/*
 * File: src/utils.rs
 * Date: 30.09.2018
 * Author: MarkAtk
 * 
 * MIT License
 * 
 * Copyright (c) 2018 MarkAtk
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is furnished to do
 * so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

use std::str;

/// Text format type for radix string conversion.
#[derive(PartialEq, Debug, Copy, Clone)]
pub enum TextFormat {
    /// Text format
    Text,
    /// Binary format
    Binary = 2,
    /// Octal format
    Octal = 8,
    /// Decimal format
    Decimal = 10,
    /// Hexadecimal format
    Hex = 16
}

/// Newline format type
#[derive(Debug, Copy, Clone, PartialEq)]
pub enum NewlineFormat {
    None,
    CarriageReturn,
    LineFeed,
    Both
}

// TODO: Replace String error type with proper error
/// Convert a hexadecimal string into a vector of bytes.
///
/// Leading 0x and whitespaces will be ignored.
pub fn bytes_from_hex_string(original_text: &str) -> Result<Vec<u8>, String> {
    let mut text = original_text.replace("0x", "");
    text = text.replace(" ", "");

    bytes_from_radix_string(&text, 16)
}

/// Convert a binary string into a vector of bytes.
///
/// Leading 0b and whitespaces will be ignored.
pub fn bytes_from_binary_string(original_text: &str) -> Result<Vec<u8>, String> {
    let mut text = original_text.replace("0b", "");
    text = text.replace(" ", "");

    bytes_from_radix_string(&text, 2)
}

/// Convert a octal string into a vector of bytes
///
/// Leading 0 and whitespaces will be ignored.
pub fn bytes_from_octal_string(original_text: &str) -> Result<Vec<u8>, String> {
    let mut text = original_text.replace(" ", "");
    if text.starts_with('0') {
        text.remove(0);
    }

    bytes_from_radix_string(&text, 8)
}

/// Convert a decimal string into a vector of bytes
///
/// Whitespaces will be ignored
pub fn bytes_from_decimal_string(original_text: &str) -> Result<Vec<u8>, String> {
    let text = original_text.replace(" ", "");

    bytes_from_radix_string(&text, 10)
}

/// Convert a radix string into a vector of bytes.
///
/// Leading and trailing whitespaces will result in an error. Conversion happens by 2 characters per byte.
pub fn bytes_from_radix_string(text: &str, radix: u32) -> Result<Vec<u8>, String> {
    let mut bytes: Vec<u8> = Vec::new();

    let mut chars = text.chars().peekable();

    while chars.peek().is_some() {
        let chunk: String = chars.by_ref().take(2).collect();

        match u8::from_str_radix(&chunk, radix) {
            Ok(value) => bytes.push(value),
            Err(e) => return Err(format!("Unable to read input string: {}", e))
        };
    }

    Ok(bytes)
}

/// Convert a vector of bytes into a radix string with given text format.
pub fn radix_string(buffer: &[u8], text_format: &TextFormat) -> String {
    if *text_format == TextFormat::Text {
        // TODO: Handle error state
        return match str::from_utf8(buffer) {
            Ok(text) => text.to_string(),
            Err(_) => String::new()
        };
    }

    let mut text = String::new();

    for b in buffer {
        match text_format {
            TextFormat::Binary => text.push_str(format!("{:08b}", b).as_str()),
            TextFormat::Octal => text.push_str(format!("{:04o}", b).as_str()),
            TextFormat::Decimal => text.push_str(format!("{}", b).as_str()),
            TextFormat::Hex => text.push_str(format!("{:02X}", b).as_str()),
            _ => ()
        };
    }

    text
}

/// Print a vector of bytes in given format.
///
/// Depending on the format newlines will be inserted after some entries as followed:
/// - Binary: 10
/// - Octal: 16
/// - Decimal: 18
/// - Hexadecimal: 20
///
/// Row entries will contain the number of entries in the last row after execution.
pub fn print_radix_string(buffer: &[u8], text_format: &TextFormat, row_entries: &mut u32) {
    let max_row_entries = match text_format {
        TextFormat::Binary => 10,
        TextFormat::Octal => 16,
        TextFormat::Decimal => 18,
        TextFormat::Hex => 20,
        _ => 0
    };

    for b in buffer {
        match text_format {
            TextFormat::Binary => print!("{:#b} ", b),
            TextFormat::Octal => print!("{:#o} ", b),
            TextFormat::Hex => print!("0x{:02X} ", b),
            _ => print!("{}", b)
        };

        *row_entries += 1;
        if max_row_entries > 0 && *row_entries > max_row_entries {
            *row_entries = 0;

            println!();
        }
    }
}

/// Escape given string
///
/// Characters escaped are: \r, \n, \t
pub fn escape_text(text: String) -> String {
    let mut text = text.replace("\\r", "\r");
    text = text.replace("\\n", "\n");
    text = text.replace("\\t", "\t");

    text
}