main.go

package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"os/signal"
	"path/filepath"
	"strconv"
	"strings"
	"time"
)

func captureSigint() {
	c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)

	go func() {
		<-c
		// Reset the TERM and exit
		fmt.Println("\033[0m\033c")
		os.Exit(0)
	}()
}

func termSize() (int, int) {
	cmd := exec.Command("stty", "size")
	cmd.Stdin = os.Stdin
	size, _ := cmd.Output()

	termWidth, _ := strconv.Atoi(strings.TrimSpace(strings.Split(string(size), " ")[1]))
	termHeight, _ := strconv.Atoi(strings.Split(string(size), " ")[0])
	return termWidth, termHeight
}

func playAudio() {
	audio, _ := filepath.Abs("assets/audio.mp3")
	cmd := exec.Command("mpg123", "-loop 0", "-q", audio)
	cmd.Start()
}

func printTime(startTime time.Time, animWidth int) {
	message := fmt.Sprintf("You have nyaned for %.f seconds!", time.Since(startTime).Seconds())
	padding := (animWidth - (len(message) + 4)) / 2

	fmt.Print(strings.Repeat(" ", padding))
	fmt.Printf("\033[1;37;17m%s", message)
}

func main() {
	var mute bool
	var hideTime bool

	// Parse options
	flag.BoolVar(&mute, "m", false, "Don't play audio")
	flag.BoolVar(&hideTime, "n", false, "Don't show the time nyaned")
	flag.Parse()

	// Set output character
	const outputChar = "  "

	// Set colors
	colors := map[string]string{
		"+": "226",
		"@": "223",
		",": "17",
		"-": "205",
		"#": "82",
		".": "15",
		"$": "219",
		"%": "217",
		";": "99",
		"&": "214",
		"=": "39",
		"'": "0",
		">": "196",
		"*": "245",
	}

	// Import frames from data file
	framesFile, _ := filepath.Abs("assets/frames.json")
	data, _ := ioutil.ReadFile(framesFile)

	var frames [][]string
	json.Unmarshal(data, &frames)

	// Get TTY size
	termWidth, termHeight := termSize()

	// Calculate the width in terms of the output char
	termWidth = termWidth / len(outputChar)

	minRow := 0
	maxRow := len(frames[0])

	minCol := 0
	maxCol := len(frames[0][0])

	if maxRow > termHeight {
		minRow = (maxRow - termHeight) / 2
		maxRow = minRow + termHeight
	}

	if maxCol > termWidth {
		minCol = (maxCol - termWidth) / 2
		maxCol = minCol + termWidth
	}

	// Calculate the final animation width
	animWidth := (maxCol - minCol) * len(outputChar)

	// Initialize term
	fmt.Print("\033[H\033[2J\033[?25l")

	// Get start time
	startTime := time.Now()

	// Capture SIGINT
	captureSigint()

	if !mute {
		// Play music
		playAudio()
	}

	for {
		for _, frame := range frames {
			// Print the next frame
			for _, line := range frame[minRow:maxRow] {
				for _, char := range line[minCol:maxCol] {
					fmt.Printf("\033[48;5;%sm%s", colors[string(char)], outputChar)
				}
				fmt.Println("\033[m")
			}

			if !hideTime {
				// Print the time so far
				printTime(startTime, animWidth)
			}

			// Reset the frame and sleep
			fmt.Print("\033[H")
			time.Sleep(90 * time.Millisecond)
		}
	}
}