tweetr 0.2.1

//! This module contains the configuration of the application.
//!
//! All options are passed individually to each function and are not bundled together.
//!
//! # Examples
//!
//! ```no_run
//! # use tweetr::options::Options;
//! let options = Options::parse();
//! println!("Config directory: {}", options.config_dir.0);
//! ```


use clap::{self, App, SubCommand, Arg, AppSettings};
use std::time::Duration;
use std::path::PathBuf;
use std::env::home_dir;
use std::str::FromStr;
use std::fs;


/// All possible subsystems, think `cargo`'s or `git`'s.
#[derive(Debug, Clone, Hash, PartialEq, Eq)]
pub enum Subsystem {
    /// Initialise global app data
    Init {
        /// Whether to override current app configuration. Default: `false`
        force: bool,
    },
    /// Add and authorise a user
    AddUser {
        /// Whether to print more user data. Default: `false`
        verbose: bool,
    },
    /// Add a tweet to the queue
    QueueTweet {
        /// File to load tweets from, if any. Default: `None`
        file_to_load: Option<PathBuf>,
    },
    /// Start the tweet-posting daemon.
    StartDaemon {
        /// How long to wait between trying to post again. Default: 60s
        delay: Duration,
        /// Whether to log all network requests. Default: `false`
        verbose: bool,
    },
}


/// Representation of the application's all configurable values.
#[derive(Debug, Clone, Hash, PartialEq, Eq)]
pub struct Options {
    /// Directory containing configuration. Default: `"$HOME/.tweetr"`
    pub config_dir: (String, PathBuf),
    /// The specified subsystem.
    pub subsystem: Subsystem,
}

impl Options {
    /// Parse `env`-wide command-line arguments into an `Options` instance
    pub fn parse() -> Options {
        let matches = App::new("tweetr")
            .version(crate_version!())
            .author(crate_authors!())
            .setting(AppSettings::ColoredHelp)
            .setting(AppSettings::VersionlessSubcommands)
            .setting(AppSettings::SubcommandRequiredElseHelp)
            .about("tweetr is a platform that allows you to create and queue tweets to be shared when YOU want.\n\
                    You create content when you have time  and then use FOSS and NOT pay whatever-ridiculous\n\
                    amount of $$$ for posting them automatically")
            .arg(Arg::from_usage("-c --config-dir=[CONFIG_DIR] 'Directory containing configuration. Default: $HOME/.tweetr'")
                .validator(Options::config_dir_validator))
            .subcommand(SubCommand::with_name("init")
                .about("Initialise global app data")
                .arg(Arg::from_usage("-f --force 'Override current app configuration'")))
            .subcommand(SubCommand::with_name("add-user")
                .about("Add and authorise a user")
                .arg(Arg::from_usage("-v --verbose 'Print more user data'")))
            .subcommand(SubCommand::with_name("queue-tweet")
                .about("Add a tweet to the queue")
                .arg(Arg::from_usage("-f --file=[file] 'Load tweets from the specified file'").validator(Options::tweets_file_validator)))
            .subcommand(SubCommand::with_name("start-daemon")
                .about("Start the tweet-posting daemon")
                .args(&[Arg::from_usage("-v --verbose 'Log all network requests'"),
                        Arg::from_usage("--delay=<delay> 'How long to wait between trying to post again [ms]'")
                            .default_value("60000")
                            .validator(Options::duration_validator)]))
            .get_matches();

        Options {
            config_dir: match matches.value_of("config-dir") {
                Some(dirs) => (dirs.to_string(), fs::canonicalize(dirs).unwrap()),
                None => {
                    match home_dir() {
                        Some(mut hd) => {
                            hd = hd.canonicalize().unwrap();
                            hd.push(".tweetr");

                            fs::create_dir_all(&hd).unwrap();
                            ("$HOME/.tweetr".to_string(), hd)
                        }
                        None => {
                            clap::Error {
                                    message: "Couldn't automatically get home directory, please specify configuration directory with the -c option".to_string(),
                                    kind: clap::ErrorKind::MissingRequiredArgument,
                                    info: None,
                                }
                                .exit()
                        }
                    }
                }
            },
            subsystem: match matches.subcommand() {
                ("init", Some(init_matches)) => Subsystem::Init { force: init_matches.is_present("force") },
                ("add-user", Some(add_user_matches)) => Subsystem::AddUser { verbose: add_user_matches.is_present("verbose") },
                ("queue-tweet", Some(queue_tweet_matches)) => {
                    Subsystem::QueueTweet { file_to_load: queue_tweet_matches.value_of("file").map(fs::canonicalize).map(Result::unwrap) }
                }
                ("start-daemon", Some(start_daemon_matches)) => {
                    Subsystem::StartDaemon {
                        delay: Duration::from_millis(u64::from_str(start_daemon_matches.value_of("delay").unwrap()).unwrap()),
                        verbose: start_daemon_matches.is_present("verbose"),
                    }
                }
                _ => panic!("No subcommand passed"),
            },
        }
    }

    fn config_dir_validator(s: String) -> Result<(), String> {
        fs::canonicalize(&s).map(|_| ()).map_err(|_| format!("Configuration directory \"{}\" not found", s))
    }

    fn tweets_file_validator(s: String) -> Result<(), String> {
        fs::canonicalize(&s).map(|_| ()).map_err(|_| format!("File with tweets \"{}\" not found", s))
    }

    fn duration_validator(s: String) -> Result<(), String> {
        u64::from_str(&s).map(|_| ()).map_err(|_| format!("\"{}\" is not a valid amount of milliseconds", s))
    }
}