#pragma once

#include <mbgl/text/glyph_range.hpp>
#include <mbgl/util/bitmask_operations.hpp>
#include <mbgl/util/font_stack.hpp>
#include <mbgl/util/rect.hpp>
#include <mbgl/util/traits.hpp>
#include <mbgl/util/optional.hpp>
#include <mbgl/util/immutable.hpp>
#include <mbgl/util/image.hpp>
#include <mbgl/util/util.hpp>

#include <cstdint>
#include <vector>
#include <string>
#include <map>
#include <set>

namespace mbgl {

using GlyphID = char16_t;
using GlyphIDs = std::set<GlyphID>;

// Note: this only works for the BMP
GlyphRange getGlyphRange(GlyphID glyph);

struct GlyphMetrics {
    uint32_t width = 0;
    uint32_t height = 0;
    int32_t left = 0;
    int32_t top = 0;
    uint32_t advance = 0;
};

inline bool operator==(const GlyphMetrics& lhs, const GlyphMetrics& rhs) {
    return lhs.width == rhs.width &&
        lhs.height == rhs.height &&
        lhs.left == rhs.left &&
        lhs.top == rhs.top &&
        lhs.advance == rhs.advance;
}

class Glyph {
public:
    // We're using this value throughout the Mapbox GL ecosystem. If this is different, the glyphs
    // also need to be reencoded.
    static constexpr const uint8_t borderSize = 3;

    GlyphID id = 0;

    // A signed distance field of the glyph with a border (see above).
    AlphaImage bitmap;

    // Glyph metrics
    GlyphMetrics metrics;
};

using Glyphs = std::map<GlyphID, optional<Immutable<Glyph>>>;
using GlyphMap = std::map<FontStackHash, Glyphs>;

class PositionedGlyph {
public:
    explicit PositionedGlyph(GlyphID glyph_,
                             float x_,
                             float y_,
                             bool vertical_,
                             FontStackHash font_,
                             float scale_,
                             Rect<uint16_t> rect_,
                             GlyphMetrics metrics_,
                             optional<std::string> imageID_,
                             std::size_t sectionIndex_ = 0)
        : glyph(glyph_),
          x(x_),
          y(y_),
          vertical(vertical_),
          font(font_),
          scale(scale_),
          rect(rect_),
          metrics(metrics_),
          imageID(std::move(imageID_)),
          sectionIndex(sectionIndex_) {}

    GlyphID glyph = 0;
    float x = 0;
    float y = 0;
    bool vertical = false;
    FontStackHash font = 0;
    float scale = 0.0;
    Rect<uint16_t> rect;
    GlyphMetrics metrics;
    optional<std::string> imageID;
    // Maps positioned glyph to TaggedString section
    std::size_t sectionIndex;
};

enum class WritingModeType : uint8_t;

struct PositionedLine {
    std::vector<PositionedGlyph> positionedGlyphs;
    float lineOffset = 0.0;
};

class Shaping {
    public:
    Shaping() = default;
    explicit Shaping(float x, float y, WritingModeType writingMode_)
        : top(y), bottom(y), left(x), right(x), writingMode(writingMode_) {}
    std::vector<PositionedLine> positionedLines;
    float top = 0;
    float bottom = 0;
    float left = 0;
    float right = 0;
    WritingModeType writingMode;
    explicit operator bool() const {
        return std::any_of(positionedLines.begin(), positionedLines.end(), [](const auto& line) {
            return !line.positionedGlyphs.empty();
        });
    }
    // The y offset *should* be part of the font metadata.
    static constexpr int32_t yOffset = -17;
    bool verticalizable = false;
    bool iconsInText = false;
};

enum class WritingModeType : uint8_t {
    None = 0,
    Horizontal = 1 << 0,
    Vertical = 1 << 1,
};

using GlyphDependencies = std::map<FontStack, GlyphIDs>;
using GlyphRangeDependencies = std::map<FontStack, std::unordered_set<GlyphRange>>;

} // end namespace mbgl