kellnr-docs 7.0.0

use std::collections::{HashMap, HashSet};
use std::path::{Path, PathBuf};
use std::sync::{Arc, LazyLock, Mutex};

use bytes::Bytes;
use kellnr_common::version::Version;
use kellnr_storage::docs_storage::{DocsName, DocsStorage};

use crate::docs_error::DocsError;

type VersionLock = Arc<tokio::sync::Mutex<()>>;

/// Locks of the crate versions whose docs are uploaded, by key prefix.
static UPLOAD_LOCKS: LazyLock<Mutex<HashMap<String, VersionLock>>> = LazyLock::new(Mutex::default);

/// Lock for the uploads of one crate version, so that the prune of one upload
/// cannot delete the files of a concurrent upload.
fn version_lock(prefix: &str) -> VersionLock {
    let mut locks = UPLOAD_LOCKS.lock().unwrap();
    locks.retain(|_, lock| Arc::strong_count(lock) > 1);
    Arc::clone(locks.entry(prefix.to_string()).or_default())
}

/// Upload every regular file under `local_root` to `docs_storage` under the
/// `{crate_name}/{version}/{key_prefix}/` prefix, then delete any pre-existing
/// key under `{crate_name}/{version}/` that wasn't just uploaded.
///
/// Symlinks are never followed, so only files that were actually written into
/// `local_root` can end up in the docs storage.
///
/// Upload-then-prune (not delete-then-upload) so a partial/failed upload
/// never leaves a doc version with zero pages. Concurrent uploads of the same
/// crate version run one after the other.
///
/// `key_prefix` lets the auto-generation queue (which walks `target/doc`
/// directly) and the manual-upload path (whose zip already contains a
/// top-level `doc/` folder) both land under `{crate}/{version}/doc/...`,
/// matching the layout `compute_doc_url` expects. Pass `""` when `local_root`
/// already contains the full relative structure.
pub async fn upload_dir_and_prune(
    local_root: &Path,
    key_prefix: &str,
    crate_name: &DocsName,
    version: &Version,
    docs_storage: &DocsStorage,
) -> Result<(), DocsError> {
    let prefix = DocsStorage::version_prefix(crate_name, version);
    let lock = version_lock(&prefix);
    let _guard = lock.lock().await;

    let root = local_root.to_path_buf();
    let files = tokio::task::spawn_blocking(move || regular_files(&root))
        .await
        .map_err(|_| DocsError::ExtractFailed)??;
    let mut uploaded_keys = HashSet::new();
    for file_path in files {
        let relative =
            file_path
                .strip_prefix(local_root)
                .map_err(|_| DocsError::PathPrefixMismatch {
                    path: file_path.display().to_string(),
                    root: local_root.display().to_string(),
                })?;
        let relative_key = relative.to_string_lossy().replace('\\', "/");
        let relative_key = if key_prefix.is_empty() {
            relative_key
        } else {
            format!("{key_prefix}/{relative_key}")
        };
        let key = DocsStorage::file_key(crate_name, version, &relative_key);

        let data = tokio::fs::read(&file_path).await?;
        docs_storage.put(&key, Bytes::from(data)).await?;
        uploaded_keys.insert(key);
    }

    for existing_key in docs_storage.list(&prefix).await? {
        if !uploaded_keys.contains(&existing_key) {
            docs_storage.delete(&existing_key).await?;
        }
    }

    Ok(())
}

/// Collect all regular files below `root` without following symlinks.
fn regular_files(root: &Path) -> std::io::Result<Vec<PathBuf>> {
    if !std::fs::symlink_metadata(root)?.is_dir() {
        return Err(std::io::Error::new(
            std::io::ErrorKind::InvalidInput,
            format!("{} is not a directory", root.display()),
        ));
    }
    let mut files = Vec::new();
    let mut dirs = vec![root.to_path_buf()];
    while let Some(dir) = dirs.pop() {
        for entry in std::fs::read_dir(&dir)? {
            let entry = entry?;
            // `DirEntry::file_type` does not follow symlinks.
            let file_type = entry.file_type()?;
            if file_type.is_dir() {
                dirs.push(entry.path());
            } else if file_type.is_file() {
                files.push(entry.path());
            }
        }
    }
    Ok(files)
}

#[cfg(test)]
mod tests {
    use kellnr_storage::fs_storage::FSStorage;

    use super::*;

    fn docs_storage() -> (tempfile::TempDir, DocsStorage) {
        let dir = tempfile::tempdir().unwrap();
        let storage = FSStorage::new(dir.path().to_str().unwrap()).unwrap();
        (dir, DocsStorage::new(Box::new(storage)))
    }

    #[tokio::test]
    async fn upload_preserves_directory_structure() {
        let (_storage_dir, docs) = docs_storage();
        let local = tempfile::tempdir().unwrap();
        tokio::fs::write(local.path().join("index.html"), b"root")
            .await
            .unwrap();
        tokio::fs::create_dir(local.path().join("nested"))
            .await
            .unwrap();
        tokio::fs::write(local.path().join("nested/page.html"), b"nested")
            .await
            .unwrap();

        upload_dir_and_prune(
            local.path(),
            "",
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("1.0.0").unwrap(),
            &docs,
        )
        .await
        .unwrap();

        assert_eq!(
            docs.get(&DocsStorage::file_key(
                &DocsName::from_folder("my-crate".to_string()),
                &Version::try_from("1.0.0").unwrap(),
                "index.html"
            ))
            .await
            .unwrap(),
            Bytes::from_static(b"root")
        );
        assert_eq!(
            docs.get(&DocsStorage::file_key(
                &DocsName::from_folder("my-crate".to_string()),
                &Version::try_from("1.0.0").unwrap(),
                "nested/page.html"
            ))
            .await
            .unwrap(),
            Bytes::from_static(b"nested")
        );
    }

    #[tokio::test]
    async fn upload_prunes_stale_keys_from_previous_build() {
        let (_storage_dir, docs) = docs_storage();
        let stale_key = DocsStorage::file_key(
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("1.0.0").unwrap(),
            "removed.html",
        );
        docs.put(&stale_key, Bytes::from_static(b"old"))
            .await
            .unwrap();

        let local = tempfile::tempdir().unwrap();
        tokio::fs::write(local.path().join("index.html"), b"new")
            .await
            .unwrap();

        upload_dir_and_prune(
            local.path(),
            "",
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("1.0.0").unwrap(),
            &docs,
        )
        .await
        .unwrap();

        assert!(!docs.exists(&stale_key).await.unwrap());
        assert!(
            docs.exists(&DocsStorage::file_key(
                &DocsName::from_folder("my-crate".to_string()),
                &Version::try_from("1.0.0").unwrap(),
                "index.html"
            ))
            .await
            .unwrap()
        );
    }

    #[tokio::test]
    async fn upload_keeps_files_with_special_characters() {
        let (_storage_dir, docs) = docs_storage();
        let local = tempfile::tempdir().unwrap();
        for file in ["a~b.html", "x%20y.html"] {
            tokio::fs::write(local.path().join(file), file)
                .await
                .unwrap();
        }

        upload_dir_and_prune(
            local.path(),
            "",
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("1.0.0").unwrap(),
            &docs,
        )
        .await
        .unwrap();

        for file in ["a~b.html", "x%20y.html"] {
            let key = DocsStorage::file_key(
                &DocsName::from_folder("my-crate".to_string()),
                &Version::try_from("1.0.0").unwrap(),
                file,
            );
            assert_eq!(docs.get(&key).await.unwrap(), Bytes::from(file), "{file}");
        }
    }

    fn local_docs(prefix: &str, files: usize) -> tempfile::TempDir {
        let local = tempfile::tempdir().unwrap();
        for i in 0..files {
            std::fs::write(local.path().join(format!("{prefix}{i}.html")), "").unwrap();
        }
        local
    }

    #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
    async fn concurrent_uploads_of_one_version_keep_the_files_of_one_upload() {
        let (_storage_dir, docs) = docs_storage();
        let docs = Arc::new(docs);
        let name = DocsName::from_folder("my-crate".to_string());
        let version = Version::try_from("1.0.0").unwrap();
        let first = local_docs("a", 20);
        let second = local_docs("b", 20);

        for _ in 0..10 {
            let uploads = [first.path().to_path_buf(), second.path().to_path_buf()].map(|dir| {
                let (docs, name, version) = (docs.clone(), name.clone(), version.clone());
                tokio::spawn(async move {
                    upload_dir_and_prune(&dir, "", &name, &version, &docs)
                        .await
                        .unwrap();
                })
            });
            for upload in uploads {
                upload.await.unwrap();
            }

            let keys = docs
                .list(&DocsStorage::version_prefix(&name, &version))
                .await
                .unwrap();
            assert_eq!(keys.len(), 20, "{keys:?}");
            let prefix = keys[0]
                .as_str()
                .split('/')
                .nth(2)
                .unwrap()
                .chars()
                .next()
                .unwrap();
            assert!(
                keys.iter()
                    .all(|k| k.as_str().split('/').nth(2).unwrap().starts_with(prefix)),
                "{keys:?}"
            );
        }
    }

    #[tokio::test]
    async fn upload_leaves_other_versions_untouched() {
        let (_storage_dir, docs) = docs_storage();
        let other_version_key = DocsStorage::file_key(
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("2.0.0").unwrap(),
            "index.html",
        );
        docs.put(&other_version_key, Bytes::from_static(b"kept"))
            .await
            .unwrap();

        let local = tempfile::tempdir().unwrap();
        tokio::fs::write(local.path().join("index.html"), b"new")
            .await
            .unwrap();

        upload_dir_and_prune(
            local.path(),
            "",
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("1.0.0").unwrap(),
            &docs,
        )
        .await
        .unwrap();

        assert!(docs.exists(&other_version_key).await.unwrap());
    }

    #[tokio::test]
    async fn upload_nests_files_under_key_prefix() {
        let (_storage_dir, docs) = docs_storage();
        let local = tempfile::tempdir().unwrap();
        tokio::fs::write(local.path().join("index.html"), b"root")
            .await
            .unwrap();

        upload_dir_and_prune(
            local.path(),
            "doc",
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("1.0.0").unwrap(),
            &docs,
        )
        .await
        .unwrap();

        assert_eq!(
            docs.get(&DocsStorage::file_key(
                &DocsName::from_folder("my-crate".to_string()),
                &Version::try_from("1.0.0").unwrap(),
                "doc/index.html"
            ))
            .await
            .unwrap(),
            Bytes::from_static(b"root")
        );
    }

    #[cfg(unix)]
    #[tokio::test]
    async fn upload_skips_symlinked_files_and_directories() {
        let (_storage_dir, docs) = docs_storage();
        let outside = tempfile::tempdir().unwrap();
        tokio::fs::write(outside.path().join("db.sqlite"), b"secret")
            .await
            .unwrap();

        let local = tempfile::tempdir().unwrap();
        tokio::fs::write(local.path().join("index.html"), b"root")
            .await
            .unwrap();
        std::os::unix::fs::symlink(
            outside.path().join("db.sqlite"),
            local.path().join("db.html"),
        )
        .unwrap();
        std::os::unix::fs::symlink(outside.path(), local.path().join("linked_dir")).unwrap();

        upload_dir_and_prune(
            local.path(),
            "",
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("1.0.0").unwrap(),
            &docs,
        )
        .await
        .unwrap();

        let keys = docs
            .list(&DocsStorage::version_prefix(
                &DocsName::from_folder("my-crate".to_string()),
                &Version::try_from("1.0.0").unwrap(),
            ))
            .await
            .unwrap();
        assert_eq!(
            keys,
            vec![DocsStorage::file_key(
                &DocsName::from_folder("my-crate".to_string()),
                &Version::try_from("1.0.0").unwrap(),
                "index.html"
            )]
        );
    }

    #[cfg(unix)]
    #[tokio::test]
    async fn upload_rejects_symlinked_root() {
        let (_storage_dir, docs) = docs_storage();
        let outside = tempfile::tempdir().unwrap();
        tokio::fs::write(outside.path().join("index.html"), b"secret")
            .await
            .unwrap();
        let local = tempfile::tempdir().unwrap();
        let root = local.path().join("doc");
        std::os::unix::fs::symlink(outside.path(), &root).unwrap();

        let result = upload_dir_and_prune(
            &root,
            "",
            &DocsName::from_folder("my-crate".to_string()),
            &Version::try_from("1.0.0").unwrap(),
            &docs,
        )
        .await;

        assert!(result.is_err());
    }
}