use clap::{App, Arg};

pub fn build() -> App<'static, 'static> {
    App::new("lsd")
        .version(crate_version!())
        .about(crate_description!())
        .arg(Arg::with_name("FILE").multiple(true).default_value("."))
        .arg(
            Arg::with_name("all")
                .short("a")
                .overrides_with("almost-all")
                .long("all")
                .multiple(true)
                .help("Do not ignore entries starting with ."),
        )
        .arg(
            Arg::with_name("almost-all")
                .short("A")
                .overrides_with("all")
                .long("almost-all")
                .multiple(true)
                .help("Do not list implied . and .."),
        )
        .arg(
            Arg::with_name("color")
                .long("color")
                .possible_value("always")
                .possible_value("auto")
                .possible_value("never")
                .default_value("auto")
                .multiple(true)
                .number_of_values(1)
                .help("When to use terminal colours"),
        )
        .arg(
            Arg::with_name("icon")
                .long("icon")
                .possible_value("always")
                .possible_value("auto")
                .possible_value("never")
                .default_value("auto")
                .multiple(true)
                .number_of_values(1)
                .help("When to print the icons"),
        )
        .arg(
            Arg::with_name("icon-theme")
                .long("icon-theme")
                .possible_value("fancy")
                .possible_value("unicode")
                .default_value("fancy")
                .multiple(true)
                .number_of_values(1)
                .help("Whether to use fancy or unicode icons"),
        )
        .arg(
            Arg::with_name("indicators")
                .short("F")
                .long("classify")
                .multiple(true)
                .help("Append indicator (one of */=>@|) at the end of the file names"),
        )
        .arg(
            Arg::with_name("long")
                .short("l")
                .long("long")
                .multiple(true)
                .help("Display extended file metadata as a table"),
        )
        .arg(
            Arg::with_name("oneline")
                .short("1")
                .long("oneline")
                .multiple(true)
                .help("Display one entry per line"),
        )
        .arg(
            Arg::with_name("recursive")
                .short("R")
                .long("recursive")
                .multiple(true)
                .conflicts_with("tree")
                .help("Recurse into directories"),
        )
        .arg(
            Arg::with_name("human_readable")
                .short("h")
                .long("human-readable")
                .help("For ls compatibility purposes ONLY, currently set by default"),
        )
        .arg(
            Arg::with_name("tree")
                .long("tree")
                .multiple(true)
                .conflicts_with("recursive")
                .help("Recurse into directories and present the result as a tree"),
        )
        .arg(
            Arg::with_name("depth")
                .long("depth")
                .multiple(true)
                .takes_value(true)
                .value_name("num")
                .help("Stop recursing into directories after reaching specified depth"),
        )
        .arg(
            Arg::with_name("directory-only")
                .short("d")
                .long("directory-only")
                .conflicts_with("all")
                .conflicts_with("almost-all")
                .conflicts_with("depth")
                .conflicts_with("recursive")
                .conflicts_with("tree")
                .help("Display directories themselves, and not their contents"),
        )
        .arg(
            Arg::with_name("size")
                .long("size")
                .possible_value("default")
                .possible_value("short")
                .possible_value("bytes")
                .default_value("default")
                .multiple(true)
                .number_of_values(1)
                .help("How to display size"),
        )
        .arg(
            Arg::with_name("total-size")
                .long("total-size")
                .multiple(true)
                .help("Display the total size of directories"),
        )
        .arg(
            Arg::with_name("date")
                .long("date")
                .validator(validate_date_argument)
                .default_value("date")
                .multiple(true)
                .number_of_values(1)
                .help("How to display date [possible values: date, relative, +date-time-format]"),
        )
        .arg(
            Arg::with_name("timesort")
                .short("t")
                .long("timesort")
                .multiple(true)
                .help("Sort by time modified"),
        )
        .arg(
            Arg::with_name("sizesort")
                .short("S")
                .long("sizesort")
                .multiple(true)
                .help("Sort by size"),
        )
        .arg(
            Arg::with_name("reverse")
                .short("r")
                .long("reverse")
                .multiple(true)
                .help("Reverse the order of the sort"),
        )
        .arg(
            Arg::with_name("group-dirs")
                .long("group-dirs")
                .possible_value("none")
                .possible_value("first")
                .possible_value("last")
                .default_value("none")
                .multiple(true)
                .number_of_values(1)
                .help("Sort the directories then the files"),
        )
        .arg(
            Arg::with_name("blocks")
                .long("blocks")
                .multiple(true)
                .number_of_values(1)
                .require_delimiter(true)
                .possible_values(&["permission", "user", "group", "size", "date", "name"])
                .help("Specify the blocks that will be displayed and in what order"),
        )
        .arg(
            Arg::with_name("classic")
                .long("classic")
                .help("Enable classic mode (no colors or icons)"),
        )
        .arg(
            Arg::with_name("no-symlink")
                .long("no-symlink")
                .multiple(true)
                .help("Do not display symlink target"),
        )
        .arg(
            Arg::with_name("ignore-glob")
                .short("I")
                .long("ignore-glob")
                .multiple(true)
                .number_of_values(1)
                .value_name("pattern")
                .default_value("")
                .help("Do not display files/directories with names matching the glob pattern(s)"),
        )
}

fn validate_date_argument(arg: String) -> Result<(), String> {
    use std::error::Error;
    if arg.starts_with('+') {
        validate_time_format(&arg).map_err(|err| err.description().to_string())
    } else if &arg == "date" || &arg == "relative" {
        Result::Ok(())
    } else {
        Result::Err("possible values: date, relative, +date-time-format".to_owned())
    }
}

fn validate_time_format(formatter: &str) -> Result<(), time::ParseError> {
    let mut chars = formatter.chars();
    loop {
        match chars.next() {
            Some('%') => match chars.next() {
                Some('A') | Some('a') | Some('B') | Some('b') | Some('C') | Some('c')
                | Some('D') | Some('d') | Some('e') | Some('F') | Some('f') | Some('G')
                | Some('g') | Some('H') | Some('h') | Some('I') | Some('j') | Some('k')
                | Some('l') | Some('M') | Some('m') | Some('n') | Some('P') | Some('p')
                | Some('R') | Some('r') | Some('S') | Some('s') | Some('T') | Some('t')
                | Some('U') | Some('u') | Some('V') | Some('v') | Some('W') | Some('w')
                | Some('X') | Some('x') | Some('Y') | Some('y') | Some('Z') | Some('z')
                | Some('+') | Some('%') => (),
                Some(c) => return Err(time::ParseError::InvalidFormatSpecifier(c)),
                None => return Err(time::ParseError::MissingFormatConverter),
            },
            None => break,
            _ => continue,
        }
    }
    Ok(())
}