package main

import (
    "fmt"
    "os"
    "strconv"
    "strings"

    "github.com/stianeikeland/go-rpio"
)

func main() {
    // usage: rpicmd board=36 phase=2
    word := 0

    pi := connect()

    for i, a := range os.Args {
        if i != 0 {
            cmds := strings.Split(a, "=")
            cmd := cmds[0]
            val, _ := strconv.Atoi(cmds[1])
            switch cmd {
            case "rw": // both
                val = val & 1
                word += val & 1
            case "sel": // r only
                val = val & 7
                word += (val << 1) & 14
            case "quad": // r only
                val = val & 3
                word += (val << 1) & 6
            case "anadr": // w only
                val = val & 15
                word += (val << 3) & 120
            case "board": // both
                val = val & 127
                word += (val << 8) & 32512
            case "phase": // w only
                val = val & 3
                word += (val << 17) & 393216
            case "pwm": // w only
                val = val & 15
                word += (val << 19) & 7864320
            }
        }
    }
    fmt.Println(word)
    fmt.Println(strconv.FormatInt(int64(word), 2))

    write(word)

}

type rpi struct {
    pins []rpio.Pin
}

func connect() rpi {
    err := rpio.Open()
    if err != nil {
        fmt.Println(err)
    }
    pi := new rpi{}
    pinids := []int{2, 3, 4, 14, 15, 17, 18, 27, 22, 23, 24, 10, 9, 25, 11, 8, 7, 5, 6, 12, 13, 19, 18, 26, 20, 21}
    for i := range pinids {
        pi.pins = append(pi.pins, rpio.Pins(pinids[i]))
    }
    return pi
}

func (pi rpi) strobe() {
    rpi.pins[15].High()
    rpi.pins[15].Low()
}

func (pi rpi) write(word int) {
    if word > 8388607 {
        fmt.Println("word too large,", word, "> 8388607")
        return
    }
    for i,p := range pi.pins {
        p.Output()
        if word&int(math.Pow(2,float64(i))) >> uint(i) == 1 {
            p.High()
        }else{
            p.Low()
        }
    }
    strobe()
}

func(p rpi) read(cmd int) (data int) {
    write(cmd)
    for i, p := range pi {
        if i < 8 {
            p.Input()
        } else {
            p.Output()
        }
    }
    strobe()
    for i,p := range pi {
        if i < 8 {
            data = (data << 1) + int(p.Read())
        }
    }
    return data
}