use byteorder::ReadBytesExt;
use encoding_rs::{SHIFT_JIS, UTF_16LE};
use std::io::Cursor;
use crate::EncodedStringsError;
type Result<T> = std::result::Result<T, EncodedStringsError>;
pub trait EncodedStringReader {
fn read_shift_jis_string(&mut self) -> Result<String>;
fn read_utf_16_string(&mut self) -> Result<String>;
}
fn read_shift_jis_impl<F, E>(mut read_u8: F) -> Result<String>
where
F: FnMut() -> std::result::Result<u8, E>,
{
let mut buffer: Vec<u8> = Vec::new();
loop {
match read_u8() {
Ok(value) => {
if value == 0 {
break;
} else {
buffer.push(value);
}
}
Err(_) => return Err(EncodedStringsError::UnterminatedString),
}
}
let (result, _, has_errors) = SHIFT_JIS.decode(buffer.as_slice());
if has_errors {
Err(EncodedStringsError::DecodingFailed("SHIFT-JIS".to_string()))
} else {
Ok(result.into())
}
}
fn read_utf_16_impl<F, E: std::fmt::Debug>(mut read_u8: F) -> Result<String>
where
F: FnMut() -> std::result::Result<u8, E>,
{
let mut buffer: Vec<u8> = Vec::new();
loop {
let next_byte_result1 = read_u8();
let next_byte_result2 = read_u8();
if next_byte_result1.is_err() || next_byte_result2.is_err() {
return Err(EncodedStringsError::UnterminatedString);
}
let next_byte1 = next_byte_result1.unwrap();
let next_byte2 = next_byte_result2.unwrap();
if next_byte1 == 0 && next_byte2 == 0 {
break;
}
buffer.push(next_byte1);
buffer.push(next_byte2);
}
let (result, _enc, errors) = UTF_16LE.decode(buffer.as_slice());
return if errors {
Err(EncodedStringsError::DecodingFailed("UTF-16".to_string()))
} else {
Ok(result.into())
};
}
impl EncodedStringReader for Cursor<&[u8]> {
fn read_shift_jis_string(&mut self) -> Result<String> {
read_shift_jis_impl(|| self.read_u8())
}
fn read_utf_16_string(&mut self) -> Result<String> {
read_utf_16_impl(|| self.read_u8())
}
}
impl<'a> EncodedStringReader for crate::BinArchiveReader<'a> {
fn read_shift_jis_string(&mut self) -> Result<String> {
let result = read_shift_jis_impl(|| self.read_u8())?;
while self.tell() % 4 != 0 {
self.skip(1);
}
Ok(result)
}
fn read_utf_16_string(&mut self) -> Result<String> {
let result = read_utf_16_impl(|| self.read_u8())?;
while self.tell() % 4 != 0 {
self.skip(1);
}
Ok(result)
}
}
pub fn to_shift_jis(string: &str) -> Result<Vec<u8>> {
let (result, _, has_errors) = SHIFT_JIS.encode(string);
if has_errors {
Err(EncodedStringsError::EncodingFailed(
string.to_string(),
"SHIFT-JIS".to_string(),
))
} else {
Ok(result.into())
}
}
pub fn to_utf_16(string: &str) -> Result<Vec<u8>> {
let bytes: Vec<[u8; 2]> = string.encode_utf16().map(|x| x.to_le_bytes()).collect();
let mut buffer: Vec<u8> = Vec::new();
for entry in bytes {
buffer.push(entry[0]);
buffer.push(entry[1]);
}
Ok(buffer)
}