use std::path::{PathBuf, Path};
use std::io::BufReader;
use std::io::prelude::*;
use std::fs::{self, File};
use std::env;
use super::std;

/// Creates a `PackageManager` struct to hold in the needed data
/// to run our commands.
#[derive(Debug, Clone, Default)]
pub struct PackageManager<'a> {
    pub name: &'a str,
    pub search: Option<Vec<&'a str>>,
    pub install: Option<Vec<&'a str>>,
    pub uninstall:  Option<Vec<&'a str>>,
    pub sup: Option<Vec<&'a str>>,
    pub purge: Option<Vec<&'a str>>,
    pub update: Option<Vec<&'a str>>,
    pub upgrade: Option<Vec<&'a str>>,
    pub cache_clear: Option<Vec<&'a str>>,
    pub complete_cache_clear: Option<Vec<&'a str>>,
    pub exe: PathBuf,
}

/// This holds the various implementations of `PackageManagers` so far.
impl<'a> PackageManager<'a> {
    pub fn pacmatic() -> PackageManager<'a> {
        PackageManager {
            name: "pacmatic",
            search: Some(vec!["pacmatic", "-Ss"]),
            install: Some(vec!["pacmatic", "-S"]),
            uninstall: Some(vec!["pacmatic", "-R"]),
            sup: Some(vec!["pacmatic", "-Syu"]),
            purge: Some(vec!["pacmatic", "-Rdns"]),
            upgrade: Some(vec!["pacmatic", "-Su"]),
            update: Some(vec!["pacmatic", "-Sy"]),
            cache_clear: Some(vec!["pacmatic", "-Sc"]),
            complete_cache_clear: Some(vec!["pacmatic", "-Scc"]),
            exe: PathBuf::from("/bin/pacmatic"),
        }
    }
    pub fn pacman() -> PackageManager<'a> {
        PackageManager {
            name: "pacman",
            search: Some(vec!["pacman", "-Ss"]),
            install: Some(vec!["pacman", "-S"]),
            uninstall: Some(vec!["pacman", "-R"]),
            sup: Some(vec!["pacman", "-Syu"]),
            purge: Some(vec!["pacman", "-Rdns"]),
            upgrade: Some(vec!["pacman", "-Su"]),
            update: Some(vec!["pacman", "-Sy"]),
            cache_clear: Some(vec!["pacman", "-Sc"]),
            complete_cache_clear: Some(vec!["pacman", "-Scc"]),
            exe: PathBuf::from("/bin/pacman"),
        }
    }

    pub fn apt() -> PackageManager<'a> {
        PackageManager {
            name: "apt",
            search: Some(vec!["apt", "search"]),
            install: Some(vec!["apt", "install"]),
            uninstall:Some(vec!["apt", "remove"]),
            sup: Some(vec!["apt", "update", "upgrade"]),
            purge: Some(vec!["apt", "purge"]),
            upgrade: Some(vec!["apt", "upgrade"]),
            update: Some(vec!["apt", "update"]),
            cache_clear: Some(vec!["apt", "clean"]),
            complete_cache_clear: Some(vec!["apt-get", "autoclean"]),
            exe: PathBuf::from("/usr/bin/apt"),
        }
    }

    pub fn xbps() -> PackageManager<'a> {
        PackageManager {
            name: "xbps",
            search: Some(vec!["xbps-query", "-Rs"]),
            install: Some(vec!["xbps-install", "-S"]),
            uninstall: Some(vec!["xbps-remove"]),
            sup: Some(vec!["xbps-install", "-Su"]),
            purge: Some(vec!["xbps-remove", "-R"]),
            upgrade: Some(vec!["xbps-install", "-Su"]),
            update: Some(vec!["xbps-install"]),
            cache_clear: Some(vec!["xbps-remove", "-0"]),
            complete_cache_clear: Some(vec!["xbps-remove", "-0"]),
            exe: PathBuf::from("bin/xbps-install"),
        }
    }
    // Allows setting the default `rux.conf` in folder `.config/rux/` in the 
    // user's home directory. Will ask once per user, including sudo.
    pub fn set_default(&self) -> std::io::Result<()> {
        let mut conf = match env::home_dir() {
            Some(path) => path,
            None => {
                println!("Could not find home! Default cannot set properly!");
                std::process::exit(1)
            }
        };
        conf.push(".config/rux/");
        fs::create_dir_all(&conf).unwrap_or_else(|why| {
            println!("! {:?}", why.kind());
        });
        conf.push("rux.conf");
        let mut file = File::create(conf)?;
        file.write_all(self.name.as_bytes())?;
        Ok(())
    }
    pub fn all() -> Vec<PackageManager<'a>> {
        let pacmatic = PackageManager::pacmatic();
        let pacman = PackageManager::pacman();
        let aptget = PackageManager::apt();
        let xbps = PackageManager::xbps();

        vec![pacmatic, pacman, aptget, xbps]
    }
}

/// Reads from default.conf and returns the appropriate `PackageManager`
/// Pulls the first line out of the default.conf and loads that.
/// If it doesn't recognize the file it will tell the user that there's an
/// issue before exiting.
pub fn read_default<'a, P: AsRef<Path>>(ruxconf: P) -> Result<PackageManager<'a>, std::io::Error> {
    /*
    let mut home = env::home_dir().unwrap_or_else(|| {
            eprintln!("Cannot load file, home directory cannot be found");
            std::process::exit(1)
    });
    home.push(".config/rux/rux.conf");
    */
    let file = File::open(&ruxconf)?;
    let buffered = BufReader::new(file);
    for line in buffered.lines() {
        match &*line.unwrap() {
            "pacmatic" => return Ok(PackageManager::pacmatic()),
            "pacman" => return Ok(PackageManager::pacman()),
            "apt" => return Ok(PackageManager::apt()),
            "xbps" => return Ok(PackageManager::xbps()),
            _ => {
                eprintln!("Default either not set or has been changed");
                std::fs::remove_file(ruxconf).unwrap_or_else(|err| {
                    eprintln!("Failed to delete: {:?}", err);
                });
                std::process::exit(1)
            }
        }
    }
    Ok(PackageManager::default())
}