extern crate regex;
extern crate gcc;
extern crate toml;

use std::borrow::ToOwned;
use std::collections::HashSet;
use std::env;
use std::fs::{File, read_dir};
use std::io::Read;
use std::path::{Path, PathBuf};
use regex::Regex;

// Fetch the 'package.exclude' list from our Cargo.toml file.  We'll
// use this to decide what sources to admit.
fn get_excluded_sources(manifest: &Path) -> HashSet<String> {
    let mut text = String::new();
    File::open(manifest).unwrap().read_to_string(&mut text).unwrap();
    let toml = toml::Parser::new(&text).parse().unwrap();
    let package = toml.get("package").unwrap().as_table().unwrap();
    let exclude = package.get("exclude").unwrap().as_slice().unwrap();
    exclude.iter().map(|e| {
        let str = e.as_str().unwrap();
        Path::new(str).file_name().unwrap().to_str().unwrap().to_string()
    }).collect()
}

// Get all the *.cc files in path that aren't excluded.
fn get_cc_files(dir: &Path, excluded: &HashSet<String>) -> Vec<PathBuf> {
    let cc_file = Regex::new(r"\.cc\z").unwrap();
    read_dir(dir).unwrap().map(|entry| {
        entry.unwrap().path()
    }).filter(|p| {
        let filename = p.file_name().unwrap().to_str().unwrap();
        cc_file.is_match(filename) && !excluded.contains(filename)
    }).map(|p| p.to_owned()).collect()
}

fn main() {
    let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
    let src = Path::new(&manifest_dir);

    // Decide what sources to build.
    let excluded = get_excluded_sources(&src.join("Cargo.toml"));
    let mut sources =
        get_cc_files(&src.join("cld2").join("internal"), &excluded);
    sources.push(src.join("src").join("wrapper.cpp"));

    // Convert the sources back to relative path &str values.
    // TODO: This required the unstable relative_from function.
    //let rel_sources: Vec<PathBuf> = sources.iter().map(|p| {
    //    p.relative_from(&src).unwrap().to_owned()
    //}).collect();

    // Run the build.
    let mut config = gcc::Config::new();
    config.cpp(true);
    let cxxflags = match env::var("CXXFLAGS") {
        Ok(val) => val + " -std=c++03",
        Err(..) => String::from("-std=c++03"),
    };
    env::set_var("CXXFLAGS", &cxxflags);
    config.include(&Path::new("cld2/public"));
    config.include(&Path::new("cld2/internal"));
    for f in sources.iter() {
        config.file(f);
    }
    config.compile("libcld2.a");
}