skillfile_deploy/

install.rs

use std::cell::Cell;
use std::collections::{BTreeMap, HashMap, HashSet};
use std::path::{Path, PathBuf};
use std::sync::atomic::{AtomicU64, Ordering};
use std::time::{SystemTime, UNIX_EPOCH};

use skillfile_core::conflict::{read_conflict, write_conflict};
use skillfile_core::error::SkillfileError;
use skillfile_core::lock::{lock_key, read_lock};
use skillfile_core::models::{
    short_sha, ConflictState, Entry, InstallOptions, InstallTarget, Manifest,
};
use skillfile_core::parser::{parse_manifest, MANIFEST_NAME};
use skillfile_core::patch::{
    apply_patch_pure, dir_patch_path, generate_patch, has_patch, patch_path, patches_root,
    read_patch, remove_dir_patch, remove_patch, walkdir, write_dir_patch, write_patch,
};
use skillfile_core::progress;
use skillfile_sources::strategy::{content_file, is_dir_entry};
use skillfile_sources::sync::{cmd_sync, vendor_dir_for};

use crate::adapter::{adapters, AdapterScope, DeployRequest, DirInstallMode, PlatformAdapter};
use crate::paths::source_path;

static SNAPSHOT_COUNTER: AtomicU64 = AtomicU64::new(0);

// ---------------------------------------------------------------------------
// Patch application helpers
// ---------------------------------------------------------------------------

fn to_patch_conflict(err: &SkillfileError, entry_name: &str) -> SkillfileError {
    SkillfileError::PatchConflict {
        message: err.to_string(),
        entry_name: entry_name.to_string(),
    }
}

struct PatchCtx<'a> {
    entry: &'a Entry,
    repo_root: &'a Path,
}

/// Rebase a patch file against a new cache: write the updated patch or remove it
/// if the upstream content already equals the patched result.
fn rebase_single_patch(
    ctx: &PatchCtx<'_>,
    source: &Path,
    patched: &str,
) -> Result<(), SkillfileError> {
    let cache_text = std::fs::read_to_string(source)?;
    let new_patch = generate_patch(&cache_text, patched, &format!("{}.md", ctx.entry.name));
    if new_patch.is_empty() {
        remove_patch(ctx.entry, ctx.repo_root)?;
    } else {
        write_patch(ctx.entry, &new_patch, ctx.repo_root)?;
    }
    Ok(())
}

/// Apply stored patch (if any) to a single installed file, then rebase the patch
/// against the new cache content so status comparisons remain correct.
fn apply_single_file_patch(
    ctx: &PatchCtx<'_>,
    dest: &Path,
    source: &Path,
) -> Result<(), SkillfileError> {
    if !has_patch(ctx.entry, ctx.repo_root) {
        return Ok(());
    }
    let patch_text = read_patch(ctx.entry, ctx.repo_root)?;
    let original = std::fs::read_to_string(dest)?;
    let patched = apply_patch_pure(&original, &patch_text)
        .map_err(|e| to_patch_conflict(&e, &ctx.entry.name))?;
    std::fs::write(dest, &patched)?;

    // Rebase: regenerate patch against new cache so `diff` shows accurate deltas.
    rebase_single_patch(ctx, source, &patched)
}

/// Apply per-file patches to all installed files of a directory entry.
/// Rebases each patch against the new cache content after applying.
fn apply_dir_patches(
    ctx: &PatchCtx<'_>,
    installed_files: &HashMap<String, PathBuf>,
    source_dir: &Path,
) -> Result<(), SkillfileError> {
    let patches_dir = patches_root(ctx.repo_root)
        .join(ctx.entry.entity_type.dir_name())
        .join(&ctx.entry.name);
    if !patches_dir.is_dir() {
        return Ok(());
    }

    let patch_files: Vec<PathBuf> = walkdir(&patches_dir)
        .into_iter()
        .filter(|p| p.extension().is_some_and(|e| e == "patch"))
        .collect();

    for patch_file in patch_files {
        let Some(rel) = patch_file
            .strip_prefix(&patches_dir)
            .ok()
            .and_then(|p| p.to_str())
            .and_then(|s| s.strip_suffix(".patch"))
            .map(str::to_string)
        else {
            continue;
        };

        let Some(target) = installed_files.get(&rel).filter(|p| p.exists()) else {
            continue;
        };

        let patch_text = std::fs::read_to_string(&patch_file)?;
        let original = std::fs::read_to_string(target)?;
        let patched = apply_patch_pure(&original, &patch_text)
            .map_err(|e| to_patch_conflict(&e, &ctx.entry.name))?;
        std::fs::write(target, &patched)?;

        // Rebase: regenerate patch against new cache content.
        let cache_file = source_dir.join(&rel);
        if !cache_file.exists() {
            continue;
        }
        let cache_text = std::fs::read_to_string(&cache_file)?;
        let new_patch = generate_patch(&cache_text, &patched, &rel);
        if new_patch.is_empty() {
            std::fs::remove_file(&patch_file)?;
        } else {
            write_dir_patch(&dir_patch_path(ctx.entry, &rel, ctx.repo_root), &new_patch)?;
        }
    }
    Ok(())
}

// ---------------------------------------------------------------------------
// Auto-pin helpers (used by install --update)
// ---------------------------------------------------------------------------

/// Check whether applying `patch_text` to `cache_text` reproduces `installed_text`.
///
/// Returns `true` when the patch already describes the installed content (no re-pin
/// needed), or when the patch is inconsistent with the cache (preserve without
/// clobbering). Returns `false` when the installed content has edits beyond what
/// the patch captures.
fn patch_already_covers(patch_text: &str, cache_text: &str, installed_text: &str) -> bool {
    match apply_patch_pure(cache_text, patch_text) {
        Ok(expected) if installed_text == expected => true, // no new edits
        Err(_) => true,                                     // cache inconsistent — preserve
        Ok(_) => false,                                     // additional edits — fall through
    }
}

fn should_skip_pin(ctx: &PatchCtx<'_>, cache_text: &str, installed_text: &str) -> bool {
    if !has_patch(ctx.entry, ctx.repo_root) {
        return false;
    }
    let Ok(pt) = read_patch(ctx.entry, ctx.repo_root) else {
        return false;
    };
    patch_already_covers(&pt, cache_text, installed_text)
}

fn divergent_auto_pin_error(entry_name: &str, labels: &[String]) -> SkillfileError {
    SkillfileError::Install(format!(
        "'{entry_name}' has divergent edits across install targets: {} — reconcile them before running `skillfile install --update`",
        labels.join(", ")
    ))
}

fn target_adapter(target: &InstallTarget) -> Result<&'static dyn PlatformAdapter, SkillfileError> {
    adapters()
        .get(&target.adapter)
        .ok_or_else(|| SkillfileError::Manifest(format!("unknown adapter '{}'", target.adapter)))
}

struct SingleInstalledVariant {
    label: String,
    content: String,
}

fn installed_single_file_variants(
    entry: &Entry,
    manifest: &Manifest,
    repo_root: &Path,
) -> Result<Vec<SingleInstalledVariant>, SkillfileError> {
    let mut variants = Vec::new();
    for target in &manifest.install_targets {
        let adapter = target_adapter(target)?;
        if !adapter.supports(entry.entity_type) {
            continue;
        }
        let scope = AdapterScope {
            scope: target.scope,
            repo_root,
        };
        let path = adapter.installed_path(entry, &scope);
        if !path.exists() {
            continue;
        }
        variants.push(SingleInstalledVariant {
            label: target.to_string(),
            content: std::fs::read_to_string(path)?,
        });
    }
    Ok(variants)
}

fn representative_single_file_content(
    entry_name: &str,
    cache_text: &str,
    variants: &[SingleInstalledVariant],
) -> Result<Option<String>, SkillfileError> {
    let modified: Vec<&SingleInstalledVariant> = variants
        .iter()
        .filter(|variant| variant.content != cache_text)
        .collect();
    if modified.is_empty() {
        return Ok(None);
    }
    let representative = &modified[0].content;
    if modified
        .iter()
        .any(|variant| variant.content != *representative)
    {
        let labels: Vec<String> = modified
            .iter()
            .map(|variant| variant.label.clone())
            .collect();
        return Err(divergent_auto_pin_error(entry_name, &labels));
    }
    Ok(Some(representative.clone()))
}

struct AutoPinSingleCtx<'a> {
    entry: &'a Entry,
    manifest: &'a Manifest,
    repo_root: &'a Path,
    cache_file: &'a Path,
}

fn auto_pin_single_file_entry(ctx: &AutoPinSingleCtx<'_>) -> Result<(), SkillfileError> {
    let cache_text = std::fs::read_to_string(ctx.cache_file)?;
    let variants = installed_single_file_variants(ctx.entry, ctx.manifest, ctx.repo_root)?;
    let Some(installed_text) =
        representative_single_file_content(&ctx.entry.name, &cache_text, &variants)?
    else {
        return Ok(());
    };

    let patch_ctx = PatchCtx {
        entry: ctx.entry,
        repo_root: ctx.repo_root,
    };
    if should_skip_pin(&patch_ctx, &cache_text, &installed_text) {
        return Ok(());
    }

    let patch_text = generate_patch(
        &cache_text,
        &installed_text,
        &format!("{}.md", ctx.entry.name),
    );
    if !patch_text.is_empty() && write_patch(ctx.entry, &patch_text, ctx.repo_root).is_ok() {
        progress!(
            "  {}: local changes auto-saved to .skillfile/patches/",
            ctx.entry.name
        );
    }
    Ok(())
}

fn auto_pin_entry(
    entry: &Entry,
    manifest: &Manifest,
    repo_root: &Path,
) -> Result<(), SkillfileError> {
    if entry.source_type() == "local" {
        return Ok(());
    }

    let Ok(locked) = read_lock(repo_root) else {
        return Ok(());
    };
    let key = lock_key(entry);
    if !locked.contains_key(&key) {
        return Ok(());
    }

    let vdir = vendor_dir_for(entry, repo_root);

    if is_dir_entry(entry) {
        return auto_pin_dir_entry(entry, manifest, repo_root);
    }

    let cf = content_file(entry);
    if cf.is_empty() {
        return Ok(());
    }
    let cache_file = vdir.join(&cf);
    if !cache_file.exists() {
        return Ok(());
    }
    auto_pin_single_file_entry(&AutoPinSingleCtx {
        entry,
        manifest,
        repo_root,
        cache_file: &cache_file,
    })
}

/// Return `true` if the dir-entry patch file at `patch_path` already describes
/// the transition from `cache_text` to `installed_text`.
fn dir_patch_already_matches(patch_path: &Path, cache_text: &str, installed_text: &str) -> bool {
    if !patch_path.exists() {
        return false;
    }
    let Ok(pt) = std::fs::read_to_string(patch_path) else {
        return false;
    };
    patch_already_covers(&pt, cache_text, installed_text)
}

fn load_cache_files(vdir: &Path) -> BTreeMap<String, PathBuf> {
    walkdir(vdir)
        .into_iter()
        .filter(|cache_file| cache_file.file_name().is_none_or(|name| name != ".meta"))
        .filter_map(|cache_file| {
            let filename = cache_file
                .strip_prefix(vdir)
                .ok()
                .and_then(|path| path.to_str())
                .map(str::to_string)?;
            Some((filename, cache_file))
        })
        .collect()
}

struct DirInstalledVariant {
    label: String,
    files: HashMap<String, PathBuf>,
}

type DirModifiedMap = BTreeMap<String, String>;

fn installed_dir_variants(
    entry: &Entry,
    manifest: &Manifest,
    repo_root: &Path,
) -> Result<Vec<DirInstalledVariant>, SkillfileError> {
    let mut variants = Vec::new();
    for target in &manifest.install_targets {
        let adapter = target_adapter(target)?;
        if !adapter.supports(entry.entity_type) {
            continue;
        }
        let scope = AdapterScope {
            scope: target.scope,
            repo_root,
        };
        let files = adapter.installed_dir_files(entry, &scope);
        if files.is_empty() {
            continue;
        }
        variants.push(DirInstalledVariant {
            label: target.to_string(),
            files,
        });
    }
    Ok(variants)
}

fn modified_dir_content(
    cache_files: &BTreeMap<String, PathBuf>,
    variant: &DirInstalledVariant,
) -> Result<DirModifiedMap, SkillfileError> {
    let mut modified = BTreeMap::new();
    for (filename, cache_file) in cache_files {
        let Some(installed_path) = variant.files.get(filename).filter(|path| path.exists()) else {
            continue;
        };
        let cache_text = std::fs::read_to_string(cache_file)?;
        let installed_text = std::fs::read_to_string(installed_path)?;
        if installed_text != cache_text {
            modified.insert(filename.clone(), installed_text);
        }
    }
    Ok(modified)
}

fn representative_dir_changes(
    entry_name: &str,
    cache_files: &BTreeMap<String, PathBuf>,
    variants: &[DirInstalledVariant],
) -> Result<Option<DirModifiedMap>, SkillfileError> {
    let mut modified = Vec::new();
    for variant in variants {
        let changed = modified_dir_content(cache_files, variant)?;
        if !changed.is_empty() {
            modified.push((variant.label.clone(), changed));
        }
    }
    if modified.is_empty() {
        return Ok(None);
    }
    let representative = &modified[0].1;
    if modified
        .iter()
        .any(|(_, changed)| changed != representative)
    {
        let labels: Vec<String> = modified.iter().map(|(label, _)| label.clone()).collect();
        return Err(divergent_auto_pin_error(entry_name, &labels));
    }
    Ok(Some(representative.clone()))
}

struct WriteDirPatchesCtx<'a> {
    entry: &'a Entry,
    repo_root: &'a Path,
    cache_files: &'a BTreeMap<String, PathBuf>,
    representative: &'a DirModifiedMap,
}

fn write_auto_pin_dir_patches(ctx: &WriteDirPatchesCtx<'_>) -> Result<Vec<String>, SkillfileError> {
    let mut pinned = Vec::new();
    for (filename, cache_file) in ctx.cache_files {
        let Some(installed_text) = ctx.representative.get(filename) else {
            remove_dir_patch(ctx.entry, filename, ctx.repo_root)?;
            continue;
        };

        let cache_text = std::fs::read_to_string(cache_file)?;
        let patch_path = dir_patch_path(ctx.entry, filename, ctx.repo_root);
        if dir_patch_already_matches(&patch_path, &cache_text, installed_text) {
            continue;
        }

        let patch_text = generate_patch(&cache_text, installed_text, filename);
        if patch_text.is_empty() {
            continue;
        }

        write_dir_patch(&patch_path, &patch_text)?;
        pinned.push(filename.clone());
    }
    Ok(pinned)
}

fn auto_pin_dir_entry(
    entry: &Entry,
    manifest: &Manifest,
    repo_root: &Path,
) -> Result<(), SkillfileError> {
    let vdir = &vendor_dir_for(entry, repo_root);
    if !vdir.is_dir() {
        return Ok(());
    }
    let installed = installed_dir_variants(entry, manifest, repo_root)?;
    if installed.is_empty() {
        return Ok(());
    }
    let cache_files = load_cache_files(vdir);
    let Some(representative) = representative_dir_changes(&entry.name, &cache_files, &installed)?
    else {
        return Ok(());
    };
    let pinned = write_auto_pin_dir_patches(&WriteDirPatchesCtx {
        entry,
        repo_root,
        cache_files: &cache_files,
        representative: &representative,
    })?;

    if !pinned.is_empty() {
        progress!(
            "  {}: local changes auto-saved to .skillfile/patches/ ({})",
            entry.name,
            pinned.join(", ")
        );
    }
    Ok(())
}

// ---------------------------------------------------------------------------
// Core install entry point
// ---------------------------------------------------------------------------

pub struct InstallCtx<'a> {
    pub repo_root: &'a Path,
    pub opts: Option<&'a InstallOptions>,
}

/// Why an install target was skipped instead of being updated.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum InstallSkipReason {
    UnknownAdapter,
    UnsupportedEntity,
    MissingSource,
    NothingDeployed,
    DryRun,
}

/// Outcome of attempting to deploy one entry to one install target.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum InstallOutcome {
    Installed,
    Skipped(InstallSkipReason),
}

pub fn install_entry(
    entry: &Entry,
    target: &InstallTarget,
    ctx: &InstallCtx<'_>,
) -> Result<(), SkillfileError> {
    let _ = install_entry_with_outcome(entry, target, ctx)?;
    Ok(())
}

fn install_failure(entry: &Entry, target: &InstallTarget, detail: &str) -> SkillfileError {
    SkillfileError::Install(format!(
        "failed to install '{}' to {target}: {detail}",
        entry.name
    ))
}

struct PathSnapshot {
    live_path: PathBuf,
    snapshot_path: Option<PathBuf>,
}

#[derive(Default)]
pub struct InstallSnapshot {
    scratch_dir: Option<PathBuf>,
    paths: Vec<PathSnapshot>,
    preserve_scratch: Cell<bool>,
}

impl Drop for InstallSnapshot {
    fn drop(&mut self) {
        if self.preserve_scratch.get() {
            return;
        }
        if let Some(path) = &self.scratch_dir {
            let _ = std::fs::remove_dir_all(path);
            remove_empty_dir(path.parent());
        }
    }
}

fn remove_empty_dir(path: Option<&Path>) {
    let Some(path) = path else {
        return;
    };
    if path
        .read_dir()
        .is_ok_and(|mut entries| entries.next().is_none())
    {
        let _ = std::fs::remove_dir(path);
    }
}

fn remove_path(path: &Path) -> std::io::Result<()> {
    let Ok(metadata) = std::fs::symlink_metadata(path) else {
        return Ok(());
    };
    let file_type = metadata.file_type();
    #[cfg(windows)]
    {
        use std::os::windows::fs::FileTypeExt as _;

        if file_type.is_symlink_dir() {
            return std::fs::remove_dir(path);
        }
    }
    if file_type.is_dir() {
        std::fs::remove_dir_all(path)
    } else {
        std::fs::remove_file(path)
    }
}

#[cfg(unix)]
fn create_symlink(target: &Path, link: &Path, _is_dir: bool) -> std::io::Result<()> {
    std::os::unix::fs::symlink(target, link)
}

#[cfg(windows)]
fn create_symlink(target: &Path, link: &Path, is_dir: bool) -> std::io::Result<()> {
    if is_dir {
        std::os::windows::fs::symlink_dir(target, link)
    } else {
        std::os::windows::fs::symlink_file(target, link)
    }
}

#[cfg(windows)]
fn symlink_is_dir(path: &Path) -> std::io::Result<bool> {
    use std::os::windows::fs::FileTypeExt as _;

    Ok(std::fs::symlink_metadata(path)?
        .file_type()
        .is_symlink_dir())
}

#[cfg(windows)]
fn copy_symlink(source: &Path, dest: &Path) -> std::io::Result<()> {
    let target = std::fs::read_link(source)?;
    create_symlink(&target, dest, symlink_is_dir(source)?)
}

#[cfg(not(windows))]
fn copy_symlink(source: &Path, dest: &Path) -> std::io::Result<()> {
    let target = std::fs::read_link(source)?;
    create_symlink(&target, dest, false)
}

fn copy_path(source: &Path, dest: &Path) -> std::io::Result<()> {
    if let Some(parent) = dest.parent() {
        std::fs::create_dir_all(parent)?;
    }
    let metadata = std::fs::symlink_metadata(source)?;
    if metadata.file_type().is_symlink() {
        copy_symlink(source, dest)
    } else if metadata.is_dir() {
        copy_snapshot_dir(source, dest)
    } else {
        std::fs::copy(source, dest).map(|_| ())
    }
}

fn copy_snapshot_dir(source: &Path, dest: &Path) -> std::io::Result<()> {
    std::fs::create_dir_all(dest)?;
    for entry in std::fs::read_dir(source)? {
        let entry = entry?;
        let source_path = entry.path();
        let dest_path = dest.join(entry.file_name());
        copy_path(&source_path, &dest_path)?;
    }
    Ok(())
}

fn snapshot_scratch_dir(repo_root: &Path) -> std::io::Result<PathBuf> {
    let stamp = SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .map_or(0, |duration| duration.as_nanos());
    let seq = SNAPSHOT_COUNTER.fetch_add(1, Ordering::Relaxed);
    let dir = repo_root.join(".skillfile").join("tmp").join(format!(
        "install-snapshot-{}-{stamp}-{seq}",
        std::process::id()
    ));
    std::fs::create_dir_all(&dir)?;
    Ok(dir)
}

fn capture_path_snapshot(
    live_path: PathBuf,
    scratch_dir: &Path,
    index: usize,
) -> std::io::Result<PathSnapshot> {
    let snapshot_path = if live_path.exists() || live_path.is_symlink() {
        let snapshot_path = scratch_dir.join(index.to_string());
        copy_path(&live_path, &snapshot_path)?;
        Some(snapshot_path)
    } else {
        None
    };
    Ok(PathSnapshot {
        live_path,
        snapshot_path,
    })
}

impl InstallSnapshot {
    fn capture(repo_root: &Path, paths: Vec<PathBuf>) -> Result<Self, SkillfileError> {
        let mut seen = HashSet::new();
        let paths: Vec<PathBuf> = paths
            .into_iter()
            .filter(|path| seen.insert(path.clone()))
            .collect();
        if paths.is_empty() {
            return Ok(Self::default());
        }

        let scratch_dir = snapshot_scratch_dir(repo_root)?;
        let mut snapshot = Self {
            scratch_dir: Some(scratch_dir.clone()),
            paths: Vec::new(),
            preserve_scratch: Cell::new(false),
        };
        for (index, path) in paths.into_iter().enumerate() {
            snapshot
                .paths
                .push(capture_path_snapshot(path, &scratch_dir, index)?);
        }
        Ok(snapshot)
    }

    pub fn restore(&self) -> Result<(), SkillfileError> {
        for snapshot in self.paths.iter().rev() {
            self.restore_path(snapshot)?;
        }
        Ok(())
    }

    fn scratch_dir(&self) -> Option<&Path> {
        self.scratch_dir.as_deref()
    }

    fn restore_path(&self, snapshot: &PathSnapshot) -> Result<(), SkillfileError> {
        let result = restore_path_snapshot(snapshot);
        if result.is_err() {
            self.preserve_scratch.set(true);
        }
        result.map_err(SkillfileError::from)
    }
}

fn restore_path_snapshot(snapshot: &PathSnapshot) -> std::io::Result<()> {
    remove_path(&snapshot.live_path)?;
    let Some(snapshot_path) = &snapshot.snapshot_path else {
        return Ok(());
    };
    copy_path(snapshot_path, &snapshot.live_path)
}

fn forward_slash(path: &Path) -> String {
    path.to_string_lossy().replace('\\', "/")
}

struct InstallValidationCtx<'a> {
    entry: &'a Entry,
    target: &'a InstallTarget,
    repo_root: &'a Path,
    source: &'a Path,
    adapter: &'a dyn PlatformAdapter,
    is_dir: bool,
    opts: &'a InstallOptions,
}

struct InstallPlan {
    expected: HashMap<String, PathBuf>,
    existing_before: HashSet<String>,
}

struct ValidatedInstall {
    installed: HashMap<String, PathBuf>,
    outcome: InstallOutcome,
}

fn flat_expected_paths(source: &Path, target_dir: &Path) -> HashMap<String, PathBuf> {
    walkdir(source)
        .into_iter()
        .filter(|path| path.extension().is_some_and(|ext| ext == "md"))
        .filter_map(|path| {
            let rel = path.strip_prefix(source).ok()?;
            let name = path.file_name()?;
            Some((forward_slash(rel), target_dir.join(name)))
        })
        .collect()
}

fn nested_expected_paths(source: &Path, dest_root: &Path) -> HashMap<String, PathBuf> {
    walkdir(source)
        .into_iter()
        .filter(|path| path.file_name().is_none_or(|name| name != ".meta"))
        .filter_map(|path| {
            let rel = path.strip_prefix(source).ok()?;
            Some((forward_slash(rel), dest_root.join(rel)))
        })
        .collect()
}

fn planned_install_paths(ctx: &InstallValidationCtx<'_>) -> HashMap<String, PathBuf> {
    let scope = AdapterScope {
        scope: ctx.target.scope,
        repo_root: ctx.repo_root,
    };
    let target_dir = ctx.adapter.target_dir(ctx.entry.entity_type, &scope);
    if !ctx.is_dir {
        let key = format!("{}.md", ctx.entry.name);
        return HashMap::from([(key, ctx.adapter.installed_path(ctx.entry, &scope))]);
    }

    match ctx.adapter.dir_mode(ctx.entry.entity_type) {
        Some(DirInstallMode::Flat) => flat_expected_paths(ctx.source, &target_dir),
        _ => nested_expected_paths(ctx.source, &target_dir.join(&ctx.entry.name)),
    }
}

fn patch_effect_path(ctx: &InstallValidationCtx<'_>) -> PathBuf {
    if ctx.is_dir {
        patches_root(ctx.repo_root)
            .join(ctx.entry.entity_type.dir_name())
            .join(&ctx.entry.name)
    } else {
        patch_path(ctx.entry, ctx.repo_root)
    }
}

fn install_effect_paths(ctx: &InstallValidationCtx<'_>) -> Vec<PathBuf> {
    let scope = AdapterScope {
        scope: ctx.target.scope,
        repo_root: ctx.repo_root,
    };
    let target_dir = ctx.adapter.target_dir(ctx.entry.entity_type, &scope);
    let mut paths = if !ctx.is_dir {
        vec![ctx.adapter.installed_path(ctx.entry, &scope)]
    } else if ctx.adapter.dir_mode(ctx.entry.entity_type) == Some(DirInstallMode::Flat) {
        flat_expected_paths(ctx.source, &target_dir)
            .into_values()
            .collect()
    } else {
        vec![target_dir.join(&ctx.entry.name)]
    };

    if ctx.adapter.dir_mode(ctx.entry.entity_type) != Some(DirInstallMode::Flat) {
        paths.push(target_dir.join(format!("{}.md", ctx.entry.name)));
    }
    paths.push(patch_effect_path(ctx));
    paths
}

pub fn capture_install_snapshot(
    entry: &Entry,
    targets: &[InstallTarget],
    repo_root: &Path,
) -> Result<InstallSnapshot, SkillfileError> {
    let mut paths = Vec::new();
    for target in targets {
        paths.extend(install_effect_paths_for_target(entry, target, repo_root));
    }
    InstallSnapshot::capture(repo_root, paths)
}

fn install_effect_paths_for_target(
    entry: &Entry,
    target: &InstallTarget,
    repo_root: &Path,
) -> Vec<PathBuf> {
    let all_adapters = adapters();
    let Some(adapter) = all_adapters.get(&target.adapter) else {
        return Vec::new();
    };
    if !adapter.supports(entry.entity_type) {
        return Vec::new();
    }
    let Some(source) = source_path(entry, repo_root).filter(|path| path.exists()) else {
        return Vec::new();
    };
    let default_opts = InstallOptions::default();
    let validation_ctx = InstallValidationCtx {
        entry,
        target,
        repo_root,
        source: &source,
        adapter,
        is_dir: is_dir_entry(entry) || source.is_dir(),
        opts: &default_opts,
    };
    install_effect_paths(&validation_ctx)
}

fn build_install_plan(ctx: &InstallValidationCtx<'_>) -> InstallPlan {
    let expected = planned_install_paths(ctx);
    let existing_before = expected
        .iter()
        .filter_map(|(key, path)| path.is_file().then_some(key.clone()))
        .collect();
    InstallPlan {
        expected,
        existing_before,
    }
}

fn cleanup_created_files(plan: &InstallPlan, installed: &HashMap<String, PathBuf>) {
    for (key, path) in installed {
        if plan.existing_before.contains(key) {
            continue;
        }
        let _ = std::fs::remove_file(path);
    }
}

fn validate_installed_files(
    ctx: &InstallValidationCtx<'_>,
    plan: &InstallPlan,
    installed: HashMap<String, PathBuf>,
) -> Result<ValidatedInstall, SkillfileError> {
    let reported_count = installed.len();
    let existing = installed
        .into_iter()
        .filter(|(_, path)| path.is_file())
        .collect::<HashMap<_, _>>();

    if existing.len() != reported_count {
        return Err(install_failure(
            ctx.entry,
            ctx.target,
            "adapter reported installed files that do not exist on disk",
        ));
    }

    let expected = plan.expected.len();
    if expected == 0 {
        return Ok(ValidatedInstall {
            installed: existing,
            outcome: InstallOutcome::Skipped(InstallSkipReason::NothingDeployed),
        });
    }

    let present = plan.expected.values().filter(|path| path.is_file()).count();
    if present == 0 {
        cleanup_created_files(plan, &existing);
        return Err(install_failure(
            ctx.entry,
            ctx.target,
            "no files were written to the target platform directory",
        ));
    }

    if present < expected {
        cleanup_created_files(plan, &existing);
        return Err(install_failure(
            ctx.entry,
            ctx.target,
            &format!("only {present} of {expected} expected file(s) were written"),
        ));
    }

    let outcome = if ctx.opts.overwrite || plan.existing_before.len() != expected {
        InstallOutcome::Installed
    } else {
        InstallOutcome::Skipped(InstallSkipReason::NothingDeployed)
    };
    Ok(ValidatedInstall {
        installed: existing,
        outcome,
    })
}

fn restore_on_install_error(snapshot: &InstallSnapshot, error: SkillfileError) -> SkillfileError {
    match snapshot.restore() {
        Ok(()) => error,
        Err(rollback_error) => {
            let snapshot_hint = snapshot.scratch_dir().map_or_else(String::new, |path| {
                format!("; rollback snapshot kept at {}", path.display())
            });
            let rollback_detail = format!(
                "rollback failed: {rollback_error}{snapshot_hint}; target may need manual cleanup"
            );
            match error {
                SkillfileError::PatchConflict {
                    message,
                    entry_name,
                } => SkillfileError::PatchConflict {
                    message: format!("{message}; {rollback_detail}"),
                    entry_name,
                },
                other => SkillfileError::Install(format!("{other}; {rollback_detail}")),
            }
        }
    }
}

fn deploy_and_patch_entry(
    validation_ctx: &InstallValidationCtx<'_>,
    plan: &InstallPlan,
) -> Result<InstallOutcome, SkillfileError> {
    let installed = validation_ctx.adapter.deploy_entry(&DeployRequest {
        entry: validation_ctx.entry,
        source: validation_ctx.source,
        scope: validation_ctx.target.scope,
        repo_root: validation_ctx.repo_root,
        opts: validation_ctx.opts,
    });

    if validation_ctx.opts.dry_run {
        return Ok(InstallOutcome::Skipped(InstallSkipReason::DryRun));
    }
    let validated = validate_installed_files(validation_ctx, plan, installed)?;
    if let InstallOutcome::Skipped(reason) = validated.outcome {
        return Ok(InstallOutcome::Skipped(reason));
    }

    let patch_ctx = PatchCtx {
        entry: validation_ctx.entry,
        repo_root: validation_ctx.repo_root,
    };
    if validation_ctx.is_dir {
        apply_dir_patches(&patch_ctx, &validated.installed, validation_ctx.source)?;
    } else {
        let key = format!("{}.md", validation_ctx.entry.name);
        if let Some(dest) = validated.installed.get(&key) {
            apply_single_file_patch(&patch_ctx, dest, validation_ctx.source)?;
        }
    }

    Ok(InstallOutcome::Installed)
}

/// Returns `Err(PatchConflict)` if a stored patch fails to apply cleanly.
pub fn install_entry_with_outcome(
    entry: &Entry,
    target: &InstallTarget,
    ctx: &InstallCtx<'_>,
) -> Result<InstallOutcome, SkillfileError> {
    let default_opts = InstallOptions::default();
    let opts = ctx.opts.unwrap_or(&default_opts);

    let all_adapters = adapters();
    let Some(adapter) = all_adapters.get(&target.adapter) else {
        return Ok(InstallOutcome::Skipped(InstallSkipReason::UnknownAdapter));
    };

    if !adapter.supports(entry.entity_type) {
        return Ok(InstallOutcome::Skipped(
            InstallSkipReason::UnsupportedEntity,
        ));
    }

    let source = match source_path(entry, ctx.repo_root) {
        Some(p) if p.exists() => p,
        _ => {
            eprintln!("  warning: source missing for {}, skipping", entry.name);
            return Ok(InstallOutcome::Skipped(InstallSkipReason::MissingSource));
        }
    };

    let is_dir = is_dir_entry(entry) || source.is_dir();
    let validation_ctx = InstallValidationCtx {
        entry,
        target,
        repo_root: ctx.repo_root,
        source: &source,
        adapter,
        is_dir,
        opts,
    };
    let plan = build_install_plan(&validation_ctx);
    let snapshot = if opts.dry_run {
        InstallSnapshot::default()
    } else {
        InstallSnapshot::capture(ctx.repo_root, install_effect_paths(&validation_ctx))?
    };
    deploy_and_patch_entry(&validation_ctx, &plan)
        .map_err(|error| restore_on_install_error(&snapshot, error))
}

// ---------------------------------------------------------------------------
// Precondition check
// ---------------------------------------------------------------------------

fn check_preconditions(manifest: &Manifest, repo_root: &Path) -> Result<(), SkillfileError> {
    if manifest.install_targets.is_empty() {
        return Err(SkillfileError::Manifest(
            "No install targets configured. Run `skillfile init` first.".into(),
        ));
    }

    if let Some(conflict) = read_conflict(repo_root)? {
        return Err(SkillfileError::Install(format!(
            "pending conflict for '{}' — \
             run `skillfile diff {}` to review, \
             or `skillfile resolve {}` to merge",
            conflict.entry, conflict.entry, conflict.entry
        )));
    }

    Ok(())
}

// ---------------------------------------------------------------------------
// Deploy all entries, handling patch conflicts
// ---------------------------------------------------------------------------

fn sha_transition_hint(old_sha: &str, new_sha: &str) -> String {
    if !old_sha.is_empty() && !new_sha.is_empty() && old_sha != new_sha {
        format!(
            "\n  upstream: {} \u{2192} {}",
            short_sha(old_sha),
            short_sha(new_sha)
        )
    } else {
        String::new()
    }
}

struct LockMaps<'a> {
    locked: &'a std::collections::BTreeMap<String, skillfile_core::models::LockEntry>,
    old_locked: &'a std::collections::BTreeMap<String, skillfile_core::models::LockEntry>,
}

struct DeployCtx<'a> {
    repo_root: &'a Path,
    opts: &'a InstallOptions,
    maps: LockMaps<'a>,
}

fn handle_patch_conflict(
    entry: &Entry,
    entry_name: &str,
    ctx: &DeployCtx<'_>,
) -> Result<(), SkillfileError> {
    let key = lock_key(entry);
    let old_sha = ctx
        .maps
        .old_locked
        .get(&key)
        .map(|l| l.sha.clone())
        .unwrap_or_default();
    let new_sha = ctx
        .maps
        .locked
        .get(&key)
        .map_or_else(|| old_sha.clone(), |l| l.sha.clone());

    write_conflict(
        ctx.repo_root,
        &ConflictState {
            entry: entry_name.to_string(),
            entity_type: entry.entity_type,
            old_sha: old_sha.clone(),
            new_sha: new_sha.clone(),
        },
    )?;

    let sha_info = sha_transition_hint(&old_sha, &new_sha);
    Err(SkillfileError::Install(format!(
        "upstream changes to '{entry_name}' conflict with your customisations.{sha_info}\n\
         Your pinned edits could not be applied to the new upstream version.\n\
         Run `skillfile diff {entry_name}` to review what changed upstream.\n\
         Run `skillfile resolve {entry_name}` when ready to merge.\n\
         Run `skillfile resolve --abort` to discard the conflict and keep the old version."
    )))
}

fn append_rollback_detail(error: SkillfileError, patch_message: &str) -> SkillfileError {
    if !patch_message.contains("rollback failed") {
        return error;
    }
    match error {
        SkillfileError::Install(message) => {
            SkillfileError::Install(format!("{message}\nRollback warning: {patch_message}"))
        }
        other => other,
    }
}

fn install_entry_or_conflict(
    entry: &Entry,
    target: &InstallTarget,
    ctx: &DeployCtx<'_>,
) -> Result<(), SkillfileError> {
    let install_ctx = InstallCtx {
        repo_root: ctx.repo_root,
        opts: Some(ctx.opts),
    };
    match install_entry(entry, target, &install_ctx) {
        Ok(()) => Ok(()),
        Err(SkillfileError::PatchConflict {
            entry_name,
            message,
        }) => handle_patch_conflict(entry, &entry_name, ctx)
            .map_err(|error| append_rollback_detail(error, &message)),
        Err(e) => Err(e),
    }
}

fn deploy_all(manifest: &Manifest, ctx: &DeployCtx<'_>) -> Result<(), SkillfileError> {
    let mode = if ctx.opts.dry_run { " [dry-run]" } else { "" };
    let all_adapters = adapters();

    for target in &manifest.install_targets {
        if !all_adapters.contains(&target.adapter) {
            eprintln!("warning: unknown platform '{}', skipping", target.adapter);
            continue;
        }
        progress!(
            "Installing for {} ({}){mode}...",
            target.adapter,
            target.scope
        );
        for entry in &manifest.entries {
            install_entry_or_conflict(entry, target, ctx)?;
        }
    }

    Ok(())
}

// ---------------------------------------------------------------------------
// cmd_install
// ---------------------------------------------------------------------------

fn apply_extra_targets(manifest: &mut Manifest, extra_targets: Option<&[InstallTarget]>) {
    let Some(targets) = extra_targets else {
        return;
    };
    if !targets.is_empty() {
        progress!("Using platform targets from personal config (Skillfile has no install lines).");
    }
    manifest.install_targets = targets.to_vec();
}

fn load_manifest(
    repo_root: &Path,
    extra_targets: Option<&[InstallTarget]>,
) -> Result<Manifest, SkillfileError> {
    let manifest_path = repo_root.join(MANIFEST_NAME);
    if !manifest_path.exists() {
        return Err(SkillfileError::Manifest(format!(
            "{MANIFEST_NAME} not found in {}. Create one and run `skillfile init`.",
            repo_root.display()
        )));
    }

    let result = parse_manifest(&manifest_path)?;
    for w in &result.warnings {
        eprintln!("{w}");
    }
    let mut manifest = result.manifest;

    // If the Skillfile has no install targets, fall back to caller-provided targets
    // (e.g. from user-global config).
    if manifest.install_targets.is_empty() {
        apply_extra_targets(&mut manifest, extra_targets);
    }

    Ok(manifest)
}

fn auto_pin_all(manifest: &Manifest, repo_root: &Path) -> Result<(), SkillfileError> {
    for entry in &manifest.entries {
        auto_pin_entry(entry, manifest, repo_root)?;
    }
    Ok(())
}

fn print_first_install_hint(manifest: &Manifest) {
    let platforms: Vec<String> = manifest
        .install_targets
        .iter()
        .map(|t| format!("{} ({})", t.adapter, t.scope))
        .collect();
    progress!("  Configured platforms: {}", platforms.join(", "));
    progress!("  Run `skillfile init` to add or change platforms.");
}

pub struct CmdInstallOpts<'a> {
    pub dry_run: bool,
    pub update: bool,
    pub extra_targets: Option<&'a [InstallTarget]>,
}

pub fn cmd_install(repo_root: &Path, opts: &CmdInstallOpts<'_>) -> Result<(), SkillfileError> {
    let manifest = load_manifest(repo_root, opts.extra_targets)?;

    check_preconditions(&manifest, repo_root)?;

    // Detect first install (cache dir absent → fresh clone or first run).
    let cache_dir = repo_root.join(".skillfile").join("cache");
    let first_install = !cache_dir.exists();

    // Read old locked state before sync (used for SHA context in conflict messages).
    let old_locked = read_lock(repo_root).unwrap_or_default();

    // Auto-pin local edits before re-fetching upstream (--update only).
    if opts.update && !opts.dry_run {
        auto_pin_all(&manifest, repo_root)?;
    }

    // Ensure cache dir exists (used as first-install marker and by sync).
    if !opts.dry_run {
        std::fs::create_dir_all(&cache_dir)?;
    }

    // Fetch any missing or stale entries.
    cmd_sync(&skillfile_sources::sync::SyncCmdOpts {
        repo_root,
        dry_run: opts.dry_run,
        entry_filter: None,
        update: opts.update,
    })?;

    // Read new locked state (written by sync).
    let locked = read_lock(repo_root).unwrap_or_default();

    // Deploy to all configured platform targets.
    let install_opts = InstallOptions {
        dry_run: opts.dry_run,
        overwrite: opts.update,
    };
    let deploy_ctx = DeployCtx {
        repo_root,
        opts: &install_opts,
        maps: LockMaps {
            locked: &locked,
            old_locked: &old_locked,
        },
    };
    deploy_all(&manifest, &deploy_ctx)?;

    if !opts.dry_run {
        progress!("Done.");

        // On first install, show configured platforms and hint about `init`.
        // Helps the clone scenario: user clones a repo with a Skillfile targeting
        // platforms they may not use, and needs to know how to add theirs.
        if first_install {
            print_first_install_hint(&manifest);
        }
    }

    Ok(())
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

#[cfg(test)]
mod tests {
    use super::*;
    use skillfile_core::models::{
        EntityType, Entry, InstallTarget, LockEntry, Scope, SourceFields,
    };
    use std::collections::BTreeMap;
    use std::path::{Path, PathBuf};

    // -----------------------------------------------------------------------
    // Fixture helpers — filesystem-only, no cross-crate function calls
    // -----------------------------------------------------------------------

    /// Return the path for a single-file entry patch.
    /// `.skillfile/patches/<type>s/<name>.patch`
    fn patch_fixture_path(dir: &Path, entry: &Entry) -> PathBuf {
        dir.join(".skillfile/patches")
            .join(entry.entity_type.dir_name())
            .join(format!("{}.patch", entry.name))
    }

    /// Return the path for a per-file patch within a directory entry.
    /// `.skillfile/patches/<type>s/<name>/<rel>.patch`
    fn dir_patch_fixture_path(dir: &Path, entry: &Entry, rel: &str) -> PathBuf {
        dir.join(".skillfile/patches")
            .join(entry.entity_type.dir_name())
            .join(&entry.name)
            .join(format!("{rel}.patch"))
    }

    /// Write a single-file patch fixture to the correct path.
    fn write_patch_fixture(dir: &Path, entry: &Entry, text: &str) {
        let p = patch_fixture_path(dir, entry);
        std::fs::create_dir_all(p.parent().unwrap()).unwrap();
        std::fs::write(p, text).unwrap();
    }

    /// Write `Skillfile.lock` as JSON. Uses `serde_json` — no cross-crate call.
    fn write_lock_fixture(dir: &Path, locked: &BTreeMap<String, LockEntry>) {
        let json = serde_json::to_string_pretty(locked).unwrap();
        std::fs::write(dir.join("Skillfile.lock"), format!("{json}\n")).unwrap();
    }

    /// Write `.skillfile/conflict` JSON from a `ConflictState`.
    fn write_conflict_fixture(dir: &Path, state: &ConflictState) {
        let p = dir.join(".skillfile/conflict");
        std::fs::create_dir_all(p.parent().unwrap()).unwrap();
        let json = serde_json::to_string_pretty(state).unwrap();
        std::fs::write(p, format!("{json}\n")).unwrap();
    }

    /// Return `true` if any `.patch` file exists under the directory-entry patch dir.
    fn has_dir_patch_fixture(dir: &Path, entry: &Entry) -> bool {
        let d = dir
            .join(".skillfile/patches")
            .join(entry.entity_type.dir_name())
            .join(&entry.name);
        if !d.is_dir() {
            return false;
        }
        std::fs::read_dir(&d).is_ok_and(|rd| {
            rd.filter_map(std::result::Result::ok)
                .any(|e| e.path().extension().is_some_and(|x| x == "patch"))
        })
    }

    // -----------------------------------------------------------------------
    // Entry and target builders
    // -----------------------------------------------------------------------

    fn make_agent_entry(name: &str) -> Entry {
        Entry {
            entity_type: EntityType::Agent,
            name: name.into(),
            source: SourceFields::Github {
                owner_repo: "owner/repo".into(),
                path_in_repo: "agents/agent.md".into(),
                ref_: "main".into(),
            },
        }
    }

    fn make_local_entry(name: &str, path: &str) -> Entry {
        Entry {
            entity_type: EntityType::Skill,
            name: name.into(),
            source: SourceFields::Local { path: path.into() },
        }
    }

    fn make_target(adapter: &str, scope: Scope) -> InstallTarget {
        InstallTarget {
            adapter: adapter.into(),
            scope,
        }
    }

    // -- install_entry: local source --

    #[test]
    fn install_local_entry_copy() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/my-skill.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# My Skill").unwrap();

        let entry = make_local_entry("my-skill", "skills/my-skill.md");
        let target = make_target("claude-code", Scope::Local);
        let outcome = install_entry_with_outcome(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();
        assert_eq!(outcome, InstallOutcome::Installed);

        let dest = dir.path().join(".claude/skills/my-skill/SKILL.md");
        assert!(dest.exists());
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# My Skill");
    }

    #[test]
    fn install_local_dir_entry_copy() {
        let dir = tempfile::tempdir().unwrap();
        // Local source is a directory (not a .md file)
        let source_dir = dir.path().join("skills/python-testing");
        std::fs::create_dir_all(&source_dir).unwrap();
        std::fs::write(source_dir.join("SKILL.md"), "# Python Testing").unwrap();
        std::fs::write(source_dir.join("examples.md"), "# Examples").unwrap();

        let entry = make_local_entry("python-testing", "skills/python-testing");
        let target = make_target("claude-code", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();

        // Must be deployed as a directory (nested mode), not as a single .md file
        let dest = dir.path().join(".claude/skills/python-testing");
        assert!(dest.is_dir(), "local dir entry must deploy as directory");
        assert_eq!(
            std::fs::read_to_string(dest.join("SKILL.md")).unwrap(),
            "# Python Testing"
        );
        assert_eq!(
            std::fs::read_to_string(dest.join("examples.md")).unwrap(),
            "# Examples"
        );
        // Must NOT create a .md file at the target
        assert!(
            !dir.path().join(".claude/skills/python-testing.md").exists(),
            "should not create python-testing.md for a dir source"
        );
    }

    #[test]
    fn install_entry_dry_run_no_write() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/my-skill.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# My Skill").unwrap();

        let entry = make_local_entry("my-skill", "skills/my-skill.md");
        let target = make_target("claude-code", Scope::Local);
        let opts = InstallOptions {
            dry_run: true,
            ..Default::default()
        };
        let outcome = install_entry_with_outcome(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: Some(&opts),
            },
        )
        .unwrap();
        assert_eq!(outcome, InstallOutcome::Skipped(InstallSkipReason::DryRun));

        let dest = dir.path().join(".claude/skills/my-skill/SKILL.md");
        assert!(!dest.exists());
    }

    #[test]
    fn install_entry_overwrites_existing() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/my-skill.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# New content").unwrap();

        let dest_dir = dir.path().join(".claude/skills/my-skill");
        std::fs::create_dir_all(&dest_dir).unwrap();
        let dest = dest_dir.join("SKILL.md");
        std::fs::write(&dest, "# Old content").unwrap();

        let entry = make_local_entry("my-skill", "skills/my-skill.md");
        let target = make_target("claude-code", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();

        assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# New content");
    }

    // -- install_entry: github (vendored) source --

    #[test]
    fn install_github_entry_copy() {
        let dir = tempfile::tempdir().unwrap();
        let vdir = dir.path().join(".skillfile/cache/agents/my-agent");
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("agent.md"), "# Agent").unwrap();

        let entry = make_agent_entry("my-agent");
        let target = make_target("claude-code", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();

        let dest = dir.path().join(".claude/agents/my-agent.md");
        assert!(dest.exists());
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# Agent");
    }

    #[test]
    fn install_github_dir_entry_copy() {
        let dir = tempfile::tempdir().unwrap();
        let vdir = dir.path().join(".skillfile/cache/skills/python-pro");
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("SKILL.md"), "# Python Pro").unwrap();
        std::fs::write(vdir.join("examples.md"), "# Examples").unwrap();

        let entry = Entry {
            entity_type: EntityType::Skill,
            name: "python-pro".into(),
            source: SourceFields::Github {
                owner_repo: "owner/repo".into(),
                path_in_repo: "skills/python-pro".into(),
                ref_: "main".into(),
            },
        };
        let target = make_target("claude-code", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();

        let dest = dir.path().join(".claude/skills/python-pro");
        assert!(dest.is_dir());
        assert_eq!(
            std::fs::read_to_string(dest.join("SKILL.md")).unwrap(),
            "# Python Pro"
        );
    }

    #[test]
    fn install_agent_dir_entry_explodes_to_individual_files() {
        let dir = tempfile::tempdir().unwrap();
        let vdir = dir.path().join(".skillfile/cache/agents/core-dev");
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("backend-developer.md"), "# Backend").unwrap();
        std::fs::write(vdir.join("frontend-developer.md"), "# Frontend").unwrap();
        std::fs::write(vdir.join(".meta"), "{}").unwrap();

        let entry = Entry {
            entity_type: EntityType::Agent,
            name: "core-dev".into(),
            source: SourceFields::Github {
                owner_repo: "owner/repo".into(),
                path_in_repo: "categories/core-dev".into(),
                ref_: "main".into(),
            },
        };
        let target = make_target("claude-code", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();

        let agents_dir = dir.path().join(".claude/agents");
        assert_eq!(
            std::fs::read_to_string(agents_dir.join("backend-developer.md")).unwrap(),
            "# Backend"
        );
        assert_eq!(
            std::fs::read_to_string(agents_dir.join("frontend-developer.md")).unwrap(),
            "# Frontend"
        );
        // No "core-dev" directory should exist — flat mode
        assert!(!agents_dir.join("core-dev").exists());
    }

    #[test]
    fn install_entry_missing_source_warns() {
        let dir = tempfile::tempdir().unwrap();
        let entry = make_agent_entry("my-agent");
        let target = make_target("claude-code", Scope::Local);

        let outcome = install_entry_with_outcome(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();
        assert_eq!(
            outcome,
            InstallOutcome::Skipped(InstallSkipReason::MissingSource)
        );
    }

    #[test]
    fn install_entry_unknown_adapter_is_skipped() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/my-skill.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# My Skill").unwrap();

        let entry = make_local_entry("my-skill", "skills/my-skill.md");
        let target = make_target("unknown-adapter", Scope::Local);
        let outcome = install_entry_with_outcome(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();
        assert_eq!(
            outcome,
            InstallOutcome::Skipped(InstallSkipReason::UnknownAdapter)
        );
    }

    #[test]
    fn install_entry_errors_when_target_path_is_blocked() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/my-skill.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# My Skill").unwrap();
        std::fs::write(dir.path().join(".claude"), "not a directory").unwrap();

        let entry = make_local_entry("my-skill", "skills/my-skill.md");
        let target = make_target("claude-code", Scope::Local);
        let result = install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        );
        assert!(matches!(
            result,
            Err(SkillfileError::Install(message))
                if message.contains("failed to install 'my-skill' to claude-code (local)")
        ));
    }

    #[test]
    fn install_snapshot_restores_previous_directory_contents() {
        let dir = tempfile::tempdir().unwrap();
        let source_dir = dir.path().join("skills/foo");
        let dest_dir = dir.path().join(".claude/skills/foo");
        std::fs::create_dir_all(&source_dir).unwrap();
        std::fs::create_dir_all(&dest_dir).unwrap();
        std::fs::write(source_dir.join("SKILL.md"), "# Source\n").unwrap();
        std::fs::write(dest_dir.join("SKILL.md"), "# Old\n").unwrap();

        let entry = make_local_entry("foo", "skills/foo");
        let target = make_target("claude-code", Scope::Local);
        let snapshot =
            capture_install_snapshot(&entry, std::slice::from_ref(&target), dir.path()).unwrap();

        std::fs::remove_dir_all(&dest_dir).unwrap();
        std::fs::create_dir_all(&dest_dir).unwrap();
        std::fs::write(dest_dir.join("SKILL.md"), "# New\n").unwrap();

        snapshot.restore().unwrap();
        assert_eq!(
            std::fs::read_to_string(dest_dir.join("SKILL.md")).unwrap(),
            "# Old\n"
        );
    }

    #[test]
    fn install_snapshot_restores_legacy_flat_file_side_effect() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/foo.md");
        let legacy_file = dir.path().join(".claude/skills/foo.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::create_dir_all(legacy_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# Source\n").unwrap();
        std::fs::write(&legacy_file, "# Legacy\n").unwrap();

        let entry = make_local_entry("foo", "skills/foo.md");
        let target = make_target("claude-code", Scope::Local);
        let snapshot =
            capture_install_snapshot(&entry, std::slice::from_ref(&target), dir.path()).unwrap();

        std::fs::remove_file(&legacy_file).unwrap();
        snapshot.restore().unwrap();
        assert_eq!(std::fs::read_to_string(&legacy_file).unwrap(), "# Legacy\n");
    }

    #[test]
    fn install_snapshot_restores_patch_file() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/foo.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# Source\n").unwrap();

        let entry = make_local_entry("foo", "skills/foo.md");
        let patch = patch_fixture_path(dir.path(), &entry);
        std::fs::create_dir_all(patch.parent().unwrap()).unwrap();
        std::fs::write(&patch, "old patch").unwrap();

        let target = make_target("claude-code", Scope::Local);
        let snapshot =
            capture_install_snapshot(&entry, std::slice::from_ref(&target), dir.path()).unwrap();
        std::fs::write(&patch, "new patch").unwrap();

        snapshot.restore().unwrap();
        assert_eq!(std::fs::read_to_string(&patch).unwrap(), "old patch");
    }

    #[cfg(unix)]
    #[test]
    fn install_entry_restores_existing_directory_when_copy_fails() {
        use std::os::unix::fs::symlink;

        let dir = tempfile::tempdir().unwrap();
        let source_dir = dir.path().join("skills/foo");
        let dest_dir = dir.path().join(".claude/skills/foo");
        std::fs::create_dir_all(&source_dir).unwrap();
        std::fs::create_dir_all(&dest_dir).unwrap();
        std::fs::write(source_dir.join("SKILL.md"), "# New\n").unwrap();
        symlink("missing-target.md", source_dir.join("dangling.md")).unwrap();
        std::fs::write(dest_dir.join("SKILL.md"), "# Old\n").unwrap();
        std::fs::write(dest_dir.join("keep.md"), "# Keep\n").unwrap();

        let entry = make_local_entry("foo", "skills/foo");
        let target = make_target("claude-code", Scope::Local);
        let result = install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        );

        assert!(matches!(
            result,
            Err(SkillfileError::Install(message))
                if message.contains("failed to install 'foo' to claude-code (local)")
        ));
        assert_eq!(
            std::fs::read_to_string(dest_dir.join("SKILL.md")).unwrap(),
            "# Old\n"
        );
        assert_eq!(
            std::fs::read_to_string(dest_dir.join("keep.md")).unwrap(),
            "# Keep\n"
        );
    }

    #[cfg(unix)]
    #[test]
    fn install_snapshot_restores_symlink_as_symlink() {
        use std::os::unix::fs::symlink;

        let dir = tempfile::tempdir().unwrap();
        let link = dir.path().join(".claude/skills/foo.md");
        std::fs::create_dir_all(link.parent().unwrap()).unwrap();
        symlink("target.md", &link).unwrap();
        let snapshot = InstallSnapshot::capture(dir.path(), vec![link.clone()]).unwrap();

        std::fs::remove_file(&link).unwrap();
        std::fs::write(&link, "# regular file\n").unwrap();

        snapshot.restore().unwrap();
        assert!(std::fs::symlink_metadata(&link)
            .unwrap()
            .file_type()
            .is_symlink());
        assert_eq!(
            std::fs::read_link(&link).unwrap(),
            PathBuf::from("target.md")
        );
    }

    #[cfg(windows)]
    #[test]
    fn install_snapshot_restores_dangling_directory_symlink_kind() {
        use std::os::windows::fs::{symlink_dir, FileTypeExt as _};

        let dir = tempfile::tempdir().unwrap();
        let link = dir.path().join(".claude/skills/foo");
        std::fs::create_dir_all(link.parent().unwrap()).unwrap();
        if symlink_dir("missing-dir", &link).is_err() {
            return;
        }
        let snapshot = InstallSnapshot::capture(dir.path(), vec![link.clone()]).unwrap();

        remove_path(&link).unwrap();
        std::fs::write(&link, "# regular file\n").unwrap();

        snapshot.restore().unwrap();
        let file_type = std::fs::symlink_metadata(&link).unwrap().file_type();
        assert!(file_type.is_symlink_dir());
        assert_eq!(
            std::fs::read_link(&link).unwrap(),
            PathBuf::from("missing-dir")
        );
    }

    #[test]
    fn install_snapshot_keeps_scratch_dir_when_restore_fails() {
        let dir = tempfile::tempdir().unwrap();
        let live_path = dir.path().join("target/foo.md");
        std::fs::create_dir_all(live_path.parent().unwrap()).unwrap();
        std::fs::write(&live_path, "# old\n").unwrap();
        let snapshot = InstallSnapshot::capture(dir.path(), vec![live_path.clone()]).unwrap();
        let scratch_dir = snapshot.scratch_dir().unwrap().to_path_buf();

        std::fs::remove_dir_all(live_path.parent().unwrap()).unwrap();
        std::fs::write(live_path.parent().unwrap(), "parent is a file").unwrap();

        let result = snapshot.restore();
        assert!(result.is_err());
        drop(snapshot);
        assert!(scratch_dir.exists());

        std::fs::remove_dir_all(&scratch_dir).unwrap();
        remove_empty_dir(scratch_dir.parent());
    }

    #[test]
    fn patch_conflict_type_survives_rollback_failure() {
        let dir = tempfile::tempdir().unwrap();
        let live_path = dir.path().join("target/foo.md");
        std::fs::create_dir_all(live_path.parent().unwrap()).unwrap();
        std::fs::write(&live_path, "# old\n").unwrap();
        let snapshot = InstallSnapshot::capture(dir.path(), vec![live_path.clone()]).unwrap();
        let scratch_dir = snapshot.scratch_dir().unwrap().to_path_buf();

        std::fs::remove_dir_all(live_path.parent().unwrap()).unwrap();
        std::fs::write(live_path.parent().unwrap(), "parent is a file").unwrap();

        let error = restore_on_install_error(
            &snapshot,
            SkillfileError::PatchConflict {
                message: "patch failed".to_string(),
                entry_name: "foo".to_string(),
            },
        );
        assert!(matches!(
            error,
            SkillfileError::PatchConflict { ref message, ref entry_name }
                if entry_name == "foo"
                    && message.contains("patch failed")
                    && message.contains("rollback failed")
        ));
        drop(snapshot);

        std::fs::remove_dir_all(&scratch_dir).unwrap();
        remove_empty_dir(scratch_dir.parent());
    }

    // -- Patch application during install --

    #[test]
    fn install_applies_existing_patch() {
        let dir = tempfile::tempdir().unwrap();

        // Set up cache
        let vdir = dir.path().join(".skillfile/cache/skills/test");
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("test.md"), "# Test\n\nOriginal.\n").unwrap();

        // Write a patch using filesystem fixture helper.
        let entry = Entry {
            entity_type: EntityType::Skill,
            name: "test".into(),
            source: SourceFields::Github {
                owner_repo: "owner/repo".into(),
                path_in_repo: "skills/test.md".into(),
                ref_: "main".into(),
            },
        };
        // Hand-written unified diff: "Original." → "Modified."
        let patch_text =
            "--- a/test.md\n+++ b/test.md\n@@ -1,3 +1,3 @@\n # Test\n \n-Original.\n+Modified.\n";
        write_patch_fixture(dir.path(), &entry, patch_text);

        let target = make_target("claude-code", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();

        let dest = dir.path().join(".claude/skills/test/SKILL.md");
        assert_eq!(
            std::fs::read_to_string(&dest).unwrap(),
            "# Test\n\nModified.\n"
        );
    }

    #[test]
    fn install_patch_conflict_returns_error() {
        let dir = tempfile::tempdir().unwrap();

        let vdir = dir.path().join(".skillfile/cache/skills/test");
        std::fs::create_dir_all(&vdir).unwrap();
        // Cache has completely different content from what the patch expects
        std::fs::write(vdir.join("test.md"), "totally different\ncontent\n").unwrap();

        let entry = Entry {
            entity_type: EntityType::Skill,
            name: "test".into(),
            source: SourceFields::Github {
                owner_repo: "owner/repo".into(),
                path_in_repo: "skills/test.md".into(),
                ref_: "main".into(),
            },
        };
        // Write a patch that expects a line that doesn't exist
        let bad_patch =
            "--- a/test.md\n+++ b/test.md\n@@ -1 +1 @@\n-expected_original_line\n+modified\n";
        write_patch_fixture(dir.path(), &entry, bad_patch);

        // Deploy the entry
        let installed_dir = dir.path().join(".claude/skills/test");
        std::fs::create_dir_all(&installed_dir).unwrap();
        std::fs::write(
            installed_dir.join("SKILL.md"),
            "totally different\ncontent\n",
        )
        .unwrap();

        let target = make_target("claude-code", Scope::Local);
        let result = install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        );
        assert!(result.is_err());
        // Should be a PatchConflict error
        matches!(result.unwrap_err(), SkillfileError::PatchConflict { .. });
    }

    #[test]
    fn install_patch_conflict_restores_previous_installed_file() {
        let dir = tempfile::tempdir().unwrap();

        let vdir = dir.path().join(".skillfile/cache/skills/test");
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("test.md"), "# New upstream\n").unwrap();

        let entry = Entry {
            entity_type: EntityType::Skill,
            name: "test".into(),
            source: SourceFields::Github {
                owner_repo: "owner/repo".into(),
                path_in_repo: "skills/test.md".into(),
                ref_: "main".into(),
            },
        };
        let bad_patch =
            "--- a/test.md\n+++ b/test.md\n@@ -1 +1 @@\n-expected_original_line\n+modified\n";
        write_patch_fixture(dir.path(), &entry, bad_patch);

        let dest = dir.path().join(".claude/skills/test/SKILL.md");
        std::fs::create_dir_all(dest.parent().unwrap()).unwrap();
        std::fs::write(&dest, "# Old installed\n").unwrap();

        let target = make_target("claude-code", Scope::Local);
        let result = install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        );

        assert!(matches!(result, Err(SkillfileError::PatchConflict { .. })));
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# Old installed\n");
    }

    // -- Multi-adapter --

    #[test]
    fn install_local_skill_gemini_cli() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/my-skill.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# My Skill").unwrap();

        let entry = make_local_entry("my-skill", "skills/my-skill.md");
        let target = make_target("gemini-cli", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();

        let dest = dir.path().join(".gemini/skills/my-skill/SKILL.md");
        assert!(dest.exists());
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# My Skill");
    }

    #[test]
    fn install_local_skill_codex() {
        let dir = tempfile::tempdir().unwrap();
        let source_file = dir.path().join("skills/my-skill.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# My Skill").unwrap();

        let entry = make_local_entry("my-skill", "skills/my-skill.md");
        let target = make_target("codex", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();

        let dest = dir.path().join(".codex/skills/my-skill/SKILL.md");
        assert!(dest.exists());
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# My Skill");
    }

    #[test]
    fn codex_skips_agent_entries() {
        let dir = tempfile::tempdir().unwrap();
        let entry = make_agent_entry("my-agent");
        let target = make_target("codex", Scope::Local);
        let outcome = install_entry_with_outcome(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();
        assert_eq!(
            outcome,
            InstallOutcome::Skipped(InstallSkipReason::UnsupportedEntity)
        );

        assert!(!dir.path().join(".codex").exists());
    }

    #[test]
    fn install_github_agent_gemini_cli() {
        let dir = tempfile::tempdir().unwrap();
        let vdir = dir.path().join(".skillfile/cache/agents/my-agent");
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("agent.md"), "# Agent").unwrap();

        let entry = make_agent_entry("my-agent");
        let target = make_target("gemini-cli", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: Some(&InstallOptions::default()),
            },
        )
        .unwrap();

        let dest = dir.path().join(".gemini/agents/my-agent.md");
        assert!(dest.exists());
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# Agent");
    }

    #[test]
    fn install_skill_multi_adapter() {
        for adapter in &["claude-code", "gemini-cli", "codex"] {
            let dir = tempfile::tempdir().unwrap();
            let source_file = dir.path().join("skills/my-skill.md");
            std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
            std::fs::write(&source_file, "# Multi Skill").unwrap();

            let entry = make_local_entry("my-skill", "skills/my-skill.md");
            let target = make_target(adapter, Scope::Local);
            install_entry(
                &entry,
                &target,
                &InstallCtx {
                    repo_root: dir.path(),
                    opts: None,
                },
            )
            .unwrap();

            let prefix = match *adapter {
                "claude-code" => ".claude",
                "gemini-cli" => ".gemini",
                "codex" => ".codex",
                _ => unreachable!(),
            };
            let dest = dir
                .path()
                .join(format!("{prefix}/skills/my-skill/SKILL.md"));
            assert!(dest.exists(), "Failed for adapter {adapter}");
            assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# Multi Skill");
        }
    }

    // -- cmd_install --

    #[test]
    fn cmd_install_no_manifest() {
        let dir = tempfile::tempdir().unwrap();
        let result = cmd_install(
            dir.path(),
            &CmdInstallOpts {
                dry_run: false,
                update: false,
                extra_targets: None,
            },
        );
        assert!(result.is_err());
        assert!(result.unwrap_err().to_string().contains("not found"));
    }

    #[test]
    fn cmd_install_no_install_targets() {
        let dir = tempfile::tempdir().unwrap();
        std::fs::write(
            dir.path().join("Skillfile"),
            "local  skill  foo  skills/foo.md\n",
        )
        .unwrap();

        let result = cmd_install(
            dir.path(),
            &CmdInstallOpts {
                dry_run: false,
                update: false,
                extra_targets: None,
            },
        );
        assert!(result.is_err());
        assert!(result
            .unwrap_err()
            .to_string()
            .contains("No install targets"));
    }

    #[test]
    fn cmd_install_extra_targets_fallback() {
        let dir = tempfile::tempdir().unwrap();
        // Skillfile with entries but NO install lines.
        std::fs::write(
            dir.path().join("Skillfile"),
            "local  skill  foo  skills/foo.md\n",
        )
        .unwrap();
        let source_file = dir.path().join("skills/foo.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# Foo").unwrap();

        // Pass extra targets — should be used as fallback.
        let targets = vec![make_target("claude-code", Scope::Local)];
        cmd_install(
            dir.path(),
            &CmdInstallOpts {
                dry_run: false,
                update: false,
                extra_targets: Some(&targets),
            },
        )
        .unwrap();

        let dest = dir.path().join(".claude/skills/foo/SKILL.md");
        assert!(
            dest.exists(),
            "extra_targets must be used when Skillfile has none"
        );
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), "# Foo");
    }

    #[test]
    fn cmd_install_skillfile_targets_win_over_extra() {
        let dir = tempfile::tempdir().unwrap();
        // Skillfile WITH install lines.
        std::fs::write(
            dir.path().join("Skillfile"),
            "install  claude-code  local\nlocal  skill  foo  skills/foo.md\n",
        )
        .unwrap();
        let source_file = dir.path().join("skills/foo.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# Foo").unwrap();

        // Pass extra targets for gemini-cli — should be IGNORED (Skillfile wins).
        let targets = vec![make_target("gemini-cli", Scope::Local)];
        cmd_install(
            dir.path(),
            &CmdInstallOpts {
                dry_run: false,
                update: false,
                extra_targets: Some(&targets),
            },
        )
        .unwrap();

        // claude-code (from Skillfile) should be deployed.
        assert!(dir.path().join(".claude/skills/foo/SKILL.md").exists());
        // gemini-cli (from extra_targets) should NOT be deployed.
        assert!(!dir.path().join(".gemini").exists());
    }

    #[test]
    fn cmd_install_dry_run_no_files() {
        let dir = tempfile::tempdir().unwrap();
        std::fs::write(
            dir.path().join("Skillfile"),
            "install  claude-code  local\nlocal  skill  foo  skills/foo.md\n",
        )
        .unwrap();
        let source_file = dir.path().join("skills/foo.md");
        std::fs::create_dir_all(source_file.parent().unwrap()).unwrap();
        std::fs::write(&source_file, "# Foo").unwrap();

        cmd_install(
            dir.path(),
            &CmdInstallOpts {
                dry_run: true,
                update: false,
                extra_targets: None,
            },
        )
        .unwrap();

        assert!(!dir.path().join(".claude").exists());
    }

    #[test]
    fn cmd_install_deploys_to_multiple_adapters() {
        let dir = tempfile::tempdir().unwrap();
        std::fs::write(
            dir.path().join("Skillfile"),
            "install  claude-code  local\n\
             install  gemini-cli  local\n\
             install  codex  local\n\
             local  skill  foo  skills/foo.md\n\
             local  agent  bar  agents/bar.md\n",
        )
        .unwrap();
        std::fs::create_dir_all(dir.path().join("skills")).unwrap();
        std::fs::write(dir.path().join("skills/foo.md"), "# Foo").unwrap();
        std::fs::create_dir_all(dir.path().join("agents")).unwrap();
        std::fs::write(dir.path().join("agents/bar.md"), "# Bar").unwrap();

        cmd_install(
            dir.path(),
            &CmdInstallOpts {
                dry_run: false,
                update: false,
                extra_targets: None,
            },
        )
        .unwrap();

        // skill deployed to all three adapters
        assert!(dir.path().join(".claude/skills/foo/SKILL.md").exists());
        assert!(dir.path().join(".gemini/skills/foo/SKILL.md").exists());
        assert!(dir.path().join(".codex/skills/foo/SKILL.md").exists());

        // agent deployed to claude-code and gemini-cli but NOT codex
        assert!(dir.path().join(".claude/agents/bar.md").exists());
        assert!(dir.path().join(".gemini/agents/bar.md").exists());
        assert!(!dir.path().join(".codex/agents").exists());
    }

    #[test]
    fn cmd_install_pending_conflict_blocks() {
        let dir = tempfile::tempdir().unwrap();
        std::fs::write(
            dir.path().join("Skillfile"),
            "install  claude-code  local\nlocal  skill  foo  skills/foo.md\n",
        )
        .unwrap();

        write_conflict_fixture(
            dir.path(),
            &ConflictState {
                entry: "foo".into(),
                entity_type: EntityType::Skill,
                old_sha: "aaa".into(),
                new_sha: "bbb".into(),
            },
        );

        let result = cmd_install(
            dir.path(),
            &CmdInstallOpts {
                dry_run: false,
                update: false,
                extra_targets: None,
            },
        );
        assert!(result.is_err());
        assert!(result.unwrap_err().to_string().contains("pending conflict"));
    }

    // -----------------------------------------------------------------------
    // Helpers shared by the new tests below
    // -----------------------------------------------------------------------

    /// Build a single-file github skill Entry.
    fn make_skill_entry(name: &str) -> Entry {
        Entry {
            entity_type: EntityType::Skill,
            name: name.into(),
            source: SourceFields::Github {
                owner_repo: "owner/repo".into(),
                path_in_repo: format!("skills/{name}.md"),
                ref_: "main".into(),
            },
        }
    }

    /// Build a directory github skill Entry (path_in_repo has no `.md` suffix).
    fn make_dir_skill_entry(name: &str) -> Entry {
        Entry {
            entity_type: EntityType::Skill,
            name: name.into(),
            source: SourceFields::Github {
                owner_repo: "owner/repo".into(),
                path_in_repo: format!("skills/{name}"),
                ref_: "main".into(),
            },
        }
    }

    /// Write a minimal Skillfile + Skillfile.lock for a single single-file github skill.
    fn setup_github_skill_repo(dir: &Path, name: &str, cache_content: &str) {
        // Manifest
        std::fs::write(
            dir.join("Skillfile"),
            format!(
                "install  claude-code  local\ngithub  skill  {name}  owner/repo  skills/{name}.md\n"
            ),
        )
        .unwrap();

        // Lock file via filesystem fixture (no cross-crate call).
        let mut locked: BTreeMap<String, LockEntry> = BTreeMap::new();
        locked.insert(
            format!("github/skill/{name}"),
            LockEntry {
                sha: "abc123def456abc123def456abc123def456abc123".into(),
                raw_url: format!(
                    "https://raw.githubusercontent.com/owner/repo/abc123def456/skills/{name}.md"
                ),
            },
        );
        write_lock_fixture(dir, &locked);

        // Vendor cache
        let vdir = dir.join(format!(".skillfile/cache/skills/{name}"));
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join(format!("{name}.md")), cache_content).unwrap();
    }

    // -----------------------------------------------------------------------
    // auto_pin_entry — single-file entry
    // -----------------------------------------------------------------------

    #[test]
    fn auto_pin_entry_local_is_skipped() {
        let dir = tempfile::tempdir().unwrap();

        // Local entry: auto_pin should be a no-op.
        let entry = make_local_entry("my-skill", "skills/my-skill.md");
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        // Provide installed file that differs from source — pin should NOT fire.
        let skills_dir = dir.path().join("skills");
        std::fs::create_dir_all(&skills_dir).unwrap();
        std::fs::write(skills_dir.join("my-skill.md"), "# Original\n").unwrap();

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        // No patch must have been written.
        assert!(
            !patch_fixture_path(dir.path(), &entry).exists(),
            "local entry must never be pinned"
        );
    }

    #[test]
    fn auto_pin_entry_missing_lock_is_skipped() {
        let dir = tempfile::tempdir().unwrap();

        let entry = make_skill_entry("test");
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        // No Skillfile.lock — should silently return without panicking.
        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        assert!(!patch_fixture_path(dir.path(), &entry).exists());
    }

    #[test]
    fn auto_pin_entry_missing_lock_key_is_skipped() {
        let dir = tempfile::tempdir().unwrap();

        // Lock exists but for a different entry.
        let mut locked: BTreeMap<String, LockEntry> = BTreeMap::new();
        locked.insert(
            "github/skill/other".into(),
            LockEntry {
                sha: "aabbcc".into(),
                raw_url: "https://example.com/other.md".into(),
            },
        );
        write_lock_fixture(dir.path(), &locked);

        let entry = make_skill_entry("test");
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        assert!(!patch_fixture_path(dir.path(), &entry).exists());
    }

    #[test]
    fn auto_pin_entry_writes_patch_when_installed_differs() {
        let dir = tempfile::tempdir().unwrap();
        let name = "my-skill";

        let cache_content = "# My Skill\n\nOriginal content.\n";
        let installed_content = "# My Skill\n\nUser-modified content.\n";

        setup_github_skill_repo(dir.path(), name, cache_content);

        // Place a modified installed file.
        let installed_dir = dir.path().join(format!(".claude/skills/{name}"));
        std::fs::create_dir_all(&installed_dir).unwrap();
        std::fs::write(installed_dir.join("SKILL.md"), installed_content).unwrap();

        let entry = make_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        assert!(
            patch_fixture_path(dir.path(), &entry).exists(),
            "patch should be written when installed differs from cache"
        );

        // Verify the patch round-trips: reset the installed file to cache_content and
        // reinstall — the patch must produce installed_content.
        std::fs::write(installed_dir.join("SKILL.md"), cache_content).unwrap();
        let target = make_target("claude-code", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();
        assert_eq!(
            std::fs::read_to_string(installed_dir.join("SKILL.md")).unwrap(),
            installed_content,
        );
    }

    #[test]
    fn auto_pin_entry_uses_second_target_when_first_is_clean() {
        let dir = tempfile::tempdir().unwrap();
        let name = "my-skill";

        let cache_content = "# My Skill\n\nOriginal content.\n";
        let installed_content = "# My Skill\n\nUser-modified content.\n";

        setup_github_skill_repo(dir.path(), name, cache_content);

        let first_installed_dir = dir.path().join(format!(".claude/skills/{name}"));
        std::fs::create_dir_all(&first_installed_dir).unwrap();
        std::fs::write(first_installed_dir.join("SKILL.md"), cache_content).unwrap();

        let second_installed_dir = dir.path().join(format!(".cursor/skills/{name}"));
        std::fs::create_dir_all(&second_installed_dir).unwrap();
        std::fs::write(second_installed_dir.join("SKILL.md"), installed_content).unwrap();

        let entry = make_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![
                make_target("claude-code", Scope::Local),
                make_target("cursor", Scope::Local),
            ],
        };

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        std::fs::write(first_installed_dir.join("SKILL.md"), cache_content).unwrap();
        install_entry(
            &entry,
            &make_target("claude-code", Scope::Local),
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();
        assert_eq!(
            std::fs::read_to_string(first_installed_dir.join("SKILL.md")).unwrap(),
            installed_content,
            "auto-pin must preserve edits from a modified secondary target"
        );
    }

    #[test]
    fn auto_pin_entry_errors_on_divergent_multi_target_edits() {
        let dir = tempfile::tempdir().unwrap();
        let name = "my-skill";

        let cache_content = "# My Skill\n\nOriginal content.\n";
        setup_github_skill_repo(dir.path(), name, cache_content);

        let first_installed_dir = dir.path().join(format!(".claude/skills/{name}"));
        std::fs::create_dir_all(&first_installed_dir).unwrap();
        std::fs::write(
            first_installed_dir.join("SKILL.md"),
            "# My Skill\n\nClaude edit.\n",
        )
        .unwrap();

        let second_installed_dir = dir.path().join(format!(".cursor/skills/{name}"));
        std::fs::create_dir_all(&second_installed_dir).unwrap();
        std::fs::write(
            second_installed_dir.join("SKILL.md"),
            "# My Skill\n\nCursor edit.\n",
        )
        .unwrap();

        let entry = make_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![
                make_target("claude-code", Scope::Local),
                make_target("cursor", Scope::Local),
            ],
        };

        let error = auto_pin_entry(&entry, &manifest, dir.path()).unwrap_err();
        assert!(
            error
                .to_string()
                .contains("divergent edits across install targets"),
            "unexpected error: {error}"
        );
    }

    #[test]
    fn auto_pin_entry_no_repin_when_patch_already_describes_installed() {
        let dir = tempfile::tempdir().unwrap();
        let name = "my-skill";

        let cache_content = "# My Skill\n\nOriginal.\n";
        let installed_content = "# My Skill\n\nModified.\n";

        setup_github_skill_repo(dir.path(), name, cache_content);

        let entry = make_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        // Pre-write the correct patch (cache → installed) using the fixture helper.
        // Hand-written unified diff: "Original." → "Modified."
        let patch_text = "--- a/my-skill.md\n+++ b/my-skill.md\n@@ -1,3 +1,3 @@\n # My Skill\n \n-Original.\n+Modified.\n";
        write_patch_fixture(dir.path(), &entry, patch_text);

        // Write installed file that matches what the patch produces.
        let installed_dir = dir.path().join(format!(".claude/skills/{name}"));
        std::fs::create_dir_all(&installed_dir).unwrap();
        std::fs::write(installed_dir.join("SKILL.md"), installed_content).unwrap();

        // Record mtime of patch so we can detect if it changed.
        let patch_path = patch_fixture_path(dir.path(), &entry);
        let mtime_before = std::fs::metadata(&patch_path).unwrap().modified().unwrap();

        // Small sleep so that any write would produce a different mtime.
        std::thread::sleep(std::time::Duration::from_millis(20));

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        let mtime_after = std::fs::metadata(&patch_path).unwrap().modified().unwrap();

        assert_eq!(
            mtime_before, mtime_after,
            "patch must not be rewritten when already up to date"
        );
    }

    #[test]
    fn auto_pin_entry_repins_when_installed_has_additional_edits() {
        let dir = tempfile::tempdir().unwrap();
        let name = "my-skill";

        let cache_content = "# My Skill\n\nOriginal.\n";
        let new_installed = "# My Skill\n\nFirst edit.\n\nSecond edit.\n";

        setup_github_skill_repo(dir.path(), name, cache_content);

        let entry = make_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        // Stored patch reflects the old installed state: "Original." → "First edit."
        let old_patch = "--- a/my-skill.md\n+++ b/my-skill.md\n@@ -1,3 +1,3 @@\n # My Skill\n \n-Original.\n+First edit.\n";
        write_patch_fixture(dir.path(), &entry, old_patch);

        // But the actual installed file has further edits.
        let installed_dir = dir.path().join(format!(".claude/skills/{name}"));
        std::fs::create_dir_all(&installed_dir).unwrap();
        std::fs::write(installed_dir.join("SKILL.md"), new_installed).unwrap();

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        // The patch was re-written to reflect new_installed. Verify by resetting the
        // installed file to cache_content and reinstalling — must yield new_installed.
        std::fs::write(installed_dir.join("SKILL.md"), cache_content).unwrap();
        let target = make_target("claude-code", Scope::Local);
        install_entry(
            &entry,
            &target,
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();
        assert_eq!(
            std::fs::read_to_string(installed_dir.join("SKILL.md")).unwrap(),
            new_installed,
            "updated patch must describe the latest installed content"
        );
    }

    // -----------------------------------------------------------------------
    // auto_pin_dir_entry
    // -----------------------------------------------------------------------

    #[test]
    fn auto_pin_dir_entry_writes_per_file_patches() {
        let dir = tempfile::tempdir().unwrap();
        let name = "lang-pro";

        // Manifest + lock (dir entry)
        std::fs::write(
            dir.path().join("Skillfile"),
            format!(
                "install  claude-code  local\ngithub  skill  {name}  owner/repo  skills/{name}\n"
            ),
        )
        .unwrap();
        let mut locked: BTreeMap<String, LockEntry> = BTreeMap::new();
        locked.insert(
            format!("github/skill/{name}"),
            LockEntry {
                sha: "deadbeefdeadbeefdeadbeef".into(),
                raw_url: format!("https://example.com/{name}"),
            },
        );
        write_lock_fixture(dir.path(), &locked);

        // Vendor cache with two files.
        let vdir = dir.path().join(format!(".skillfile/cache/skills/{name}"));
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("SKILL.md"), "# Lang Pro\n\nOriginal.\n").unwrap();
        std::fs::write(vdir.join("examples.md"), "# Examples\n\nOriginal.\n").unwrap();

        // Installed dir (nested mode for skills).
        let inst_dir = dir.path().join(format!(".claude/skills/{name}"));
        std::fs::create_dir_all(&inst_dir).unwrap();
        std::fs::write(inst_dir.join("SKILL.md"), "# Lang Pro\n\nModified.\n").unwrap();
        std::fs::write(inst_dir.join("examples.md"), "# Examples\n\nOriginal.\n").unwrap();

        let entry = make_dir_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        // Patch for the modified file should exist.
        let skill_patch = dir_patch_fixture_path(dir.path(), &entry, "SKILL.md");
        assert!(skill_patch.exists(), "patch for SKILL.md must be written");

        // Patch for the unmodified file should NOT exist.
        let examples_patch = dir_patch_fixture_path(dir.path(), &entry, "examples.md");
        assert!(
            !examples_patch.exists(),
            "patch for examples.md must not be written (content unchanged)"
        );
    }

    #[test]
    fn auto_pin_dir_entry_uses_second_target_when_first_is_clean() {
        let dir = tempfile::tempdir().unwrap();
        let name = "lang-pro";

        std::fs::write(
            dir.path().join("Skillfile"),
            format!(
                "install  claude-code  local\ninstall  cursor  local\ngithub  skill  {name}  owner/repo  skills/{name}\n"
            ),
        )
        .unwrap();
        let mut locked: BTreeMap<String, LockEntry> = BTreeMap::new();
        locked.insert(
            format!("github/skill/{name}"),
            LockEntry {
                sha: "deadbeefdeadbeefdeadbeef".into(),
                raw_url: format!("https://example.com/{name}"),
            },
        );
        write_lock_fixture(dir.path(), &locked);

        let vdir = dir.path().join(format!(".skillfile/cache/skills/{name}"));
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("SKILL.md"), "# Lang Pro\n\nOriginal.\n").unwrap();

        let first_inst_dir = dir.path().join(format!(".claude/skills/{name}"));
        std::fs::create_dir_all(&first_inst_dir).unwrap();
        std::fs::write(first_inst_dir.join("SKILL.md"), "# Lang Pro\n\nOriginal.\n").unwrap();

        let second_inst_dir = dir.path().join(format!(".cursor/skills/{name}"));
        std::fs::create_dir_all(&second_inst_dir).unwrap();
        std::fs::write(
            second_inst_dir.join("SKILL.md"),
            "# Lang Pro\n\nModified.\n",
        )
        .unwrap();

        let entry = make_dir_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![
                make_target("claude-code", Scope::Local),
                make_target("cursor", Scope::Local),
            ],
        };

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        std::fs::write(first_inst_dir.join("SKILL.md"), "# Lang Pro\n\nOriginal.\n").unwrap();
        install_entry(
            &entry,
            &make_target("claude-code", Scope::Local),
            &InstallCtx {
                repo_root: dir.path(),
                opts: None,
            },
        )
        .unwrap();
        assert_eq!(
            std::fs::read_to_string(first_inst_dir.join("SKILL.md")).unwrap(),
            "# Lang Pro\n\nModified.\n",
            "auto-pin must preserve dir-entry edits from a modified secondary target"
        );
    }

    #[test]
    fn auto_pin_dir_entry_skips_when_vendor_dir_missing() {
        let dir = tempfile::tempdir().unwrap();
        let name = "lang-pro";

        // Write lock so we don't bail out there.
        let mut locked: BTreeMap<String, LockEntry> = BTreeMap::new();
        locked.insert(
            format!("github/skill/{name}"),
            LockEntry {
                sha: "abc".into(),
                raw_url: "https://example.com".into(),
            },
        );
        write_lock_fixture(dir.path(), &locked);

        let entry = make_dir_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        // No vendor dir — must silently return without panicking.
        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        assert!(!has_dir_patch_fixture(dir.path(), &entry));
    }

    #[test]
    fn auto_pin_dir_entry_no_repin_when_patch_already_matches() {
        let dir = tempfile::tempdir().unwrap();
        let name = "lang-pro";

        let cache_content = "# Lang Pro\n\nOriginal.\n";
        let modified = "# Lang Pro\n\nModified.\n";

        // Write lock.
        let mut locked: BTreeMap<String, LockEntry> = BTreeMap::new();
        locked.insert(
            format!("github/skill/{name}"),
            LockEntry {
                sha: "abc".into(),
                raw_url: "https://example.com".into(),
            },
        );
        write_lock_fixture(dir.path(), &locked);

        // Vendor cache.
        let vdir = dir.path().join(format!(".skillfile/cache/skills/{name}"));
        std::fs::create_dir_all(&vdir).unwrap();
        std::fs::write(vdir.join("SKILL.md"), cache_content).unwrap();

        // Installed dir.
        let inst_dir = dir.path().join(format!(".claude/skills/{name}"));
        std::fs::create_dir_all(&inst_dir).unwrap();
        std::fs::write(inst_dir.join("SKILL.md"), modified).unwrap();

        let entry = make_dir_skill_entry(name);
        let manifest = Manifest {
            entries: vec![entry.clone()],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        // Pre-write the correct patch: "Original." → "Modified." for SKILL.md
        let patch_text = "--- a/SKILL.md\n+++ b/SKILL.md\n@@ -1,3 +1,3 @@\n # Lang Pro\n \n-Original.\n+Modified.\n";
        let dp = dir_patch_fixture_path(dir.path(), &entry, "SKILL.md");
        std::fs::create_dir_all(dp.parent().unwrap()).unwrap();
        std::fs::write(&dp, patch_text).unwrap();

        let patch_path = dir_patch_fixture_path(dir.path(), &entry, "SKILL.md");
        let mtime_before = std::fs::metadata(&patch_path).unwrap().modified().unwrap();

        std::thread::sleep(std::time::Duration::from_millis(20));

        auto_pin_entry(&entry, &manifest, dir.path()).unwrap();

        let mtime_after = std::fs::metadata(&patch_path).unwrap().modified().unwrap();

        assert_eq!(
            mtime_before, mtime_after,
            "dir patch must not be rewritten when already up to date"
        );
    }

    // -----------------------------------------------------------------------
    // apply_dir_patches
    // -----------------------------------------------------------------------

    #[test]
    fn apply_dir_patches_applies_patch_and_rebases() {
        let dir = tempfile::tempdir().unwrap();

        // Old upstream → user's installed version (what the stored patch records).
        let cache_content = "# Skill\n\nOriginal.\n";
        let installed_content = "# Skill\n\nModified.\n";
        // New upstream has a different body line but same structure.
        let new_cache_content = "# Skill\n\nOriginal v2.\n";
        // After rebase, the rebased patch encodes the diff from new_cache to installed.
        // Applying that rebased patch to new_cache must yield installed_content.
        let expected_rebased_to_new_cache = installed_content;

        let entry = make_dir_skill_entry("lang-pro");

        // Create patch dir with a valid patch (old cache → installed): "Original." → "Modified."
        let patch_text = "--- a/SKILL.md\n+++ b/SKILL.md\n@@ -1,3 +1,3 @@\n # Skill\n \n-Original.\n+Modified.\n";
        let dp = dir_patch_fixture_path(dir.path(), &entry, "SKILL.md");
        std::fs::create_dir_all(dp.parent().unwrap()).unwrap();
        std::fs::write(&dp, patch_text).unwrap();

        // Installed file starts at cache content (patch not yet applied).
        let inst_dir = dir.path().join(".claude/skills/lang-pro");
        std::fs::create_dir_all(&inst_dir).unwrap();
        std::fs::write(inst_dir.join("SKILL.md"), cache_content).unwrap();

        // New cache (simulates upstream update).
        let new_cache_dir = dir.path().join(".skillfile/cache/skills/lang-pro");
        std::fs::create_dir_all(&new_cache_dir).unwrap();
        std::fs::write(new_cache_dir.join("SKILL.md"), new_cache_content).unwrap();

        // Build the installed_files map as deploy_all would.
        let mut installed_files = std::collections::HashMap::new();
        installed_files.insert("SKILL.md".to_string(), inst_dir.join("SKILL.md"));

        apply_dir_patches(
            &PatchCtx {
                entry: &entry,
                repo_root: dir.path(),
            },
            &installed_files,
            &new_cache_dir,
        )
        .unwrap();

        // The installed file should have the original patch applied.
        let installed_after = std::fs::read_to_string(inst_dir.join("SKILL.md")).unwrap();
        assert_eq!(installed_after, installed_content);

        // The stored patch must now describe the diff from new_cache to installed_content.
        // Verify by resetting the installed file to new_cache and reinstalling — must
        // yield installed_content (== expected_rebased_to_new_cache).
        std::fs::write(inst_dir.join("SKILL.md"), new_cache_content).unwrap();
        let mut reinstall_files = std::collections::HashMap::new();
        reinstall_files.insert("SKILL.md".to_string(), inst_dir.join("SKILL.md"));
        apply_dir_patches(
            &PatchCtx {
                entry: &entry,
                repo_root: dir.path(),
            },
            &reinstall_files,
            &new_cache_dir,
        )
        .unwrap();
        assert_eq!(
            std::fs::read_to_string(inst_dir.join("SKILL.md")).unwrap(),
            expected_rebased_to_new_cache,
            "rebased patch applied to new_cache must reproduce installed_content"
        );
    }

    #[test]
    fn apply_dir_patches_removes_patch_when_rebase_yields_empty_diff() {
        let dir = tempfile::tempdir().unwrap();

        // The "new" cache content IS the patched content — patch becomes a no-op.
        let original = "# Skill\n\nOriginal.\n";
        let modified = "# Skill\n\nModified.\n";
        // New upstream == modified, so after applying patch the result equals new cache.
        let new_cache = modified; // upstream caught up

        let entry = make_dir_skill_entry("lang-pro");

        // Hand-written patch: "Original." → "Modified."
        let patch_text = "--- a/SKILL.md\n+++ b/SKILL.md\n@@ -1,3 +1,3 @@\n # Skill\n \n-Original.\n+Modified.\n";
        let dp = dir_patch_fixture_path(dir.path(), &entry, "SKILL.md");
        std::fs::create_dir_all(dp.parent().unwrap()).unwrap();
        std::fs::write(&dp, patch_text).unwrap();

        // Installed file starts at original (patch not yet applied).
        let inst_dir = dir.path().join(".claude/skills/lang-pro");
        std::fs::create_dir_all(&inst_dir).unwrap();
        std::fs::write(inst_dir.join("SKILL.md"), original).unwrap();

        let new_cache_dir = dir.path().join(".skillfile/cache/skills/lang-pro");
        std::fs::create_dir_all(&new_cache_dir).unwrap();
        std::fs::write(new_cache_dir.join("SKILL.md"), new_cache).unwrap();

        let mut installed_files = std::collections::HashMap::new();
        installed_files.insert("SKILL.md".to_string(), inst_dir.join("SKILL.md"));

        apply_dir_patches(
            &PatchCtx {
                entry: &entry,
                repo_root: dir.path(),
            },
            &installed_files,
            &new_cache_dir,
        )
        .unwrap();

        // Patch file must be removed (rebase produced empty diff).
        let removed_patch = dir_patch_fixture_path(dir.path(), &entry, "SKILL.md");
        assert!(
            !removed_patch.exists(),
            "patch file must be removed when rebase yields empty diff"
        );
    }

    #[test]
    fn apply_dir_patches_no_op_when_no_patches_dir() {
        let dir = tempfile::tempdir().unwrap();

        // No patches directory at all.
        let entry = make_dir_skill_entry("lang-pro");
        let installed_files = std::collections::HashMap::new();
        let source_dir = dir.path().join(".skillfile/cache/skills/lang-pro");
        std::fs::create_dir_all(&source_dir).unwrap();

        // Must succeed without error.
        apply_dir_patches(
            &PatchCtx {
                entry: &entry,
                repo_root: dir.path(),
            },
            &installed_files,
            &source_dir,
        )
        .unwrap();
    }

    // -----------------------------------------------------------------------
    // apply_single_file_patch — rebase removes patch when result equals cache
    // -----------------------------------------------------------------------

    #[test]
    fn apply_single_file_patch_removes_patch_when_rebase_is_empty() {
        let dir = tempfile::tempdir().unwrap();

        let original = "# Skill\n\nOriginal.\n";
        let modified = "# Skill\n\nModified.\n";
        // New cache == modified: after rebase, new_patch is empty → patch removed.
        let new_cache = modified;

        let entry = make_skill_entry("test");

        // Write patch using filesystem fixture: "Original." → "Modified."
        let patch_text =
            "--- a/test.md\n+++ b/test.md\n@@ -1,3 +1,3 @@\n # Skill\n \n-Original.\n+Modified.\n";
        write_patch_fixture(dir.path(), &entry, patch_text);

        // Set up vendor cache (the "new" version).
        let vdir = dir.path().join(".skillfile/cache/skills/test");
        std::fs::create_dir_all(&vdir).unwrap();
        let source = vdir.join("test.md");
        std::fs::write(&source, new_cache).unwrap();

        // Installed file is the original (patch not yet applied).
        let installed_dir = dir.path().join(".claude/skills");
        std::fs::create_dir_all(&installed_dir).unwrap();
        let dest = installed_dir.join("test.md");
        std::fs::write(&dest, original).unwrap();

        apply_single_file_patch(
            &PatchCtx {
                entry: &entry,
                repo_root: dir.path(),
            },
            &dest,
            &source,
        )
        .unwrap();

        // The installed file must be the patched (== new cache) result.
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), modified);

        // Patch file must have been removed.
        assert!(
            !patch_fixture_path(dir.path(), &entry).exists(),
            "patch must be removed when new cache already matches patched content"
        );
    }

    #[test]
    fn apply_single_file_patch_rewrites_patch_after_rebase() {
        let dir = tempfile::tempdir().unwrap();

        // Old upstream, user edit, new upstream (different body — no overlap with user edit).
        let original = "# Skill\n\nOriginal.\n";
        let modified = "# Skill\n\nModified.\n";
        let new_cache = "# Skill\n\nOriginal v2.\n";
        // The rebase stores generate_patch(new_cache, modified).
        // Applying that to new_cache must reproduce `modified`.
        let expected_rebased_result = modified;

        let entry = make_skill_entry("test");

        // Hand-written patch: "Original." → "Modified."
        let patch_text =
            "--- a/test.md\n+++ b/test.md\n@@ -1,3 +1,3 @@\n # Skill\n \n-Original.\n+Modified.\n";
        write_patch_fixture(dir.path(), &entry, patch_text);

        // New vendor cache (upstream updated).
        let vdir = dir.path().join(".skillfile/cache/skills/test");
        std::fs::create_dir_all(&vdir).unwrap();
        let source = vdir.join("test.md");
        std::fs::write(&source, new_cache).unwrap();

        // Installed still at original content (patch not applied yet).
        let installed_dir = dir.path().join(".claude/skills");
        std::fs::create_dir_all(&installed_dir).unwrap();
        let dest = installed_dir.join("test.md");
        std::fs::write(&dest, original).unwrap();

        apply_single_file_patch(
            &PatchCtx {
                entry: &entry,
                repo_root: dir.path(),
            },
            &dest,
            &source,
        )
        .unwrap();

        // Installed must now be the patched content.
        assert_eq!(std::fs::read_to_string(&dest).unwrap(), modified);

        // The rebased patch must still exist (new_cache != modified).
        assert!(
            patch_fixture_path(dir.path(), &entry).exists(),
            "rebased patch must still exist (new_cache != modified)"
        );
        // Verify the rebased patch yields expected_rebased_result when applied to new_cache.
        // Reset dest to new_cache and call apply_single_file_patch again.
        std::fs::write(&dest, new_cache).unwrap();
        std::fs::write(&source, new_cache).unwrap();
        apply_single_file_patch(
            &PatchCtx {
                entry: &entry,
                repo_root: dir.path(),
            },
            &dest,
            &source,
        )
        .unwrap();
        assert_eq!(
            std::fs::read_to_string(&dest).unwrap(),
            expected_rebased_result,
            "rebased patch applied to new_cache must reproduce installed content"
        );
    }

    // -----------------------------------------------------------------------
    // check_preconditions
    // -----------------------------------------------------------------------

    #[test]
    fn check_preconditions_no_targets_returns_error() {
        let dir = tempfile::tempdir().unwrap();
        let manifest = Manifest {
            entries: vec![],
            install_targets: vec![],
        };
        let result = check_preconditions(&manifest, dir.path());
        assert!(result.is_err());
        assert!(result
            .unwrap_err()
            .to_string()
            .contains("No install targets"));
    }

    #[test]
    fn check_preconditions_pending_conflict_returns_error() {
        let dir = tempfile::tempdir().unwrap();
        let manifest = Manifest {
            entries: vec![],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };

        write_conflict_fixture(
            dir.path(),
            &ConflictState {
                entry: "my-skill".into(),
                entity_type: EntityType::Skill,
                old_sha: "aaa".into(),
                new_sha: "bbb".into(),
            },
        );

        let result = check_preconditions(&manifest, dir.path());
        assert!(result.is_err());
        assert!(result.unwrap_err().to_string().contains("pending conflict"));
    }

    #[test]
    fn check_preconditions_ok_with_target_and_no_conflict() {
        let dir = tempfile::tempdir().unwrap();
        let manifest = Manifest {
            entries: vec![],
            install_targets: vec![make_target("claude-code", Scope::Local)],
        };
        check_preconditions(&manifest, dir.path()).unwrap();
    }
}