use std::fs::File;
use std::path::Path;
use std::result::Result;
use std::process::Command;

use reqwest::Client;
use reqwest::header::ETAG;

fn err_and_exit(msg: String, code: i32) {
    println!("ERROR!: {}", msg);
    std::process::exit(code);
}

fn main() -> Result<(), std::io::Error> {
    let client = Client::new();

    let args: Vec<_> = std::env::args().collect();
    if args.len() < 2 {
        println!("[PACK]: Please enter a package name...");
        std::process::exit(1);
    }

    let split = args[1].as_str().split("::");
    let vec: Vec<&str> = split.collect();
    if vec.len() < 2 {
       err_and_exit("Please enter a repo to download from!".to_string(), 0); 
    }
    
    println!("[PACK]: Downloading {}", vec[0]);

    if !Path::new(format!("/usr/pack/repo/{}", vec[1]).as_str()).exists() {
        err_and_exit(format!("Path /usr/pack/repo/{} does not exist. Please setup your environment.", vec[1]), 1);
    }

    let full_path: Vec<&str> = vec[0].split("/").collect();
    let pkgname = full_path[full_path.len() - 1];
    let repo = match vec[1] {
        "arch_core" => "http://mirrors.advancedhosters.com/archlinux/core/os/x86_64/",
        "arch_extra" => "http://mirrors.advancedhosters.com/archlinux/extra/os/x86_64/",
        _ => {
            println!("ERROR!: Repo {} is not supported...", vec[1]);
            std::process::exit(0);
        },
    };

    print!("[PACK]: Making request...");
    let url = reqwest::Url::parse(&(repo.to_string() + pkgname)).expect("Failed to parse URL");
    let mut resp = match client.get(url).send() {
        Ok(a) => a,
        Err(e) => {
            println!("ERROR!: Couldn't get package from url. Are you connected to the internet?\n\n{}", e);
            std::process::exit(0);
        },
    };
    
    if resp.status().is_success() {
        println!("OK");
        if let Some(etag) = resp.headers().get(ETAG) {
            std::fs::write("etag", etag.as_bytes()).expect("Failed to write ETAG...");
        }

        let mut file = match File::create(format!("/usr/pack/repo/{}/tarballs/{}", vec[1], pkgname)) {
            Ok(res) => res,
            Err(e) => {
                println!("Failed to create file...did you setup you environment? Do you have permission to create files?\n\n{}", e);
                std::process::exit(0);
            },
        };

        resp.copy_to(&mut file).expect("failed to write file");
    } else {
        println!("FAIL!");
        std::process::exit(1);
    }

    let spltdirname: Vec<&str> = pkgname.split(".").collect();
    let dirname = spltdirname[0];

    print!("[PACK]: Creating package dir...");
    std::fs::create_dir(format!("/usr/pack/repo/{}/{}", vec[1], dirname)).expect("Failed to create directory");
    println!("OK");

    print!("[PACK]: Executing tar...");
    Command::new("tar")
        .arg(format!("-C/usr/pack/repo/{}/{}", vec[1], dirname))
        .arg("-xf")
        .arg(format!("/usr/pack/repo/{}/tarballs/{}", vec[1], pkgname))
        .output()
        .expect("Failed to execute tar");
    println!("OK");

    let paths = std::fs::read_dir(format!("/usr/pack/repo/{}/{}/usr/bin/", vec[1], dirname)).expect("Failed to read dir...");
    println!("[PACK]: Creating symlinks");
    for file in paths {
        let pth = &file.expect("Failed to read file").path();
        let strpth = pth.to_str().expect("Failed to convert to str...");
        println!("\tAdding file {} to /usr/pack/bin/", strpth);
        
        let a: Vec<&str> = strpth.split("/").collect();
        let name = a[a.len() - 1];
        std::os::unix::fs::symlink(pth, format!("/usr/pack/bin/{}", name)).expect("Failed to symlink...");
    }

    Ok(())
}