ioquatix/utopia-gallery

# Copyright, 2012, by Samuel G. D. Williams. <http://www.codeotaku.com>
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

require 'vips/thumbnail'
require 'fileutils'

require 'utopia/path'

module Utopia
    module Gallery
        class Process
            def initialize(name)
                @name = name.to_sym
            end
            
            attr :name
            
            # The relative path for the output generated by this process, given a specific input media:
            def relative_path(media)
                source_path = media.path
                
                File.join(File.dirname(source_path), @name.to_s, File.basename(source_path))
            end
            
            def self.mtime(path)
                File.lstat(path).mtime
            end
            
            def self.fresh?(input_path, output_path)
                # We are not fresh if the output path doesn't exist:
                return false unless File.exist?(output_path)
                
                # We are not fresh if the input is newere than the output:
                return false if mtime(input_path) > mtime(output_path)
                
                # Otherwise, we are so fresh:
                return true
            end
            
            def self.link(input_path, output_path)
                # Compute a path to input_path, relative to output_path
                shortest_path = Utopia::Path.shortest_path(input_path, output_path)
                FileUtils.ln_s(shortest_path, output_path, force: true)
            end
        end
        
        class ResizeImage < Process
            def initialize(name, size = [800, 800], method = :resize_to_fit, **options)
                super(name)
                
                @size = size
                @method = method
                @options = options
            end
            
            attr :size
            attr :method
            attr :options
            
            def relative_path(media)
                path = super
                
                if path.match?(/\.(pdf|svg)$/)
                    path += ".png"
                end
                
                return path
            end
            
            def generate_output(resizer, output_path)
                if output_image = resizer.send(@method, @size)
                    output_image.write_to_file output_path, **@options
                else
                    Process.link(resizer.input_path, output_path)
                end
            end
            
            def resizer_for(input_path)
                Vips::Thumbnail::Resizer.new(input_path)
            end
            
            def call(cache)
                input_path = cache.input_path
                output_path = cache.output_path_for(self)
                
                return if Process.fresh?(input_path, output_path)
                
                resizer = resizer_for(cache.input_path)
                
                FileUtils.mkdir_p(File.dirname(output_path))
                
                generate_output(resizer, output_path)
            ensure
                resizer&.close
            end
        end
        
        class ResizeVector < ResizeImage
            def initialize(*args, extension: ".png", scale: 1, **options)
                super(*args, **options)
                @extension = extension
                @scale = scale
            end
            
            def relative_path(media)
                super + @extension
            end
            
            def generate_output(resizer, output_path)
                if output_image = resizer.send(@method, @size)
                    output_image.write_to_file output_path, **@options
                else
                    resizer.input_image.write_to_file output_path, **@options
                end
            end
            
            def resizer_for(input_path)
                Vips::Thumbnail::Resizer.new(input_path, scale: @scale)
            end
        end
    end
end