rawloader 0.10.0

use std::collections::HashMap;
use decoders::basics::*;
use std::str;
use num::FromPrimitive;

enum_from_primitive! {
#[derive(Debug, Copy, Clone, PartialEq)]
pub enum Tag {
  ImageWidth     = 0x0100,
  ImageLength    = 0x0101,
  BitsPerSample  = 0x0102,
  Compression    = 0x0103,
  Make           = 0x010F,
  Model          = 0x0110,
  StripOffsets   = 0x0111,
  StripByteCounts= 0x0117,
  SubIFDs        = 0x014A,
  SonyCurve      = 0x7010,
  SonyOffset     = 0x7200,
  SonyLength     = 0x7201,
  SonyKey        = 0x7221,
  SonyGRBG       = 0x7303,
  SonyRGGB       = 0x7313,
  ExifIFDPointer = 0x8769,
  DNGPrivateArea = 0xC634,
}
}
                          // 0-1-2-3-4-5-6-7-8-9-10-11-12-13
const DATASHIFTS: [u8;14] = [0,0,0,1,2,3,0,0,1,2, 3, 2, 3, 2];

fn t (tag: Tag) -> u16 {
  tag as u16
}

#[derive(Debug, Copy, Clone)]
pub struct TiffEntry<'a> {
  tag: u16,
  typ: u16,
  count: u32,
  data: &'a [u8],
  endian: Endian,
}

#[derive(Debug, Clone)]
pub struct TiffIFD<'a> {
  entries: HashMap<u16,TiffEntry<'a>>,
  subifds: Vec<TiffIFD<'a>>,
  nextifd: usize,
  endian: Endian,
}

impl<'a> TiffIFD<'a> {
  pub fn new_root(buf: &'a[u8], offset: usize, depth: u32, e: Endian) -> TiffIFD<'a> {
    let mut subifds = Vec::new();
    let mut nextifd = e.ru32(buf, offset) as usize;

    for _ in 0..100 { // Never read more than 100 IFDs
      let ifd = TiffIFD::new(buf, nextifd, 0, depth, e).unwrap();
      nextifd = ifd.nextifd;
      subifds.push(ifd);
      if nextifd == 0 {
        break
      }
    }

    TiffIFD {
      entries: HashMap::new(),
      subifds: subifds,
      nextifd: 0,
      endian: e,
    }
  }

  pub fn new(buf: &'a[u8], offset: usize, base_offset: usize, depth: u32, e: Endian) -> Result<TiffIFD<'a>, String> {
    let mut entries = HashMap::new();
    let mut subifds = Vec::new();

    let num = e.ru16(buf, offset); // Directory entries in this IFD
    if num > 4000 {
      return Err("too many entries in IFD".to_string())
    }
    for i in 0..num {
      let entry_offset: usize = offset + 2 + (i as usize)*12;
      if Tag::from_u16(e.ru16(buf, entry_offset)).is_none() {
        // Skip entries we don't know about to speedup decoding
        continue;
      }
      let entry = TiffEntry::new(buf, entry_offset, base_offset, e);

      if entry.tag == t(Tag::SubIFDs) || entry.tag == t(Tag::ExifIFDPointer) {
        if depth < 10 { // Avoid infinite looping IFDs
          for i in 0..entry.count {
            let ifd = TiffIFD::new(buf, entry.get_u32(i as usize) as usize, base_offset, depth+1, e);
            match ifd {
              Ok(val) => {subifds.push(val);},
              Err(_) => {entries.insert(entry.tag, entry);}, // Ignore unparsable IFDs
            }
          }
        }
      } else {
        entries.insert(entry.tag, entry);
      }
    }

    Ok(TiffIFD {
      entries: entries,
      subifds: subifds,
      nextifd: e.ru32(buf, offset + (2+num*12) as usize) as usize,
      endian: e,
    })
  }

  pub fn find_entry(&self, tag: Tag) -> Option<&TiffEntry> {
    if self.entries.contains_key(&t(tag)) {
      self.entries.get(&t(tag))
    } else {
      for ifd in &self.subifds {
        match ifd.find_entry(tag) {
          Some(x) => return Some(x),
          None => {},
        }
      }
      None
    }
  }

  pub fn find_ifds_with_tag(&self, tag: Tag) -> Vec<&TiffIFD> {
    let mut ifds = Vec::new();
    for ifd in &self.subifds {
      if ifd.entries.contains_key(&t(tag)) {
        ifds.push(ifd);
      }
      ifds.extend(ifd.find_ifds_with_tag(tag));
    }
    ifds
  }
}

impl<'a> TiffEntry<'a> {
  pub fn new(buf: &'a[u8], offset: usize, base_offset: usize, e: Endian) -> TiffEntry<'a> {
    let tag = e.ru16(buf, offset);
    let mut typ = e.ru16(buf, offset+2);
    let count = e.ru32(buf, offset+4);

    // If we don't know the type assume byte data
    if typ == 0 || typ > 13 {
      typ = 1;
    }

    let bytesize: usize = (count as usize) << DATASHIFTS[typ as usize];
    let doffset: usize = if bytesize <= 4 {
      (offset + 8)
    } else {
      (e.ru32(buf, offset+8) as usize) - base_offset
    };

    TiffEntry {
      tag: tag,
      typ: typ,
      count: count,
      data: &buf[doffset .. doffset+bytesize],
      endian: e,
    }
  }

  pub fn get_u32(&self, idx: usize) -> u32 {
    self.endian.ru32(self.data, idx*4)
  }

  pub fn get_u16(&self, idx: usize) -> u16 {
    self.endian.ru16(self.data, idx*2)
  }

  pub fn get_str(&self) -> &str {
    match str::from_utf8(&self.data[0..self.data.len()-1]) {
      Result::Ok(val) => val.trim(),
      Result::Err(err) => panic!(err),
    }
  }
}