use std::io::Read;

use crate::{cfg::{TciConfig, TciScriptConfig}, error::{TciErr, TciResult}, git::{RefUpdateVecHelper, TciRepo}};

pub struct Tci {
	cfg: TciConfig,
	repo: TciRepo,
	// stdin: String,
}

impl Tci {
	pub fn new() -> TciResult<Self> {
		let cfg = TciConfig::load()
			.unwrap_or_else(|e| {
				eprintln!("[!] invalid config: {e}");
				TciConfig::default()
			});

		// check which branches are being updated
		let mut stdin = String::new();
		std::io::stdin().read_to_string(&mut stdin)
			.unwrap_or_else(|e| {
				eprintln!("[!] could not read refs from stdin: {e}");
				0
			});

		let repo = TciRepo::new(&stdin)?;

		Ok(Tci{cfg, repo})
	}

	/// check if tci is allowed to run for this repository
	pub fn allowed(&self) -> bool {
		if !self.cfg.allow_all && !self.repo.cfg.get_bool("tci.allow").unwrap_or(false) {
			return false; // we are in whitelist mode and this repo is not whitelisted
		}

		if let Some(ref branch) = self.cfg.branch {
			if !self.repo.updates.contains_branch(branch) {
				return false; // tci is not allowed to run on changes for this branch
			}
		}

		true
	}

	pub fn run(&self) -> TciResult<()> {
		// run hooks
		for hook in &self.cfg.hooks {
			println!("[*] running hook ({hook})");
			Tci::exec(&self.repo.path, hook)?;
		}

		if !self.allowed() { return Ok(()) }

		let env = self.prepare_env()?;

		let tci_script = self.repo.cfg.get_string("tci.path")
			.unwrap_or_else(|_| ".tci".into());
		let tci_path = env.path().join(tci_script);

		if !tci_path.is_file() && !tci_path.is_dir() {
			return Err(TciErr::Missing);
		}

		for setup in &self.cfg.setup {
			println!("[+] setting up ({setup})");
			Tci::exec(&self.repo.path, setup)?;
		}

		let res = if tci_path.is_file() {
			println!("[=] running tci script for {}", self.repo.name);
			Tci::exec(env.path(), tci_path)
		} else if tci_path.is_dir() {
			self.run_tci_hook(env.path(), &tci_path)
		} else { Ok(()) }; // will never happen but rustc doesn't know
	
		for cleanup in &self.cfg.cleanup {
			println!("[-] cleaning up ({cleanup}) ");
			Tci::exec(&self.repo.path, cleanup)?;
		}

		res?; // if there was an error, return it now
	
		println!("[o] tci complete");
	
		Ok(())
	}

	fn prepare_env(&self) -> TciResult<tempdir::TempDir> {
		let tmp = tempdir::TempDir::new(
			&format!("tci-{}", self.repo.name.replace('/', "_"))
		)?;
	
		// TODO allow customizing clone? just clone recursive? just let hook setup submodules?
		git2::Repository::clone(
			self.repo.path.to_str()
				.ok_or(TciErr::FsError("repo path is not a valid string"))?,
			tmp.path(),
		)?;

		Ok(tmp)
	}

	fn run_tci_hook(&self, cwd: &std::path::Path, dir: &std::path::Path) -> TciResult<()> {
		let cfg = TciScriptConfig::load(&dir.join("config.toml"))?;

		if let Some(branch) = cfg.branch {
			if !self.repo.updates.contains_branch(&branch) {
				return Ok(()); // tci is not configured to run on this branch
			}
		}

		// TODO calculate which files changed and decide if we should
		//      run depending on cfg.filter (regex match idk?)

		for script in cfg.scripts {
			println!("[=] running tci script '{script}' for {}", self.repo.name);
			Tci::exec(cwd, dir.join(script))?;
		}

		Ok(())
	}

	fn exec<S : AsRef<std::ffi::OsStr>>(cwd: &std::path::Path, s: S) -> TciResult<()> {
		match std::process::Command::new(s)
			.current_dir(cwd)
			// .stdin(self.stdin.clone()) // TODO not this easy
			.status()?
			.code()
		{
			Some(0) => Ok(()),
			Some(x) => Err(crate::error::TciErr::SubprocessError(x)),
			None => Err(crate::error::TciErr::SubprocessTerminated),
		}
	}
}