# -----------------------------------------------------------------------------
# 
# Simple mercator projection
# 
# -----------------------------------------------------------------------------
# Copyright 2010 Daniel Azuma
# 
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
# * Redistributions of source code must retain the above copyright notice,
#   this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
# * Neither the name of the copyright holder, nor the names of any other
#   contributors to this software, may be used to endorse or promote products
#   derived from this software without specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# -----------------------------------------------------------------------------
;


module RGeo
  
  module Geography
    
    module SimpleMercator
      
      
      EQUATORIAL_RADIUS = 6378137.0
      
      
      class Projector
        
        def initialize(geography_factory_, opts_={})
          @geography_factory = geography_factory_
          if ::RGeo.const_defined?(:Geos) && Geos.supported?
            @projection_factory = Geos.factory(:srid => 3857, :buffer_resolution => opts_[:buffer_resolution], :lenient_multi_polygon_assertions => opts_[:lenient_multi_polygon_assertions])
          else
            @projection_factory = nil
          end
        end
        
        
        def projection_factory
          @projection_factory
        end
        
        
        def project(geometry_)
          geometry_.projection
        end
        
        
        def unproject(geometry_)
          case geometry_
          when Features::Point
            dpr_ = Common::Helper::DEGREES_PER_RADIAN
            radius_ = EQUATORIAL_RADIUS
            @geography_factory.point(geometry_.x / radius_ * dpr_,
              (2.0 * ::Math.atan(::Math.exp(geometry_.y / radius_)) - ::Math::PI / 2.0) * dpr_)
          when Features::Line
            @geography_factory.line(unproject(geometry_.start_point), unproject(geometry_.end_point))
          when Features::LinearRing
            @geography_factory.linear_ring(geometry_.points.map{ |p_| unproject(p_) })
          when Features::LineString
            @geography_factory.line_string(geometry_.points.map{ |p_| unproject(p_) })
          when Features::Polygon
            @geography_factory.polygon(unproject(geometry_.exterior_ring),
                                      geometry_.interior_rings.map{ |p_| unproject(p_) })
          when Features::MultiPoint
            @geography_factory.multi_point(geometry_.map{ |p_| unproject(p_) })
          when Features::MultiLineString
            @geography_factory.multi_line_string(geometry_.map{ |p_| unproject(p_) })
          when Features::MultiPolygon
            @geography_factory.multi_polygon(geometry_.map{ |p_| unproject(p_) })
          when Features::GeometryCollection
            @geography_factory.collection(geometry_.map{ |p_| unproject(p_) })
          else
            nil
          end
        end
        
        
        def wraps?
          true
        end
        
        
        def limits_window
          @limits_window ||= ProjectedWindow.new(@geography_factory, -20037508.342789, -20037508.342789, 20037508.342789, 20037508.342789, :is_limits => true)
        end
        
        
      end
      
      
    end
    
  end
  
end