use crate::Meta;
use clap::{App, AppSettings, Arg, SubCommand};

pub struct AppState {
    pub meta: Meta,
    pub cmd: Command,
}

pub enum Command {
    Init,
    Generate,
    Install,
    Set(String, Option<String>),
}

pub fn parse() -> AppState {
    let project_id =
        Arg::with_name("project id").help("The project identifier.  Format: [client/]<project>");

    let timefile = Arg::with_name("timefile")
        .help("Location of the project's time file")
        .takes_value(true)
        .long("file")
        .short("f")
        .default_value("./time.cass");

    let template = Arg::with_name("template")
        .help("Override the default application template")
        .long("templ")
        .short("t")
        .takes_value(true)
        .default_value("$XDG_CONFIG_HOME/k-office/template.tex");

    let revision = Arg::with_name("revision")
        .help("Override the default revision system")
        .long("rev")
        .short("r")
        .takes_value(true);

    let app = App::new("invoice")
        .version(env!("CARGO_PKG_VERSION"))
        .about("A k-office tool to generate and manage invoices")
        .settings(&[
            AppSettings::SubcommandRequired,
            AppSettings::GlobalVersion,
            AppSettings::DontCollapseArgsInUsage,
        ])
        .subcommand(
            SubCommand::with_name("init")
                .about("Initialise a new invoice config")
                .arg(project_id.clone())
                .arg(timefile)
                .arg(revision.clone()),
        )
        .subcommand(
            SubCommand::with_name("generate")
                .about("Generate an invoice PDF for a client/ project based on a template")
                .arg(project_id)
                .arg(revision)
                .arg(template),
        )
        .subcommand(
            SubCommand::with_name("set")
                .about("Set a variable in the k-office configuration")
                .arg(
                    Arg::with_name("key")
                        .required(true)
                        .takes_value(true)
                        .help("The configuration key to set"),
                )
                .arg(
                    Arg::with_name("value")
                        .takes_value(true)
                        .help("The value to set the key to.  Missing value deletes the key"),
                ),
        );

    let matches = app.get_matches();

    let project_id = match matches.subcommand() {
        ("init", Some(vals)) => vals.value_of("project id"),
        ("generate", Some(vals)) => vals.value_of("project id"),
        _ => None,
    };

    let timefile = match matches.subcommand() {
        ("init", Some(vals)) => vals.value_of("timefile"),
        ("generate", Some(vals)) => vals.value_of("timefile"),
        _ => None,
    };

    let template = match matches.subcommand() {
        ("init", Some(vals)) => vals.value_of("template"),
        ("generate", Some(vals)) => vals.value_of("template"),
        _ => None,
    };

    let revision = match matches.subcommand() {
        ("init", Some(vals)) => vals.value_of("revision"),
        ("generate", Some(vals)) => vals.value_of("revision"),
        _ => None,
    };

    let (key, value) = match matches.subcommand() {
        ("set", Some(vals)) => (vals.value_of("key"), vals.value_of("value")),
        _ => (None, None),
    };

    AppState {
        meta: crate::base::init(project_id, timefile, template, revision),
        cmd: match matches.subcommand() {
            ("init", _) => Command::Init,
            ("generate", _) => Command::Generate,
            ("set", _) => Command::Set(key.unwrap().into(), value.map(Into::into)),
            _ => unreachable!(),
        },
    }
}