cargo-sweep 0.4.1

use clap::{
    app_from_crate, crate_authors, crate_description, crate_name, crate_version, Arg, ArgGroup,
    SubCommand,
};
use fern::colors::{Color, ColoredLevelConfig};
use log::{debug, error, info};
use std::{
    env,
    path::{Path, PathBuf},
    time::Duration,
};
use walkdir::WalkDir;

mod fingerprint;
mod stamp;
mod util;
use self::fingerprint::{remove_not_built_with, remove_older_then, remove_older_until_fits};
use self::stamp::Timestamp;
use self::util::format_bytes;

/// Setup logging according to verbose flag.
fn setup_logging(verbose: bool) {
    // configure colors for the whole line
    let colors_line = ColoredLevelConfig::new()
        .error(Color::Red)
        .warn(Color::Yellow)
        .info(Color::White)
        .debug(Color::White)
        .trace(Color::BrightBlack);

    let level = if verbose {
        log::LevelFilter::Debug
    } else {
        log::LevelFilter::Info
    };

    let colors_level = colors_line.info(Color::Green);
    fern::Dispatch::new()
        .format(move |out, message, record| {
            out.finish(format_args!(
                "{color_line}[{level}{color_line}] {message}\x1B[0m",
                color_line = format_args!(
                    "\x1B[{}m",
                    colors_line.get_color(&record.level()).to_fg_str()
                ),
                level = colors_level.color(record.level()),
                message = message,
            ));
        })
        .level(level)
        .level_for("pretty_colored", log::LevelFilter::Trace)
        .chain(std::io::stdout())
        .apply()
        .unwrap();
}

/// Returns whether the given path to a Cargo.toml points to a real target directory.
fn is_cargo_root(path: &Path) -> Option<PathBuf> {
    if let Ok(metadata) = cargo_metadata::metadata(Some(path)) {
        let out = Path::new(&metadata.target_directory).to_path_buf();
        if out.exists() {
            return Some(out);
        }
    }
    None
}

/// is a `DirEntry` a unix stile hidden file, ie starts with `.`
fn is_hidden(entry: &walkdir::DirEntry) -> bool {
    entry
        .file_name()
        .to_str()
        .map(|s| s.starts_with('.'))
        .unwrap_or(false)
}

/// Find all cargo project under the given root path.
fn find_cargo_projects(root: &Path, include_hidden: bool) -> Vec<PathBuf> {
    let mut target_paths = std::collections::BTreeSet::new();

    let mut iter = WalkDir::new(root).min_depth(1).into_iter();

    while let Some(entry) = iter.next() {
        if let Ok(entry) = entry {
            if entry.file_type().is_dir() {
                if !include_hidden && is_hidden(&entry) {
                    iter.skip_current_dir();
                    continue;
                }
                if entry.path().ancestors().any(|a| target_paths.contains(a)) {
                    // no reason to look at the contents of something we are already cleaning.
                    // Yes ancestors is a inefficient way to check. We can use a trie or something if it is slow.
                    iter.skip_current_dir();
                    continue;
                }
            }
            if entry.file_name() != "Cargo.toml" {
                continue;
            }
            if let Some(target_directory) = is_cargo_root(entry.path()) {
                target_paths.insert(target_directory);
                iter.skip_current_dir(); // no reason to look at the src and such
            }
        }
    }
    target_paths.into_iter().collect()
}

fn main() {
    let matches = app_from_crate!()
        .subcommand(
            SubCommand::with_name("sweep")
                .arg(
                    Arg::with_name("verbose")
                        .short("v")
                        .help("Turn verbose information on"),
                )
                .arg(
                    Arg::with_name("recursive")
                        .short("r")
                        .help("Apply on all projects below the given path"),
                )
                .arg(
                    Arg::with_name("hidden")
                        .long("hidden")
                        .help("The `recursive` flag defaults to ignoring directories \
                        that start with a `.`, `.git` for example is unlikely to include a \
                        Cargo project, this flag changes it to look in them."),
                )
                .arg(
                    Arg::with_name("dry-run")
                        .short("d")
                        .help("Dry run which will not delete any files"),
                )
                .arg(
                    Arg::with_name("stamp")
                        .short("s")
                        .long("stamp")
                        .help("Store timestamp file at the given path, is used by file option"),
                )
                .arg(
                    Arg::with_name("file")
                        .short("f")
                        .long("file")
                        .help("Load timestamp file in the given path, cleaning everything older"),
                )
                .arg(
                    Arg::with_name("installed")
                        .short("i")
                        .long("installed")
                        .help("Keep only artifacts made by Toolchains currently installed by rustup")
                )
                .arg(
                    Arg::with_name("toolchains")
                        .long("toolchains")
                        .value_name("toolchains")
                        .help("Toolchains (currently installed by rustup) that should have there artifacts kept.")
                        .takes_value(true),
                )
                .arg(
                    Arg::with_name("maxsize")
                        .long("maxsize")
                        .value_name("maxsize")
                        .help("Remove oldest artefact's until the target directory is below the specified size in MB")
                        .takes_value(true),
                )
                .arg(
                    Arg::with_name("time")
                        .short("t")
                        .long("time")
                        .value_name("days")
                        .help("Number of days backwards to keep. If no value is set uses 30.")
                        .takes_value(true),
                )
                .group(
                    ArgGroup::with_name("timestamp")
                        .args(&["stamp", "file", "time", "installed", "toolchains", "maxsize"])
                        .required(true),
                )
                .arg(
                    Arg::with_name("path")
                        .index(1)
                        .value_name("path")
                        .help("Path to check"),
                ),
        )
        .get_matches();

    if let Some(matches) = matches.subcommand_matches("sweep") {
        let verbose = matches.is_present("verbose");
        setup_logging(verbose);

        let dry_run = matches.is_present("dry-run");

        // Default to current invocation path.
        let path = match matches.value_of("path") {
            Some(p) => PathBuf::from(p),
            None => env::current_dir().expect("Failed to get current directory"),
        };

        let keep_duration = if matches.is_present("file") {
            let ts = Timestamp::load(path.as_path()).expect("Failed to load timestamp file");
            Duration::from(ts)
        } else {
            let days_to_keep: u64 = matches
                .value_of("time")
                .unwrap_or("30")
                .parse()
                .expect("Invalid time format");
            Duration::from_secs(days_to_keep * 24 * 3600)
        };

        if matches.is_present("stamp") {
            debug!("Writing timestamp file in: {:?}", path);
            match Timestamp::new().store(path.as_path()) {
                Ok(_) => {}
                Err(e) => error!("Failed to write timestamp file: {}", e),
            }
            return;
        }

        let paths = if matches.is_present("recursive") {
            find_cargo_projects(&path, matches.is_present("hidden"))
        } else if let Ok(metadata) = cargo_metadata::metadata(None) {
            let out = Path::new(&metadata.target_directory).to_path_buf();
            if out.exists() {
                vec![out]
            } else {
                error!("Failed to clean {:?} as it does not exist.", out);
                return;
            }
        } else {
            error!("Failed to clean {:?} as it is not a cargo project.", path);
            return;
        };

        if matches.is_present("installed") || matches.is_present("toolchains") {
            for project_path in &paths {
                match remove_not_built_with(project_path, matches.value_of("toolchains"), dry_run) {
                    Ok(cleaned_amount) if dry_run => {
                        info!("Would clean: {}", format_bytes(cleaned_amount))
                    }
                    Ok(cleaned_amount) => info!("Cleaned {}", format_bytes(cleaned_amount)),
                    Err(e) => error!("Failed to clean {:?}: {}", project_path, e),
                };
            }

            return;
        }

        if matches.is_present("maxsize") {
            // TODO: consider parsing units like GB, KB ...
            let size = match matches
                .value_of("maxsize")
                .and_then(|s| s.parse::<u64>().ok())
            {
                Some(s) => s * 1024 * 1024,
                None => {
                    error!("maxsize has to be a number");
                    return;
                }
            };

            for project_path in &paths {
                match remove_older_until_fits(project_path, size, dry_run) {
                    Ok(cleaned_amount) if dry_run => {
                        info!("Would clean: {}", format_bytes(cleaned_amount))
                    }
                    Ok(cleaned_amount) => info!("Cleaned {}", format_bytes(cleaned_amount)),
                    Err(e) => error!("Failed to clean {:?}: {}", project_path, e),
                };
            }

            return;
        }

        for project_path in &paths {
            match remove_older_then(project_path, &keep_duration, dry_run) {
                Ok(cleaned_amount) if dry_run => {
                    info!("Would clean: {}", format_bytes(cleaned_amount))
                }
                Ok(cleaned_amount) => info!("Cleaned {}", format_bytes(cleaned_amount)),
                Err(e) => error!("Failed to clean {:?}: {}", project_path, e),
            };
        }
    }
}