feat: add init-config helper

AGENTS.md

@@ -28,15 +28,16 @@ This document equips future agents with the current mental model for the `studip
 
 ## Runtime Flow
 
-1. `studip-sync auth` collects credentials (CL flags, env, or interactive prompts), Base64-encodes `username:password`, and persists it in the active profile.
-2. `studip-sync list-courses` builds a `StudipClient`, resolves/caches the user ID via `/users/me`, paginates `/users/{id}/courses`, fetches missing semesters, upserts course metadata into `state.toml`, and prints a table sorted by semester/title.
-3. `studip-sync sync`:
+1. `studip-sync init-config` writes a config template (optionally overriding `download_root` and guarded by `--force`).
+2. `studip-sync auth` collects credentials (CL flags, env, or interactive prompts), Base64-encodes `username:password`, and persists it in the active profile.
+3. `studip-sync list-courses` builds a `StudipClient`, resolves/caches the user ID via `/users/me`, paginates `/users/{id}/courses`, fetches missing semesters, upserts course metadata into `state.toml`, and prints a table sorted by semester/title.
+4. `studip-sync sync`:
    - Resolves download root (`config.download_root` or `$XDG_DATA_HOME/studip-sync/downloads`) and ensures directories exist unless `--dry-run`.
    - Refreshes course + semester info, then for each course performs a depth-first walk: `/courses/{id}/folders` ➜ `/folders/{id}/file-refs` ➜ `/folders/{id}/folders`. Pagination is handled by `fetch_all_pages`.
    - Normalizes path components and uses `NameRegistry` to avoid collisions, guaranteeing human-readable yet unique names.
    - Checks file state (size, modified timestamp, checksum) against `state.toml` to skip unchanged files; downloads stream to `*.part` before rename.
    - Records remote metadata + local path hints in state. `--dry-run` reports actions without touching disk; `--prune` (plus non–dry-run) deletes stray files/dirs with `walkdir`.
-4. HTTP errors propagate via `anyhow`, but 401/403 currently surface as generic failures—production UX should point users to `studip-sync auth`.
+5. HTTP errors propagate via `anyhow`, but 401/403 currently surface as generic failures—production UX should point users to `studip-sync auth`.
 
 ## Configuration & State
 

README.md

@@ -4,6 +4,7 @@
 
 ## 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.
@@ -27,6 +28,9 @@
    ```
 3. **First run**:
    ```bash
+   # 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
 
@@ -63,6 +67,7 @@ max_concurrent_downloads = 3 # placeholder for future concurrency control
 
 | 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` *(reserved for future API filters)* |

src/cli.rs

@@ -16,7 +16,7 @@ use std::{
     collections::{HashMap, HashSet},
     env,
     fmt::Write as FmtWrite,
-    fs::File,
+    fs::{File, OpenOptions},
     io::{self, BufReader, Read, Write},
     path::{Path, PathBuf},
 };
@@ -56,6 +56,8 @@ pub struct Cli {
 enum Command {
     /// Configure credentials and other persistent settings.
     Auth(AuthArgs),
+    /// Write a default config template to disk.
+    InitConfig(InitConfigArgs),
     /// Perform a one-way sync from Stud.IP to the local filesystem.
     Sync(SyncArgs),
     /// Show known courses, optionally refreshing from Stud.IP.
@@ -72,6 +74,16 @@ pub struct AuthArgs {
     pub password: Option<String>,
 }
 
+#[derive(Debug, Parser)]
+pub struct InitConfigArgs {
+    /// Overwrite an existing config file.
+    #[arg(long = "force", action = ArgAction::SetTrue)]
+    pub force: bool,
+    /// Optional download root to bake into the template.
+    #[arg(long = "download-root", value_hint = ValueHint::DirPath)]
+    pub download_root: Option<PathBuf>,
+}
+
 #[derive(Debug, Parser)]
 pub struct SyncArgs {
     #[arg(long = "dry-run", action = ArgAction::SetTrue)]
@@ -134,6 +146,7 @@ impl Cli {
 
         match self.command {
             Command::Auth(args) => args.execute(&mut ctx).await?,
+            Command::InitConfig(args) => args.execute(&mut ctx).await?,
             Command::Sync(args) => args.execute(&mut ctx).await?,
             Command::ListCourses(args) => args.execute(&mut ctx).await?,
         }
@@ -349,6 +362,49 @@ impl AuthArgs {
     }
 }
 
+impl InitConfigArgs {
+    async fn execute(&self, ctx: &mut CommandContext) -> Result<()> {
+        let config_path = ctx.paths().config_file();
+        if config_path.exists() && !self.force {
+            bail!(
+                "Config file {} already exists. Use --force to overwrite.",
+                config_path.display()
+            );
+        }
+
+        let download_root = self
+            .download_root
+            .clone()
+            .unwrap_or_else(|| ctx.paths().data_dir.join("downloads"));
+        let template = render_default_config_template(&download_root);
+
+        if let Some(parent) = config_path.parent() {
+            std::fs::create_dir_all(parent)?;
+        }
+
+        let mut file = OpenOptions::new()
+            .create(true)
+            .write(true)
+            .truncate(true)
+            .open(&config_path)?;
+        #[cfg(unix)]
+        {
+            use std::os::unix::fs::PermissionsExt;
+            let mut perms = file.metadata()?.permissions();
+            perms.set_mode(0o600);
+            file.set_permissions(perms)?;
+        }
+        file.write_all(template.as_bytes())?;
+
+        info!(
+            profile = ctx.profile_name(),
+            path = %config_path.display(),
+            "wrote default config template"
+        );
+        Ok(())
+    }
+}
+
 fn prompt_username(prompt: &str) -> Result<String> {
     let mut stdout = io::stdout();
     stdout.write_all(prompt.as_bytes())?;
@@ -1030,3 +1086,21 @@ fn hex_encode(bytes: &[u8]) -> String {
     }
     out
 }
+
+fn render_default_config_template(download_root: &Path) -> String {
+    let download_root = download_root.to_string_lossy();
+    format!(
+        r#"# studip-sync configuration
+# Run `studip-sync auth` to set credentials for the active profile.
+default_profile = "default"
+
+[profiles.default]
+# Optional convenience field for display purposes only.
+# username = "uni-id"
+base_url = "https://studip.uni-trier.de"
+jsonapi_path = "/jsonapi.php/v1"
+download_root = "{download_root}"
+max_concurrent_downloads = 3
+"#
+    )
+}