From 183e6598390f8ff366d92026a703b9d533b914e5 Mon Sep 17 00:00:00 2001
From: alemi <me@alemi.dev>
Date: Tue, 13 Feb 2024 19:42:03 +0100
Subject: [PATCH] feat: parse config file, run setup and cleanup

---
 Cargo.toml  |   3 ++
 src/main.rs | 132 +++++++++++++++++++++++++++++++++++++---------------
 2 files changed, 98 insertions(+), 37 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 992a862..bdd7578 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,10 @@ repository = "https://git.alemi.dev/tci.git"
 
 [dependencies]
 git2 = "0.18.2"
+serde = { version = "1.0.196", features = ["derive"] }
 tempdir = "0.3.7"
+thiserror = "1.0.57"
+toml = { version = "0.8.10", features = ["parse"] }
 
 [dev-dependencies]
 
diff --git a/src/main.rs b/src/main.rs
index 74fbd9a..39c6f06 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,58 +1,116 @@
 use git2::{Config, Repository};
 
+#[derive(Debug, thiserror::Error)]
+enum TciError {
+	#[error("could not understand file system structure, bailing out")]
+	FsError,
+
+	#[error("missing tci script")]
+	MissingScript,
+
+	#[error("there is no argv0 (wtf??), can't figure out which hook invoked tci!")]
+	MissingArgv0,
+}
+
+#[derive(Debug, Default, serde::Deserialize)]
+struct TciConfig {
+	#[serde(default)]
+	allow_all: bool,
+
+	#[serde(default)]
+	setup: Option<String>,
+
+	#[serde(default)]
+	cleanup: Option<String>,
+}
+
 fn main() {
-	let callback = std::path::Path::new(&std::env::args().next().expect("no argv0??"))
-		.file_name()
-		.expect("path terminates with '...'")
-		.to_str()
-		.expect("could not represent OsStr")
+	if let Err(e) = tci() {
+		println!("[!] error running tci: {e}");
+	}
+}
+
+fn tci() -> Result<(), Box<dyn std::error::Error>> {
+	// load tci config
+	let config_path = std::env::args().nth(1)
+		.as_deref()
+		.unwrap_or("/etc/tci/tci.toml")
 		.to_string();
 
-	let repo_path = std::env::current_dir()
-		.expect("not in a directory???");
+	let cfg_raw = std::fs::read_to_string(config_path)
+		.unwrap_or_default();
+
+	let cfg = toml::from_str(&cfg_raw)
+		.unwrap_or_else(|e| {
+			println!("[!] invalid config: {e}");
+			TciConfig::default()
+		});
+
+	// find out which hook is invoking tci
+	let callback = std::path::Path::new(&std::env::args().next().ok_or(TciError::MissingArgv0)?)
+		.file_name().ok_or(TciError::FsError)?
+		.to_str().ok_or(TciError::FsError)?
+		.to_string();
+
+	let repo_path = std::env::current_dir()?;
 
 	let repo_name = repo_path
-		.parent()
-		.expect("in root???")
-		.file_name()
-		.expect("path terminates with '...'")
-		.to_str()
-		.expect("could not represent OsStr")
+		.parent().ok_or(TciError::FsError)?
+		.file_name().ok_or(TciError::FsError)?
+		.to_str().ok_or(TciError::FsError)?
 		.to_string();
 
 	// check config before even creating temp dir and cloning repo
-	let cfg = Config::open(&repo_path.join("config")).expect("could not read git config");
-	let Ok(true) = cfg.get_bool("tci.allow") else {
-		std::process::exit(0);
-	};
+	let git_config = Config::open(&repo_path.join("config"))?;
+	if !cfg.allow_all && !git_config.get_bool("tci.allow").unwrap_or(false) {
+		return Ok(()); // we are in whitelist mode and this repo is not whitelisted
+	}
 
-	let tmp = tempdir::TempDir::new(&format!("tci-{repo_name}")).expect("could not create tempdir");
+	let tmp = tempdir::TempDir::new(&format!("tci-{repo_name}"))?;
 
-	let repo = Repository::clone(repo_path.to_str().unwrap(), tmp.path()).expect("could not clone repository");
-	std::env::set_current_dir(tmp.path()).expect("could not change directory");
+	Repository::clone(repo_path.to_str().ok_or(TciError::FsError)?, tmp.path())?;
+	std::env::set_current_dir(tmp.path())?;
 
-	println!("[+] running tci hook [{callback}] for repo '{repo_name}'");
-	let tci_script = cfg.get_str("tci.script").unwrap_or(".tci").to_string();
+	if let Some(setup) = cfg.setup {
+		print!("[+] setting up ('{setup}')");
+		let res = shell(setup)?;
+		if !res.is_empty() {
+			print!(": {res}");
+		}
+		println!();
+	}
+
+	println!("[o] running tci hook [{callback}] for repo '{repo_name}'");
+	let tci_script = git_config.get_str("tci.script").unwrap_or(".tci").to_string();
 
 	if !tmp.path().join(&tci_script).is_file() {
-		println!("[?] tci enabled for repo, but no .tci script found");
-		std::process::exit(1);
+		return Err(Box::new(TciError::MissingScript));
 	}
 
-	let output = match std::process::Command::new(tmp.path().join(&tci_script)).output() {
-		Ok(out) => out,
-		Err(e) => {
-			println!("[!] error running tci script: {e}");
-			std::process::exit(1);
-		}
-	};
+	let res = shell(tmp.path().join(&tci_script))?;
+	println!("{res}");
 
-	match std::str::from_utf8(&output.stdout) {
-		Ok(s) => println!("{s}"),
-		Err(e) => {
-			println!("[?] script produced non-utf8 output ({e}), showing as bytes");
-			println!("{:?}", output.stdout);
-		},
+
+	if let Some(cleanup) = cfg.cleanup {
+		print!("[-] cleaning up ('{cleanup}')");
+		let res = shell(cleanup)?;
+		if !res.is_empty() {
+			print!(": {res}");
+		}
+		println!();
 	}
 	
+	Ok(())
+}
+
+fn shell<S : AsRef<std::ffi::OsStr>>(cmd: S) -> std::io::Result<String> {
+	let output = std::process::Command::new(cmd).output()?;
+
+	match std::str::from_utf8(&output.stdout) {
+		Ok(s) => Ok(s.to_string()),
+		Err(e) => {
+			println!("[?] script produced non-utf8 output ({e}), showing as bytes");
+			Ok(format!("{:?}", output.stdout))
+		},
+	}
 }