#![allow(dead_code)] // this is exported to lib.rs
use clap::{ArgGroup, Parser};
use clap_num::maybe_hex;
use libpt::bintols::split;

pub type Num = u128;

/// formats supported by numf
#[derive(Copy, Clone, Debug)]
pub enum Format {
    Dec,
    Hex,
    Bin,
    Octal,
    Base64,
    Base32,
}

/// Describes what the formatter should do
///
/// Use [Self::default] to get a basic variant or create a object yourself.
///
/// This struct can be parsed with [clap] derive.
#[derive(Parser, Debug, Clone, PartialEq, Eq, Hash)]
#[clap(author, version, about, long_about = None)]
#[command(
    author,
    version,
    about,
    long_about,
    help_template = r#"{about-section}
{usage-heading} {usage}
{all-args}{tab}

{name}: {version}
Author: {author-with-newline}
"#
)]
#[clap(group(
            ArgGroup::new("format")
                .args(&["hex", "bin", "oct", "dec", "base64", "base32"]),
        ))]
pub struct FormatOptions {
    #[arg(short, long)]
    /// add a prefix (like "0x" for hex)
    prefix: bool,
    #[arg(short = 'P', long)]
    /// add a padding to make the number at least one byte long
    ///
    /// For example, `0b1100` will be `0b00001100` with this.
    /// This does not apply to all formats, only hexadecimal and binary.
    padding: bool,
    #[arg(short = 'x', long, default_value_t = true)]
    /// format to hexadecimal
    hex: bool,
    #[arg(short, long)]
    /// format to binary
    bin: bool,
    #[arg(short, long)]
    /// format to decimal
    dec: bool,
    #[arg(short, long)]
    /// format to octal
    oct: bool,
    #[arg(short = 's', long)]
    /// format to base64
    base64: bool,
    #[arg(short = 'z', long)]
    /// format to base32
    base32: bool,
    #[clap(value_parser=maybe_hex::<Num>, required=true)]
    /// at least one number that should be formatted
    ///
    /// supports either base 10 or base 16 inputs (with 0xaaaa)
    numbers: Vec<Num>,
}

impl FormatOptions {
    /// get the format that the user has configured
    pub fn format(&self) -> Format {
        if self.oct {
            Format::Octal
        } else if self.bin {
            Format::Bin
        } else if self.dec {
            Format::Dec
        } else if self.base64 {
            Format::Base64
        } else if self.base32 {
            Format::Base32
        } else if self.hex {
            Format::Hex
        } else {
            unreachable!()
        }
    }

    /// set the format manually
    pub fn set_format(&mut self, format: Format) {
        self.bin = false;
        self.oct = false;
        self.dec = false;
        self.hex = false;
        self.base64 = false;
        self.base32 = false;
        match format {
            Format::Bin => self.bin = true,
            Format::Hex => self.hex = true,
            Format::Octal => self.oct = true,
            Format::Base64 => self.base64 = true,
            Format::Base32 => self.base32 = true,
            Format::Dec => self.dec = true,
        }
    }

    /// get numbers
    pub fn numbers(&self) -> &[u128] {
        self.numbers.as_ref()
    }

    /// set numbers manually
    pub fn set_numbers(&mut self, numbers: Vec<Num>) {
        self.numbers = numbers;
    }

    /// get padding
    pub fn padding(&self) -> bool {
        self.padding
    }

    /// get prefix
    pub fn prefix(&self) -> bool {
        self.prefix
    }
}

impl Default for FormatOptions {
    fn default() -> Self {
        Self {
            padding: false,
            prefix: false,
            oct: false,
            hex: true,
            bin: false,
            base32: false,
            base64: false,
            dec: false,
            numbers: vec![],
        }
    }
}

impl Format {
    pub fn prefix(&self) -> String {
        match self {
            // apperently used nowhere, sometimes 0 is used as a prefix but I
            // think this makes it more clear that this is decimal
            Format::Dec => "0d",
            // very common
            Format::Hex => "0x",
            // very common
            Format::Bin => "0b",
            // somewhat common
            Format::Octal => "0o",
            // perl and a few other programs seem to use this too
            Format::Base64 => "0s",
            // no idea, I made this up
            Format::Base32 => "032s",
        }
        .to_string()
    }
    pub fn format(&self, num: Num, options: &FormatOptions) -> String {
        let mut buf = String::new();
        if options.prefix {
            buf += &self.prefix();
        }
        match self {
            Format::Hex => {
                if options.padding {
                    let tmp = &format!("{num:X}");
                    buf += &("0".repeat((2 - tmp.len() % 2) % 2) + tmp);
                } else {
                    buf += &format!("{num:X}");
                }
            }
            Format::Bin => {
                if options.padding {
                    let tmp = &format!("{num:b}");
                    buf += &("0".repeat((8 - tmp.len() % 8) % 8) + tmp);
                } else {
                    buf += &format!("{num:b}");
                }
            }
            Format::Octal => {
                buf += &format!("{num:o}");
            }
            Format::Dec => {
                buf += &format!("{num}");
            }
            Format::Base64 => buf += &fast32::base64::RFC4648.encode(&split::unsigned_to_vec(num)),
            Format::Base32 => buf += &fast32::base32::RFC4648.encode(&split::unsigned_to_vec(num)),
        }
        buf
    }
}