package status // import "hhvn.uk/hbspbar/status"

import (
	"fmt"
	"errors"
	"strings"

	"hhvn.uk/hbspbar/drw"
	"hhvn.uk/hbspbar/config"
	"hhvn.uk/hbspbar/common"
)

func getcpus(c chan [][]string, e chan error) {
	var ret [][]string

	lines, err := common.FileAsLines("/proc/stat")
	if err != nil {
		c <- nil
		e <- err
		return
	}

	for _, l := range lines {
		var tok []string

		tokempty := strings.Split(l, " ")

		if !strings.HasPrefix(tokempty[0], "cpu") ||
				strings.HasSuffix(tokempty[0], "u") {
			continue
		}

		for _, t := range tokempty {
			if t != "" { tok = append(tok, t) }
		}

		ret = append(ret, tok)
	}

	c <- ret

	// This is only used if ret == nil
	e <- errors.New("apparently this computer has no cores")
}

func cpu(name string) error {
	u := newUpdate(name)

	cpus := [2]chan [][]string{
		make(chan [][]string),
		make(chan [][]string) }

	cpuerr := [2]chan error{
		make(chan error),
		make(chan error) }

	go getcpus(cpus[0], cpuerr[0])
	sleep(1)
	go getcpus(cpus[1], cpuerr[1])

	start := <- cpus[0]
	if start == nil { return <- cpuerr[0] }

	end := <- cpus[1]
	if end == nil { return <- cpuerr[1] }

	if len(start) != len(end) {
		return errors.New("somehow we lost/gained some cores")
	}

	ncores := len(start)

	total := make([]int, ncores)
	idle  := make([]int, ncores)

	for i, c := range start {
		for j, v := range c {
			if j == 0 { continue }
			n, err := common.Intify(v)
			if err != nil { return err }
			total[i] += n
		}

		n, err := common.Intify(c[4])
		if err != nil { return err }
		idle[i] = n
	}

	cx := 0

	for i, c := range end {
		ltotal := 0

		for j, v := range c {
			if j == 0 { continue }
			n, err := common.Intify(v)
			if err != nil { return err }
			ltotal += n
		}

		n, err := common.Intify(c[4])
		if err != nil { return err }
		lidle  := n - idle[i]
		ltotal  = ltotal - total[i]
		used   := int((100 * (ltotal - lidle)) / ltotal)

		tbpad := 3
		th    := int(config.H) - tbpad * 2 + 1
		h     := int(th * used / 100)
		fg    := blendGYR(used)
		bg    := drw.Blend(fg, config.Status, 75)

		u.drawRect(cx, tbpad - 1, 3, th, bg, true)
		u.drawRect(cx, tbpad + th - h - 1, 3, h, fg, true)
		cx += 5
	}

	temps := 0

	for i := 0; i < ncores; i ++ {
		file := fmt.Sprintf("/sys/class/thermal/thermal_zone%d/temp", i)
		content, err := common.FileAsLines(file)
		if err != nil { return err }

		n, err := common.Intify(content[0])
		if err != nil { return err }

		temps += n / 1000
	}

	// <=40: green. >=80: red.
	cp := float64(temps/ncores - 40)
	cp /= 40
	cp *= 100
	if cp > 100 { cp = 100 }

	u.drawText(cx, blendGYR(int(cp)), fmt.Sprintf("%d°C", temps / ncores))

	updates <- u
	return nil
}

func init() {
	name := "cpu"
	register(name)

	go func(){
		for {
			checkError(name, cpu(name))
		}
	}()
}