/*

 * Copyright © 2009,2010  Red Hat, Inc.

 * Copyright © 2010,2011,2012,2013  Google, Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Red Hat Author(s): Behdad Esfahbod

 * Google Author(s): Behdad Esfahbod

 */

#ifndef HB_OT_MAP_PRIVATE_HH

#define HB_OT_MAP_PRIVATE_HH

#include "hb-buffer-private.hh"

struct hb_ot_shape_plan_t;

static const hb_tag_t table_tags[2] = {HB_OT_TAG_GSUB, HB_OT_TAG_GPOS};

struct hb_ot_map_t

{

  friend struct hb_ot_map_builder_t;

  public:

  struct feature_map_t {

    hb_tag_t tag; /* should be first for our bsearch to work */

    unsigned int index[2]; /* GSUB/GPOS */

    unsigned int stage[2]; /* GSUB/GPOS */

    unsigned int shift;

    hb_mask_t mask;

    hb_mask_t _1_mask; /* mask for value=1, for quick access */

    unsigned int needs_fallback : 1;

    unsigned int auto_zwnj : 1;

    unsigned int auto_zwj : 1;

    static int cmp (const feature_map_t *a, const feature_map_t *b)

    { return a->tag < b->tag ? -1 : a->tag > b->tag ? 1 : 0; }

  };

  struct lookup_map_t {

    unsigned short index;

    unsigned short auto_zwnj : 1;

    unsigned short auto_zwj : 1;

    hb_mask_t mask;

    static int cmp (const lookup_map_t *a, const lookup_map_t *b)

    { return a->index < b->index ? -1 : a->index > b->index ? 1 : 0; }

  };

  typedef void (*pause_func_t) (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer);

  struct stage_map_t {

    unsigned int last_lookup; /* Cumulative */

    pause_func_t pause_func;

  };

  hb_ot_map_t (void) { memset (this, 0, sizeof (*this)); }

  inline hb_mask_t get_global_mask (void) const { return global_mask; }

  inline hb_mask_t get_mask (hb_tag_t feature_tag, unsigned int *shift = NULL) const {

    const feature_map_t *map = features.bsearch (&feature_tag);

    if (shift) *shift = map ? map->shift : 0;

    return map ? map->mask : 0;

  }

  inline bool needs_fallback (hb_tag_t feature_tag) const {

    const feature_map_t *map = features.bsearch (&feature_tag);

    return map ? map->needs_fallback : false;

  }

  inline hb_mask_t get_1_mask (hb_tag_t feature_tag) const {

    const feature_map_t *map = features.bsearch (&feature_tag);

    return map ? map->_1_mask : 0;

  }

  inline unsigned int get_feature_index (unsigned int table_index, hb_tag_t feature_tag) const {

    const feature_map_t *map = features.bsearch (&feature_tag);

    return map ? map->index[table_index] : HB_OT_LAYOUT_NO_FEATURE_INDEX;

  }

  inline unsigned int get_feature_stage (unsigned int table_index, hb_tag_t feature_tag) const {

    const feature_map_t *map = features.bsearch (&feature_tag);

    return map ? map->stage[table_index] : (unsigned int) -1;

  }

  inline void get_stage_lookups (unsigned int table_index, unsigned int stage,

				 const struct lookup_map_t **plookups, unsigned int *lookup_count) const {

    if (unlikely (stage == (unsigned int) -1)) {

      *plookups = NULL;

      *lookup_count = 0;

      return;

    }

    assert (stage <= stages[table_index].len);

    unsigned int start = stage ? stages[table_index][stage - 1].last_lookup : 0;

    unsigned int end   = stage < stages[table_index].len ? stages[table_index][stage].last_lookup : lookups[table_index].len;

    *plookups = end == start ? NULL : &lookups[table_index][start];

    *lookup_count = end - start;

  }

  HB_INTERNAL void collect_lookups (unsigned int table_index, hb_set_t *lookups) const;

  template <typename Proxy>

  HB_INTERNAL inline void apply (const Proxy &proxy,

				 const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;

  HB_INTERNAL void substitute (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;

  HB_INTERNAL void position (const struct hb_ot_shape_plan_t *plan, hb_font_t *font, hb_buffer_t *buffer) const;

  inline void finish (void) {

    features.finish ();

    for (unsigned int table_index = 0; table_index < 2; table_index++)

    {

      lookups[table_index].finish ();

      stages[table_index].finish ();

    }

  }

  public:

  hb_tag_t chosen_script[2];

  bool found_script[2];

  private:

  hb_mask_t global_mask;

  hb_prealloced_array_t<feature_map_t, 8> features;

  hb_prealloced_array_t<lookup_map_t, 32> lookups[2]; /* GSUB/GPOS */

  hb_prealloced_array_t<stage_map_t, 4> stages[2]; /* GSUB/GPOS */

};

enum hb_ot_map_feature_flags_t {

  F_NONE		= 0x0000u,

  F_GLOBAL		= 0x0001u, /* Feature applies to all characters; results in no mask allocated for it. */

  F_HAS_FALLBACK	= 0x0002u, /* Has fallback implementation, so include mask bit even if feature not found. */

  F_MANUAL_ZWNJ		= 0x0004u, /* Don't skip over ZWNJ when matching **context**. */

  F_MANUAL_ZWJ		= 0x0008u, /* Don't skip over ZWJ when matching **input**. */

  F_GLOBAL_SEARCH	= 0x0010u  /* If feature not found in LangSys, look for it in global feature list and pick one. */

};

HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);

/* Macro version for where const is desired. */

#define F_COMBINE(l,r) (hb_ot_map_feature_flags_t ((unsigned int) (l) | (unsigned int) (r)))

struct hb_ot_map_builder_t

{

  public:

  HB_INTERNAL hb_ot_map_builder_t (hb_face_t *face_,

				   const hb_segment_properties_t *props_);

  HB_INTERNAL void add_feature (hb_tag_t tag, unsigned int value,

				hb_ot_map_feature_flags_t flags);

  inline void add_global_bool_feature (hb_tag_t tag)

  { add_feature (tag, 1, F_GLOBAL); }

  inline void add_gsub_pause (hb_ot_map_t::pause_func_t pause_func)

  { add_pause (0, pause_func); }

  inline void add_gpos_pause (hb_ot_map_t::pause_func_t pause_func)

  { add_pause (1, pause_func); }

  HB_INTERNAL void compile (hb_ot_map_t  &m,

			    const int    *coords,

			    unsigned int  num_coords);

  inline void finish (void) {

    feature_infos.finish ();

    for (unsigned int table_index = 0; table_index < 2; table_index++)

    {

      stages[table_index].finish ();

    }

  }

  private:

  HB_INTERNAL void add_lookups (hb_ot_map_t  &m,

				hb_face_t    *face,

				unsigned int  table_index,

				unsigned int  feature_index,

				unsigned int  variations_index,

				hb_mask_t     mask,

				bool          auto_zwnj = true,

				bool          auto_zwj = true);

  struct feature_info_t {

    hb_tag_t tag;

    unsigned int seq; /* sequence#, used for stable sorting only */

    unsigned int max_value;

    hb_ot_map_feature_flags_t flags;

    unsigned int default_value; /* for non-global features, what should the unset glyphs take */

    unsigned int stage[2]; /* GSUB/GPOS */

    static int cmp (const feature_info_t *a, const feature_info_t *b)

    { return (a->tag != b->tag) ?  (a->tag < b->tag ? -1 : 1) :

	     (a->seq < b->seq ? -1 : a->seq > b->seq ? 1 : 0); }

  };

  struct stage_info_t {

    unsigned int index;

    hb_ot_map_t::pause_func_t pause_func;

  };

  HB_INTERNAL void add_pause (unsigned int table_index, hb_ot_map_t::pause_func_t pause_func);

  public:

  hb_face_t *face;

  hb_segment_properties_t props;

  hb_tag_t chosen_script[2];

  bool found_script[2];

  unsigned int script_index[2], language_index[2];

  private:

  unsigned int current_stage[2]; /* GSUB/GPOS */

  hb_prealloced_array_t<feature_info_t, 32> feature_infos;

  hb_prealloced_array_t<stage_info_t, 8> stages[2]; /* GSUB/GPOS */

};

#endif /* HB_OT_MAP_PRIVATE_HH */