package pipe

import (
	"testing"
)

const Values = 999
const Multiplier = 1000

func createCountPipe() <-chan int {
	cout := make(chan int)

	go func(<-chan int) {
		for i := 1; i < Values; i++ {
			cout <- i
		}
		close(cout)
	}(cout)

	return cout
}

func multiply(in int) int {
	return in * Multiplier
}

func devide(in int) int {
	return in / Multiplier
}

func TestProc(t *testing.T) {
	c := createCountPipe()
	am := Proc(c, 8, multiply)
	ad := Proc(am, 8, devide)
	a := Proc(ad, 8, multiply)

	out := make([]int, Values-1)

	count := 0
	for i := range a {
		out[count] = i
		count++
	}

	for _, v := range out {
		if v < Multiplier {
			t.Errorf("Invalid output %d", v)
		}
	}
}

func TestYield(t *testing.T) {
	lin := make([]int, Values)

	for i := 0; i < Values; i++ {
		lin[i] = i
	}

	cout := Yield(lin)

	count := 0
	for out := range cout {
		if out != lin[count] {
			t.Errorf("Invalid output %d", out)
		}
		count++
	}
}

type buffer struct {
	value int
}

func createBuffers() []*buffer {
	buffers := make([]*buffer, Values)

	for i := 0; i < Values; i++ {
		buffers[i] = &buffer{value: i}
	}

	return buffers
}

func multiplyBuffer(in *buffer) *buffer {
	in.value = in.value * Multiplier
	return in
}

func devideBuffer(in *buffer) {
	in.value = in.value / Multiplier
}

func TestTailProc(t *testing.T) {
	buffers := createBuffers()
	c := Yield(buffers)
	am := Proc(c, 8, multiplyBuffer)
	TailProc(am, 8, devideBuffer)

	for i, v := range buffers {
		if v.value != i {
			t.Errorf("Invalid output %d != %d", v.value, i)
		}
	}
}

func TestWait(t *testing.T) {
	buffers := createBuffers()
	c := Yield(buffers)
	am := Proc(c, 8, multiplyBuffer)
	Wait(am)

	for i, v := range buffers {
		if v.value != (i * Multiplier) {
			t.Errorf("Invalid output %d != %d", v.value, i)
		}
	}
}