/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#[cfg(not(target_os = "android"))]
use std::env;
use std::fs::File;
use std::io::{self, Read};
use std::path::{Path, PathBuf};
use std::sync::{Arc, Mutex};

lazy_static! {
    static ref CMD_RESOURCE_DIR: Arc<Mutex<Option<String>>> = {
        Arc::new(Mutex::new(None))
    };
}

pub fn set_resources_path(path: Option<String>) {
    let mut dir = CMD_RESOURCE_DIR.lock().unwrap();
    *dir = path;
}

#[cfg(target_os = "android")]
pub fn resources_dir_path() -> PathBuf {
    PathBuf::from("/sdcard/servo/")
}

#[cfg(not(target_os = "android"))]
pub fn resources_dir_path() -> PathBuf {
    let mut dir = CMD_RESOURCE_DIR.lock().unwrap();

    if let Some(ref path) = *dir {
        return PathBuf::from(path);
    }

    // FIXME: Find a way to not rely on the executable being
    // under `<servo source>[/$target_triple]/target/debug`
    // or `<servo source>[/$target_triple]/target/release`.
    let mut path = env::current_exe().expect("can't get exe path");
    // Follow symlink
    path = path.canonicalize().expect("path does not exist");
    path.pop();
    path.push("resources");
    if !path.is_dir() {   // resources dir not in same dir as exe?
        // exe is probably in target/{debug,release} so we need to go back to topdir
        path.pop();
        path.pop();
        path.pop();
        path.push("resources");
        if !path.is_dir() {
            // exe is probably in target/$target_triple/{debug,release} so go back one more
            path.pop();
            path.pop();
            path.push("resources");
        }
    }
    *dir = Some(path.to_str().unwrap().to_owned());
    path
}

pub fn read_resource_file<P: AsRef<Path>>(relative_path: P) -> io::Result<Vec<u8>> {
    let mut path = resources_dir_path();
    path.push(relative_path);
    let mut file = try!(File::open(&path));
    let mut data = Vec::new();
    try!(file.read_to_end(&mut data));
    Ok(data)
}