fif/src/parameters.rs

//! [Clap] struct used to parse command line arguments.

use crate::string_type::String as StringType;
use cfg_if::cfg_if;
use clap::{AppSettings, Clap};
use std::collections::BTreeSet;
use std::path::PathBuf;

cfg_if! {
	if #[cfg(windows)] {
		const DEFAULT_FORMAT: &str = "powershell";
	} else {
		const DEFAULT_FORMAT: &str = "sh";
	}
}

#[derive(Clap, PartialEq, Debug)]
pub enum OutputFormat {
	/// A Bourne shell compatible script.
	#[clap(alias = "shell", alias = "bash")]
	Sh,
	/// A PowerShell script.
	#[clap(alias = "powershell")]
	PowerShell,
	/// Plain text.
	Text,
	/// JSON.
	#[cfg(feature = "json")]
	Json,
}

// TODO: convert this to macro style?: https://docs.rs/clap/3.0.0-beta.2/clap/index.html#using-macros

#[derive(Clap, Debug)]
#[clap(
	version = option_env!("CARGO_PKG_VERSION").unwrap_or("???"),
	author = option_env!("CARGO_PKG_AUTHORS").unwrap_or("Lynnesbian"),
	about = option_env!("CARGO_PKG_DESCRIPTION").unwrap_or("File Info Fixer"),
	before_help = "Copyright © 2021 Lynnesbian under the GPL3 (or later) License.",
	before_long_help = "Copyright © 2021 Lynnesbian\n\
	This program is free software: you can redistribute it and/or modify \
	it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 \
	of the License, or (at your option) any later version.",
	setting(AppSettings::ColoredHelp)
)]
pub struct Parameters {
	// NOTE: clap's comma-separated argument parser makes it impossible to specify extensions with commas in their name -
	// `-e sil\,ly` is treated as ["sil", "ly"] rather than as ["silly"], no matter how i escape the comma (in bash,
	// anyway). is this really an issue? it does technically exclude some perfectly valid extensions, but i've never seen
	// a file extension with a comma in its name before.
	/// Only examine files with these extensions.
	/// Multiple extensions can be specified by either using the flag multiple times (`-e jpg -e png -e gif`), or by
	/// separating them with commas (`-e jpg,png,gif`).
	#[clap(short, long, use_delimiter = true, require_delimiter = true, value_name = "ext", validator = lowercase_exts)]
	pub exts: Option<Vec<StringType>>,

	/// Use these preset lists of extensions as the search filter (comma-separated list).
	/// `media` includes all extensions from the `audio`, `video`, and `images` sets, making `-E media` equivalent to
	/// `-E audio,video,images`.
	#[clap(
		short = 'E',
		long,
		arg_enum,
		use_delimiter = true,
		require_delimiter = true,
		value_name = "set"
	)]
	pub ext_set: Vec<ExtensionSet>,

	/// Don't scan files with these extensions.
	/// This option takes precedence over extensions specified with `-e` or `-E`.
	#[clap(short = 'x', long, use_delimiter = true, require_delimiter = true, value_name = "ext", validator = lowercase_exts)]
	pub exclude: Option<Vec<StringType>>,

	/// Exclude files using a preset list of extensions.
	/// This option takes precedence over extensions specified with `-e` or `-E`.
	#[clap(
		short = 'X',
		long,
		arg_enum,
		use_delimiter = true,
		require_delimiter = true,
		value_name = "set"
	)]
	pub exclude_set: Vec<ExtensionSet>,

	/// Don't skip hidden files and directories.
	/// Even if this flag is not present, fif will still recurse into a hidden root directory - for example, `fif
	/// ~/.hidden` will recurse into `~/.hidden` regardless of whether or not -s was passed as an argument.
	#[clap(short, long)]
	pub scan_hidden: bool,

	/// Scan files without extensions.
	/// By default, fif will ignore files without extensions - for example, a jpeg file named `photo` won't be considered
	/// misnamed. Supplying the -S flag will cause fif to recommend renaming this file to `photo.jpg`.
	#[clap(short = 'S', long)]
	pub scan_extensionless: bool,

	/// Output format to use.
	/// By default, fif will output a PowerShell script on Windows, and a Bourne Shell script on other platforms.
	#[clap(short, long, default_value = DEFAULT_FORMAT, arg_enum, value_name = "format")]
	pub output_format: OutputFormat,

	/// Follow symlinks.
	#[clap(short, long)]
	pub follow_symlinks: bool,

	/// Output verbosity. Each additional `-v` increases verbosity.
	/// Can be overridden by RUST_LOG.
	#[clap(short, long, parse(from_occurrences), group = "verbosity")]
	pub verbose: u8,

	/// Output quietness. Each additional `-q` decreases verbosity.
	#[clap(short, long, parse(from_occurrences), group = "verbosity")]
	pub quiet: u8,

	/// The directory to process.
	#[clap(name = "DIR", default_value = ".", parse(from_os_str))]
	pub dir: PathBuf,
}

fn lowercase_exts(exts: &str) -> Result<(), String> {
	// TODO: i would much rather accept uppercase exts and convert them to lowercase than just rejecting lowercase exts...
	if exts.to_lowercase() != exts {
		return Err(String::from("Supplied extensions must be lowercase"));
	}
	Ok(())
}

/// Further options relating to scanning.
#[derive(PartialEq, Debug)]
pub struct ScanOpts {
	/// Whether hidden files and directories should be scanned.
	pub hidden: bool,
	/// Whether files without extensions should be scanned.
	pub extensionless: bool,
	/// Should symlinks be followed?
	pub follow_symlinks: bool,
}

impl Parameters {
	/// Returns an optional vec of the extensions to be scanned - i.e., extensions specified via the `-e` or `-E` flag,
	/// minus the extensions excluded with the `-x` flag; i.e., the difference between the included and excluded sets.
	pub fn extensions(&self) -> Option<BTreeSet<&str>> {
		if let Some(included) = self.included_extensions() {
			if let Some(excluded) = self.excluded_extensions() {
				// return included extensions without excluded extensions
				// ...maybe i should have called them "suffixes" instead of extensions...
				Some(included.into_iter().filter(|ext| !excluded.contains(ext)).collect())
			} else {
				// no extensions excluded - just return all included
				Some(included)
			}
		} else {
			// no extensions included - return none
			None
		}
	}

	/// Returns an optional vec of extensions that were specified by `-e` or `-E`. Note that this doesn't account for
	/// extensions excluded by the exclusion flags.
	pub fn included_extensions(&self) -> Option<BTreeSet<&str>> {
		let mut included = BTreeSet::new();
		if let Some(exts) = self.exts.as_ref() {
			// -e
			included.extend(exts.iter().map(|ext| ext.as_str()));
		}

		if !&self.ext_set.is_empty() {
			// -E
			included.extend(self.ext_set.iter().flat_map(|set| set.extensions()));
		}

		match included {
			x if x.is_empty() => None,
			x => Some(x),
		}
	}

	/// Returns an optional vec of extensions that were specified by `-x` or `-X`.
	pub fn excluded_extensions(&self) -> Option<BTreeSet<&str>> {
		let mut excluded = BTreeSet::new();
		if let Some(exclude) = self.exclude.as_ref() {
			// -x
			excluded.extend(exclude.iter().map(|ext| ext.as_str()));
		}

		if !&self.exclude_set.is_empty() {
			// -X
			excluded.extend(self.exclude_set.iter().flat_map(|set| set.extensions()));
		}

		// excluded doesn't sound like a word anymore
		// tongue twister: enter X-options' excellent extension exclusion
		match excluded {
			x if x.is_empty() => None,
			x => Some(x),
		}
	}

	pub const fn get_scan_opts(&self) -> ScanOpts {
		ScanOpts {
			hidden: self.scan_hidden,
			extensionless: self.scan_extensionless,
			follow_symlinks: self.follow_symlinks,
		}
	}

	pub fn default_verbosity(&self) -> &'static str {
		#![allow(clippy::missing_const_for_fn)]
		// match was not permitted inside const functions until 1.46

		match self.quiet {
			0 => {
				match self.verbose {
					0 => "info",  // no verbosity flags specified
					1 => "debug", // -v
					_ => "trace", // -vv...
				}
			}
			1 => "warn",  // -q
			2 => "error", // -qq
			_ => "off",   // -qqq...
		}
	}
}

/// Sets of extensions for use with [Parameter](crate::parameters::Parameters)'s `-E` flag.
#[derive(Clap, PartialEq, Debug)]
pub enum ExtensionSet {
	/// Extensions used for image file formats, such as `png`, `jpeg`, `webp`, etc.
	Images,
	/// Extensions used for audio file formats, such as `mp3`, `ogg`, `flac`, etc.
	Audio,
	/// Extensions used for video file formats, such as `mkv`, `mp4`, `mov`, etc.
	#[clap(alias = "videos")]
	Video,
	/// Extensions used for media file formats. This acts as a combination of the [Images](ExtensionSet::Images),
	/// [Audio](ExtensionSet::Audio) and [Videos](ExtensionSet::Videos) variants.
	Media,
	/// Extensions used for document file formats, such as `pdf`, `odt`, `docx`, etc.
	Documents,
	/// Extensions used for text file formats, such as `txt`, `toml`, `html`, etc.
	Text,
	/// Extensions used for archive file formats, such as `zip`, `zst`, `gz`, etc.
	Archives,
	/// Extensions used for system file formats, such as `mbr`, `crash`, `dll`, etc.
	System,
}

impl ExtensionSet {
	/// The list of known extensions for this `ExtensionSet`.
	pub fn extensions(&self) -> Vec<&str> {
		match self {
			Self::Images => mime_guess::get_mime_extensions_str("image/*").unwrap().to_vec(),
			Self::Audio => mime_guess::get_mime_extensions_str("audio/*").unwrap().to_vec(),
			Self::Video => mime_guess::get_mime_extensions_str("video/*").unwrap().to_vec(),
			Self::Media => [
				Self::Images.extensions(),
				Self::Audio.extensions(),
				Self::Video.extensions(),
			]
			.concat(),
			Self::Documents => vec![
				"pdf", "doc", "docx", "ppt", "pptx", "xls", "xlsx", "csv", "tsv", "odt", "ods", "odp", "oda", "rtf", "ps",
				"pages", "key", "numbers",
			],
			Self::Text => [
				mime_guess::get_mime_extensions_str("text/*").unwrap(),
				&["js", "pl", "csh", "sh", "bash", "zsh", "fish", "bat", "php"],
			]
			.concat(),
			// many compressed file types follow the name scheme "application/x.+compressed.*" - maybe this can be used
			// somehow to extract extensions for compressed files from mime_guess?
			Self::Archives => vec![
				"zip", "tar", "gz", "zst", "xz", "rar", "7z", "bz", "bz2", "tgz", "rpa", "txz", "tz2", "sea", "sitx", "z",
				"cpio",
			],
			Self::System => vec![
				"com", "dll", "exe", "sys", "reg", "nt", "cpl", "msi", "efi", "bio", "rcv", "mbr", "sbf", "grub", "ko",
				"dylib", "pdb", "hdmp", "crash", "cab",
			],
		}
	}
}