package frame

import (
	"errors"
	"git.gammaspectra.live/S.O.N.G/Ignite/colorspace"
)

type uint8Frame struct {
	colorSpace colorspace.ColorSpace
	width      int
	height     int
	Y          []uint8
	Cb         []uint8
	Cr         []uint8
}

func NewUint8FrameFromBytes(space colorspace.ColorSpace, width, height int, data []byte) (*uint8Frame, error) {
	if frameLength, _ := space.FrameSize(width, height); frameLength != len(data) {
		return nil, errors.New("wrong length of data")
	}

	if space.BitDepth > 8 {
		return nil, errors.New("wrong bit depth")
	}

	iY := space.PlaneLumaSamples(width, height)
	iCb := space.PlaneCbSamples(width, height)
	iCr := space.PlaneCrSamples(width, height)

	return &uint8Frame{
		colorSpace: space,
		height:     height,
		width:      width,
		Y:          data[:iY],
		Cb:         data[iY : iY+iCb],
		Cr:         data[iY+iCb : iY+iCb+iCr],
	}, nil
}

func (i *uint8Frame) Get16(x, y int) (Y uint16, Cb uint16, Cr uint16) {
	cy, cb, cr := i.GetNative(x, y)

	return uint16(cy) << (16 - i.colorSpace.BitDepth), uint16(cb) << (16 - i.colorSpace.BitDepth), uint16(cr) << (16 - i.colorSpace.BitDepth)
}

func (i *uint8Frame) Get8(x, y int) (Y uint8, Cb uint8, Cr uint8) {
	return i.GetNative(x, y)
}

func (i *uint8Frame) Width() int {
	return i.width
}

func (i *uint8Frame) Height() int {
	return i.height
}

func (i *uint8Frame) ColorSpace() colorspace.ColorSpace {
	return i.colorSpace
}

func (i *uint8Frame) GetNative(x, y int) (Y uint8, Cb uint8, Cr uint8) {
	Yindex := x + y*i.width

	Cwidth := (i.width * int(i.colorSpace.Subsampling.A)) / int(i.colorSpace.Subsampling.J)
	if i.colorSpace.Subsampling.B == 0 {
		y /= 2
	}
	Cindex := (x*int(i.colorSpace.Subsampling.A))/int(i.colorSpace.Subsampling.J) + y*Cwidth
	Y = i.Y[Yindex]
	Cb = i.Cb[Cindex]
	Cr = i.Cr[Cindex]
	return
}

func (i *uint8Frame) GetNativeLuma() []uint8 {
	return i.Y
}

func (i *uint8Frame) GetNativeCb() []uint8 {
	return i.Cb
}

func (i *uint8Frame) GetNativeCr() []uint8 {
	return i.Cr
}