/* Common structures and methods used across all coreutils */

package jsh

import (
	"encoding/json"
	"fmt"
)

type JshFrame struct {
	StdOut interface{}
	StdErr interface{}
}

// Size prefixes as integers, using binary representation
type Unit int

const (
	B  Unit = 2 ^ 0
	KB Unit = 2 ^ 10
	MB Unit = 2 ^ 20
	GB Unit = 2 ^ 30
	TB Unit = 2 ^ 40
)

// Converts a JshFrame into a JSON string
func (j JshFrame) ToJson() *string {
	jsonOut, err := json.Marshal(j)
	if err != nil {
		panic(err)
	}
	jsonString := string(jsonOut)
	return &jsonString
}

// goroutine for outputing frames. Pass it a channel of pointers to JshFrames,
// and it will send "true" to the done channel once you close the queue channel.
func OutputFrames(queue chan *JshFrame, done chan bool) {
	fmt.Printf("[")
	isFirst := true
	for {
		frame, more := <-queue
		if more {
			if !isFirst {
				fmt.Printf(",")
			} else {
				isFirst = false
			}
			fmt.Printf(*frame.ToJson())
		} else {
			fmt.Printf("]\n")
			done <- true
			return
		}
	}
}