/*
 * This file is part of the internal font implementation.
 *
 * Copyright (C) 2006, 2008, 2010 Apple Inc. All rights reserved.
 * Copyright (C) 2007-2008 Torch Mobile, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SIMPLE_FONT_DATA_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SIMPLE_FONT_DATA_H_

#include <memory>
#include <mutex>
#include <utility>

#include "build/build_config.h"
#include "third_party/blink/renderer/platform/bindings/v8_external_memory_accounter.h"
#include "third_party/blink/renderer/platform/fonts/canvas_rotation_in_vertical.h"
#include "third_party/blink/renderer/platform/fonts/custom_font_data.h"
#include "third_party/blink/renderer/platform/fonts/font_baseline.h"
#include "third_party/blink/renderer/platform/fonts/font_data.h"
#include "third_party/blink/renderer/platform/fonts/font_metrics.h"
#include "third_party/blink/renderer/platform/fonts/font_metrics_override.h"
#include "third_party/blink/renderer/platform/fonts/font_platform_data.h"
#include "third_party/blink/renderer/platform/fonts/font_vertical_position_type.h"
#include "third_party/blink/renderer/platform/fonts/glyph.h"
#include "third_party/blink/renderer/platform/fonts/shaping/han_kerning.h"
#include "third_party/blink/renderer/platform/fonts/typesetting_features.h"
#include "third_party/blink/renderer/platform/heap/member.h"
#include "third_party/blink/renderer/platform/platform_export.h"
#include "third_party/blink/renderer/platform/wtf/casting.h"
#include "third_party/blink/renderer/platform/wtf/text/string_hash.h"
#include "third_party/skia/include/core/SkFont.h"
#include "ui/gfx/geometry/rect_f.h"

#if BUILDFLAG(IS_APPLE)
#include "third_party/blink/renderer/platform/fonts/glyph_metrics_map.h"
#endif

namespace blink {

class NGShapeCache;

// Holds the glyph index and the corresponding SimpleFontData information for a
// given
// character.
struct GlyphData {
  STACK_ALLOCATED();

 public:
  GlyphData(
      Glyph g = 0,
      const SimpleFontData* f = nullptr,
      CanvasRotationInVertical rotation = CanvasRotationInVertical::kRegular)
      : glyph(g), font_data(f), canvas_rotation(rotation) {}
  Glyph glyph;
  const SimpleFontData* font_data;
  CanvasRotationInVertical canvas_rotation;
};

class FontDescription;

class PLATFORM_EXPORT SimpleFontData final : public FontData {
 public:
  // Used to create platform fonts.
  SimpleFontData(
      const FontPlatformData*,
      const CustomFontData* custom_data = nullptr,
      bool subpixel_ascent_descent = false,
      const FontMetricsOverride& metrics_override = FontMetricsOverride());

  void Trace(Visitor* visitor) const override;

  SimpleFontData(const SimpleFontData&) = delete;
  SimpleFontData(SimpleFontData&&) = delete;
  ~SimpleFontData() override;
  SimpleFontData& operator=(const SimpleFontData&) = delete;
  SimpleFontData& operator=(const SimpleFontData&&) = delete;

  const FontPlatformData& PlatformData() const { return *platform_data_; }
  NGShapeCache& GetShapeCache() const { return *shape_cache_; }

  SimpleFontData* SmallCapsFontData(const FontDescription&) const;
  SimpleFontData* EmphasisMarkFontData(const FontDescription&) const;
  SimpleFontData* MetricsOverriddenFontData(const FontMetricsOverride&) const;

  FontMetrics& GetFontMetrics() { return font_metrics_; }
  const FontMetrics& GetFontMetrics() const { return font_metrics_; }
  float InternalLeading() const {
    return GetFontMetrics().FloatHeight() - PlatformData().size();
  }

  // The approximated advance of fullwidth ideographic characters in the inline
  // axis. This is currently used to support the `ic` unit.
  // https://drafts.csswg.org/css-values-4/#ic
  const std::optional<float>& IdeographicInlineSize() const;
  const std::optional<float>& IdeographicAdvanceWidth() const;
  const std::optional<float>& IdeographicAdvanceHeight() const;

  // The approximated advance of “0” (ZERO, U+0030) character in the inline
  // axis. This is currently used to support the `ch` unit.
  // https://drafts.csswg.org/css-values-4/#ch
  inline float ZeroInlineSize() const;

  // |sTypoAscender| and |sTypoDescender| in |OS/2| table, normalized to 1em.
  // This metrics can simulate ideographics em-box when the font doesn't have
  // better ways to compute it.
  // https://docs.microsoft.com/en-us/typography/opentype/spec/baselinetags#ideoembox
  FontHeight NormalizedTypoAscentAndDescent(
      FontBaseline baseline_type = kAlphabeticBaseline) const;
  LayoutUnit NormalizedTypoAscent(FontBaseline = kAlphabeticBaseline) const;
  LayoutUnit NormalizedTypoDescent(FontBaseline = kAlphabeticBaseline) const;

  LayoutUnit VerticalPosition(FontVerticalPositionType, FontBaseline) const;

  float MaxCharWidth() const { return max_char_width_; }
  void SetMaxCharWidth(float max_char_width) {
    max_char_width_ = max_char_width;
  }

  float AvgCharWidth() const { return avg_char_width_; }
  void SetAvgCharWidth(float avg_char_width) {
    avg_char_width_ = avg_char_width;
  }

  const HanKerning::FontData& HanKerningData(const LayoutLocale& locale,
                                             bool is_horizontal) const;

  gfx::RectF BoundsForGlyph(Glyph) const;
  void BoundsForGlyphs(const Vector<Glyph, 256>&, Vector<SkRect, 256>*) const;
  gfx::RectF PlatformBoundsForGlyph(Glyph) const;
  float WidthForGlyph(Glyph) const;

  float SpaceWidth() const { return space_width_; }
  void SetSpaceWidth(float space_width) { space_width_ = space_width; }

  Glyph SpaceGlyph() const { return space_glyph_; }
  void SetSpaceGlyph(Glyph space_glyph) { space_glyph_ = space_glyph; }
  Glyph ZeroGlyph() const { return zero_glyph_; }
  void SetZeroGlyph(Glyph zero_glyph) { zero_glyph_ = zero_glyph; }

  const SimpleFontData* FontDataForCharacter(UChar32) const override;

  Glyph GlyphForCharacter(UChar32) const;

  bool IsCustomFont() const override { return custom_font_data_; }
  bool IsLoading() const override {
    return custom_font_data_ ? custom_font_data_->IsLoading() : false;
  }
  bool IsLoadingFallback() const override {
    return custom_font_data_ ? custom_font_data_->IsLoadingFallback() : false;
  }
  bool IsPendingDataUrlCustomFont() const {
    return custom_font_data_ ? custom_font_data_->IsPendingDataUrl() : false;
  }
  bool IsSegmented() const override;
  bool ShouldSkipDrawing() const override {
    return custom_font_data_ && custom_font_data_->ShouldSkipDrawing();
  }

  const CustomFontData* GetCustomFontData() const {
    return custom_font_data_.Get();
  }

 private:
  void PlatformInit(bool subpixel_ascent_descent, const FontMetricsOverride&);
  void PlatformGlyphInit();

  SimpleFontData* CreateScaledFontData(const FontDescription&,
                                       float scale_factor) const;

  void ComputeNormalizedTypoAscentAndDescent() const;
  bool TrySetNormalizedTypoAscentAndDescent(float ascent, float descent) const;

  FontMetrics font_metrics_;
  float max_char_width_ = -1;
  float avg_char_width_ = -1;

  Member<const FontPlatformData> platform_data_;
  Member<NGShapeCache> shape_cache_;
  const SkFont font_;

  Glyph space_glyph_ = 0;
  float space_width_ = 0;
  Glyph zero_glyph_ = 0;

  mutable Member<SimpleFontData> small_caps_;
  mutable Member<SimpleFontData> emphasis_mark_;

  Member<const CustomFontData> custom_font_data_;

  mutable std::once_flag ideographic_inline_size_once_;
  mutable std::once_flag ideographic_advance_width_once_;
  mutable std::once_flag ideographic_advance_height_once_;
  mutable std::optional<float> ideographic_inline_size_;
  mutable std::optional<float> ideographic_advance_width_;
  mutable std::optional<float> ideographic_advance_height_;

  // Simple LRU cache for `HanKerning::FontData`. The cache has 2 entries
  // because one additional language or horizontal/vertical mixed document is
  // possible, but more than that are very unlikely.
  struct HanKerningCacheEntry {
    scoped_refptr<const LayoutLocale> locale;
    bool is_horizontal;
    HanKerning::FontData data;
  };
  mutable HanKerningCacheEntry han_kerning_cache_[2];

  mutable FontHeight normalized_typo_ascent_descent_;

// See discussion on crbug.com/631032 and Skia issue
// https://bugs.chromium.org/p/skia/issues/detail?id=5328 :
// On Mac we're still using path based glyph metrics, and they seem to be
// too slow to be able to remove the caching layer we have here.
#if BUILDFLAG(IS_APPLE)
  mutable std::unique_ptr<GlyphMetricsMap<gfx::RectF>> glyph_to_bounds_map_;
#endif

  NO_UNIQUE_ADDRESS V8ExternalMemoryAccounterBase external_memory_accounter_;
};

ALWAYS_INLINE gfx::RectF SimpleFontData::BoundsForGlyph(Glyph glyph) const {
#if !BUILDFLAG(IS_APPLE)
  return PlatformBoundsForGlyph(glyph);
#else
  if (glyph_to_bounds_map_) {
    if (std::optional<gfx::RectF> glyph_bounds =
            glyph_to_bounds_map_->MetricsForGlyph(glyph)) {
      return *glyph_bounds;
    }
  }

  gfx::RectF bounds_result = PlatformBoundsForGlyph(glyph);
  if (!glyph_to_bounds_map_)
    glyph_to_bounds_map_ = std::make_unique<GlyphMetricsMap<gfx::RectF>>();
  glyph_to_bounds_map_->SetMetricsForGlyph(glyph, bounds_result);

  return bounds_result;
#endif
}

template <>
struct DowncastTraits<SimpleFontData> {
  static bool AllowFrom(const FontData& fontData) {
    return !fontData.IsSegmented();
  }
};

}  // namespace blink
#endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_SIMPLE_FONT_DATA_H_