package main

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"os"
	"os/exec"
	"strconv"
	"strings"
	"time"
)

const HEADER = "{\"version\": 1}"
const TEST_BLOCK = "[{\"full_text\": \"test\"}]"
const SEPARATOR_WIDTH = 22

type Bar struct {
	Blocks []BarBlock `json:"blocks"`
}

type BarBlock struct {
	FullText string `json:"full_text"`
	//ShortText string `json:"short_text"`
	//Color string `json:"color"`
	//Background string `json:"background"`
	//Border string `json:"border"`
	//BorderTop int `json:"border_top"`
	//BorderBottom int `json:"border_bottom"`
	//BorderLeft int `json:"border_left"`
	//BorderRight int `json:"border_right"`
	//MinWidth string `json:"min_width"`
	//Align string `json:"align"`
	//Name string `json:"name"`
	//Instance string `json:"instance"`
	Urgent              bool `json:"urgent"`
	Separator           bool `json:"separator"`
	SeparatorBlockWidth int  `json:"separator_block_width"`
	//Markup string `json:"markup"`
}

func NewBlock() BarBlock {
	return BarBlock{SeparatorBlockWidth: SEPARATOR_WIDTH}
}

func getDateTimeBlock() BarBlock {
	format := "02 15:04"
	block := NewBlock()
	block.FullText = time.Now().Local().Format(format)
	return block
}

func getBatteryBlock(battery string) BarBlock {
	// TODO Check that `/sys/class/power_supply/{battery} exists
	block := NewBlock()
	block.Separator = true
	percentageContent, _ := ioutil.ReadFile("/sys/class/power_supply/" + battery + "/capacity")
	percentageInt, _ := strconv.Atoi(strings.TrimSpace(string(percentageContent)))
	block.FullText = strconv.Itoa(percentageInt) + "%"

	statusContent, _ := ioutil.ReadFile("/sys/class/power_supply/" + battery + "/status")
	batteryStatus := strings.TrimSpace(string(statusContent))

	if batteryStatus == "Charging" {
		block.FullText = block.FullText + "+"
	} else if batteryStatus == "Discharging" {
		block.FullText = block.FullText + "-"
	}

	if percentageInt <= 10 {
		block.Urgent = true
	}

	return block
}

func getVolumeLevelBlock() BarBlock {
	block := NewBlock()
	block.Separator = true
	cmd := exec.Command("bash", "-c", "amixer get Master | grep 'Left:' | awk -F\"[][]\" '{ print $2 }'")
	cmd.Env = os.Environ()
	out, err := cmd.Output()
	if err != nil {
		fmt.Println(err)
	}

	block.FullText = strings.TrimSpace(string(out))

	return block
}

func main() {
	fmt.Println(HEADER)
	fmt.Print("[")
	for {
	bar := Bar{}
		var volumeBlock = getVolumeLevelBlock()
		bar.Blocks = append(bar.Blocks, volumeBlock)
		var batteryBlock = getBatteryBlock("BAT0")
		bar.Blocks = append(bar.Blocks, batteryBlock)
		var timeBlock = getDateTimeBlock()
		bar.Blocks = append(bar.Blocks, timeBlock)
		blockJSON, _ := json.Marshal(bar.Blocks)
		fmt.Print(string(blockJSON), ",")
		time.Sleep((1250 * 10) * time.Millisecond)
	}
}