//! QuickDraw PICT format loader.

use crate::durandal::{bin::*, err::*, image::*};
use generic_array::*;

const PACK_DEFAULT: u16 = 0;
const PACK_NONE   : u16 = 1;
const PACK_NOPAD  : u16 = 2;
const PACK_RLE16  : u16 = 3;
const PACK_RLE32  : u16 = 4;

/// Process a CopyBits operation.
pub fn read_bitmap_area(mut im: Image, b: &[u8], packed: bool, clip: bool) -> ResultS<Image>
{
   let mut p = if !packed {4} else {0};

   let (w, h) = (im.w(), im.h());

   let pitch_fl = b.c_u16b(p   )?;
   let      top = b.c_u16b(p+ 2)? as usize;
   let     left = b.c_u16b(p+ 4)? as usize;
   let   bottom = b.c_u16b(p+ 6)? as usize;
   let    right = b.c_u16b(p+ 8)? as usize;
   //   version = b.c_u16b(p+10)?;
   let pack_typ = b.c_u16b(p+12)?;
   //  pack_siz = b.c_u32b(p+14)?;
   //  horz_dpi = b.c_u32b(p+18)?;
   //  vert_dpi = b.c_u32b(p+22)?;
   //    format = b.c_u16b(p+26)?;
   let    depth = b.c_u16b(p+28)?;
   //    comp_n = b.c_u16b(p+30)?;
   //    comp_d = b.c_u16b(p+32)?;
   //  planeofs = b.c_u32b(p+34)?;
   //   clut_id = b.c_u32b(p+38)?;

   if pitch_fl & 0x8000 == 0 {
      return err_msg("PICT1 not supported");
   }
   if right - left != w || bottom - top != h {
      return err_msg("image bounds are incorrect");
   }

   p += 46; // size of header

   // get CLUT if packed
   let clut = if packed {
      let (clut, sz) = get_clut(&b[p..])?;
      p += sz;
      Some(clut)
   } else {
      None
   };

   p += 18; // srcRect, dstRect, mode

   if clip {p += b.c_u16b(p)? as usize;} // maskRgn

   let rle = pack_typ == PACK_DEFAULT              ||
            (pack_typ == PACK_RLE16 && depth == 16) ||
            (pack_typ == PACK_RLE32 && depth == 32);

   let pitch = (pitch_fl & 0x3fff) as usize;

   match depth {
   1 | 2 | 4 | 8 => {
      let clut = clut.ok_or_else(|| err_msg_v("no clut in indexed mode"))?;
      if pitch < 8 && depth == 8 {
         // uncompressed 8-bit colormap indices
         for _ in 0..h {
            for _ in 0..w {
               im.cr.push(clut[b[(p, p += 1).0] as usize].clone());
            }
         }

         Ok(im)
      } else if rle {
         // RLE compressed 1, 2, 4 or 8 bit colormap indices
         for _ in 0..h {
            let (d, pp) = read_rle(&b[p..], pitch, false)?;
            let d = if depth < 8 {expand_data(d, depth)?} else {d};

            p += pp;

            for x in 0..w {im.cr.push(clut[d[x] as usize].clone());}
         }

         Ok(im)
      }
      else {err_msg("invalid configuration")}
   },
   16 =>
      if pitch < 8 || pack_typ == PACK_NONE {
         // uncompressed R5G5B5
         for _ in 0..h {
            for _ in 0..w {
               im.cr.push(Color::from_r5g5b5(b.c_u16b((p, p += 2).0)?));
            }
         }

         Ok(im)
      } else if rle {
         // RLE compressed R5G5B5
         for _ in 0..h {
            let (d, pp) = read_rle(&b[p..], pitch, true)?;

            p += pp;

            for x in 0..w {im.cr.push(Color::from_r5g5b5(d.c_u16b(x*2)?));}
         }

         Ok(im)
      }
      else {err_msg("invalid configuration")},
   32 =>
      if pitch < 8 || pack_typ == PACK_NONE || pack_typ == PACK_NOPAD {
         // uncompressed RGB8 or XRGB8
         for _ in 0..h {
            for _ in 0..w {
               if pack_typ != PACK_NOPAD {p += 1;}
               let (r, g, b) = (b[p], b[p+1], b[p+2]);
               p += 3;
               im.cr.push(Color{r, g, b, a: 255});
            }
         }

         Ok(im)
      } else if rle {
         // RLE compressed RGB8
         let pitch = pitch - w; // remove padding byte from pitch
         for _ in 0..h {
            let (d, pp) = read_rle(&b[p..], pitch, false)?;

            p += pp;

            for x in 0..w {
               let (r, g, b) = (d[x+w*0], d[x+w*1], d[x+w*2]);
               im.cr.push(Color{r, g, b, a: 255});
            }
         }

         Ok(im)
      }
      else {err_msg("invalid configuration")},
   _ => err_msg("invalid bit depth")
   }
}

/// Process a CompressedQuickTime operation.
pub fn read_quicktime_c(_im: Image, _b: &[u8]) -> ResultS<Image>
{
   err_msg("compressed quicktime format not implemented")
}

/// Load a PICT image.
pub fn load_pict(b: &[u8]) -> ResultS<Image>
{
   //  size = b.c_u16b(0)?;
   //   top = b.c_u16b(2)?;
   //  left = b.c_u16b(4)?;
   let    h = b.c_u16b(6)? as usize;
   let    w = b.c_u16b(8)? as usize;
   let   im = Image::new(w, h);

   let mut p = 10; // size of header

   while p < b.len() {
      let op = b.c_u16b((p, p += 2).0)?;

      match op {
      0x0098 => return read_bitmap_area(im, &b[p..], true,  false), // PackBitsRect
      0x0099 => return read_bitmap_area(im, &b[p..], true,  true ), // PackBitsRgn
      0x009a => return read_bitmap_area(im, &b[p..], false, false), // DirectBitsRect
      0x009b => return read_bitmap_area(im, &b[p..], false, true ), // DirectBitsRgn
      0x8200 => return read_quicktime_c(im, &b[p..]),               // CompressedQuickTime
      0x00ff => break,   // OpEndPic
      // help i'm trapped in an awful metafile format from the 80s
      0x0000 |           // NoOp
      0x001c |           // HiliteMode
      0x001e |           // DefHilite
      0x0038 |           // FrameSameRect
      0x0039 |           // PaintSameRect
      0x003a |           // EraseSameRect
      0x003b |           // InvertSameRect
      0x003c |           // FillSameRect
      0x8000 |           // Reserved
      0x8100 => (),      // Reserved
      0x0003 |           // TxFont
      0x0004 |           // TxFace
      0x0005 |           // TxMode
      0x0008 |           // PnMode
      0x000d |           // TxSize
      0x0011 |           // VersionOp
      0x0015 |           // PnLocHFrac
      0x0016 |           // ChExtra
      0x0023 |           // ShortLineFrom
      0x00a0 |           // ShortComment
      0x02ff => p += 2,  // Version
      0x0006 |           // SpExtra
      0x0007 |           // PnSize
      0x000b |           // OvSize
      0x000c |           // Origin
      0x000e |           // FgCol
      0x000f |           // BkCol
      0x0021 => p += 4,  // LineFrom
      0x001a |           // RGBFgCol
      0x001b |           // RGBBkCol
      0x001d |           // TxRatio
      0x0022 => p += 6,  // ShortLine
      0x0002 |           // BkPat
      0x0009 |           // PnPat
      0x0010 |           // TxRatio
      0x0020 |           // Line
      0x002e |           // GlyphState
      0x0030 |           // FrameRect
      0x0031 |           // PaintRect
      0x0032 |           // EraseRect
      0x0033 |           // InvertRect
      0x0034 => p += 8,  // FillRect
      0x002d => p += 10, // LineJustify
      0x0c00 => p += 24, // HeaderOp
      0x0001 => p += (b.c_u16b(p  )? & !1) as usize,     // Clip
      0x00a1 => p += (b.c_u16b(p+2)? & !1) as usize + 2, // LongComment
      0x100..=
      0x7fff => p += (op >> 8) as usize * 2, // Reserved
      _      => return err_msg("invalid op in PICT")
      }
   }

   err_msg("no image in data")
}

/// Read a colorTable structure.
pub fn get_clut(b: &[u8]) -> ResultS<(Vec<Color>, usize)>
{
   //  sed = b.c_u32b(0)?;
   let dev = b.c_u16b(4)? & 0x8000 != 0;
   let num = b.c_u16b(6)? as usize + 1;

   let mut p = 8;
   let mut clut = vec![Color{r: 0, g: 0, b: 0, a: 0}; num];

   for i in 0..num {
      // with device mapping, we ignore the index entirely
      let n = if !dev {b[p + 1] as usize} else {i};
      let r = b[p+2];
      let g = b[p+4];
      let b = b[p+6];

      if n >= clut.len() {return err_msg("bad clut index");}
      clut[n] = Color{r, g, b, a: 255};

      p += 8;
   }

   Ok((clut, p))
}

/// Read run-length encoded data.
pub fn read_rle(b: &[u8], pitch: usize, ln: bool) -> ResultS<(Vec<u8>, usize)>
{
   let mut p = 0;
   let mut o = Vec::with_capacity(pitch);
   let    sz = if pitch > 250 {(b.c_u16b(0)? as usize + 2, p += 2).0}
               else           {(b[0]         as usize + 1, p += 1).0};

   while p < sz {
      let szf = b[(p, p += 1).0];
      let cmp = szf & 0x80 != 0;
      let len = if cmp {!szf + 2} else {szf + 1} as usize;

      o.reserve(len);

      if ln {read_rle_data(cmp, len, &mut o, || (arr![u8; b[p], b[p+1]], p += 2).0)}
      else  {read_rle_data(cmp, len, &mut o, || (arr![u8; b[p]        ], p += 1).0)}
   }

   if o.len() == pitch {Ok((o, p))}
   else                {err_msg("incorrect size for compressed scanline")}
}

/// Read a sequence of packed RLE data.
fn read_rle_data<F, N>(cmp: bool, len: usize, out: &mut Vec<u8>, mut read: F)
   where F: FnMut() -> GenericArray<u8, N>,
         N: ArrayLength<u8>
{
   if cmp {
      let d = read();
      for _ in 0..len                 {for v in d.iter() {out.push(*v);}}
   } else {
      for _ in 0..len {let d = read(); for v in d.iter() {out.push(*v);}}
   }
}

/// Expand packed pixel data based on bit depth.
pub fn expand_data(b: Vec<u8>, depth: u16) -> ResultS<Vec<u8>>
{
   let mut o = Vec::with_capacity(match depth {
   4 => b.len() * 2,
   2 => b.len() * 4,
   1 => b.len() * 8,
   _ => return err_msg("invalid bit depth")
   });

   for ch in b {
      match depth {
      4 => for i in 1..=0 {o.push(ch >> i * 4 & 0xfu8);}, // 2 nibbles
      2 => for i in 3..=0 {o.push(ch >> i * 2 & 0x3u8);}, // 4 dibits
      1 => for i in 7..=0 {o.push(ch >> i * 1 & 0x1u8);}, // 8 bits
      _ => return err_msg("invalid bit depth")
      }
   }

   Ok(o)
}

// EOF