use anyhow::Result;
use serde::{Deserialize, Serialize};

use super::super::errors::*;
use super::super::sps_datatypes::{BitPosition, DataEvaluation, UnparsedSPSDataType};

#[derive(Debug, Serialize, Deserialize, Copy, Clone, PartialEq, Eq)]
pub struct UDIntType {
    length: u32,
    position: BitPosition,
}
impl UDIntType {
    const LEN: usize = 4;
    pub fn new(byte: u32, bit: Option<u32>) -> Result<Self, Errors> {
        Ok(UDIntType {
            length: Self::LEN as u32,
            position: BitPosition { byte, bit },
        })
    }
}
impl DataEvaluation for UDIntType {
    fn into_unparsed(&self) -> UnparsedSPSDataType {
        UnparsedSPSDataType {
            data_type: self.into_string(),
            data_byte: self.position.byte,
            data_bit: self.position.bit,
            data_length: None,
        }
    }
    fn into_string(&self) -> String {
        "udint".to_string()
    }
    fn get_end_byte(&self) -> u32 {
        self.position.byte + self.length
    }
    fn get_byte_positon(&self) -> u32 {
        self.position.byte
    }
    fn get_length(&self) -> u32 {
        self.length
    }
    fn parse_serial(&self, data: &[&str]) -> Result<String> {
        Ok(data
            .get((self.position.byte) as usize)
            .ok_or_else(|| serial_error(self.into_string(), self.position.byte))?
            .to_string())
    }
    fn parse_s7(&self, data: &[u8]) -> Result<String> {
        let bytes = data
            .get((self.position.byte) as usize..(self.position.byte + self.length) as usize)
            .ok_or_else(|| s7_read_error(self.into_string(), self.position.byte))?;
        let mut slice: [u8; Self::LEN] = Default::default();
        slice.copy_from_slice(bytes);
        let parsed = u32::from_be_bytes(slice);
        Ok(parsed.to_string())
    }

    fn sql_equivalent(&self) -> &str {
        r"BIGINT UNSIGNED DEFAULT 0"
    }
}

#[test]
fn test() {
    const INTPOS: u32 = 5;
    const INT: u32 = 25890920;
    const LEN: usize = 4;
    let test_item = UDIntType::new(INTPOS, None).unwrap();
    let raw_data: [u8; 50] = [255; 50];
    let mut test_vec: Vec<u8> = raw_data.to_vec();
    test_vec.splice(
        INTPOS as usize..INTPOS as usize + LEN,
        INT.to_be_bytes().iter().cloned(),
    );

    let result = match test_item.parse_s7(&test_vec) {
        Ok(res) => res,
        Err(_) => "Error".to_string(),
    };
    assert_eq!(result, INT.to_string())
}