var graf = require('graf')
var crypto = require('crypto')

function a(x, y) { return x + y }
function add() {
	return Array.prototype.slice.call(arguments).reduce(a)
}

function m(x, y) { return x * y }
function multiply() {
	return Array.prototype.slice.call(arguments).reduce(m)
}

var g = graf(
	{
		input: ['a', 'b', 'x'],
		nodes: {
			sum: {
				input: ['a', 'b'],
				syncFn: add
			},
			multiply: {
				input: ['sum', 'sum', 'randomInt'],
				syncFn: multiply
			},
			randomBytes: {
				input: ['x'],
				fn: crypto.randomBytes
			},
			randomInt: {
				input: ['randomBytes'],
				syncFn: function (bytes) {
					return bytes.readUInt8(0)
				}
			},
			foo: {
				input: ['sum', 'randomInt'],
				syncFn: function (sum, int) {
					console.log("sum: %d int: %d", sum, int)
				}
			}
		},
		output: 'multiply'
	}
)

g(3, 2, 1, console.log)

var spec = {
	input: ['x', 'y', 'z']
}

var g = graf(spec)

g(1, 2, 3)

// x = 1
// y = 2
// z = 3

var spec = {
	input: ['r', 'b'],
	nodes: {
		red: {
			input: ['r'],
			fn: computeRed
		},
		blue: {
			input: ['red', 'b'],
			fn: computeBlue
		},
		green: {
			after: ['blue'],
			fn: computeGreen
		}
	}
}

/*
Red will run first, followed by blue, then green.

Green has no input, so it could have run at the same time
as red if it didn't have an "after" set. "after" is useful
for manually ordering execution.
*/

var spec = {
	nodes: {
		red: {
			fn: function (cb) { cb(null, "red") }
		},
		blue: {
			input: ['red'],
			syncFn: function (red) { return "hello " + red }
		}
	},
	output: 'blue'
}

var g = graf(spec)

g(console.log)

// null "hello red"