use super::DBError;
use std::{collections::HashMap, fmt, str};

#[derive(Clone)]
pub enum CacheType {
    Raw(String),
}

impl CacheType {
    fn entry_type(&self) -> String {
        match self {
            CacheType::Raw(_) => "Raw".to_string(),
        }
    }

    pub fn to_bytes(&self) -> Vec<u8> {
        let mut output = self.entry_type().into_bytes();
        output.push(0);
        match self {
            CacheType::Raw(s) => output.append(&mut s.as_bytes().to_vec()),
        }
        return output;
    }

    pub fn from_bytes(data: Vec<u8>) -> CacheType {
        let mut data_iter = data.iter();
        let mut holder: u8 = *data_iter.next().unwrap();
        while holder != 0 {
            holder = *data_iter.next().unwrap();
        }
        let mut output: Vec<u8> = Vec::new();
        for letter in data_iter {
            output.push(letter.clone());
        }
        CacheType::Raw(str::from_utf8(&output).unwrap().to_string())
    }
}

impl fmt::Display for CacheType {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            CacheType::Raw(s) => write!(f, "{}", s),
        }
    }
}

#[cfg(test)]
mod raw {
    use super::*;

    #[test]
    fn get_bytes() {
        let data = "addams";
        let holder = CacheType::Raw(data.to_string());
        let mut expected = holder.entry_type().into_bytes();
        expected.push(0);
        expected.append(&mut data.as_bytes().to_vec());
        let output = holder.to_bytes();
        assert_eq!(output, expected);
    }

    #[test]
    fn from_bytes() {
        let holder = CacheType::Raw("stored item".to_string());
        let data = holder.to_bytes();
        let output = CacheType::from_bytes(data);
        assert_eq!(output.to_string(), holder.to_string());
    }
}

#[cfg(test)]
mod enum_ctype {
    use super::*;

    #[test]
    fn get_raw_type() {
        let holder = CacheType::Raw("nothing important".to_string());
        assert_eq!(holder.entry_type(), "Raw");
    }
}