use std::io;

use crate::isatty;

use super::colormap::{map_char_to_color, map_u8_to_color};

const GLOBAL_BUFFER_LENGTH: usize = 16;

fn dump_to_hex(bytes: &mut [u8]) -> String {
    let out_vec: Vec<String> = bytes
        .chunks(2)
        .map(|c| {
            if c.len() == 2 {
                format!("{}{}", map_u8_to_color(c[0]), map_u8_to_color(c[1]))
            } else {
                format!("{}  ", map_u8_to_color(c[0]))
            }
        })
        .collect();
    let padding_length = (8 - out_vec.len()) * 5;
    format!("{}{}", out_vec.join(" "), " ".repeat(padding_length))
}

fn dump_to_chr(bytes: &mut [u8]) -> String {
    let out_vec: Vec<String> = bytes.iter().map(|ord| map_char_to_color(*ord)).collect();
    out_vec.join("")
}

pub fn hexdump(mut reader: Box<dyn io::Read>, length: usize) {
    let mut buf = [0; GLOBAL_BUFFER_LENGTH];
    let mut offset: usize = 0;
    let mut bytes_left = length;

    loop {
        let bytes_read = reader.read(&mut buf);
        match bytes_read {
            Ok(num) => {
                let mut to_read = num;
                if num > bytes_left {
                    to_read = bytes_left;
                }
                bytes_left -= to_read;

                if to_read == 0 {
                    break;
                } else {
                    println!(
                        "{:08x}: {:40}{}{:10}",
                        offset,
                        dump_to_hex(&mut buf[0..to_read]),
                        if isatty() { "  ".to_string() } else { " ".to_string() },
                        dump_to_chr(&mut buf[0..to_read])
                    );
                    offset += GLOBAL_BUFFER_LENGTH;
                }
            }
            Err(e) => {
                eprintln!("hd: {}", e);
                break;
            }
        }
    }
}