use clap::App;

use clap::AppSettings;

use clap::Arg;

use clap::ArgGroup;

use clap::ArgMatches;

use clap::SubCommand;

use hg::operations::DebugDataKind;

use std::convert::TryFrom;

mod commands;

mod error;

mod exitcode;

mod ui;

use commands::Command;

use error::CommandError;

fn main() {

    let app = App::new("rhg")

        .setting(AppSettings::AllowInvalidUtf8)

        .setting(AppSettings::SubcommandRequired)

        .setting(AppSettings::VersionlessSubcommands)

        .version("0.0.1")

        .subcommand(

            SubCommand::with_name("root").about(commands::root::HELP_TEXT),

        )

        .subcommand(

            SubCommand::with_name("files").about(commands::files::HELP_TEXT),

        )

        .subcommand(

            SubCommand::with_name("debugdata")

                .about(commands::debugdata::HELP_TEXT)

                .arg(

                    Arg::with_name("changelog")

                        .help("open changelog")

                        .short("-c")

                        .long("--changelog"),

                )

                .arg(

                    Arg::with_name("manifest")

                        .help("open manifest")

                        .short("-m")

                        .long("--manifest"),

                )

                .group(

                    ArgGroup::with_name("")

                        .args(&["changelog", "manifest"])

                        .required(true),

                )

                .arg(

                    Arg::with_name("rev")

                        .help("revision")

                        .required(true)

                        .value_name("REV"),

                ),

        );

    let matches = app.clone().get_matches_safe().unwrap_or_else(|err| {

        let _ = ui::Ui::new().writeln_stderr_str(&err.message);

        std::process::exit(exitcode::UNIMPLEMENTED_COMMAND)

    });

    let ui = ui::Ui::new();

    let command_result = match_subcommand(matches, &ui);

    match command_result {

        Ok(_) => std::process::exit(exitcode::OK),

        Err(e) => {

            let message = e.get_error_message_bytes();

            if let Some(msg) = message {

                match ui.write_stderr(&msg) {

                    Ok(_) => (),

                    Err(_) => std::process::exit(exitcode::ABORT),

                };

            };

            e.exit()

        }

    }

}

fn match_subcommand(

    matches: ArgMatches,

    ui: &ui::Ui,

) -> Result<(), CommandError> {

    match matches.subcommand() {

        ("root", _) => commands::root::RootCommand::new().run(&ui),

        ("files", _) => commands::files::FilesCommand::new().run(&ui),

        ("debugdata", Some(matches)) => {

            commands::debugdata::DebugDataCommand::try_from(matches)?.run(&ui)

        }

        _ => unreachable!(), // Because of AppSettings::SubcommandRequired,

    }

}

impl<'a> TryFrom<&'a ArgMatches<'_>>

    for commands::debugdata::DebugDataCommand<'a>

{

    type Error = CommandError;

    fn try_from(args: &'a ArgMatches) -> Result<Self, Self::Error> {

        let rev = args

            .value_of("rev")

            .expect("rev should be a required argument");

        let kind = match (

            args.is_present("changelog"),

            args.is_present("manifest"),

        ) {

            (true, false) => DebugDataKind::Changelog,

            (false, true) => DebugDataKind::Manifest,

            (true, true) => {

                unreachable!("Should not happen since options are exclusive")

            }

            (false, false) => {

                unreachable!("Should not happen since options are required")

            }

        };

        Ok(commands::debugdata::DebugDataCommand::new(rev, kind))

    }

}