module Ouija

# File lib/ouija/ouija.rb, line 16
def session(topic, context={})
  topic = topic.to_s
  unless topics.include?(topic)
    raise Error.new "Unknown topic \"#{topic}\""
  end
  Planchette.new(scope_topic(topic, context))
end

# File lib/ouija/ouija.rb, line 5
def setup(options={})
  @options = options
  # ToDo: For other mediums, include options logic here (defaulting to YAML)
  @channel = stringify_keys_recursive(Medium::Yaml.new.channel(options))
  true
end

# File lib/ouija/ouija.rb, line 12
def topics
  @channel.keys
end

# File lib/ouija/ouija.rb, line 68
def get_environment
  @options[:environment] || @options[:env] || ENV['RAILS_ENV'] || ENV['OUIJA_ENV'] || 'development'
end

# File lib/ouija/ouija.rb, line 72
def get_hostname
  @options[:hostname] || @options[:host] || begin
    require 'socket'
    Socket.gethostname rescue nil
  end
end

# File lib/ouija/ouija.rb, line 56
def recursive_merge!(hash, other_hash)
  other_hash.each_pair do |k, v|
    cur_val = hash[k]
    if cur_val.is_a?(Hash) && v.is_a?(Hash)
      hash[k] = recursive_merge!(cur_val, v)
    elsif !v.nil?
      hash[k] = v
    end
  end
  hash
end

# File lib/ouija/ouija.rb, line 37
def scope_topic(topic, context={})
  hash = @channel[topic] || {}
  environment = context[:environment] || context[:env] || get_environment
  hostname = context[:hostname] || context[:host] || get_hostname

  #puts "Loading config for environment \"#{environment}\" and hostname \"#{hostname}\"."

  base_hash = hash.has_key?('default') ? hash['default'].dup : {}
  if !environment.nil? && !environment.empty? && !hash['environments'].nil? && !hash['environments'][environment.to_s].nil?
    env_hash = hash['environments'][environment.to_s]
    recursive_merge!(base_hash, env_hash)
  end
  if !hostname.nil? && !hostname.empty? && !hash['hosts'].nil? && !hash['hosts'][hostname.to_s].nil?
    host_hash = hash['hosts'][hostname.to_s]
    recursive_merge!(base_hash, host_hash)
  end
  base_hash
end

# File lib/ouija/ouija.rb, line 27
def stringify_keys_recursive(hash)
  stringified_hash = {}
  hash.each_pair do |k,v|
    key = k.kind_of?(Symbol) ? k.to_s : k
    value = v.is_a?(Hash) ? stringify_keys_recursive(v) : v
    stringified_hash[key] = value
  end
  stringified_hash
end