package main

import (
	"bufio"
	"fmt"
	hsv "git.snrd.eu/sunred/humanshader/validator"
	"os"
	"strconv"
)

func main() {
	args := os.Args[1:]

	// TODO: Better argument parsing
	if len(args) == 1 || len(args) == 3 || len(args) == 5 {
		fmt.Printf("Writing PPM image to %s.\n", args[0])
		if len(args) == 3 || len(args) == 5 {
			width, _ := strconv.Atoi(args[1])
			height, _ := strconv.Atoi(args[2])
			if len(args) == 5 {
				startx, _ := strconv.Atoi(args[3])
				starty, _ := strconv.Atoi(args[4])
				writePPM(args[0], width, height, startx, starty)
			} else {
				writePPM(args[0], width, height, 0, 0)
			}
		} else {
			writePPM(args[0], 71, 40, 0, 0)
		}
		fmt.Println("Done")
	} else if len(args) == 2 {
		pxX, _ := strconv.Atoi(args[0])
		pxY, _ := strconv.Atoi(args[1])
		printPixel(pxX, pxY)
	} else {
		input := bufio.NewScanner(os.Stdin)
		fmt.Print("Pixel x coordinate: ")
		input.Scan()
		pxX, _ := strconv.Atoi(input.Text())
		fmt.Print("Pixel y coordinate: ")
		input.Scan()
		pxY, _ := strconv.Atoi(input.Text())
		fmt.Println()
		printPixel(pxX, pxY)
	}
}

func printPixel(x int, y int) {
	val := hsv.NewValidator(true)
	r, g, b := val.Calculate(x, y).GetRGB()
	fmt.Printf("\nR: %d\nG: %d\nB: %d\nHEX: #%02X%02X%02X\n", r, g, b, r, g, b)
}

func writePPM(path string, width int, height int, startx int, starty int) {
	f, err := os.Create(path)
	if err != nil {
		panic(err)
	}
	defer f.Close()

	bw := bufio.NewWriter(f)
	bw.WriteString("P3\n")
	bw.WriteString(fmt.Sprintf("%d %d\n", width, height))
	bw.WriteString("255\n")
	for y := startx; y < startx+height; y++ {
		for x := starty; x < starty+width; x++ {
			v := hsv.NewValidator(false)
			r, g, b := v.Calculate(x, y).GetRGB()
			bw.WriteString(fmt.Sprintf("%d %d %d ", r, g, b))
		}
		bw.WriteString("\n")
	}
	bw.Flush()
}