//!
//! XmlSec Bindings Generation
//!
use bindgen::Builder   as BindgenBuilder;
use bindgen::Formatter as BindgenFormatter;

use pkg_config::Config as PkgConfig;

use std::env;
use std::path::PathBuf;
use std::process::Command;


const BINDINGS: &str = "bindings.rs";


fn main()
{
    println!("cargo:rustc-link-lib=xmlsec1-openssl");  // -lxmlsec1-openssl
    println!("cargo:rustc-link-lib=xmlsec1");          // -lxmlsec1
    println!("cargo:rustc-link-lib=xml2");             // -lxml2
    println!("cargo:rustc-link-lib=ssl");              // -lssl
    println!("cargo:rustc-link-lib=crypto");           // -lcrypto

    let path_out      = PathBuf::from(env::var("OUT_DIR").unwrap());
    let path_bindings = path_out.join(BINDINGS);

    if !path_bindings.exists()
    {
        PkgConfig::new()
            .probe("xmlsec1")
            .expect("Could not find xmlsec1 using pkg-config");

        let bindbuild = BindgenBuilder::default()
            .header("bindings.h")
            .clang_args(fetch_xmlsec_config_flags())
            .clang_args(fetch_xmlsec_config_libs())
            .layout_tests(true)
            .formatter(BindgenFormatter::default())
            .generate_comments(true);

        let bindings = bindbuild.generate()
            .expect("Unable to generate bindings");

        bindings.write_to_file(path_bindings)
            .expect("Couldn't write bindings!");
    }
}


fn fetch_xmlsec_config_flags() -> Vec<String>
{
    let out = Command::new("xmlsec1-config")
        .arg("--cflags")
        .output()
        .expect("Failed to get --cflags from xmlsec1-config. Is xmlsec1 installed?")
        .stdout;

    args_from_output(out)
}


fn fetch_xmlsec_config_libs() -> Vec<String>
{
    let out = Command::new("xmlsec1-config")
        .arg("--libs")
        .output()
        .expect("Failed to get --libs from xmlsec1-config. Is xmlsec1 installed?")
        .stdout;

    args_from_output(out)
}


fn args_from_output(args: Vec<u8>) -> Vec<String>
{
    let decoded = String::from_utf8(args)
        .expect("Got invalid UTF8 from xmlsec1-config");

    let args = decoded.split_whitespace()
        .map(|p| p.to_owned())
        .collect::<Vec<String>>();

    args
}