package nori

import (
	"fmt"
	"image"
	"image/draw"
	"strings"

	"git.tuxpa.in/a/zlog/log"
	"github.com/phrozen/blend"
	"gitlab.com/gfxlabs/gfximg/apng"
)

func RenderAnimations(n *Nori) ([]*apng.APNG, error) {
	apngs := make([]*apng.APNG, 0, len(n.Animations))
	for i := range n.Animations {
		a, err := RenderAnimation(n, i)
		if err != nil {
			if strings.Contains(err.Error(), "no frame") {
				continue
			}
			return nil, err
		}
		apngs = append(apngs, a)
	}
	return apngs, nil
}

func RenderAnimation(n *Nori, num int) (*apng.APNG, error) {
	g := n.Gawi
	a := &apng.APNG{
		Frames: make([]apng.Frame, 0, len(g.Images)),
	}
	if len(n.Animations[num].Frames) == 0 {
		return nil, fmt.Errorf("no frames found for animation")
	}
	images := make([]*image.NRGBA64, 0, len(n.Animations[num].Frames))
	for _, frame := range n.Animations[num].Frames {
		planes := frame.Planes
		var canvasRect image.Rectangle
		for i, plane := range planes {
			if int(plane.BitmapId) >= len(n.Gawi.Images) {
				log.Printf("could not find bitmap %d, only have %d", plane.BitmapId, len(n.Gawi.Images))
			}
			bitmap := n.Gawi.Images[plane.BitmapId]
			pt := image.Pt(int(plane.PlaneX), int(plane.PlaneY)) // where to put the point
			rc := bitmap.Img.Bounds().Add(pt)                    // translate rectangle to put in the global canvas
			if i == 0 {
				canvasRect = rc
			} else {
				canvasRect = canvasRect.Union(rc)
			}
		}
		img := image.NewNRGBA64(canvasRect)
		for _, plane := range planes {
			bitmap := n.Gawi.Images[plane.BitmapId]
			transparent := false
			//flipx
			if plane.RenderFlag&1 != 0 {
			}
			//flipy
			if plane.RenderFlag&2 != 0 {
			}
			// is transparent
			if plane.RenderFlag&0x20 != 0 {
				transparent = true
			}
			_ = transparent
			pt := image.Pt(int(plane.PlaneX), int(plane.PlaneY)) // where to put the point
			rc := bitmap.Img.Bounds().Add(pt)
			src := bitmap.Img
			switch plane.Blend {
			case BlendMode_Alpha:
			case BlendMode_Mul, BlendMode_Mul7:
				blend.BlendImage(img, bitmap.Img, blend.Multiply)
			case BlendMode_Add, BlendMode_Add8:
				blend.BlendImage(img, bitmap.Img, blend.Add)
			case BlendMode_InvertMul, BlendMode_InvertMul5:
				blend.BlendImage(img, bitmap.Img, blend.Multiply)
			case BlendMode_None:
			default:
				return nil, fmt.Errorf("unknown blend mode: %d", plane.Blend)
			}
			draw.Draw(
				img,
				rc,
				src,
				src.Bounds().Min,
				draw.Over,
			)
		}
		images = append(images, img)
	}
	or := images[0].Bounds()
	for _, realFrame := range images {
		or = realFrame.Bounds().Union(or)
	}
	if or.Size().X == 0 || or.Size().Y == 0 {
		return nil, fmt.Errorf("no frames found for animation")
	}
	for i, realFrame := range images {
		//log.Info().Int("frame", num).Interface("rect", or).Interface("frame", realFrame.Bounds()).Msg("")
		src := realFrame
		big := image.NewNRGBA64(or)
		draw.Draw(
			big,
			src.Bounds(),
			src,
			src.Bounds().Min,
			draw.Src,
		)
		fr := apng.Frame{
			Image:            big,
			DelayDenominator: 1000,
		}
		if g.Images[i].Delay != 0 {
			fr.DelayNumerator = uint16(g.Images[i].Delay)
		}
		a.Frames = append(a.Frames, fr)
	}
	return a, nil
}