#!/usr/bin/env ruby

require 'pathname'
require 'configurability'
require 'strelka'

require 'strelka/cms' unless defined?( Strelka::CMS )
require 'strelka/cms/page' unless defined?( Strelka::CMS::Page )

# A catalog of Strelka::CMS::Page objects. It provides a collection interface
# over a group of pages, suitable for searching for, or iterating over
# pages matching one or more criteria.
class Strelka::CMS::PageCatalog
	extend Loggability
	include Enumerable

	# Loggability API -- log to the deveiate logger
	log_to :strelka_cms


	# The default glob pattern to match pages.
	DEFAULT_GLOB_PATTERN = '**/*.page'


	#################################################################
	###	I N S T A N C E   M E T H O D S
	#################################################################

	### Create a new PageCatalog that will find and read pages from the configured
	### directory.
	def initialize( basedir=Pathname.pwd, pattern=DEFAULT_GLOB_PATTERN )
		pattern.slice!( 0, 1 ) if pattern.start_with?( '/' )
		self.log.debug "New catalog for pages matching: %s in: %s" % [ pattern, basedir ]
		@basedir  = Pathname( basedir )
		@pageglob = pattern
	end


	######
	public
	######

	# The base directory of the catalog
	attr_reader :basedir

	# The glob pattern that will match a collection of one or more pages
	attr_reader :pageglob


	### Return the glob pattern for pages in this catalog.
	def glob
		return (self.basedir + self.pageglob).to_s
	end


	### Enumerable interface -- if called with a block, load and yield each page matching the
	### #pageglob. If called without a block, return an Enumerator.
	def each
		iter = self.page_enumerator
		if block_given?
			block = Proc.new
			iter.each( &block )
		else
			return iter
		end
	end


	### Return a clone of the directory that will limit the pages in the catalog to those
	### under the given +dir+.
	def relative_to( dir )
		dir = dir.to_s
		dir.slice!( 0, 1 ) if dir.start_with?( '/' )
		self.log.debug "Build new catalog for %p relative to %s" % [ dir, self.basedir ]
		self.class.new( self.basedir + dir, self.pageglob )
	end


	### Return a clone of the directory that will use the specified +pattern+ to find pages
	### instead of the original.
	def matching_pattern( pattern )
		self.class.new( self.basedir, pattern )
	end


	### Return the catalog object as a human-readable string.
	def inspect
		"#<%s:0x%0x %s, %d documents>" % [
			self.class.name,
			self.object_id / 2,
			self.glob,
			self.page_path_enumerator.count,
		]
	end


	#########
	protected
	#########

	### Return an Enumerator that will yield a Pathname for each page matching the #pageglob
	def page_path_enumerator
		self.log.debug "Fetching an enumerator for %s" % [ self.glob ]
		Pathname.glob( self.glob ).each
	end


	### Return an Enumerator that will yield a Strelka::CMS::Page object for each page matching
	### the #pageglob.
	def page_enumerator
		Enumerator.new do |yielder|
			self.page_path_enumerator.each do |path|
				page = Strelka::CMS::Page.load( path, self )
				yielder.yield( page )
			end
		end
	end


end # class Strelka::CMS::PageCatalog