use std::fs::{ self, File, };
use clap::{ Arg, ArgMatches, SubCommand, App, };
use crate::cmd::{ Command, CommandError, };

const CARGO_TOML_FILE: &str = "Cargo.toml";

const MAIN_RS: &str = include_str!("main.rs_template");
const CMD_RS: &str = include_str!("cmd.rs");
const CMD_DEFAULT_RS: &str = include_str!("cmd_default.rs");
const CMD_SAMPLE_RS: &str = include_str!("cmd_sample.rs");
const CARGO_TOML: &str = include_str!("Carto.toml_template");

pub struct CommandNewCliApp;

impl Command for CommandNewCliApp {

    fn name(&self) -> &str { "newcliapp" }

    fn subcommand<'a>(&self) -> App<'a, 'a> {
        SubCommand::with_name(self.name()).about("New cli app")
            .arg(Arg::with_name("APP_NAME").required(true).index(1).help("App name"))
            .arg(Arg::with_name("verbose").long("verbose").short("V").help("Verbose"))
    }

    fn run(&self, _arg_matches: &ArgMatches, sub_arg_matches: &ArgMatches) -> CommandError {
        let is_verbose = sub_arg_matches.is_present("verbose");

        if is_file_exists(CARGO_TOML_FILE) || is_file_exists("src") {
            println!("[ERROR] File exists: {}, or dir exists: src/", CARGO_TOML_FILE);
            return Ok(());
        }

        let app_name = sub_arg_matches.value_of("APP_NAME").expect("APP_NAME is required!");
        let cargo_toml = CARGO_TOML.replace("{{NAME}}", app_name);

        if is_verbose { println!("[INFO] Create dir: src/"); }
        fs::create_dir("src/")?;
        if is_verbose { println!("[INFO] Create file: src/main.rs"); }
        fs::write("src/main.rs", MAIN_RS.as_bytes())?;
        if is_verbose { println!("[INFO] Create file: src/cmd.rs"); }
        fs::write("src/cmd.rs", CMD_RS.as_bytes())?;
        if is_verbose { println!("[INFO] Create file: src/cmd_default.rs"); }
        fs::write("src/cmd_default.rs", CMD_DEFAULT_RS.as_bytes())?;
        if is_verbose { println!("[INFO] Create file: src/cmd_sample.rs"); }
        fs::write("src/cmd_sample.rs", CMD_SAMPLE_RS.as_bytes())?;
        if is_verbose { println!("[INFO] Create file: Cargo.toml"); }
        fs::write(CARGO_TOML_FILE, cargo_toml.as_bytes())?;

        println!("[INFO] Project created!");
        Ok(())
    }
}

fn is_file_exists(file_name: &str) -> bool {
    File::open(file_name).is_ok()
}