use std::path::PathBuf;
use structopt::StructOpt;
use structopt::clap::ErrorKind as ClapError;

// To get effective user id (EUID) so that setuid works
use users::{get_effective_uid,get_user_by_uid};
// For home directory
use users::os::unix::UserExt;

use crate::log;
use crate::log::Context;

#[derive(Debug, StructOpt)]
#[structopt(
    name = "forgebuild",
    about = "Update your repositories and trigger tasks"
)]
pub struct Cli {
    #[structopt(short = "f", long = "force")]
    pub force: bool,

    #[structopt(short = "b", long = "basedir")]
    pub basedir: Option<String>,

    #[structopt(long = "inbox")]
    pub inbox: bool,

    #[structopt(long = "inbox-folder")]
    pub inboxdir: Option<String>,

    //#[structopt(def)]
    pub tasks: Vec<String>,
}

impl Cli {
    /// Builds the command-line from passed arguments
    /// Returns the Cli instance alongside a PathBuf of the basedir
    pub fn build() -> (Self, PathBuf) {
        // We create a dedicated context so we don't have to pass it as argument
        let mut context = Context::new();

        // We don't want to use structopt's error handler for unknown argument as we have our own
        // error message for that case (unknown_arg). So we use from_iter_safe() not from_args()
        match Cli::from_iter_safe(std::env::args()) {
            Ok(cmd) => {
                // Parsing was successful, but we'd like to ensure requested basedir exists
                match cmd.basedir().canonicalize() {
                    Ok(p) => {
                        (cmd, p)
                    },
                    Err(_) => {
                        // Missing basedir
                        context.insert("$i18n_basedir".to_string(), cmd.basedir().to_str().unwrap().to_string());
                        log::error("missing_basedir", &context);
                        std::process::exit(1);
                    }
                }
            },
            Err(e) => {
                match &e.kind {
                    ClapError::UnknownArgument => {
                        context.insert("$i18n_arg".to_string(), e.info.unwrap().first().unwrap().to_string());
                        log::error("unknown_arg", &context);
                        std::process::exit(1);
                    },
                    _ => e.exit()
                }
            }
        }
    }

    /// Returns a PathBuf to the basedir. If it's a relative link,
    /// it's not expanded here! Panics if no basedir is provided and $HOME isn't defined
    pub fn basedir(&self) -> PathBuf {
        if let Some(basedir) = &self.basedir {
            // Returns an error when the path doesn't exist
            PathBuf::from(basedir)
        } else {
            let owner = get_effective_uid();
            let mut home_path = get_user_by_uid(owner).expect("Failed owner profile")
                .home_dir().to_path_buf();
            home_path.push(".forgebuild");
            home_path
        }
    }
}