studipsync/README.md

studip-sync

studip-sync is a Rust CLI that performs a one-way sync of Stud.IP course materials (via the Uni Trier JSON:API) into a local directory tree. The tool persists config/state in TOML, talks to the API with HTTP Basic auth, and keeps the local filesystem organized as <download_root>/<semester>/<course>/<folder>/<files>.

Key Features

• init-config writes a ready-to-edit config template (respecting --download-root and --force to overwrite).
• auth subcommand stores Base64-encoded credentials per profile (passwords are never logged).
• list-courses fetches /users/me, paginates enrolled courses, infers semester keys, caches the metadata, and prints a concise table.
• sync traverses every course folder/file tree, normalizes names, streams downloads to disk, tracks checksums/remote timestamps, and supports --dry-run plus --prune to delete orphaned files.
• XDG-compliant config (~/.config/studip-sync/config.toml) and state (~/.local/share/studip-sync/state.toml) stores everything in TOML.
• Extensive logging controls: --quiet, --verbose/-v, --debug, and --json.

Directory Layout & Data Files

• Config lives under ${XDG_CONFIG_HOME:-~/.config}/studip-sync/config.toml. Override this with --config-dir if you want the config somewhere else.
• State is cached in ${XDG_DATA_HOME:-~/.local/share}/studip-sync/state.toml; --data-dir only changes this location (and anything else the tool stores under data, such as the default downloads folder). Use this when you want the state cache on a different disk but keep the config where it is.
• download_root determines where files land. If omitted, it falls back to <data-dir>/downloads, so moving the data dir automatically relocates the default downloads. Setting download_root explicitly decouples it from the data dir. Each path segment is sanitized to keep names human-readable yet filesystem-safe.

Getting Started

1. Prerequisites – Install a recent Rust toolchain (Rust 1.75+ recommended) and ensure you can reach https://studip.uni-trier.de.
2. Build & validate – From the repo root run:

   cargo fmt --all -- --check
   cargo clippy --all-targets --all-features -- -D warnings
   cargo test
   

3. First run:

   # Optionally scaffold a config template (safe no-op if it exists)
   cargo run -- init-config --download-root "$HOME/StudIP"
   
   # Store credentials (prompts for username/password by default)
   cargo run -- auth
   
   # Inspect courses and cache semester data
   cargo run -- list-courses --refresh
   
   # Perform a dry-run sync to see planned actions
   cargo run -- sync --dry-run
   
   # Run the real sync (omit --dry-run); add --prune to delete stray files
   cargo run -- sync --prune
   

   Use --profile, --config-dir, or --data-dir when working with multiple identities or non-standard paths.

Configuration Reference

Example config.toml:

default_profile = "default"

[profiles.default]
base_url = "https://studip.uni-trier.de"
jsonapi_path = "/jsonapi.php/v1"
basic_auth_b64 = "base64(username:password)"
download_root = "/home/alex/StudIP"
max_concurrent_downloads = 3 # placeholder for future concurrency control

• The file is written with 0600 permissions. Never commit credentials—auth manages them interactively or through --username/--password / STUDIP_SYNC_USERNAME|PASSWORD.
• Multiple profiles can be added under [profiles.<name>]; pass --profile <name> when invoking the CLI to switch.

CLI Reference

Subcommand	Description	Helpful flags
init-config	Write a default config template (fails if config exists unless forced).	--force, --download-root
auth	Collect username/password, encode them, and save them to the active profile.	--non-interactive, --username, --password
list-courses	List cached or freshly fetched courses with semester keys and IDs.	--refresh
sync	Download files for every enrolled course into the local tree.	--dry-run, --prune, --since (currently just records the user-provided timestamp; the API filtering hook is planned but not implemented yet)

Global flags: --quiet, --debug, --json, -v/--verbose (stackable), --config-dir, --data-dir (state + default downloads), --profile.

Sync Behavior

1. Resolve user ID (cached in state.toml) and fetch current courses.
2. Cache missing semesters via /semesters/{id} and infer keys like ws2425 / ss25.
3. For each course:
   • Walk folders using the JSON:API pagination helpers; fetch nested folders via /folders/{id}/folders.
   • List file refs via /folders/{id}/file-refs, normalize filenames, and ensure unique siblings through a NameRegistry.
   • Skip downloads when the local file exists and matches the stored checksum / size / remote chdate.
   • Stream downloads to *.part, hash contents on the fly, then rename atomically to the final path.
4. Maintain a set of remote files so --prune can remove local files that no longer exist remotely (and optionally delete now-empty directories). --since is accepted for future incremental sync work and currently acts as an annotation only—no API filters are applied yet.
5. --dry-run prints planned work but never writes to disk.

Development Notes

• The HTTP client limits itself to GETs with Basic auth; non-success responses are surfaced verbatim via anyhow.
• All downloads currently run sequentially; ConfigProfile::max_concurrent_downloads is in place for a future bounded task executor.
• Offline JSON:API documentation lives under docs/studip/ to keep this repo usable without network access.

Roadmap / Known Gaps

1. Implement real concurrent downloads that honor max_concurrent_downloads.
2. Wire --since into Stud.IP filters (if available) or local heuristics to reduce API load.
3. Add unit/integration tests (semesters::infer_key, naming helpers, pruning) and consider fixtures for Stud.IP responses.
4. Improve auth failure UX by detecting 401/403 and prompting the user to re-run studip-sync auth.
5. Evaluate whether the crate should target Rust 2021 (per the original requirement) or explicitly document Rust 2024 as the minimum supported version.