#pragma once

namespace nall {

struct image {
  enum class blend : unsigned {
    add,
    sourceAlpha,  //color = sourceColor * sourceAlpha + targetColor * (1 - sourceAlpha)
    sourceColor,  //color = sourceColor
    targetAlpha,  //color = targetColor * targetAlpha + sourceColor * (1 - targetAlpha)
    targetColor,  //color = targetColor
  };

  struct channel {
    channel(uint64_t mask, unsigned depth, unsigned shift) : _mask(mask), _depth(depth), _shift(shift) {
    }

    auto operator==(const channel& source) const -> bool {
      return _mask == source._mask && _depth == source._depth && _shift == source._shift;
    }

    auto operator!=(const channel& source) const -> bool {
      return !operator==(source);
    }

    alwaysinline auto mask() const { return _mask; }
    alwaysinline auto depth() const { return _depth; }
    alwaysinline auto shift() const { return _shift; }

  private:
    uint64_t _mask;
    unsigned _depth;
    unsigned _shift;
  };

  //core.hpp
  inline image(const image& source);
  inline image(image&& source);
  inline image(bool endian, unsigned depth, uint64_t alphaMask, uint64_t redMask, uint64_t greenMask, uint64_t blueMask);
  inline image(const string& filename);
  inline image(const vector<uint8_t>& buffer);
  inline image(const uint8_t* data, unsigned size);
  inline image();
  inline ~image();

  inline auto operator=(const image& source) -> image&;
  inline auto operator=(image&& source) -> image&;

  inline explicit operator bool() const;
  inline auto operator==(const image& source) const -> bool;
  inline auto operator!=(const image& source) const -> bool;

  inline auto read(const uint8_t* data) const -> uint64_t;
  inline auto write(uint8_t* data, uint64_t value) const -> void;

  inline auto free() -> void;
  inline auto empty() const -> bool;
  inline auto load(const string& filename) -> bool;
  inline auto allocate(unsigned width, unsigned height) -> void;

  //fill.hpp
  inline auto fill(uint64_t color = 0) -> void;
  inline auto gradient(uint64_t a, uint64_t b, uint64_t c, uint64_t d) -> void;
  inline auto gradient(uint64_t a, uint64_t b, signed radiusX, signed radiusY, signed centerX, signed centerY, function<double (double, double)> callback) -> void;
  inline auto crossGradient(uint64_t a, uint64_t b, signed radiusX, signed radiusY, signed centerX, signed centerY) -> void;
  inline auto diamondGradient(uint64_t a, uint64_t b, signed radiusX, signed radiusY, signed centerX, signed centerY) -> void;
  inline auto horizontalGradient(uint64_t a, uint64_t b, signed radiusX, signed radiusY, signed centerX, signed centerY) -> void;
  inline auto radialGradient(uint64_t a, uint64_t b, signed radiusX, signed radiusY, signed centerX, signed centerY) -> void;
  inline auto sphericalGradient(uint64_t a, uint64_t b, signed radiusX, signed radiusY, signed centerX, signed centerY) -> void;
  inline auto squareGradient(uint64_t a, uint64_t b, signed radiusX, signed radiusY, signed centerX, signed centerY) -> void;
  inline auto verticalGradient(uint64_t a, uint64_t b, signed radiusX, signed radiusY, signed centerX, signed centerY) -> void;

  //scale.hpp
  inline auto scale(unsigned width, unsigned height, bool linear = true) -> void;

  //blend.hpp
  inline auto impose(blend mode, unsigned targetX, unsigned targetY, image source, unsigned x, unsigned y, unsigned width, unsigned height) -> void;

  //utility.hpp
  inline auto crop(unsigned x, unsigned y, unsigned width, unsigned height) -> bool;
  inline auto alphaBlend(uint64_t alphaColor) -> void;
  inline auto alphaMultiply() -> void;
  inline auto transform(const image& source = {}) -> void;
  inline auto transform(bool endian, unsigned depth, uint64_t alphaMask, uint64_t redMask, uint64_t greenMask, uint64_t blueMask) -> void;

  //static.hpp
  static inline auto bitDepth(uint64_t color) -> unsigned;
  static inline auto bitShift(uint64_t color) -> unsigned;
  static inline auto normalize(uint64_t color, unsigned sourceDepth, unsigned targetDepth) -> uint64_t;

  //access
  alwaysinline auto data() { return _data; }
  alwaysinline auto data() const { return _data; }
  alwaysinline auto width() const { return _width; }
  alwaysinline auto height() const { return _height; }

  alwaysinline auto endian() const { return _endian; }
  alwaysinline auto depth() const { return _depth; }
  alwaysinline auto stride() const { return (_depth + 7) >> 3; }

  alwaysinline auto pitch() const { return _width * stride(); }
  alwaysinline auto size() const { return _height * pitch(); }

  alwaysinline auto alpha() const { return _alpha; }
  alwaysinline auto red() const { return _red; }
  alwaysinline auto green() const { return _green; }
  alwaysinline auto blue() const { return _blue; }

private:
  //core.hpp
  inline auto allocate(unsigned width, unsigned height, unsigned stride) -> uint8_t*;

  //scale.hpp
  inline auto scaleLinearWidth(unsigned width) -> void;
  inline auto scaleLinearHeight(unsigned height) -> void;
  inline auto scaleLinear(unsigned width, unsigned height) -> void;
  inline auto scaleNearest(unsigned width, unsigned height) -> void;

  //load.hpp
  inline auto loadBMP(const string& filename) -> bool;
  inline auto loadBMP(const uint8_t* data, unsigned size) -> bool;
  inline auto loadPNG(const string& filename) -> bool;
  inline auto loadPNG(const uint8_t* data, unsigned size) -> bool;

  //interpolation.hpp
  alwaysinline auto isplit(uint64_t* component, uint64_t color) -> void;
  alwaysinline auto imerge(const uint64_t* component) -> uint64_t;
  alwaysinline auto interpolate1f(uint64_t a, uint64_t b, double x) -> uint64_t;
  alwaysinline auto interpolate1f(uint64_t a, uint64_t b, uint64_t c, uint64_t d, double x, double y) -> uint64_t;
  alwaysinline auto interpolate1i(int64_t a, int64_t b, uint32_t x) -> uint64_t;
  alwaysinline auto interpolate1i(int64_t a, int64_t b, int64_t c, int64_t d, uint32_t x, uint32_t y) -> uint64_t;
  inline auto interpolate4f(uint64_t a, uint64_t b, double x) -> uint64_t;
  inline auto interpolate4f(uint64_t a, uint64_t b, uint64_t c, uint64_t d, double x, double y) -> uint64_t;
  inline auto interpolate4i(uint64_t a, uint64_t b, uint32_t x) -> uint64_t;
  inline auto interpolate4i(uint64_t a, uint64_t b, uint64_t c, uint64_t d, uint32_t x, uint32_t y) -> uint64_t;

  uint8_t* _data   = nullptr;
  unsigned _width  = 0;
  unsigned _height = 0;

  bool _endian     =  0;  //0 = lsb, 1 = msb
  unsigned _depth  = 32;

  channel _alpha{255u << 24, 8, 24};
  channel _red  {255u << 16, 8, 16};
  channel _green{255u <<  8, 8,  8};
  channel _blue {255u <<  0, 8,  0};
};

}