use std::{
    fs::File,
    io::{self, Read},
    path::Path,
};

/// Validates a WAD file to make sure that it is a legitimate file
///
/// Parameters:
/// - path: &str - Path to the WAD to validate
pub fn validate_wad(path: &str) -> io::Result<bool> {
    let wad_file = Path::new(path);

    // Check to see if the WAD exists
    if !(wad_file.exists()) {
        // Return back false because we didn't pass a valid file
        return Ok(false);
    }

    // If the file exists open it and read the first 4 bytes
    // of the file and see if we get "IWAD" or "PWAD"
    let mut file = File::open(wad_file)?;
    let mut magic = [0u8; 4];
    file.read_exact(&mut magic)?;

    // Now we return based on what we found
    Ok(magic == *b"IWAD" || magic == *b"PWAD")
}

pub fn read_ascii(bytes: &[u8]) -> String {
    std::str::from_utf8(&bytes[..bytes.len()])
        .unwrap_or("")
        .trim_end_matches('\0')
        .to_string()
}

pub fn read_u32_le(bytes: &[u8]) -> u32 {
    if bytes.len() < 4 {
        0
    } else {
        u32::from_le_bytes(bytes[..4].try_into().unwrap())
    }
}

pub fn read_i16_le(bytes: &[u8]) -> i16 {
    if bytes.len() < 2 {
        0
    } else {
        i16::from_le_bytes(bytes[..2].try_into().unwrap())
    }
}