# rubygems
require 'rubygems'
require 'optparse'
require 'liquid'

require 'core_ext/hash'

require 'stack/configuration'
require 'stack/generator'
require 'stack/runner'

require 'stack/template'
require 'stack/parsable'

require 'stack/templates/page'
require 'stack/templates/layout'

module Stack
  # Default options used by stack, overridden from the command line or YML configration file.
  DEFAULTS = {
    :source => '.',
    :target => File.join('.', '_stack')
  }.freeze
  
  # Array of valid commands stack can use
  COMMANDS = %w(create generate server)
  
  # Array of valid extensions
  EXTENSIONS = %w(.html .markdown .mdown)
  
  class << self
    attr_accessor :runner
  end
  
  # Parses the options configuration from the command line
  def self.parse!(argv)
    config = { }
    
    parser = OptionParser.new do |opts|
      opts.banner = "Usage: stack [options] #{Stack::COMMANDS.join('|')}"

      opts.on("-s", "--source [DIR]", "Directory to use as the source for generating a stack") do |l|
        if !l.nil?
          config[:source] = l
          config[:target] = "#{config[:source]}_stack"
        end
      end
      opts.on("-t", "--target [DIR]", "Directory to use as the target directory") do |l| config[:target] = l unless l.nil? end
      
      opts.on_tail("-h", "--help", "Show this message") { puts opts; exit }
      opts.on_tail("-v", "--version" "Show version") do puts "stack #{Stack::version}"; exit; end
    end
    
    parser.parse! argv
    
    options = Stack::configuration(config)
    
    options
  end
  
  # Merges the configuration from YAML file, command line and defaults
  def self.configuration(override)
    config = { }
    source = File.join(override['source'] || Stack::DEFAULTS[:source])
    
    config_file = File.join(source, "_stack.yml")
    
    begin
      yml = YAML.load_file(config_file)
      
      raise "Invalid configuration - #{config_file}" if !config.is_a?(Hash)
      
      yml.each { |key, value| config[key.to_sym] = value }
      
      STDOUT.puts "Configuration loaded from #{config_file}"
    rescue => error
      STDERR.puts "WARNING: Could not read configuration. Using defaults (and options)."
      STDERR.puts "\t" + error.to_s
    end
    
    # Merge configuration with defaults
    Stack::DEFAULTS.deep_merge(override).deep_merge(config)
  end
  
  # Stacks current version
  def self.version
    version_file = File.join(File.dirname(__FILE__), *%w[.. VERSION.yml])
    
    if File.exist?(version_file)
      yml = YAML.load(File.read(version_file))
    
      "#{yml[:major]}.#{yml[:minor]}.#{yml[:patch]}"
    else
      "0.0.0"
    end
  end
end