(function(){

	var vec2, Rect
	if ('window' in this) {
		vec2 = window.vec2
		Rect = window.Rect
	}
	else {
		vec2 = require('./vec2')
		Rect = require('./rect')
	}
	
	var Surface = function (face){
		this.bounds = new Rect (new vec2(0, 0), new vec2(0, 0))
		this.faces = []
		if (face) {
			this.add(face)
		}
	}
	Surface.prototype.add = function(rect){
		if (this.faces.length == 0) {
			this.bounds.x.a = rect.x.a
			this.bounds.x.b = rect.x.a
			this.bounds.y.a = rect.y.a
			this.bounds.y.b = rect.y.a
		}
		this.bounds.x.b += rect.width()
		this.bounds.y.b = Math.max(this.bounds.y.b, rect.height())
		this.faces.push(rect)
	}
	Surface.prototype.fits_scale = function(v, scale){
		v = v.clone().mul(scale)
		return this.fits(v)
	}
	Surface.prototype.fits = function(v){
		var faces = this.faces
		var scratch
		if (this.bounds.x.b < v.a || this.bounds.y.b < v.b) {
			return null
		}
		for (var i = 0; i < faces.length; i++) {
			if (faces[i].fits(v)) {
				return faces[i]
			}
		}
		scratch = new Rect (0,0,0,0)
		for (var i = 0; i < faces.length; i++) {
			if (faces[i].y.length() < v.b) {
				continue
			}
			scratch.x.a = faces[i].x.a
			scratch.x.b = faces[i].x.b
			scratch.y.a = faces[i].y.a
			scratch.y.b = faces[i].y.b
			SEARCH: for (var j = i+1; j < faces.length; j++) {
				if (faces[j].y.a > scratch.y.a) {
					scratch.y.a = faces[j].y.a
				}
				if (faces[j].y.b < scratch.y.b) {
					scratch.y.b = faces[j].y.b
				}
				if (scratch.y.b <= scratch.y.a || scratch.y.length() < v.b) {
					break SEARCH
				}
				scratch.x.b = faces[j].x.b
				if (scratch.fits(v)) {
					return scratch
				}
			}
		}
		return null
	}

	function center_for (dimension, position, delta) {
		var center = new vec2( position.a + dimension.a/2, position.b + dimension.b/2 )
    if (delta) {
      center.a += delta.a
      center.b += delta.b
    }
    return center
	}

	Surface.prototype.clamp_delta = function (bounds, dimension, position, delta) {
		var left_edge = position.a + delta.a - bounds.x.a
		if (left_edge < 0) {
			delta.a -= left_edge
		}

		var right_edge = position.a + dimension.a + delta.a - bounds.x.b
		if (right_edge > 0) {
			delta.a -= right_edge
		}

		var bottom_edge = position.b + delta.b + bounds.y.a
		if (bottom_edge < 0) {
			delta.b -= bottom_edge
		}
		
		var top_edge = position.b + dimension.b + delta.b - bounds.y.b
		if (top_edge > 0) {
			delta.b -= top_edge
		}
	}

	Surface.prototype.translate = function (old_bounds, dimension, position, delta) {
		this.clamp_delta( this.bounds, dimension, position, delta )
		
    var left_side =  this.index_for_x( position.a + delta.a, 0 )
    var right_side = this.index_for_x( position.a + dimension.a + delta.a, left_side )

    var bounds = this.sides[left_side].clone()

    for (var i = left_side+1; i <= right_side; i++) {
			if (this.faces[i].y.a > bounds.y.a) {
				bounds.y.a = this.faces[i].y.a
			}
			if (this.faces[i].y.b < bounds.y.b) {
				bounds.y.b = this.faces[i].y.b
			}
      bounds.x.b = this.faces[i].x.b
    }

    if (bounds.width() > dimension.a || bounds.height() > dimension.b) {
      bounds = old_bounds
    }

    this.clamp_delta(bounds, dimension, position, delta)
    return bounds
	}
	
	Surface.prototype.index_for_x = function(x, min_i){
    min_i = min_i || 0
		if (x < 0 || x > width) {
			return -1
		}
		for (var i = min_i; i < this.faces.length; i++) {
			if (this.faces[i].x.contains(x)) {
				return i
			}
		}
		return -1
	}

	Surface.prototype.bounds_at_index_with_dimensions = function(index, dimensions){
    var faces = this.faces
    if (index == -1) index = this.faces.length-1

		var bounds, intersection
		var width = dimensions.a
    var height = dimensions.b

		for (var i = index; i >= 0; i--) {
			var face = faces[i]
			if (face.y.length() < height) {
        if (bounds) break
        else continue
			}
      if (! bounds) {
        bounds = face.clone()
        bounds.last = i
      }
      else if (bounds.width() < width) {
      	intersection = bounds.y.intersection(face.y)
      	if (intersection.length() < height) {
      		break
      	}
      	else {
      		bounds.y.a = intersection.a
      		bounds.y.b = intersection.b
					bounds.x.a = face.x.a
					bounds.first = i
					continue
				}
      }
      else {
				if (face.y.a > bounds.y.a) break
				if (face.y.b < bounds.y.b) break
			}
			bounds.x.a = face.x.a
			bounds.first = i
		}

		for (var i = bounds ? bounds.last+1 : index+1; i < faces.length; i++) {
			var face = faces[i]
			if (face.y.length() < height) {
        if (bounds) break
        else continue
			}
      if (! bounds) {
        bounds = face.clone()
        bounds.first = i
      }
      else if (bounds.width() < width) {
      	intersection = bounds.y.intersection(face.y)
      	if (intersection.length() < height) {
      		break
      	}
      	else {
      		bounds.y.a = intersection.a
      		bounds.y.b = intersection.b
      		bounds.x.b = face.x.b
      		bounds.last = i
      		continue
      	}
      }
			if (face.y.a > bounds.y.a) break
			if (face.y.b < bounds.y.b) break
			bounds.x.b = face.x.b
			bounds.last = i
		}

    if (! bounds) {
    	// console.log('no bounds')
      return false
    }
    else if (bounds.width() < width) {
    	// console.log('too narrow')
      return false
    }
		return bounds
	}
	
	Surface.prototype.bounds_at_index = function(index){
    var faces = this.faces
    if (index == -1) index = this.faces.length-1

		var bounds = faces[index].clone()
		var height = faces[index].height()
		bounds.first = bounds.last = index

		for (var i = index-1; i >= 0; i--) {
			var face = faces[i]
			if (face.y.length() < height) break
			if (face.y.a > bounds.y.a) break
			if (face.y.b < bounds.y.b) break
      
			bounds.x.a = face.x.a
			bounds.first = i
		}
		
		for (var i = index+1; i < faces.length; i++) {
			var face = faces[i]
			if (face.y.length() < height) break
			if (face.y.a > bounds.y.a) break
			if (face.y.b < bounds.y.b) break
			
			bounds.x.b = face.x.b
			bounds.last = i
		}
		return bounds
	}
	
	if ('window' in this) {
		window.Surface = Surface
	}
	else {
		module.exports = Surface
	}
})()