(function(){

	var vec2, Rect, Rooms, UidGenerator, Wall, Surface, sort, _
	if ('window' in this) {
		vec2 = window.vec2
		Rect = window.Rect
		Surface = window.Surface
		Rooms = window.Rooms
		UidGenerator = window.UidGenerator
		Wall = window.Wall
		sort = window.sort
		_ = window._
	}
	else {
		Rooms = require('./_rooms')
		UidGenerator = require('../../util/uid')
		vec2 = require('../../models/vec2')
		Rect = require('../../models/rect')
		Wall = require('../../models/wall')
		Surface = require('../../models/surface')
		sort = require('../../util/sort')
		_ = require('lodash')
		FRONT = 0x1, BACK = 0x2, LEFT = 0x4, RIGHT = 0x8, FLOOR = 0x10, CEILING = 0x20
		PI = Math.PI
		HALF_PI = PI/2
		TOP = CEILING, BOTTOM = FLOOR
		function sidesToString(sides){
			var s = ""
			if (sides & FRONT) s += "front "
			if (sides & BACK)  s += "back "
			if (sides & LEFT)  s += "left "
			if (sides & RIGHT) s += "right "
			if (sides & TOP)  s += "top "
			if (sides & BOTTOM) s += "bottom "
			return s
		}
	}

	Rooms.grouper = new function(){

		var base = this

		base.list = {}
		
		base.uid = new UidGenerator(base.list)
		
		base.build = function (){
			var walls = []
			var collections = base.collect()
			base.cull(collections)
			base.group(walls, collections, FRONT)
			base.group(walls, collections, BACK)
			base.group(walls, collections, LEFT)
			base.group(walls, collections, RIGHT)
			Walls.assign( walls )
			Walls.bind()
		}
		base.collect = function(){			
			var collections = {}
			collections[FRONT] = []
			collections[BACK] = []
			collections[LEFT] = []
			collections[RIGHT] = []
			
			Rooms.forEach(function(room){
				room.mx_walls.forEach(function(mx){
					var side = mx.side || mx.half_side
					collections[side].push(mx)
				})
			})
			
			base.cull(collections)
			
			return collections
		}
		base.cull = function(collections){
			[FRONT, BACK, LEFT, RIGHT].forEach(function(side){
				var collection = collections[side]
				var useX = side & FRONT_BACK
				var useA = side & (FRONT | RIGHT)
				var last_mx
				var widthVec, heightVec
				
				collection.sort( useX ? sort.compare_zx : sort.compare_xz )
				collection.forEach(function(mx){
				  if (mx.culled) {
				    return
				  }
					if (last_mx && mx && last_mx.rect.eq(mx.rect)) {
					  // culls half-walls
						if (last_mx.rect.id == mx.rect.id) {
							last_mx.height += mx.height/2
							last_mx.y += mx.height/4
							last_mx.face.y.b += mx.height/2
						}
						last_mx.side = side
						if (! mx.culled) {
              scene.remove(mx)
              mx.destroy()
              mx.culled = true
            }
						return
					}
					widthVec = mx.rect[useX ? 'x' : 'y'].clone()
					heightVec = new vec2( mx.y - mx.height/2, mx.y + mx.height/2 )
					mx.face = new Rect( widthVec, heightVec )
					last_mx = mx
				})
			})
			return collections
		}
		base.group = function(walls, collections, side){
			var collection = collections[side]
			var useX = side & FRONT_BACK
			var useA = side & (FRONT | LEFT)

			// collection.sort( useX ? sort.compare_zx : sort.compare_xz )
			
			var planes = {}
						
			collection.forEach(function(mx){
				if (mx.culled) return
				var edge = mx.rect[useX ? 'y': 'x'][ useA ? 'a': 'b']
				planes[edge] = planes[edge] || []
				planes[edge].push(mx)
			})
			
			var edges = _.keys(planes)
			edges.forEach(function(edge){
			
				var wall
				
				planes[edge].forEach(function(mx){        
				  
          if (wall) {
            if (useX && wall.vec.b == mx.rect.x.a) {
              wall.vec.b = mx.rect.x.b
              wall.mx.push(mx)
              wall.surface.add(mx.face)
              return
            }
            else if (! useX && wall.vec.b == mx.rect.y.a) {
              wall.vec.b = mx.rect.y.b
              wall.mx.push(mx)
              wall.surface.add(mx.face)
              return
            }
          }
          wall = new Wall ({
            side:    side,
            mx:      [ mx ],
            surface: new Surface( mx.face ),
            vec:     mx.rect[ useX ? 'x' : 'y' ].clone(),
            edge:    mx.rect[ useX ? 'y' : 'x' ][ useA ? 'a' : 'b' ],
          })
          walls.push(wall)
        })
      })
      
			return walls
		}

	}

})()