
    }
}

fn absolutize(repo_root: &Path, path: &Path) -> PathBuf {
    if path.is_absolute() {
        path.to_path_buf()
    } else {
        repo_root.join(path)
    }
}

/// POSIX single-quote escaping for a path embedded in the generated `/bin/sh`
/// shim: wrap in single quotes and replace any embedded single quote with `'\''`
/// so no metacharacter (`;`, `$()`, `'`, spaces, …) can break or inject shell.
fn quote_git_arg(path: &Path) -> String {
    let value = path.to_string_lossy();
    format!("'{}'", value.replace('\'', "'\\''"))
}

pub fn render_shim(hook: HookName, global_args: &str) -> String {
    format!(
        "#!/bin/sh\n{MANAGED_MARKER}\nexec truth-mirror {global_args}hook-dispatch {} \"$@\"\n",
        hook.as_str()
    )
}

fn render_husky_block(hook: HookName, global_args: &str) -> String {
    format!(
        "{MANAGED_MARKER}\nif command -v truth-mirror >/dev/null 2>&1; then truth-mirror {global_args}hook-dispatch {} \"$@\"; else :; fi\n{MANAGED_END_MARKER}\n",
        hook.as_str()
    )
}

fn render_custom_forwarder_stub(hook: HookName) -> String {
    format!(
        "#!/bin/sh\n{MANAGED_MARKER}\nexec \"$(dirname \"$0\")/{FORWARDER_NAME}\" {} \"$@\"\n",
        hook.as_str()
    )
}

fn detect_hook_mode(repo_root: &Path, state_dir: &Path) -> Result<HookInstallMode> {
    let Some(configured) = git_config_get(repo_root, "core.hooksPath")? else {
        return Ok(HookInstallMode::Plain);
    };
    let configured = configured.trim().to_owned();
    if configured.is_empty() {
        return Ok(HookInstallMode::Plain);
    }
    if is_managed_hooks_path(repo_root, state_dir, &configured) {
        return Ok(HookInstallMode::LegacyTruthMirrorHooksPath {
            configured_path: configured,
        });
    }
    if configured.contains(".husky") {
        let hooks_path = repo_relative_path(repo_root, Path::new(&configured));
        let content_dir = if hooks_path.file_name().and_then(|name| name.to_str()) == Some("_") {
            hooks_path
                .parent()
                .map_or_else(|| repo_root.join(".husky"), Path::to_path_buf)
        } else {
            hooks_path
        };
        return Ok(HookInstallMode::Husky { content_dir });
    }
    Ok(HookInstallMode::CustomCommitted {
        hooks_path: repo_relative_path(repo_root, Path::new(&configured)),
    })
}

fn repo_relative_path(repo_root: &Path, path: &Path) -> PathBuf {
    if path.is_absolute() {
        path.to_path_buf()
    } else {
        repo_root.join(path)
    }
}

fn is_managed_hooks_path(repo_root: &Path, state_dir: &Path, configured: &str) -> bool {
    let configured_path = normalize_path(&repo_relative_path(repo_root, Path::new(configured)));
    [
        state_dir.join("hooks"),
        PathBuf::from(crate::config::DEFAULT_STATE_DIR).join("hooks"),
        PathBuf::from(crate::config::LEGACY_STATE_DIR).join("hooks"),
    ]
    .iter()
    .any(|candidate| normalize_path(&repo_relative_path(repo_root, candidate)) == configured_path)
}

fn normalize_path(path: &Path) -> PathBuf {
    let mut normalized = PathBuf::new();
    for component in path.components() {
        match component {
            Component::CurDir => {}
            Component::ParentDir => {
                if normalized.as_os_str().is_empty()
                    || (!normalized.has_root() && normalized.ends_with(".."))
                {
                    normalized.push("..");
                } else {
                    normalized.pop();
                }
            }
            Component::Normal(part) => normalized.push(part),
            Component::RootDir | Component::Prefix(_) => normalized.push(component.as_os_str()),
        }
    }
    normalized
}

fn install(plan: &HookInstallPlan, inject_forwarder: bool) -> Result<()> {
    let state_dir = state_dir_from_hooks_path(&plan.hooks_path);
    match &plan.mode {
        HookInstallMode::Plain => {
            prepare_state_hooks(plan)?;
            migrate_truth_md(&plan.repo_root, state_dir)?;
            install_plain(plan)
        }
        HookInstallMode::LegacyTruthMirrorHooksPath { .. } => {
            prepare_state_hooks(plan)?;
            migrate_truth_md(&plan.repo_root, state_dir)?;
            unset_core_hooks_path(&plan.repo_root)?;
            install_plain(plan)
        }
        HookInstallMode::Husky { content_dir } => {
            prepare_state_hooks(plan)?;
            migrate_truth_md(&plan.repo_root, state_dir)?;
            install_husky(plan, content_dir)
        }
        HookInstallMode::CustomCommitted { hooks_path } => {
            install_custom(plan, hooks_path, inject_forwarder)
        }
    }
}

fn uninstall(plan: &HookInstallPlan) -> Result<()> {
    match &plan.mode {
        HookInstallMode::Plain => uninstall_plain(plan)?,
        HookInstallMode::LegacyTruthMirrorHooksPath { .. } => {
            unset_core_hooks_path(&plan.repo_root)?;
            uninstall_plain(plan)?;
        }
        HookInstallMode::Husky { content_dir } => uninstall_husky(plan, content_dir)?,
        HookInstallMode::CustomCommitted { hooks_path } => {
            uninstall_plain(plan)?;
            uninstall_custom_forwarders(hooks_path)?;
        }
    }

    if plan.hooks_path.exists() {
        fs::remove_dir_all(&plan.hooks_path)?;
    }
    Ok(())
}

fn state_dir_from_hooks_path(hooks_path: &Path) -> &Path {
    hooks_path.parent().unwrap_or(hooks_path)
}

fn prepare_state_hooks(plan: &HookInstallPlan) -> Result<()> {
    ensure_state_gitignore(&plan.repo_root, state_dir_from_hooks_path(&plan.hooks_path))?;
    fs::create_dir_all(&plan.hooks_path)?;
    fs::create_dir_all(plan.hooks_path.join("chained"))?;
    clear_chained_hooks(plan)
}

fn install_plain(plan: &HookInstallPlan) -> Result<()> {
    let git_hooks = plan.repo_root.join(".git/hooks");
    fs::create_dir_all(&git_hooks)?;
    for hook in INSTALLED_HOOKS {
        install_local_hook(plan, &git_hooks, *hook)?;
    }
    Ok(())
}

fn install_local_hook(plan: &HookInstallPlan, git_hooks: &Path, hook: HookName) -> Result<()> {
    let active = git_hooks.join(hook.as_str());
    let backup = backup_path(&active, "pre-truth-mirror");
    let chained = plan.hooks_path.join("chained").join(hook.as_str());
    remove_file_if_exists(&chained)?;

    let source = local_hook_source(&active, &backup)?;
    if let Some(source) = source {
        if source.path != backup {
            fs::copy(&source.path, &backup)?;
            make_executable(&backup)?;
        }
        if !has_outer_hook_marker(&source.content) {
            fs::copy(&source.path, &chained)?;
            make_executable(&chained)?;
        }
    }

    fs::write(&active, render_shim(hook, &plan.global_args))?;
    make_executable(&active)?;
    Ok(())
}

fn uninstall_plain(plan: &HookInstallPlan) -> Result<()> {
    let git_hooks = plan.repo_root.join(".git/hooks");
    for hook in INSTALLED_HOOKS {
        let active = git_hooks.join(hook.as_str());
        let backup = backup_path(&active, "pre-truth-mirror");
        let active_content = read_to_string_if_file(&active)?;
        if active_content
            .as_deref()
            .is_some_and(is_truth_mirror_managed)
        {
            if backup.is_file() {
                fs::copy(&backup, &active)?;
                make_executable(&active)?;
                fs::remove_file(&backup)?;
            } else {
                remove_file_if_exists(&active)?;
            }
        }
        remove_file_if_exists(&plan.hooks_path.join("chained").join(hook.as_str()))?;
    }
    Ok(())
}

fn install_husky(plan: &HookInstallPlan, content_dir: &Path) -> Result<()> {
    fs::create_dir_all(content_dir)?;
    for hook in INSTALLED_HOOKS {
        let target = content_dir.join(hook.as_str());
        let block = render_husky_block(*hook, &plan.global_args);
        let next = match read_to_string_if_file(&target)? {
            Some(content) => append_managed_block(&content, &block),
            None => format!("#!/bin/sh\n{block}"),
        };
        fs::write(&target, next)?;
        make_executable(&target)?;
    }
    Ok(())
}

fn uninstall_husky(_plan: &HookInstallPlan, content_dir: &Path) -> Result<()> {
    for hook in INSTALLED_HOOKS {
        let target = content_dir.join(hook.as_str());
        if let Some(content) = read_to_string_if_file(&target)? {
            let next = remove_managed_block(&content);
            if is_empty_or_shebang_only(&next) {
                fs::remove_file(&target)?;
            } else {
                fs::write(&target, next)?;
                make_executable(&target)?;
            }
        }
    }
    Ok(())
}

fn install_custom(plan: &HookInstallPlan, hooks_path: &Path, inject_forwarder: bool) -> Result<()> {
    let missing_forwarder = INSTALLED_HOOKS
        .iter()
        .any(|hook| !custom_forwarder_present(hooks_path, *hook));
    if missing_forwarder && !inject_forwarder {
        bail!(
            "{} core.hooksPath is set to '{}' (a non-husky committed directory).\nTo install, either:\n  (a) run `{}` to write a _forward-local.sh forwarder into that directory (a committed repo change), or\n  (b) unset core.hooksPath and re-run install-hooks",
            crate::messages::diagnostic_prefix(),
            hooks_path.display(),
            crate::messages::command_for_cli(&plan.global_args, "install-hooks --inject-forwarder"),
        );
    }

    if inject_forwarder {
        inject_custom_forwarders(hooks_path)?;
    }

    prepare_state_hooks(plan)?;
    let state_dir = state_dir_from_hooks_path(&plan.hooks_path);
    migrate_truth_md(&plan.repo_root, state_dir)?;
    let git_hooks = plan.repo_root.join(".git/hooks");
    fs::create_dir_all(&git_hooks)?;
    for hook in INSTALLED_HOOKS {
        install_local_hook(plan, &git_hooks, *hook)?;
    }
    Ok(())
}

fn inject_custom_forwarders(hooks_path: &Path) -> Result<()> {
    fs::create_dir_all(hooks_path)?;
    let forwarder = hooks_path.join(FORWARDER_NAME);
    fs::write(&forwarder, FORWARDER_SOURCE)?;
    make_executable(&forwarder)?;

    for hook in INSTALLED_HOOKS {
        let target = hooks_path.join(hook.as_str());
        if custom_forwarder_present(hooks_path, *hook) {
            continue;
        }
        if target.is_file() {
            fs::copy(&target, backup_path(&target, "pre-truth-mirror"))?;
        }
        fs::write(&target, render_custom_forwarder_stub(*hook))?;
        make_executable(&target)?;
    }
    eprintln!(
        "hint: commit the truth-mirror forwarder changes in {}",
        hooks_path.display()
    );
    Ok(())
}

fn uninstall_custom_forwarders(hooks_path: &Path) -> Result<()> {
    for hook in INSTALLED_HOOKS {
        let target = hooks_path.join(hook.as_str());
        let backup = backup_path(&target, "pre-truth-mirror");
        let content = read_to_string_if_file(&target)?;
        if content.as_deref().is_some_and(is_truth_mirror_managed) {
            if backup.is_file() {
                fs::copy(&backup, &target)?;
                make_executable(&target)?;
                fs::remove_file(&backup)?;
            } else {
                remove_file_if_exists(&target)?;
            }
        }
    }
    let forwarder = hooks_path.join(FORWARDER_NAME);
    if read_to_string_if_file(&forwarder)?.as_deref() == Some(FORWARDER_SOURCE) {
        fs::remove_file(forwarder)?;
    }
    Ok(())
}

fn append_managed_block(content: &str, block: &str) -> String {
    let mut next = remove_managed_block(content);
    if !next.ends_with('\n') {
        next.push('\n');
    }
    next.push_str(block);
    next
}

fn remove_managed_block(content: &str) -> String {
    let mut out = Vec::new();
    let mut skipping = false;
    for line in content.lines() {
        if line == MANAGED_MARKER {
            skipping = true;
            continue;
        }
        if skipping {
            if line == MANAGED_END_MARKER {
                skipping = false;
            }
            continue;
        }
        out.push(line);
    }
    if out.is_empty() {
        String::new()
    } else {
        format!("{}\n", out.join("\n"))
    }
}

fn is_empty_or_shebang_only(content: &str) -> bool {
    let lines = content
        .lines()
        .map(str::trim)
        .filter(|line| !line.is_empty())
        .collect::<Vec<_>>();
    lines.is_empty() || lines == ["#!/bin/sh"]
}

/// Check whether a shell script parses successfully with `sh -n`.
fn shell_syntax_ok(path: &Path) -> bool {
    std::process::Command::new("sh")
        .args(["-n"])
        .arg(path)
        .status()
        .map(|status| status.success())
        .unwrap_or(false)
}

/// True when the only non-comment content left is a shebang and shell options.
/// Used after stripping legacy truth-mirror lines so that bare `set -e` lines
/// do not keep an otherwise-empty husky hook file alive.
fn is_effectively_empty_shell(content: &str) -> bool {
    content
        .lines()
        .map(str::trim)
        .filter(|line| !line.is_empty() && !line.starts_with('#'))
        .all(|line| line == "#!/bin/sh" || line == "#!/usr/bin/env sh" || line.starts_with("set "))
}

#[derive(Debug)]
struct LocalHookSource {
    path: PathBuf,
    content: String,
}

fn local_hook_source(active: &Path, backup: &Path) -> Result<Option<LocalHookSource>> {
    let Some(active_content) = read_to_string_if_file(active)? else {
        return Ok(None);
    };
    if is_truth_mirror_managed(&active_content) {
        return read_to_string_if_file(backup)?.map_or(Ok(None), |content| {
            Ok(Some(LocalHookSource {
                path: backup.to_path_buf(),
                content,
            }))
        });
    }
    Ok(Some(LocalHookSource {
        path: active.to_path_buf(),
        content: active_content,
    }))
}

fn custom_forwarder_present(hooks_path: &Path, hook: HookName) -> bool {
    read_to_string_if_file(&hooks_path.join(hook.as_str()))
        .ok()
        .flatten()
        .is_some_and(|content| {
            active_hook_lines(&content).any(|line| line.contains(FORWARDER_NAME))
                || content_forwards_to_local_git_hook(&content, hook)
                || is_truth_mirror_managed(&content)
        })
}

fn ensure_state_gitignore(repo_root: &Path, state_dir: &Path) -> Result<()> {
    let state_dir = absolutize(repo_root, state_dir);
    fs::create_dir_all(&state_dir)?;
    let gitignore = state_dir.join(".gitignore");
    let existing = read_to_string_if_file(&gitignore)?.unwrap_or_default();
    let content = render_state_gitignore(&existing);
    fs::write(&gitignore, content)?;
    print_tracked_runtime_hints(repo_root, &state_dir)?;
    Ok(())
}

fn render_state_gitignore(existing: &str) -> String {
    let mut content = String::new();
    content.push_str(STATE_GITIGNORE_HEADER);
    content.push('\n');
    for line in STATE_GITIGNORE_LINES {
        content.push_str(line);
        content.push('\n');
    }

    let standard = |line: &str| {
        let trimmed = line.trim();
        trimmed == STATE_GITIGNORE_HEADER || STATE_GITIGNORE_LINES.contains(&trimmed)
    };

    let mut wrote_separator = false;
    for line in existing.lines().filter(|line| !standard(line)) {
        if !wrote_separator {
            content.push('\n');
            wrote_separator = true;
        }
        content.push_str(line);
        content.push('\n');
    }

    content
}

fn print_tracked_runtime_hints(repo_root: &Path, state_dir: &Path) -> Result<()> {
    let rel_state = state_dir.strip_prefix(repo_root).unwrap_or(state_dir);
    for path in [
        rel_state.join("ledger.jsonl"),
        rel_state.join("ledger.md"),
        rel_state.join("review-queue.jsonl"),
        rel_state.join("runs"),
        rel_state.join("tmp"),
        rel_state.join("logs"),
    ] {
        let output = Command::new("git")
            .args(["ls-files", "--"])
            .arg(&path)
            .current_dir(repo_root)
            .output()?;
        if output.status.success() {
            for tracked in String::from_utf8_lossy(&output.stdout)
                .lines()
                .filter(|line| !line.trim().is_empty())
            {
                eprintln!("hint: run: git rm --cached {tracked}");
            }
        }
    }
    Ok(())
}

fn clear_chained_hooks(plan: &HookInstallPlan) -> Result<()> {
    for hook in INSTALLED_HOOKS {
        remove_file_if_exists(&plan.hooks_path.join("chained").join(hook.as_str()))?;
    }
    Ok(())
}

fn has_outer_hook_marker(content: &str) -> bool {
    content.lines().take(20).any(|line| {
        OUTER_HOOK_MARKERS
            .iter()
            .any(|marker| line.contains(marker))
            || (!line.trim_start().starts_with('#') && line_invokes_truth_hook_dispatch(line, None))
    })
}

fn is_truth_mirror_managed(content: &str) -> bool {
    content.contains(MANAGED_MARKER)
        || active_hook_lines(content).any(|line| line_invokes_truth_hook_dispatch(line, None))
}

/// Markers that indicate a hook file also contains Entire CLI integration.
/// When removing legacy truth-mirror references we must preserve Entire.
const ENTIRE_MARKERS: &[&str] = &[
    "# Entire CLI hooks",
    "entire hooks git",
    "command -v entire",
];

/// Detect content that references truth-mirror but does not carry the current
/// managed-block markers. Old husky installs, hand-rolled bridges, and scripts
/// that assign `truth_mirror_bin` all match so that uninstall can finish the
/// teardown that marker-based removal alone cannot.
fn is_legacy_truth_reference(content: &str) -> bool {
    content.contains("truth-mirror")
        || content.contains("truth_mirror_bin")
        || is_truth_mirror_managed(content)
}

/// True when a `.pre-entire` file is already the simple Entire→husky bridge
/// that install/uninstall want to preserve.
fn is_simple_pre_entire_bridge(content: &str, hook_name: &str) -> bool {
    // Normalize whitespace so hand-formatted variants still match.
    let normalized: String = content
        .lines()
        .map(str::trim)
        .filter(|line| !line.is_empty() && !line.starts_with('#'))
        .collect::<Vec<_>>()
        .join(" ");
    normalized == format!(r#"exec "$(dirname "$0")/{hook_name}" "$@""#)
}

/// Remove lines that are obviously part of a legacy truth-mirror hook, while
/// leaving Entire or other foreign content intact.
fn strip_legacy_truth_lines(content: &str) -> String {
    let mut out = Vec::new();
    for line in content.lines() {
        let trimmed = line.trim();
        if trimmed.contains("truth-mirror")
            || trimmed.contains("truth_mirror_bin")
            || trimmed.starts_with("# Truthfulness gate")
            || trimmed.starts_with("# truth-mirror's")
        {
            continue;
        }
        out.push(line);
    }
    if out.is_empty() {
        String::new()
    } else {
        format!("{}\n", out.join("\n"))
    }
}

/// Scrub legacy truth-mirror references from `.husky/`, `.git/hooks/`, and
/// `.truth-mirror/hooks/` files that were not written with the current managed
/// block markers. Files that are solely truth-mirror are removed; files that
/// also contain Entire integration are stripped of truth-mirror lines.
///
/// `.pre-entire` bridges created by the husky+Entire+truth-mirror chain are
/// rewritten to a simple bridge so Entire keeps forwarding to the husky hook.
fn uninstall_legacy_hook_references(repo_root: &Path) -> Result<()> {
    let husky_dir = repo_root.join(".husky");
    let git_hooks = repo_root.join(".git/hooks");
    let legacy_hooks = repo_root
        .join(crate::config::LEGACY_STATE_DIR)
        .join("hooks");

    for hook in INSTALLED_HOOKS {
        let hook_name = hook.as_str();
        let names: Vec<String> = vec![hook_name.to_owned(), format!("{hook_name}.pre-entire")];
        for dir in [&husky_dir, &git_hooks, &legacy_hooks] {
            for name in &names {
                let path = dir.join(name);
                let Some(content) = read_to_string_if_file(&path)? else {
                    continue;
                };
                if content.contains(MANAGED_MARKER) {
                    continue;
                }
                if name.ends_with(".pre-entire") {
                    if is_simple_pre_entire_bridge(&content, hook_name) {
                        continue;
                    }
                    if is_legacy_truth_reference(&content) || !shell_syntax_ok(&path) {
                        // Keep the Entire forwarding bridge but drop any custom
                        // truth-mirror logic that may leave broken `else` blocks.
                        let bridge =
                            format!("#!/bin/sh\nexec \"$(dirname \"$0\")/{hook_name}\" \"$@\"\n");
                        fs::write(&path, bridge)?;
                        make_executable(&path)?;
                    }
                    continue;
                }
                if !is_legacy_truth_reference(&content) {
                    continue;
                }
                if ENTIRE_MARKERS.iter().any(|marker| content.contains(marker)) {
                    let stripped = strip_legacy_truth_lines(&content);
                    if is_effectively_empty_shell(&stripped) {
                        fs::remove_file(&path)?;
                    } else {
                        fs::write(&path, stripped)?;
                        make_executable(&path)?;
                    }
                } else {
                    fs::remove_file(&path)?;
                }
            }
        }
    }
    Ok(())
}

/// Move legacy TRUTH.md locations into the current state dir so that install
/// leaves the repo following the `.truth/TRUTH.md` convention.
fn migrate_truth_md(repo_root: &Path, state_dir: &Path) -> Result<()> {
    let target = state_dir.join("TRUTH.md");
    if target.is_file() {
        return Ok(());
    }
    let legacy = repo_root
        .join(crate::config::LEGACY_STATE_DIR)
        .join("TRUTH.md");
    if legacy.is_file() {
        fs::copy(&legacy, &target)?;
        fs::remove_file(&legacy)?;
        return Ok(());
    }
    let root = repo_root.join("TRUTH.md");
    if root.is_file() {
        fs::rename(&root, &target)?;
    }
    Ok(())
}

fn active_hook_lines(content: &str) -> impl Iterator<Item = &str> {
    content
        .lines()
        .map(str::trim_start)
        .filter(|line| !line.trim().is_empty() && !line.starts_with('#'))
}

fn content_forwards_to_local_git_hook(content: &str, hook: HookName) -> bool {
    let resolves_git_dir =
        content.contains("--git-common-dir") || content.contains("git rev-parse --git-common-dir");
    resolves_git_dir
        && active_hook_lines(content)
            .any(|line| line_forwards_to_local_git_hook_with_args(line, hook))
}

fn line_forwards_to_local_git_hook_with_args(line: &str, hook: HookName) -> bool {
    line.contains("$@")
        && (line.contains(&format!("hooks/{}", hook.as_str()))
            || line.contains("hooks/$name")
            || line.contains("hooks/${name}")
            || line.contains("hooks/$hook")
            || line.contains("hooks/${hook}"))
}

fn line_invokes_truth_hook_dispatch(line: &str, expected_hook: Option<HookName>) -> bool {
    crate::shell::shellish_token_segments(line)
        .iter()
        .any(|tokens| token_segment_invokes_truth_hook_dispatch(tokens, expected_hook))
}

fn token_segment_invokes_truth_hook_dispatch(
    tokens: &[&str],
    expected_hook: Option<HookName>,
) -> bool {
    for (index, token) in tokens.iter().enumerate() {
        if !is_truth_binary(token) {
            continue;
        }
        let Some(dispatch_offset) = tokens[index + 1..]
            .iter()
            .position(|candidate| *candidate == "hook-dispatch")
        else {
            continue;
        };
        let hook_index = index + 1 + dispatch_offset + 1;
        let Some(hook) = tokens.get(hook_index) else {
            continue;
        };
        if expected_hook.is_some_and(|expected| hook == &expected.as_str())
            || expected_hook.is_none() && token_is_installed_hook(hook)
        {
            return true;
        }
    }
    false
}

fn is_truth_binary(token: &str) -> bool {
    token == "truth"
        || token == "truth-mirror"
        || token.ends_with("/truth")
        || token.ends_with("/truth-mirror")
}

fn token_is_installed_hook(token: &str) -> bool {
    INSTALLED_HOOKS.iter().any(|hook| token == hook.as_str())
}

fn backup_path(path: &Path, suffix: &str) -> PathBuf {
    let file_name = path
        .file_name()
        .and_then(|name| name.to_str())
        .unwrap_or("hook");
    path.with_file_name(format!("{file_name}.{suffix}"))
}

fn read_to_string_if_file(path: &Path) -> Result<Option<String>> {
    match fs::read_to_string(path) {
        Ok(content) => Ok(Some(content)),
        Err(error) if error.kind() == io::ErrorKind::NotFound => Ok(None),
        Err(error) => Err(error.into()),
    }
}

/// Read a path as raw bytes, returning `Ok(None)` when absent.
fn read_bytes_if_file(path: &Path) -> Result<Option<Vec<u8>>> {
    match fs::read(path) {
        Ok(bytes) => Ok(Some(bytes)),
        Err(error) if error.kind() == io::ErrorKind::NotFound => Ok(None),
        Err(error) => Err(error.into()),
    }
}

fn remove_file_if_exists(path: &Path) -> Result<()> {
    match fs::remove_file(path) {
        Ok(()) => Ok(()),
        Err(error) if error.kind() == io::ErrorKind::NotFound => Ok(()),
        Err(error) => Err(error.into()),
    }
}

fn unset_core_hooks_path(repo_root: &Path) -> Result<()> {
    let status = Command::new("git")
        .args(["config", "--unset", "core.hooksPath"])
        .current_dir(repo_root)
        .status()?;
    if !status.success() {
        // Git exits non-zero when the key is already absent; migration should be idempotent.
        return Ok(());
    }
    Ok(())
}

fn dispatch_commit_msg(
    state_dir: &Path,
    args: &[String],
    config: &crate::config::TruthMirrorConfig,
) -> Result<()> {
    let commit_msg_path = args
        .first()
        .context("commit-msg hook requires COMMIT_EDITMSG path")?;
    let commit_message = fs::read_to_string(commit_msg_path)?;
    let diff = git_stdout(&["diff", "--cached"])?;
    let claim_file = fs::read_to_string(state_dir.join("claim.txt")).ok();
    let policy = config.gates.to_policy();
    claim::evaluate_commit_message(&commit_message, claim_file.as_deref(), Some(&diff), &policy)?;
    Ok(())
}

fn dispatch_post_commit(state_dir: &Path) -> Result<()> {
    let sha = git_stdout(&["rev-parse", "HEAD"])?;
    ReviewQueue::new(state_dir).enqueue(sha.trim())?;
    // Enqueuing a claim must be sufficient to guarantee a consumer exists: kick the
    // idempotent watcher lifecycle so the queue drains without a human running
    // `watch` by hand. Best-effort and non-fatal — a failed spawn must never fail
    // the commit hook, and the next enqueue (or a manual `watch`) will retry.
    if let Err(error) = crate::watcher::ensure_watcher(state_dir) {
        tracing::warn!(%error, "post-commit: failed to ensure a review watcher");
    }
    Ok(())
}

fn dispatch_pre_push(
    state_dir: &Path,
    config_path: Option<&Path>,
    config: &crate::config::TruthMirrorConfig,
    args: &[String],
) -> Result<()> {
    let remote_name = pre_push_remote_name_from_args(args);
    let mut stdin = String::new();
    io::stdin().read_to_string(&mut stdin)?;
    for line in stdin.lines() {
        if let Some(range) = pre_push_range_from_line_for_remote(line, remote_name) {
            gate::run(
                cli::GateArgs {
                    pre_push: Some(range),
                    commit_msg: None,
                    claim_file: None,
                    diff_file: None,
                    fake_markers: Vec::new(),
                    pre_tool_use: false,
                    tool: None,
                },
                state_dir,
                config_path,
                config,
            )?;
        }
    }
    Ok(())
}

fn pre_push_range_from_line_for_remote(line: &str, remote_name: Option<&str>) -> Option<String> {
    let parts = line.split_whitespace().collect::<Vec<_>>();
    let local_sha = parts.get(1)?;
    let remote_sha = parts.get(3)?;
    if is_zero_sha(local_sha) {
        return None;
    }

    if is_zero_sha(remote_sha) {
        match remote_name.filter(|name| safe_pre_push_remote_name(name)) {
            Some(remote_name) => Some(format!("new:{remote_name}:{local_sha}")),
            None => Some(format!("new:{local_sha}")),
        }
    } else {
        Some(format!("{remote_sha}..{local_sha}"))
    }
}

fn pre_push_remote_name_from_args(args: &[String]) -> Option<&str> {
    let remote_name = args.first()?.as_str();
    let remote_url = args.get(1).map(String::as_str);
    if remote_url == Some(remote_name) || !safe_pre_push_remote_name(remote_name) {
        return None;
    }
    Some(remote_name)
}

fn safe_pre_push_remote_name(value: &str) -> bool {
    !value.is_empty()
        && !value.starts_with('-')
        && !value.contains(':')
        && !value.contains("..")
        && !value
            .chars()
            .any(|character| character.is_whitespace() || character.is_control())
        && !value
            .chars()
            .any(|character| matches!(character, '*' | '?' | '['))
}

fn is_zero_sha(value: &str) -> bool {
    value.chars().all(|character| character == '0')
}

fn run_chained_hook(state_dir: &Path, hook: HookName, args: &[String]) -> Result<()> {
    let chained = state_dir.join("hooks/chained").join(hook.as_str());
    if !chained.is_file() {
        return Ok(());
    }
    let content = fs::read_to_string(&chained)?;
    if has_outer_hook_marker(&content) {
        eprintln!(
            "{} skipping unsafe chained hook {} because it appears to invoke an outer hook manager",
            crate::messages::diagnostic_prefix(),
            chained.display()
        );
        return Ok(());
    }

    let status = Command::new(&chained).args(args).status()?;
    if !status.success() {
        bail!(
            "chained hook {} failed with status {status}",
            chained.display()
        );
    }
    Ok(())
}

fn git_root() -> Result<PathBuf> {
    Ok(PathBuf::from(
        git_stdout(&["rev-parse", "--show-toplevel"])?.trim(),
    ))
}

fn git_stdout(args: &[&str]) -> Result<String> {
    let output = Command::new("git").args(args).output()?;
    if !output.status.success() {
        bail!(
            "git {} failed: {}",
            args.join(" "),
            String::from_utf8_lossy(&output.stderr)
        );
    }
    Ok(String::from_utf8_lossy(&output.stdout).into_owned())
}

fn git_config_get(repo_root: &Path, key: &str) -> Result<Option<String>> {
    let output = Command::new("git")
        .args(["config", "--get", key])
        .current_dir(repo_root)
        .output()?;
    if output.status.success() {
        return Ok(Some(String::from_utf8_lossy(&output.stdout).into_owned()));
    }
    if output.status.code() == Some(1) {
        return Ok(None);
    }
    bail!(
        "git config --get {key} failed: {}",
        String::from_utf8_lossy(&output.stderr)
    );
}

#[cfg(unix)]
fn make_executable(path: &Path) -> Result<()> {
    use std::os::unix::fs::PermissionsExt;

    let mut permissions = fs::metadata(path)?.permissions();
    permissions.set_mode(0o755);
    fs::set_permissions(path, permissions)?;
    Ok(())
}

#[cfg(not(unix))]
fn make_executable(_path: &Path) -> Result<()> {
    Ok(())
}

#[cfg(test)]
mod tests {
    use std::{fs, process::Command};

    use proptest::prelude::*;

    use super::{HookInstallPlan, pre_push_range_from_line_for_remote, render_shim};
    use crate::cli::HookName;

    #[test]
    fn hook_shim_is_only_exec_delegation() {
        let shim = render_shim(HookName::CommitMsg, "");
        let lines = shim.lines().collect::<Vec<_>>();

        assert_eq!(lines.len(), 3);
        assert_eq!(lines[0], "#!/bin/sh");
        assert_eq!(lines[1], super::MANAGED_MARKER);
        assert_eq!(
            lines[2],
            "exec truth-mirror hook-dispatch commit-msg \"$@\""
        );
    }

    #[test]
    fn quote_git_arg_escapes_shell_metacharacters() {
        use std::path::Path;
        assert_eq!(super::quote_git_arg(Path::new("/a/b.toml")), "'/a/b.toml'");
        // metacharacters are neutralized by single-quoting
        assert_eq!(
            super::quote_git_arg(Path::new("/a/c;$(touch x).toml")),
            "'/a/c;$(touch x).toml'"
        );
        // an embedded single quote is escaped as '\''
        assert_eq!(
            super::quote_git_arg(Path::new("/a/it's.toml")),
            "'/a/it'\\''s.toml'"
        );
    }

    #[test]
    fn normalize_path_preserves_unmatched_relative_parents() {
        use std::path::{Path, PathBuf};

        assert_eq!(
            super::normalize_path(Path::new("../hooks")),
            PathBuf::from("../hooks")
        );
        assert_eq!(
            super::normalize_path(Path::new("a/../../hooks")),
            PathBuf::from("../hooks")
        );
    }

    #[test]
    fn hook_shim_preserves_global_args() {
        let shim = render_shim(HookName::PrePush, "--config /abs/enforce.toml ");
        let lines = shim.lines().collect::<Vec<_>>();

        assert_eq!(lines.len(), 3, "shim stays <=3 lines + exec-only");
        assert_eq!(
            lines[2],
            "exec truth-mirror --config /abs/enforce.toml hook-dispatch pre-push \"$@\""
        );
    }

    #[test]
    fn dry_run_plan_names_hooks_and_hooks_path() {
        let plan = HookInstallPlan::new(
            std::path::Path::new("/repo"),
            std::path::Path::new("/repo/.truth/hooks"),
            false,
        );
        let rendered = plan.render();

        assert!(rendered.contains("commit-msg"));
        assert!(rendered.contains("post-commit"));
        assert!(rendered.contains("pre-push"));
        assert!(rendered.contains("stateHooks=/repo/.truth/hooks"));
        assert!(rendered.contains("path=/repo/.git/hooks/commit-msg"));
        assert!(rendered.contains("body:\n#!/bin/sh\n# truth-mirror managed hook"));
    }

    #[test]
    fn managed_block_replace_is_idempotent() {
        let block = super::render_husky_block(HookName::CommitMsg, "");
        let original = "#!/bin/sh\necho before\n";
        let once = super::append_managed_block(original, &block);
        let twice = super::append_managed_block(&once, &block);

        assert_eq!(twice.matches(super::MANAGED_MARKER).count(), 1);
        assert!(twice.contains("echo before"));
    }

    #[test]
    fn chained_hook_safety_filter_detects_outer_tools() {
        assert!(super::has_outer_hook_marker(
            "#!/bin/sh\n# Entire CLI hooks\nentire hooks git commit-msg\n"
        ));
        assert!(super::has_outer_hook_marker(
            "#!/bin/sh\n# truth-mirror managed hook\nexec truth-mirror hook-dispatch commit-msg \"$@\"\n"
        ));
        assert!(super::has_outer_hook_marker(
            "#!/bin/sh\nexec truth hook-dispatch commit-msg \"$@\"\n"
        ));
        assert!(super::has_outer_hook_marker(
            "#!/bin/sh\nexec /usr/local/bin/truth hook-dispatch commit-msg \"$@\"\n"
        ));
        assert!(!super::has_outer_hook_marker(
            "#!/bin/sh\n# exec truth hook-dispatch commit-msg \"$@\"\n"
        ));
        assert!(!super::has_outer_hook_marker("#!/bin/sh\necho safe\n"));
    }

    #[test]
    fn managed_detection_ignores_commented_and_unrelated_truth_lines() {
        assert!(!super::is_truth_mirror_managed(
            "#!/bin/sh\n# exec truth hook-dispatch commit-msg \"$@\"\n"
        ));
        assert!(!super::is_truth_mirror_managed(
            "#!/bin/sh\nexec truth unrelated \"$@\"\n"
        ));
        assert!(!super::is_truth_mirror_managed(
            "#!/bin/sh\nexec truth --version && hook-dispatch commit-msg \"$@\"\n"
        ));
        assert!(!super::is_truth_mirror_managed(
            "#!/bin/sh\nhook-dispatch commit-msg \"$@\"; exec truth --version\n"
        ));
        assert!(super::is_truth_mirror_managed(
            "#!/bin/sh\nexec /opt/bin/truth hook-dispatch pre-push \"$@\"\n"
        ));
    }

    #[test]
    fn run_chained_hook_skips_marker_bearing_stale_hook() {
        let temp = tempfile::tempdir().unwrap();
        let chained = temp.path().join("hooks/chained/commit-msg");
        std::fs::create_dir_all(chained.parent().unwrap()).unwrap();
        std::fs::write(&chained, "#!/bin/sh\n# Entire CLI hooks\nexit 42\n").unwrap();
        super::make_executable(&chained).unwrap();

        super::run_chained_hook(temp.path(), HookName::CommitMsg, &[]).unwrap();
    }

    #[test]
    fn pre_push_line_maps_to_git_range() {
        let line = "refs/heads/main abc123 refs/heads/main def456";

        assert_eq!(
            pre_push_range_from_line_for_remote(line, None),
            Some("def456..abc123".to_owned())
        );
    }

    #[test]
    fn pre_push_new_branch_maps_to_new_branch_token() {
        let line =
            "refs/heads/topic abc123 refs/heads/topic 0000000000000000000000000000000000000000";

        assert_eq!(
            pre_push_range_from_line_for_remote(line, None),
            Some("new:abc123".to_owned())
        );
    }

    #[test]
    fn pre_push_new_branch_includes_safe_remote_name_when_available() {
        let line =
            "refs/heads/topic abc123 refs/heads/topic 0000000000000000000000000000000000000000";

        assert_eq!(
            pre_push_range_from_line_for_remote(line, Some("origin")),
            Some("new:origin:abc123".to_owned())
        );
        assert_eq!(
            pre_push_range_from_line_for_remote(line, Some("../bad")),
            Some("new:abc123".to_owned())
        );
    }

    #[test]
    fn pre_push_args_omit_remote_name_for_direct_path_pushes() {
        assert_eq!(
            super::pre_push_remote_name_from_args(&[
                "origin".to_owned(),
                "git@example/repo".to_owned()
            ]),
            Some("origin")
        );
        assert_eq!(
            super::pre_push_remote_name_from_args(&[
                "../repo.git".to_owned(),
                "../repo.git".to_owned()
            ]),
            None
        );
    }

    #[test]
    fn pre_push_args_omit_glob_like_remote_names() {
        for remote_name in ["bad*remote", "bad?remote", "bad[remote"] {
            assert_eq!(
                super::pre_push_remote_name_from_args(&[
                    remote_name.to_owned(),
                    "git@example/repo".to_owned()
                ]),
                None
            );
        }
    }

    #[test]
    fn legacy_truth_only_husky_hook_is_removed() {
        let temp = tempfile::tempdir().unwrap();
        let husky = temp.path().join(".husky");
        fs::create_dir_all(&husky).unwrap();
        let hook = husky.join("commit-msg");
        fs::write(
            &hook,
            "#!/usr/bin/env sh\nset -e\n# Truthfulness gate\nif command -v truth-mirror >/dev/null 2>&1; then truth-mirror hook-dispatch commit-msg \"$@\"; else :; fi\n",
        )
        .unwrap();
        super::make_executable(&hook).unwrap();
        super::uninstall_legacy_hook_references(temp.path()).unwrap();
        assert!(!hook.exists());
    }

    #[test]
    fn legacy_truth_hook_with_entire_is_stripped_not_removed() {
        let temp = tempfile::tempdir().unwrap();
        let husky = temp.path().join(".husky");
        fs::create_dir_all(&husky).unwrap();
        let hook = husky.join("pre-push");
        fs::write(
            &hook,
            "#!/bin/sh\nif command -v entire >/dev/null 2>&1; then entire hooks git pre-push \"$1\"; fi\nexec truth-mirror hook-dispatch pre-push \"$@\"\n",
        )
        .unwrap();
        super::make_executable(&hook).unwrap();
        super::uninstall_legacy_hook_references(temp.path()).unwrap();
        let content = fs::read_to_string(&hook).unwrap();
        assert!(!content.contains("truth-mirror"));
        assert!(content.contains("entire hooks git pre-push"));
    }

    #[test]
    fn legacy_truth_mirror_bin_pre_entire_bridge_is_rewritten_to_simple_bridge() {
        let temp = tempfile::tempdir().unwrap();
        let husky = temp.path().join(".husky");
        fs::create_dir_all(&husky).unwrap();
        let bridge = husky.join("pre-push.pre-entire");
        fs::write(
            &bridge,
            "#!/usr/bin/env sh\ntruth_mirror_bin=\"$(command -v truth-mirror || true)\"\n[ -n \"$truth_mirror_bin\" ] || exit 0\n\"$truth_mirror_bin\" hook-dispatch pre-push \"$@\"\n",
        )
        .unwrap();
        super::make_executable(&bridge).unwrap();
        super::uninstall_legacy_hook_references(temp.path()).unwrap();
        let content = fs::read_to_string(&bridge).unwrap();
        assert!(!content.contains("truth-mirror"));
        assert!(content.contains(r#"exec "$(dirname "$0")/pre-push" "$@""#));
    }

    #[test]
    fn broken_pre_entire_bridge_is_rewritten_even_without_truth_reference() {
        let temp = tempfile::tempdir().unwrap();
        let husky = temp.path().join(".husky");
        fs::create_dir_all(&husky).unwrap();
        let bridge = husky.join("pre-push.pre-entire");
        // A stripped legacy bridge can end up with an empty `else` branch,
        // which `sh -n` rejects.
        fs::write(
            &bridge,
            "#!/usr/bin/env sh\nset -e\nif command -v entire >/dev/null; then\n  echo ok\nelse\nfi\n",
        )
        .unwrap();
        super::make_executable(&bridge).unwrap();
        super::uninstall_legacy_hook_references(temp.path()).unwrap();
        let content = fs::read_to_string(&bridge).unwrap();
        assert!(content.contains(r#"exec "$(dirname "$0")/pre-push" "$@""#));
    }

    #[test]
    fn simple_pre_entire_bridge_is_preserved() {
        let temp = tempfile::tempdir().unwrap();
        let husky = temp.path().join(".husky");
        fs::create_dir_all(&husky).unwrap();
        let bridge = husky.join("commit-msg.pre-entire");
        fs::write(
            &bridge,
            "#!/bin/sh\nexec \"$(dirname \"$0\")/commit-msg\" \"$@\"\n",
        )
        .unwrap();
        super::make_executable(&bridge).unwrap();
        super::uninstall_legacy_hook_references(temp.path()).unwrap();
        let content = fs::read_to_string(&bridge).unwrap();
        assert!(content.contains(r#"exec "$(dirname "$0")/commit-msg" "$@""#));
    }

    #[test]
    fn install_migrates_root_truth_md_to_state_dir() {
        let temp = tempfile::tempdir().unwrap();
        let repo_root = temp.path().join("repo");
        fs::create_dir_all(&repo_root).unwrap();
        Command::new("git")
            .args(["init"])
            .current_dir(&repo_root)
            .output()
            .unwrap();
        let root_truth = repo_root.join("TRUTH.md");
        fs::write(&root_truth, "# truth\n").unwrap();
        let state_dir = repo_root.join(".truth");
        fs::create_dir_all(&state_dir).unwrap();
        super::migrate_truth_md(&repo_root, &state_dir).unwrap();
        assert!(state_dir.join("TRUTH.md").is_file());
        assert!(!root_truth.exists());
        assert_eq!(
            fs::read_to_string(state_dir.join("TRUTH.md")).unwrap(),
            "# truth\n"
        );
    }

    #[test]
    fn install_migrates_legacy_truth_mirror_md_to_state_dir() {
        let temp = tempfile::tempdir().unwrap();
        let repo_root = temp.path().join("repo");
        fs::create_dir_all(&repo_root).unwrap();
        let legacy_dir = repo_root.join(".truth-mirror");
        fs::create_dir_all(&legacy_dir).unwrap();
        fs::write(legacy_dir.join("TRUTH.md"), "# legacy truth\n").unwrap();
        let state_dir = repo_root.join(".truth");
        fs::create_dir_all(&state_dir).unwrap();
        super::migrate_truth_md(&repo_root, &state_dir).unwrap();
        assert!(state_dir.join("TRUTH.md").is_file());
        assert!(!legacy_dir.join("TRUTH.md").exists());
    }

    proptest! {
        #[test]
        fn hook_shim_rendering_stays_tiny_exec_only(index in 0usize..3) {
            let hook = [HookName::CommitMsg, HookName::PostCommit, HookName::PrePush][index];
            let shim = render_shim(hook, "");
            let lines = shim.lines().collect::<Vec<_>>();

            prop_assert_eq!(lines.len(), 3);
            prop_assert_eq!(lines[0], "#!/bin/sh");
            prop_assert_eq!(lines[1], super::MANAGED_MARKER);
            prop_assert!(lines[2].starts_with("exec truth-mirror hook-dispatch "));
            prop_assert!(lines[2].contains(hook.as_str()));
            prop_assert_eq!(shim.matches(super::MANAGED_MARKER).count(), 1);
            prop_assert_eq!(shim.matches("exec truth-mirror").count(), 1);
        }
    }
}