moros/src/usr/help.rs

use crate::api::console::Style;
use crate::api::process::ExitCode;

pub fn main(args: &[&str]) -> Result<(), ExitCode> {
    match args.len() {
        1 => help_summary(),
        2 => help_command(args[1]),
        _ => {
            help();
            Err(ExitCode::UsageError)
        }
    }
}

fn help_command(cmd: &str) -> Result<(), ExitCode> {
    match cmd {
        "-h" | "--help" => { help(); Ok(()) },
        "date" => help_date(),
        "edit" => help_edit(),
        _      => help_unknown(cmd),
    }
}

fn help_unknown(cmd: &str) -> Result<(), ExitCode> {
    error!("Help not found for command '{}'", cmd);
    Err(ExitCode::Failure)
}

fn print_usage(alias: &str, command: &str, usage: &str) {
    let csi_col1 = Style::color("LightGreen");
    let csi_col2 = Style::color("LightCyan");
    let csi_reset = Style::reset();
    println!("  {}{}{}{:21}{}{}", csi_col1, alias, csi_col2, command, csi_reset, usage);
}

fn help_summary() -> Result<(), ExitCode> {
    let csi_color = Style::color("Yellow");
    let csi_reset = Style::reset();

    println!("{}Usage:{}", csi_color, csi_reset);
    print_usage("",  "<dir>",            " Change directory");
    print_usage("",  "<cmd>",            " Execute command");
    println!();

    println!("{}Commands:{}", csi_color, csi_reset);
    print_usage("c", "opy <file> <file>",    "Copy file from source to destination");
    print_usage("d", "elete <file>",         "Delete file or empty directory");
    print_usage("e", "dit <file>",           "Edit existing or new file");
    print_usage("f", "ind <str> <path>",     "Find pattern in path");
    print_usage("h", "elp <cmd>",            "Display help about a command");
    print_usage("l", "ist <dir>",            "List entries in directory");
    print_usage("m", "ove <file> <file>",    "Move file from source to destination");
    print_usage("p", "rint <str>",           "Print string to screen");
    print_usage("q", "uit",                  "Quit the console");
    print_usage("r", "ead <file>",           "Read file to screen");
    print_usage("w", "rite <file>",          "Write file or directory");
    println!();

    println!("{}Credits:{}", csi_color, csi_reset);
    println!("  Made with <3 in 2019-2023 by Vincent Ollivier <v@vinc.cc>");
    Ok(())
}

fn help_edit() -> Result<(), ExitCode> {
    let csi_color = Style::color("Yellow");
    let csi_reset = Style::reset();
    println!("MOROS text editor is a very simple editor inspired by Pico, Nano, and Micro.");
    println!();
    println!("{}Commands:{}", csi_color, csi_reset);
    let commands = [
        ("^Q", "Quit editor"),
        ("^W", "Write to file"),
        ("^X", "Write to file and quit"),
        ("^T", "Go to top of file"),
        ("^B", "Go to bottom of file"),
        ("^A", "Go to beginning of line"),
        ("^E", "Go to end of line"),
        ("^D", "Cut line"),
        ("^Y", "Copy line"),
        ("^P", "Paste line"),
    ];
    for (command, usage) in &commands {
        let csi_color = Style::color("LightCyan");
        let csi_reset = Style::reset();
        println!("  {}{}{}    {}", csi_color, command, csi_reset, usage);
    }
    Ok(())
}

fn help_date() -> Result<(), ExitCode> {
    let csi_color = Style::color("Yellow");
    let csi_reset = Style::reset();
    println!("The date command's formatting behavior is based on strftime from C.");
    println!();
    println!("{}Specifiers:{}", csi_color, csi_reset);
    let specifiers = [
        ("%a", "Abbreviated weekday name", "Thu"),
        ("%A", "Full weekday name", "Thursday"),
        ("%b", "Abbreviated month name", "Aug"),
        ("%B", "Full month name", "August"),
        ("%c", "Date and time representation, equivalent to %a %b %-d %-H:%M:%S %-Y", "Thu Aug 23 14:55:02 2001"),
        ("%C", "Year divided by 100 and truncated to integer (00-99)", "20"),
        ("%d", "Day of the month, zero-padded (01-31)", "23"),
        ("%D", "Short MM/DD/YY date, equivalent to %-m/%d/%y", "8/23/01"),
        ("%F", "Short YYYY-MM-DD date, equivalent to %-Y-%m-%d", "2001-08-23"),
        ("%g", "Week-based year, last two digits (00-99)", "01"),
        ("%G", "Week-based year", "2001"),
        ("%H", "Hour in 24h format (00-23)", "14"),
        ("%I", "Hour in 12h format (01-12)", "02"),
        ("%j", "Day of the year (001-366)", "235"),
        ("%m", "Month as a decimal number (01-12)", "08"),
        ("%M", "Minute (00-59)", "55"),
        ("%N", "Subsecond nanoseconds. Always 9 digits", "012345678"),
        ("%p", "am or pm designation", "pm"),
        ("%P", "AM or PM designation", "PM"),
        ("%r", "12-hour clock time, equivalent to %-I:%M:%S %p", "2:55:02 pm"),
        ("%R", "24-hour HH:MM time, equivalent to %-H:%M", "14:55"),
        ("%S", "Second (00-59)", "02"),
        ("%T", "24-hour clock time with seconds, equivalent to %-H:%M:%S", "14:55:02"),
        ("%u", "ISO 8601 weekday as number with Monday as 1 (1-7)", "4"),
        ("%U", "Week number with the first Sunday as the start of week one (00-53)", "33"),
        ("%V", "ISO 8601 week number (01-53)", "34"),
        ("%w", "Weekday as a decimal number with Sunday as 0 (0-6)", "4"),
        ("%W", "Week number with the first Monday as the start of week one (00-53)", "34"),
        ("%y", "Year, last two digits (00-99)", "01"),
        ("%Y", "Full year, including + if ≥10,000", "2001"),
        ("%z", "ISO 8601 offset from UTC in timezone (+HHMM)", "+0100"),
        ("%%", "Literal %", "%"),
    ];
    for (specifier, usage, _exemple) in &specifiers {
        let csi_color = Style::color("LightCyan");
        let csi_reset = Style::reset();
        println!("  {}{}{}    {}", csi_color, specifier, csi_reset, usage);
    }
    Ok(())
}

fn help() {
    let csi_option = Style::color("LightCyan");
    let csi_title = Style::color("Yellow");
    let csi_reset = Style::reset();
    println!("{}Usage:{} help {}[<command>]{}", csi_title, csi_reset, csi_option, csi_reset);
}