require 'find'
require 'open4'
require 'watchful/defaultconfiguration'
require "commandline"

module Watchful
	
	def self.each_source_file_in_dir(path = Dir.pwd)
		Find.find(path) do |filepath|
			next if FileTest.directory?(filepath)
			yield(filepath)
		end
	end
	
	def self.check_for_interrupts
		begin
			sleep 1
		rescue Interrupt
			puts # new line
			exit 0
		end
	end
	
	CONFIGURATION_FILE_NAME = 'watchful'
	
	def self.load_configuration(path, use_default = false)

		# todo: more efficient loading of configurations
		# todo: check that relative paths work on Windows
		
		local = File.expand_path("#{path}/#{CONFIGURATION_FILE_NAME}")
		user = File.expand_path("~/#{CONFIGURATION_FILE_NAME}")
		
		if File.exists? local
			debug "Loading #{local}"
			load local
		elsif File.exists? user
			debug "Loading #{user}"
			load user
		end
		
	end
	
	@files_with_errors = Hash.new # {:path => '', :mtime => ### }
	
	def self.watch_files(path)
		@output_file_extensions = Configuration.active_configuration.actions.collect do |a|
			a.out
		end
		loop do
			check_for_interrupts
			each_source_file_in_dir(path) do |file_path|
				extension = compound_extension_of(file_path)
				
				action = Configuration.active_configuration.actions.find { |a| a.input_file? file_path}
				
				next if action.nil?
				
				output_path = action.output_path_for(file_path)
				
				if (!File.exists?(output_path)) or younger_than(file_path, output_path)
					error_mtime = @files_with_errors[file_path]
					next if error_mtime && error_mtime >= File.stat(file_path).mtime
					do_action(file_path, action)
				end
				
			end
		end
	end
	
	def self.do_action(source_file, action)

		puts "#{action.name}: #{source_file}"

		command = action.command_string(source_file)
		
		debug "\t#{command}"
		
		proc_pid, proc_stdin, proc_stdout, proc_stderr = Open4::popen4(command)
		proc_ignored, proc_status = Process::waitpid2(proc_pid)

		error = proc_stderr.gets

		if proc_status && !error
			if HAVE_GROWL
				growl = Growl.new
		        growl.title = action.name
		        growl.message = "#{source_file}"
		        growl.run
			end
			@files_with_errors.delete(source_file)
		else
			$stderr.puts("ERROR -- #{action.name} -- #{source_file}")
			$stderr.puts(error)
			if HAVE_GROWL
				growl = Growl.new
		        growl.title = "ERROR: #{action.name}"
		        growl.message = error
		        growl.run
			end
			@files_with_errors[source_file] = File.stat(source_file).mtime
		end
		
	end
	
end