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

use crate::extension_set::ExtensionSet;
use crate::string_type::String as StringType;
use cfg_if::cfg_if;
use clap::{AppSettings, Clap};
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.
	Sh,
	/// A PowerShell script.
	PowerShell,
	/// Also a PowerShell script, with different casing to allow for `fif -o powershell`.
	Powershell,
	/// Plain text.
	Text,
}

// 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 {
	/// Only examine files with these extensions (Comma-separated list).
	/// This argument conflicts with `-E`.
	#[clap(short, long, use_delimiter = true, require_delimiter = true, group = "extensions")]
	pub exts: Option<Vec<StringType>>,

	/// Use a preset list of extensions as the search filter.
	/// `media` includes all extensions from the `audio`, `video`, and `images` sets. This argument conflicts with `-e`.
	#[clap(short = 'E', long, arg_enum, group = "extensions")]
	pub ext_set: Option<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)]
	pub output_format: OutputFormat,

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

	/// The directory to process.
	// TODO: right now this can only take a single directory - should this be improved?
	#[clap(name = "DIR", default_value = ".", parse(from_os_str))]
	pub dirs: PathBuf,
}

/// 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 {
	pub fn extensions(&self) -> Option<Vec<&str>> {
		if let Some(exts) = &self.exts {
			// extensions supplied like "-e png,jpg,jpeg"
			Some(exts.iter().map(|s| s.as_str()).collect())
		} else if let Some(exts) = &self.ext_set {
			// extensions supplied like "-E images"
			Some(exts.extensions())
		} else {
			// neither -E nor -e was passed
			None
		}
	}

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