package main

import (
	"fmt"
	"image"
	"image/color"
	"image/gif"
	"log"
	"sort"

	"git.red-green.com/david/point2d"
)

type HitList []point2d.Point

func (h HitList) Len() int {
	return len(h)
}

func (h HitList) Swap(i, j int) {
	h[i], h[j] = h[j], h[i]
}

func (h HitList) Less(i, j int) bool {
	return h[i].LessThan(&h[j])
}

func Scan(filename string) (hits []HitList, err error) {
	var (
		gif      *gif.GIF
		size     image.Point
		pix      color.Color
		r        uint32
		g        uint32
		b        uint32
		hitframe HitList
	)
	gif, err = DecodeGif(filename)
	if err != nil {
		return nil, fmt.Errorf("DecodeGif(\"%s\") > %v", filename, err)
	}
	for _, frame := range gif.Image {
		size = frame.Bounds().Size()
		hitframe = HitList{}
		for y := range make([]byte, size.Y) {
			for x := range make([]byte, size.X) {
				pix = frame.At(x, y)
				r, g, b, _ = pix.RGBA()
				r /= 255
				g /= 255
				b /= 255
				// Now to determine if this pixel is considerable as rain
				if (r <= 47 && g >= 90 && b <= 51) || (r >= 240 && g >= 240 && b <= 10) || (r >= 240 && g <= 10 && b <= 10) {
					//fmt.Printf("{(%d, %d) [%d, %d, %d, %s]}\r\n", x, y, r, g, b, rgbToHex(r, g, b))
					frame.Set(x, y, color.RGBA{R: 255, G: 0, B: 0, A: 255})
					hitframe = append(hitframe, *point2d.AsPoint(x, y))
				}
			}
		}
		hits = append(hits, hitframe)
	}
	err = EncodeGif(filename+".out", gif)
	if err != nil {
		return nil, fmt.Errorf("EncodeGif(\"%s.out\", gif) > %v", filename, err)
	}
	return hits, nil
}

func main() {
	var (
		err  error
		hits []HitList
		diff point2d.Point
	)
	/*
		err = GrabPascoGif()
		if err != nil {
			log.Panic("GrabPascoGif() >", err)
		}
	*/

	hits, err = Scan("pasco.gif")
	if err != nil {
		log.Panic(err)
	}
	for _, frame := range hits {
		sort.Sort(&frame)
	}
	for _, pos := range hits[0] {
		if diff.IsZero() {
			diff = pos
		} else {
			dist := diff.DistanceTo(&pos)
			if dist > 1 {
				fmt.Printf("0] (%s) diff=(%s) dist=%d\r\n", pos.String(), diff.String(), dist)
			}
			if dist > 1 {
				diff = pos
			}
		}
	}
}