use crate::error::CommandError;

use clap::Arg;

use format_bytes::format_bytes;

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("--rev")

                .value_name("REV")

                .takes_value(true),

        )

        .arg(

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

                .required(true)

                .multiple(true)

                .empty_values(false)

                .value_name("FILE")

                .help("Files to output"),

        )

        .about(HELP_TEXT)

}

#[timed]

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

    let cat_enabled_default = true;

    let cat_enabled = invocation.config.get_option(b"rhg", b"cat")?;

    if !cat_enabled.unwrap_or(cat_enabled_default) {

        return Err(CommandError::unsupported(

            "cat is disabled in rhg (enable it with 'rhg.cat = true' \

            or enable fallback with 'rhg.on-unsupported = fallback')",

        ));

    }

    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 working_directory = repo.working_directory_path();

    let working_directory = cwd.join(working_directory); // Make it absolute

    let mut files = vec![];

    for file in file_args.iter() {

        if file.starts_with("set:") {

            let message = "fileset";

            return Err(CommandError::unsupported(message));

        }

        let normalized = cwd.join(&file);

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

        let dotted = normalized.components().any(|c| c.as_os_str() == "..");

        if file == &"." || dotted {

            let message = "`..` or `.` path segment";

            return Err(CommandError::unsupported(message));

        }

        let stripped = normalized

            .strip_prefix(&working_directory)

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

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

        files.push(hg_file);

    }

    let files = files.iter().map(|file| file.as_ref()).collect();

    // TODO probably move this to a util function like `repo.default_rev` or

    // something when it's used somewhere else

    let rev = match rev {

        Some(r) => r.to_string(),

        None => format!("{:x}", repo.dirstate_parents()?.p1),

    };

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

    for (_file, contents) in output.results {

        invocation.ui.write_stdout(&contents)?;

    }

    if !output.missing.is_empty() {

        let short = format!("{:x}", output.node.short()).into_bytes();

        for path in &output.missing {

            invocation.ui.write_stderr(&format_bytes!(

                b"{}: no such file in rev {}\n",

                path.as_bytes(),

                short

            ))?;

        }

    }

    if output.found_any {

        Ok(())

    } else {

        Err(CommandError::Unsuccessful)

    }

}