use std::convert::TryFrom;
use std::io::{Read, Seek};
use crate::tags::Tag;
use crate::{TiffError, TiffFormatError, TiffResult};
use super::ifd::{Directory, Value};
use super::stream::SmartReader;
use super::Limits;
pub(crate) struct TagReader<'a, R: Read + Seek> {
pub reader: &'a mut SmartReader<R>,
pub ifd: &'a Directory,
pub limits: &'a Limits,
pub bigtiff: bool,
}
impl<'a, R: Read + Seek> TagReader<'a, R> {
pub(crate) fn find_tag(&mut self, tag: Tag) -> TiffResult<Option<Value>> {
Ok(match self.ifd.get(&tag) {
Some(entry) => Some(entry.clone().val(self.limits, self.bigtiff, self.reader)?),
None => None,
})
}
pub(crate) fn require_tag(&mut self, tag: Tag) -> TiffResult<Value> {
match self.find_tag(tag)? {
Some(val) => Ok(val),
None => Err(TiffError::FormatError(
TiffFormatError::RequiredTagNotFound(tag),
)),
}
}
pub fn find_tag_uint_vec<T: TryFrom<u64>>(&mut self, tag: Tag) -> TiffResult<Option<Vec<T>>> {
self.find_tag(tag)?
.map(|v| v.into_u64_vec())
.transpose()?
.map(|v| {
v.into_iter()
.map(|u| {
T::try_from(u).map_err(|_| TiffFormatError::InvalidTagValueType(tag).into())
})
.collect()
})
.transpose()
}
}