use serde::{Deserialize, Serialize};
use std::fmt::{Display, Formatter};
use std::io::{BufRead, BufReader, Error, Read};
use std::num::ParseIntError;
use std::path::Path;
use std::str::FromStr;
use std::string::FromUtf8Error;

#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum InputTypes {
    Array,
    String,
    Binary,
}

impl FromStr for InputTypes {
    type Err = String;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let s = s.to_lowercase();

        match s.as_str() {
            "array" | "a" => Ok(Self::Array),
            "string" | "s" => Ok(Self::String),
            "binary" | "b" => Ok(Self::Binary),
            _ => Err(format!("Invalid input type '{}'", s)),
        }
    }
}

impl InputTypes {
    fn parse_byte_default(element: &str) -> Result<u8, ParseIntError> {
        if element.starts_with("0x") || element.starts_with("0X") {
            u8::from_str_radix(&element[2..], 16)
        } else if element.starts_with("0b") || element.starts_with("0B") {
            u8::from_str_radix(&element[2..], 2)
        } else if element.starts_with('h') || element.starts_with('H') {
            u8::from_str_radix(&element[1..], 16)
        } else if element.len() > 1 && element.starts_with('0') {
            u8::from_str_radix(&element[1..], 8)
        } else {
            element.parse()
        }
    }

    fn parse_byte_base(element: &str, base: u32) -> Result<u8, ParseIntError> {
        u8::from_str_radix(element, base)
    }

    fn parse_array(elements: Vec<String>, base: Option<u32>) -> Result<Vec<u8>, ParseIntError> {
        elements
            .iter()
            .map(|element| {
                if let Some(base) = base {
                    Self::parse_byte_base(element, base)
                } else {
                    Self::parse_byte_default(element)
                }
            })
            .collect()
    }

    pub fn parse_arg_input(
        &self,
        src: Vec<String>,
        base: Option<u32>,
    ) -> Result<Vec<u8>, ByteArrayParseErr> {
        if src.is_empty() {
            return Err(ByteArrayParseErr::EmptySrcArray);
        }

        let str_arr = if src.len() == 1 {
            src[0]
                .replace(',', " ")
                .replace('[', "")
                .replace(']', "")
                .split_whitespace()
                .map(|s| s.to_string())
                .collect()
        } else {
            src
        };

        let data = match self {
            InputTypes::Array => Self::parse_array(str_arr, base)?,
            InputTypes::String => str_arr.join(" ").as_bytes().to_vec(),
            InputTypes::Binary => return Err(ByteArrayParseErr::UnsupportedFormat),
        };

        Ok(data)
    }

    #[allow(clippy::unused_io_amount)]
    fn parse_data_from_file(
        &self,
        mut buf_reader: Box<dyn BufRead>,
        base: Option<u32>,
    ) -> Result<Vec<u8>, ByteArrayParseErr> {
        let mut data: Vec<u8> = Vec::new();
        let mut done = false;

        while !done {
            let mut buf: Vec<u8> = vec![0; 2048];
            let len = buf_reader.read(&mut buf)?;

            if len < buf.len() {
                buf.truncate(len);
                data.append(&mut buf);
                done = true;
            } else if len > 0 {
                data.append(&mut buf);
            } else {
                done = true;
            }
        }

        match self {
            InputTypes::Array | InputTypes::String => {
                let str_data = String::from_utf8(data)?;
                self.parse_arg_input(vec![str_data], base)
            }
            InputTypes::Binary => Ok(data),
        }
    }

    pub fn parse_file(
        &self,
        file_path: &Path,
        base: Option<u32>,
    ) -> Result<Vec<u8>, ByteArrayParseErr> {
        let reader = Box::new(BufReader::new(std::fs::File::open(file_path)?));
        self.parse_data_from_file(reader, base)
    }

    pub fn parse_stdin(&self, base: Option<u32>) -> Result<Vec<u8>, ByteArrayParseErr> {
        let reader = Box::new(BufReader::new(std::io::stdin()));
        self.parse_data_from_file(reader, base)
    }
}

#[derive(Debug)]
pub enum ByteArrayParseErr {
    EmptySrcArray,
    ParseIntError(ParseIntError),
    UnsupportedFormat,
    FileError(std::io::Error),
    ParseStringError(FromUtf8Error),
}

impl From<ParseIntError> for ByteArrayParseErr {
    fn from(e: ParseIntError) -> Self {
        ByteArrayParseErr::ParseIntError(e)
    }
}

impl From<std::io::Error> for ByteArrayParseErr {
    fn from(e: Error) -> Self {
        Self::FileError(e)
    }
}

impl From<FromUtf8Error> for ByteArrayParseErr {
    fn from(e: FromUtf8Error) -> Self {
        Self::ParseStringError(e)
    }
}

impl Display for ByteArrayParseErr {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        let err_msg = match self {
            ByteArrayParseErr::EmptySrcArray => "Provided array is empty!".to_string(),
            ByteArrayParseErr::ParseIntError(e) => format!("Failed to parse as int: {}", e),
            ByteArrayParseErr::UnsupportedFormat => {
                "Format is not support with the supplied input type".to_string()
            }
            ByteArrayParseErr::FileError(e) => format!("Unable to parse file: {}", e),
            ByteArrayParseErr::ParseStringError(e) => format!("Unable to parse string: {}", e),
        };

        write!(f, "{}", err_msg)
    }
}

#[cfg(test)]
mod tests {
    use crate::parser::InputTypes;

    #[test]
    fn parse_base_10_array() {
        let array = vec!["[0, 1, 2, 3, 4]".to_string()];

        let out = InputTypes::Array.parse_arg_input(array, None).unwrap();

        assert_eq!(out, vec![0, 1, 2, 3, 4])
    }

    #[test]
    fn parse_base_2_array() {
        let array = vec!["[0b0, 0b1, 0b10, 0b11, 0b100]".to_string()];

        let out = InputTypes::Array.parse_arg_input(array, None).unwrap();

        assert_eq!(out, vec![0, 1, 2, 3, 4])
    }

    #[test]
    fn parse_base_8_array() {
        let array = vec!["[00, 01, 02, 03, 04]".to_string()];

        let out = InputTypes::Array.parse_arg_input(array, None).unwrap();

        assert_eq!(out, vec![0, 1, 2, 3, 4])
    }

    #[test]
    fn parse_base_16_array() {
        let array = vec!["[0x0, 0x1, 0x2, h3, H4]".to_string()];

        let out = InputTypes::Array.parse_arg_input(array, None).unwrap();

        assert_eq!(out, vec![0, 1, 2, 3, 4])
    }

    #[test]
    fn parse_base_mixed() {
        let array = vec!["[00 0x1, 2, h3, H4]".to_string()];

        let out = InputTypes::Array.parse_arg_input(array, None).unwrap();

        assert_eq!(out, vec![0, 1, 2, 3, 4])
    }

    #[test]
    fn parse_no_braces_multi_args() {
        let array = vec![
            "0".to_string(),
            "1".to_string(),
            "2".to_string(),
            "3".to_string(),
            "4".to_string(),
        ];
        let out = InputTypes::Array.parse_arg_input(array, None).unwrap();

        assert_eq!(out, vec![0, 1, 2, 3, 4])
    }

    #[test]
    fn parse_no_braces_one_arg() {
        let array = vec!["0 1 2 3 4".to_string()];
        let out = InputTypes::Array.parse_arg_input(array, None).unwrap();

        assert_eq!(out, vec![0, 1, 2, 3, 4])
    }

    #[test]
    fn parse_string() {
        let string = "Hello World!";

        let out = InputTypes::String
            .parse_arg_input(vec![string.to_string()], None)
            .unwrap();

        assert_eq!(string.as_bytes(), out)
    }
}