use crate::error::CommandError;

use clap::Arg;

use hg::operations::cat;

use hg::utils::hg_path::HgPathBuf;

use micro_timer::timed;

use std::convert::TryFrom;

pub const HELP_TEXT: &str = "

Output the current or given revision of files

";

pub fn args() -> clap::App<'static, 'static> {

    clap::SubCommand::with_name("cat")

        .arg(

            Arg::with_name("rev")

                .help("search the repository as it is in REV")

                .short("-r")

                .long("--revision")

                .value_name("REV")

                .takes_value(true),

        )

        .arg(

            clap::Arg::with_name("files")

                .required(true)

                .multiple(true)

                .empty_values(false)

                .value_name("FILE")

                .help("Activity to start: activity@category"),

        )

        .about(HELP_TEXT)

}

#[timed]

pub fn run(invocation: &crate::CliInvocation) -> Result<(), CommandError> {

    let rev = invocation.subcommand_args.value_of("rev");

    let file_args = match invocation.subcommand_args.values_of("files") {

        Some(files) => files.collect(),

        None => vec![],

    };

    let repo = invocation.repo?;

    let cwd = hg::utils::current_dir()?;

    let mut files = vec![];

    for file in file_args.iter() {

        // TODO: actually normalize `..` path segments etc?

        let normalized = cwd.join(&file);

        let stripped = normalized

            .strip_prefix(&repo.working_directory_path())

            // TODO: error message for path arguments outside of the repo

            .map_err(|_| CommandError::abort(""))?;

        let hg_file = HgPathBuf::try_from(stripped.to_path_buf())

            .map_err(|e| CommandError::abort(e.to_string()))?;

        files.push(hg_file);

    }

    match rev {

        Some(rev) => {

            let data = cat(&repo, rev, &files).map_err(|e| (e, rev))?;

            invocation.ui.write_stdout(&data)?;

            Ok(())

        }

    }

}