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

trait RunCommandAsEnUs {
    fn en_us(&mut self) -> &mut Self;
}

impl RunCommandAsEnUs for Command {
    fn en_us(&mut self) -> &mut Self {
        self.env("LANG", "en_US")
    }
}

pub fn get_git_base_path() -> Option<PathBuf> {
    match PathBuf::from(".").canonicalize() {
        Err(e) => {
            warn!("Get current path failed: {}", e);
            None
        },
        Ok(mut path) => loop {
            if path.join(".git").is_dir() {
                debug!("Found git base dir: {:?}", path);
                return Some(path);
            }
            if !path.pop() {
                return None;
            }
        }
    }
}

pub fn check_git_status() -> bool {
    trace!("Run: git fetch --dry-run");
    match Command::new("git").en_us().args(&["fetch", "--dry-run"]).output() {
        Err(e) => {
            warn!("Error in run git fetch --dry-run: {}", e);
            return false;
        },
        Ok(o) => match String::from_utf8(o.stdout) {
            Err(e) => {
                warn!("Error in get utf8 git fetch --dry-run stdout: {}", e);
                return false;
            },
            Ok(stdout) => if !stdout.trim().is_empty() {
                warn!("Std out is not empty git fetch --dry-run: {}", stdout);
                return false;
            },
        },
    }
    trace!("Run: git status");
    match Command::new("git").en_us().args(&["status"]).output() {
        Err(e) => {
            warn!("Error in run git status: {}", e);
            return false;
        },
        Ok(o) => match String::from_utf8(o.stdout) {
            Err(e) => {
                warn!("Error in get utf8 git status: {}", e);
                return false;
            },
            Ok(stdout) => if [
                    "Changes not staged for commit",
                    "Your branch is ahead of",
                    "Untracked files" ].iter().any(|s| stdout.contains(s)) {
                warn!("Std out check failed git status: {}", stdout);
                return false;
            }
        }
    }
    true
}

pub fn get_git_hash() -> Option<String> {
    trace!("Run: git rev-parse HEAD");
    match Command::new("git").en_us().args(&["rev-parse", "HEAD"]).output(){
        Err(e) => {
            warn!("Error in run git rev-parse HEAD: {}", e);
            None
        },
        Ok(o) => match String::from_utf8(o.stdout) {
            Err(e) => {
                warn!("Error in get utf8 git rev-parse HEAD: {}", e);
                None
            },
            Ok(stdout) => Some(stdout.trim().into()),
        }
    }
}