extern crate serde;
extern crate toml;

use serde::Deserialize;
use std::env;
use std::fs::File;
use std::io::prelude::*;
use std::path::PathBuf;

macro_rules! set_rustc_env_var {
	($name: expr, $value: expr) => {{
		println!("cargo:rustc-env={}={}", $name, $value);
	}};
}

macro_rules! set_env_var_if_absent {
	($name: expr, $default_value: expr) => {{
		if let Err(_) = env::var($name) {
			set_rustc_env_var!($name, $default_value);
		}
	}};
}

macro_rules! set_specific_path_if_absent {
	($env_name: expr, $env_default: expr, $with_dir: expr, $name: expr, $default_value: expr) => {{
		let prefix = env::var($env_name).unwrap_or(String::from($env_default));
		let mut value = PathBuf::new();
		value.push(prefix);
		if ($with_dir) {
			value.push("acmed");
		}
		value.push($default_value);
		set_env_var_if_absent!($name, value.to_str().unwrap());
	}};
}

macro_rules! set_data_path_if_absent {
	($name: expr, $default_value: expr) => {{
		set_specific_path_if_absent!("VARLIBDIR", "/var/lib", true, $name, $default_value);
	}};
}

macro_rules! set_cfg_path_if_absent {
	($name: expr, $default_value: expr) => {{
		set_specific_path_if_absent!("SYSCONFDIR", "/etc", true, $name, $default_value);
	}};
}

macro_rules! set_runstate_path_if_absent {
	($name: expr, $default_value: expr) => {{
		set_specific_path_if_absent!("RUNSTATEDIR", "/run", false, $name, $default_value);
	}};
}

#[derive(Deserialize)]
pub struct Lock {
	package: Vec<Package>,
}

#[derive(Deserialize)]
struct Package {
	name: String,
	version: String,
}

struct Error;

impl From<std::io::Error> for Error {
	fn from(_error: std::io::Error) -> Self {
		Error {}
	}
}

impl From<toml::de::Error> for Error {
	fn from(_error: toml::de::Error) -> Self {
		Error {}
	}
}

fn get_lock() -> Result<Lock, Error> {
	let mut path = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
	path.pop();
	path.push("Cargo.lock");
	let mut file = File::open(path)?;
	let mut contents = String::new();
	file.read_to_string(&mut contents)?;
	let ret: Lock = toml::from_str(&contents)?;
	Ok(ret)
}

fn set_lock() {
	let lock = match get_lock() {
		Ok(l) => l,
		Err(_) => {
			return;
		}
	};
	for p in lock.package.iter() {
		if p.name == "reqwest" {
			let agent = format!("{}/{}", p.name, p.version);
			set_rustc_env_var!("ACMED_HTTP_LIB_AGENT", agent);
			set_rustc_env_var!("ACMED_HTTP_LIB_NAME", p.name);
			set_rustc_env_var!("ACMED_HTTP_LIB_VERSION", p.version);
			return;
		}
	}
}

fn set_target() {
	if let Ok(target) = env::var("TARGET") {
		set_rustc_env_var!("ACMED_TARGET", target);
	};
}

fn set_default_values() {
	set_data_path_if_absent!("ACMED_DEFAULT_ACCOUNTS_DIR", "accounts");
	set_data_path_if_absent!("ACMED_DEFAULT_CERT_DIR", "certs");
	set_env_var_if_absent!(
		"ACMED_DEFAULT_CERT_FORMAT",
		"{{ name }}_{{ key_type }}.{{ file_type }}.{{ ext }}"
	);
	set_cfg_path_if_absent!("ACMED_DEFAULT_CONFIG_FILE", "acmed.toml");
	set_runstate_path_if_absent!("ACMED_DEFAULT_PID_FILE", "acmed.pid");
}

fn main() {
	set_target();
	set_lock();
	set_default_values();
}