// Package webp provides an interface to libwebp library to decoding/encoding
// WebP image.
package webp

/*
#cgo LDFLAGS: -lwebp -lm

#include <stdlib.h>
#include <webp/encode.h>

*/
import "C"

// ColorSpace represents encoding color space in WebP
type ColorSpace int

const (
	// YUV420 specifies YUV4:2:0
	YUV420 ColorSpace = C.WEBP_YUV420
	// YUV420A specifies YUV4:2:0 with alpha channel
	YUV420A ColorSpace = C.WEBP_YUV420A
)

// ImageHint corresponds to C.WebPImageHint.
type ImageHint int

const (
	HintDefault ImageHint = C.WEBP_HINT_DEFAULT
	HintPicture ImageHint = C.WEBP_HINT_PICTURE
	HintPhoto   ImageHint = C.WEBP_HINT_PHOTO
	HintGraph   ImageHint = C.WEBP_HINT_GRAPH
	HintLast    ImageHint = C.WEBP_HINT_LAST
)

// Preset corresponds to C.WebPPreset.
type Preset int

const (
	// PresetDefault corresponds to WEBP_PRESET_DEFAULT, for default preset.
	PresetDefault Preset = C.WEBP_PRESET_DEFAULT
	// PresetPicture corresponds to WEBP_PRESET_PICTURE, for digital picture, like portrait, inner shot
	PresetPicture Preset = C.WEBP_PRESET_PICTURE
	// PresetPhoto corresponds to WEBP_PRESET_PHOTO, for outdoor photograph, with natural lighting
	PresetPhoto Preset = C.WEBP_PRESET_PHOTO
	// PresetDrawing corresponds to WEBP_PRESET_DRAWING, for hand or line drawing, with high-contrast details
	PresetDrawing Preset = C.WEBP_PRESET_DRAWING
	// PresetIcon corresponds to WEBP_PRESET_ICON, for small-sized colorful images
	PresetIcon Preset = C.WEBP_PRESET_ICON
	// PresetText corresponds to WEBP_PRESET_TEXT, for text-like
	PresetText Preset = C.WEBP_PRESET_TEXT
)

// FilterType corresponds to filter types in compression parameters.
type FilterType int

const (
	// SimpleFilter (=0, default)
	SimpleFilter FilterType = iota
	// StrongFilter (=1)
	StrongFilter
)

// Preprocessing corresponds to preprocessing filter parameter.
type Preprocessing int

const (
	// PreprocessingNone specifies to disable preprocessing filter.
	PreprocessingNone = 0
	// PreprocessingSegmentSmooth specifies segment-smooth filter.
	PreprocessingSegmentSmooth = 1
	//PreprocessingPseudoRandomDithering specifies pseudo-random dithering filter.
	PreprocessingPseudoRandomDithering = 2
)