#!/usr/bin/env ruby

#--
# Copyright (c) 2006 Jeff Barczewski
#
# 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.
#++
#
# Setup hook to intercept template_exist? calls and read_template_file
# so that rails can find masterview templates. MasterView cannot use the 
# provided hooks because rails always assumes everything is file based
# and that there will be a file for each thing to render. If the 
# template dispatching code is enriched in the future we may be able 
# to rewrite this code to use the provided hooks
# 
#

MasterView::Log.info { 'Adding hooks to enable Rails to read erb directly from MasterView' }

module ActionView #:nodoc:
  class Base #:nodoc:

    # checks for template existence, uses standard rails file based check first and if not found
    # check MasterView paths because might not exist on file system
    alias :template_exists_pre_mv? :template_exists? #:nodoc:
    def template_exists?(template_path, extension) #:nodoc:
      short_path = template_path+'.'+extension.to_s
      template_exists_pre_mv?(template_path, extension) || MasterView::IOMgr.erb.path(short_path).exist?
    end

    # checks for the existence of the template in MasterView first before using the 
    # rails file system based read_template_file
    alias :read_template_file_pre_mv :read_template_file  #:nodoc:
    def read_template_file(template_path, extension)  #:nodoc:
      short_path_mio = MasterView::IOMgr.erb.path(short_relative_path_mv(template_path))
      if short_path_mio.exist?
        short_path_mio.read
      else # use original rails read_template_file
        read_template_file_pre_mv(template_path, extension)
      end
    end

    # Check whether compilation is necessary.
    # Since rails compile_templat? is file based there was no easy way to hook into
    # this, so much of this method had to be duplicated.
    # If file_name exists in MasterView then check mtime from it otherwise defer to 
    # original code.
    alias :compile_template_pre_mv? :compile_template?   #:nodoc:
    def compile_template?(template, file_name, local_assigns) #:nodoc:
      short_path_mio = (file_name && !file_name.empty?) ? MasterView::IOMgr.erb.path(short_relative_path_mv(file_name)) : nil
      if short_path_mio && short_path_mio.exist? # mio template
        method_key    = file_name || template
        render_symbol = @@method_names[method_key]

        if @@compile_time[render_symbol] && supports_local_assigns?(render_symbol, local_assigns)
          if file_name && !@@cache_template_loading 
            need_to_compile = (@@compile_time[render_symbol] < short_path_mio.mtime) # use mio.mtime instead of File.mtime
            MasterView::Log.debug{ 'compile_template? template_short_path = '+short_path_mio.pathname.to_s+' compile?='+need_to_compile.to_s }
            need_to_compile
          end
        else
          true
        end
      else # use original file based mtime checking
        compile_template_pre_mv?(template, file_name, local_assigns)
      end
    end

    private

    # returns the short path relative to view_base since MasterView uses relative paths exclusively
    def short_relative_path_mv(template_path) #:nodoc:
      (template_path.starts_with?(self.base_path)) ? template_path[self.base_path.length+1..-1] : template_path
    end

  end


  # The TemplateError exception is raised when the compilation of the template fails. This exception then gathers a
  # bunch of intimate details and uses it to report a very precise exception message.
  # Extend source_extract to be able to pull from MasterView if exists and fallback to file system
  class TemplateError < ActionViewError #:nodoc:

    def source_extract(indention = 0) #:nodoc:

      #added/modified the following three lines to support reading from MasterView with fallback to file system
      relative_path = (@file_name.starts_with?(@base_path)) ? @file_name[@base_path.length+1..-1] : @file_name
      short_path_mio = (relative_path && !relative_path.empty?) ? MasterView::IOMgr.erb.path(relative_path) : nil
      source_code = (short_path_mio && short_path_mio.exist?) ? StringIO.new(short_path_mio.read).readlines : IO.readlines(@file_name)
      
      start_on_line = [ line_number - SOURCE_CODE_RADIUS - 1, 0 ].max
      end_on_line   = [ line_number + SOURCE_CODE_RADIUS - 1, source_code.length].min

      line_counter = start_on_line
      extract = source_code[start_on_line..end_on_line].collect do |line| 
        line_counter += 1
        "#{' ' * indention}#{line_counter}: " + line
      end

      extract.join
    end
  end

end




module ActionController #:nodoc:
  module Layout #:nodoc:
    module ClassMethods

      # get list of layout template paths, original rails implementation assumes everything is file based
      # so this method is enhanced to pull layouts out of MasterView and concatenate them to the list
      # from rails
      alias :layout_list_pre_mv :layout_list
      def layout_list
        mv_layouts = []
        MasterView::IOMgr.erb.find do |mio|
         mv_layouts << "#{template_root}/"+mio.pathname.to_s if mio.pathname.to_s.starts_with?('layouts/')
        end
        layout_list_pre_mv.concat( mv_layouts )
      end

    end
  end
end

MasterView::LoadedFeatures[:rails_erb_mv_direct] = true