chrono-lc/build.rs

use serde_derive::Deserialize;
use serde_json::Error as JsonError;
use std::env;
use std::fs::File;
use std::io::{Error as IoError, Read, Write};
use std::path::Path;

use walkdir::{DirEntry, WalkDir};

#[derive(Deserialize)]
pub struct Locale {
	short_months: Option<Vec<String>>,
	long_months: Option<Vec<String>>,
	short_weekdays: Option<Vec<String>>,
	long_weekdays: Option<Vec<String>>,
	ampm: Option<Vec<String>>,
}

fn main() {
	let out_dir = env::var("OUT_DIR").unwrap();
	let dest_path = Path::new(&out_dir).join("locales.rs");
	let mut f = File::create(&dest_path).unwrap();

	let _ = f.write_all(
		r#####"lazy_static! {
		pub static ref LOCALES: Locales = {
			let mut res = Locales {
				short_months: HashMap::new(),
				long_months: HashMap::new(),
				short_weekdays: HashMap::new(),
				long_weekdays: HashMap::new(),
				ampm: HashMap::new(),
			};
	"#####
			.as_bytes(),
	);

	println!("Building...");
	for entry in WalkDir::new("locales") {
		let entry = entry.unwrap();
		println!("Found {}", entry.path().display());

		if entry.path().extension().map(|e| e != "json").unwrap_or(false) {
			println!("Not a json file");
			continue;
		}

		let locale_name = entry.path().file_stem().map(|n| n.to_string_lossy());
		if locale_name.is_none() {
			continue;
		}

		let locale_name = locale_name.unwrap().to_string();
		if let Ok(locale_data) = load_locale(&entry) {
			if let Some(long_months) = locale_data.long_months {
				if long_months.len() == 12 {
					let _ = f
						.write_all(
							format!(
								"res.long_months.insert(\"{}\".into(), vec![{}]);\n",
								locale_name,
								long_months.iter().map(|s| format!("\"{}\"", s)).collect::<Vec<String>>().join(",")
							).as_bytes(),
						).unwrap();
				}
			}

			if let Some(short_months) = locale_data.short_months {
				if short_months.len() == 12 {
					let _ = f
						.write_all(
							format!(
								"res.short_months.insert(\"{}\".into(), vec![{}]);\n",
								locale_name,
								short_months.iter().map(|s| format!("\"{}\"", s)).collect::<Vec<String>>().join(",")
							).as_bytes(),
						).unwrap();
				}
			}

			if let Some(long_weekdays) = locale_data.long_weekdays {
				if long_weekdays.len() == 7 {
					let _ = f
						.write_all(
							format!(
								"res.long_weekdays.insert(\"{}\".into(), vec![{}]);\n",
								locale_name,
								long_weekdays.iter().map(|s| format!("\"{}\"", s)).collect::<Vec<String>>().join(",")
							).as_bytes(),
						).unwrap();
				}
			}

			if let Some(short_weekdays) = locale_data.short_weekdays {
				if short_weekdays.len() == 7 {
					let _ = f
						.write_all(
							format!(
								"res.short_weekdays.insert(\"{}\".into(), vec![{}]);\n",
								locale_name,
								short_weekdays.iter().map(|s| format!("\"{}\"", s)).collect::<Vec<String>>().join(",")
							).as_bytes(),
						).unwrap();
				}
			}

			if let Some(ampm) = locale_data.ampm {
				if ampm.len() == 4 {
					let _ = f
						.write_all(
							format!(
								"res.ampm.insert(\"{}\".into(), vec![{}]);\n",
								locale_name,
								ampm.iter().map(|s| format!("\"{}\"", s)).collect::<Vec<String>>().join(",")
							).as_bytes(),
						).unwrap();
				}
			}
		}
	}

	let _ = f.write_all(
		r####"		res
			};
		}
		"####
			.as_bytes(),
	);
}

fn load_locale(entry: &DirEntry) -> Result<Locale, BuildError> {
	let mut locale_data = String::new();
	let mut f = File::open(entry.path())?;
	f.read_to_string(&mut locale_data)?;
	let locale = serde_json::from_str::<Locale>(&locale_data)?;
	Ok(locale)
}

enum BuildError {
	Io(IoError),
	Json(JsonError),
}

impl From<IoError> for BuildError {
	fn from(e: IoError) -> Self {
		BuildError::Io(e)
	}
}

impl From<JsonError> for BuildError {
	fn from(e: JsonError) -> Self {
		BuildError::Json(e)
	}
}