#
# Author:: Adam Jacob (<adam@opscode.com>)
# Author:: Christopher Brown (<cb@opscode.com>)
# Copyright:: Copyright (c) 2009 Opscode, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require 'forwardable'
require 'chef/version'
require 'mixlib/cli'
require 'chef/workstation_config_loader'
require 'chef/mixin/convert_to_class_name'
require 'chef/mixin/path_sanity'
require 'chef/knife/core/subcommand_loader'
require 'chef/knife/core/ui'
require 'chef/local_mode'
require 'chef/rest'
require 'chef/http/authenticator'
require 'pp'

class Chef
  class Knife

    Chef::REST::RESTRequest.user_agent = "Chef Knife#{Chef::REST::RESTRequest::UA_COMMON}"

    include Mixlib::CLI
    include Chef::Mixin::PathSanity
    extend Chef::Mixin::ConvertToClassName
    extend Forwardable

    # Backwards Compat:
    # Ideally, we should not vomit all of these methods into this base class;
    # instead, they should be accessed by hitting the ui object directly.
    def_delegator :@ui, :stdout
    def_delegator :@ui, :stderr
    def_delegator :@ui, :stdin
    def_delegator :@ui, :msg
    def_delegator :@ui, :ask_question
    def_delegator :@ui, :pretty_print
    def_delegator :@ui, :output
    def_delegator :@ui, :format_list_for_display
    def_delegator :@ui, :format_for_display
    def_delegator :@ui, :format_cookbook_list_for_display
    def_delegator :@ui, :edit_data
    def_delegator :@ui, :edit_hash
    def_delegator :@ui, :edit_object
    def_delegator :@ui, :confirm

    attr_accessor :name_args
    attr_accessor :ui

    # Configure mixlib-cli to always separate defaults from user-supplied CLI options
    def self.use_separate_defaults?
      true
    end

    def self.ui
      @ui ||= Chef::Knife::UI.new(STDOUT, STDERR, STDIN, {})
    end

    def self.msg(msg="")
      ui.msg(msg)
    end

    def self.reset_config_loader!
      @@chef_config_dir = nil
      @config_loader = nil
    end

    def self.reset_subcommands!
      @@subcommands = {}
      @subcommands_by_category = nil
    end

    def self.inherited(subclass)
      unless subclass.unnamed?
        subcommands[subclass.snake_case_name] = subclass
      end
    end

    # Explicitly set the category for the current command to +new_category+
    # The category is normally determined from the first word of the command
    # name, but some commands make more sense using two or more words
    # ===Arguments
    # new_category::: A String to set the category to (see examples)
    # ===Examples:
    # Data bag commands would be in the 'data' category by default. To put them
    # in the 'data bag' category:
    #   category('data bag')
    def self.category(new_category)
      @category = new_category
    end

    def self.subcommand_category
      @category || snake_case_name.split('_').first unless unnamed?
    end

    def self.snake_case_name
      convert_to_snake_case(name.split('::').last) unless unnamed?
    end

    def self.common_name
      snake_case_name.split('_').join(' ')
    end

    # Does this class have a name? (Classes created via Class.new don't)
    def self.unnamed?
      name.nil? || name.empty?
    end

    def self.subcommand_loader
      @subcommand_loader ||= Knife::SubcommandLoader.new(chef_config_dir)
    end

    def self.load_commands
      @commands_loaded ||= subcommand_loader.load_commands
    end

    def self.subcommands
      @@subcommands ||= {}
    end

    def self.subcommands_by_category
      unless @subcommands_by_category
        @subcommands_by_category = Hash.new { |hash, key| hash[key] = [] }
        subcommands.each do |snake_cased, klass|
          @subcommands_by_category[klass.subcommand_category] << snake_cased
        end
      end
      @subcommands_by_category
    end

    # Print the list of subcommands knife knows about. If +preferred_category+
    # is given, only subcommands in that category are shown
    def self.list_commands(preferred_category=nil)
      load_commands

      category_desc = preferred_category ? preferred_category + " " : ''
      msg "Available #{category_desc}subcommands: (for details, knife SUB-COMMAND --help)\n\n"

      if preferred_category && subcommands_by_category.key?(preferred_category)
        commands_to_show = {preferred_category => subcommands_by_category[preferred_category]}
      else
        commands_to_show = subcommands_by_category
      end

      commands_to_show.sort.each do |category, commands|
        next if category =~ /deprecated/i
        msg "** #{category.upcase} COMMANDS **"
        commands.sort.each do |command|
          msg subcommands[command].banner if subcommands[command]
        end
        msg
      end
    end

    # Shared with subclasses
    @@chef_config_dir = nil

    def self.config_loader
      @config_loader ||= WorkstationConfigLoader.new(nil, Chef::Log)
    end

    def self.load_config(explicit_config_file)
      config_loader.explicit_config_file = explicit_config_file
      config_loader.load

      ui.warn("No knife configuration file found") if config_loader.no_config_found?

      config_loader
    rescue Exceptions::ConfigurationError => e
      ui.error(ui.color("CONFIGURATION ERROR:", :red) + e.message)
      exit 1
    end

    def self.chef_config_dir
      @@chef_config_dir ||= config_loader.chef_config_dir
    end

    # Run knife for the given +args+ (ARGV), adding +options+ to the list of
    # CLI options that the subcommand knows how to handle.
    # ===Arguments
    # args::: usually ARGV
    # options::: A Mixlib::CLI option parser hash. These +options+ are how
    # subcommands know about global knife CLI options
    def self.run(args, options={})
      # Fallback debug logging. Normally the logger isn't configured until we
      # read the config, but this means any logging that happens before the
      # config file is read may be lost. If the KNIFE_DEBUG variable is set, we
      # setup the logger for debug logging to stderr immediately to catch info
      # from early in the setup process.
      if ENV['KNIFE_DEBUG']
        Chef::Log.init($stderr)
        Chef::Log.level(:debug)
      end

      load_commands
      subcommand_class = subcommand_class_from(args)
      subcommand_class.options = options.merge!(subcommand_class.options)
      subcommand_class.load_deps
      instance = subcommand_class.new(args)
      instance.configure_chef
      instance.run_with_pretty_exceptions
    end

    def self.guess_category(args)
      category_words = args.select {|arg| arg =~ /^(([[:alnum:]])[[:alnum:]\_\-]+)$/ }
      category_words.map! {|w| w.split('-')}.flatten!
      matching_category = nil
      while (!matching_category) && (!category_words.empty?)
        candidate_category = category_words.join(' ')
        matching_category = candidate_category if subcommands_by_category.key?(candidate_category)
        matching_category || category_words.pop
      end
      matching_category
    end

    def self.subcommand_class_from(args)
      command_words = args.select {|arg| arg =~ /^(([[:alnum:]])[[:alnum:]\_\-]+)$/ }

      subcommand_class = nil

      while ( !subcommand_class ) && ( !command_words.empty? )
        snake_case_class_name = command_words.join("_")
        unless subcommand_class = subcommands[snake_case_class_name]
          command_words.pop
        end
      end
      # see if we got the command as e.g., knife node-list
      subcommand_class ||= subcommands[args.first.gsub('-', '_')]
      subcommand_class || subcommand_not_found!(args)
    end

    def self.dependency_loaders
      @dependency_loaders ||= []
    end

    def self.deps(&block)
      dependency_loaders << block
    end

    def self.load_deps
      dependency_loaders.each do |dep_loader|
        dep_loader.call
      end
    end

    private

    OFFICIAL_PLUGINS = %w[ec2 rackspace windows openstack terremark bluebox]

    # :nodoc:
    # Error out and print usage. probably because the arguments given by the
    # user could not be resolved to a subcommand.
    def self.subcommand_not_found!(args)
      ui.fatal("Cannot find sub command for: '#{args.join(' ')}'")

      if category_commands = guess_category(args)
        list_commands(category_commands)
      elsif missing_plugin = ( OFFICIAL_PLUGINS.find {|plugin| plugin == args[0]} )
        ui.info("The #{missing_plugin} commands were moved to plugins in Chef 0.10")
        ui.info("You can install the plugin with `(sudo) gem install knife-#{missing_plugin}`")
        ui.info("Use `chef gem install knife-#{missing_plugin}` instead if using ChefDK")
      else
        list_commands
      end

      exit 10
    end

    def self.reset_config_path!
      @@chef_config_dir = nil
    end

    reset_config_path!

    public

    # Create a new instance of the current class configured for the given
    # arguments and options
    def initialize(argv=[])
      super() # having to call super in initialize is the most annoying anti-pattern :(
      @ui = Chef::Knife::UI.new(STDOUT, STDERR, STDIN, config)

      command_name_words = self.class.snake_case_name.split('_')

      # Mixlib::CLI ignores the embedded name_args
      @name_args = parse_options(argv)
      @name_args.delete(command_name_words.join('-'))
      @name_args.reject! { |name_arg| command_name_words.delete(name_arg) }

      # knife node run_list add requires that we have extra logic to handle
      # the case that command name words could be joined by an underscore :/
      command_name_words = command_name_words.join('_')
      @name_args.reject! { |name_arg| command_name_words == name_arg }

      if config[:help]
        msg opt_parser
        exit 1
      end

      # copy Mixlib::CLI over so that it can be configured in knife.rb
      # config file
      Chef::Config[:verbosity] = config[:verbosity]
    end

    def parse_options(args)
      super
    rescue OptionParser::InvalidOption => e
      puts "Error: " + e.to_s
      show_usage
      exit(1)
    end

    # Returns a subset of the Chef::Config[:knife] Hash that is relevant to the
    # currently executing knife command. This is used by #configure_chef to
    # apply settings from knife.rb to the +config+ hash.
    def config_file_settings
      config_file_settings = {}
      self.class.options.keys.each do |key|
        config_file_settings[key] = Chef::Config[:knife][key] if Chef::Config[:knife].has_key?(key)
      end
      config_file_settings
    end

    # Apply Config in this order:
    # defaults from mixlib-cli
    # settings from config file, via Chef::Config[:knife]
    # config from command line
    def merge_configs
      # Apply config file settings on top of mixlib-cli defaults
      combined_config = default_config.merge(config_file_settings)
      # Apply user-supplied options on top of the above combination
      combined_config = combined_config.merge(config)
      # replace the config hash from mixlib-cli with our own.
      # Need to use the mutate-in-place #replace method instead of assigning to
      # the instance variable because other code may have a reference to the
      # original config hash object.
      config.replace(combined_config)
    end

    # Catch-all method that does any massaging needed for various config
    # components, such as expanding file paths and converting verbosity level
    # into log level.
    def apply_computed_config
      Chef::Config[:color] = config[:color]

      case Chef::Config[:verbosity]
      when 0, nil
        Chef::Config[:log_level] = :warn
      when 1
        Chef::Config[:log_level] = :info
      else
        Chef::Config[:log_level] = :debug
      end

      Chef::Config[:log_level] = :debug if ENV['KNIFE_DEBUG']

      Chef::Config[:node_name]         = config[:node_name]       if config[:node_name]
      Chef::Config[:client_key]        = config[:client_key]      if config[:client_key]
      Chef::Config[:chef_server_url]   = config[:chef_server_url] if config[:chef_server_url]
      Chef::Config[:environment]       = config[:environment]     if config[:environment]

      Chef::Config.local_mode = config[:local_mode] if config.has_key?(:local_mode)

      Chef::Config.listen = config[:listen] if config.has_key?(:listen)

      if Chef::Config.local_mode && !Chef::Config.has_key?(:cookbook_path) && !Chef::Config.has_key?(:chef_repo_path)
        Chef::Config.chef_repo_path = Chef::Config.find_chef_repo_path(Dir.pwd)
      end
      Chef::Config.chef_zero.host = config[:chef_zero_host] if config[:chef_zero_host]
      Chef::Config.chef_zero.port = config[:chef_zero_port] if config[:chef_zero_port]

      # Expand a relative path from the config directory. Config from command
      # line should already be expanded, and absolute paths will be unchanged.
      if Chef::Config[:client_key] && config[:config_file]
        Chef::Config[:client_key] = File.expand_path(Chef::Config[:client_key], File.dirname(config[:config_file]))
      end

      Mixlib::Log::Formatter.show_time = false
      Chef::Log.init(Chef::Config[:log_location])
      Chef::Log.level(Chef::Config[:log_level] || :error)

      if Chef::Config[:node_name] && Chef::Config[:node_name].bytesize > 90
        # node names > 90 bytes only work with authentication protocol >= 1.1
        # see discussion in config.rb.
        Chef::Config[:authentication_protocol_version] = "1.1"
      end
    end

    def configure_chef
      # knife needs to send logger output to STDERR by default
      Chef::Config[:log_location] = STDERR
      config_loader = self.class.load_config(config[:config_file])
      config[:config_file] = config_loader.config_location

      merge_configs
      apply_computed_config
      # This has to be after apply_computed_config so that Mixlib::Log is configured
      Chef::Log.info("Using configuration from #{config[:config_file]}") if config[:config_file]
    end

    def show_usage
      stdout.puts("USAGE: " + self.opt_parser.to_s)
    end

    def run_with_pretty_exceptions(raise_exception = false)
      unless self.respond_to?(:run)
        ui.error "You need to add a #run method to your knife command before you can use it"
      end
      enforce_path_sanity
      Chef::LocalMode.with_server_connectivity do
        run
      end
    rescue Exception => e
      raise if raise_exception || Chef::Config[:verbosity] == 2
      humanize_exception(e)
      exit 100
    end

    def humanize_exception(e)
      case e
      when SystemExit
        raise # make sure exit passes through.
      when Net::HTTPServerException, Net::HTTPFatalError
        humanize_http_exception(e)
      when OpenSSL::SSL::SSLError
        ui.error "Could not establish a secure connection to the server."
        ui.info "Use `knife ssl check` to troubleshoot your SSL configuration."
        ui.info "If your Chef Server uses a self-signed certificate, you can use"
        ui.info "`knife ssl fetch` to make knife trust the server's certificates."
        ui.info ""
        ui.info  "Original Exception: #{e.class.name}: #{e.message}"
      when Errno::ECONNREFUSED, Timeout::Error, Errno::ETIMEDOUT, SocketError
        ui.error "Network Error: #{e.message}"
        ui.info "Check your knife configuration and network settings"
      when NameError, NoMethodError
        ui.error "knife encountered an unexpected error"
        ui.info  "This may be a bug in the '#{self.class.common_name}' knife command or plugin"
        ui.info  "Please collect the output of this command with the `-VV` option before filing a bug report."
        ui.info  "Exception: #{e.class.name}: #{e.message}"
      when Chef::Exceptions::PrivateKeyMissing
        ui.error "Your private key could not be loaded from #{api_key}"
        ui.info  "Check your configuration file and ensure that your private key is readable"
      when Chef::Exceptions::InvalidRedirect
        ui.error "Invalid Redirect: #{e.message}"
        ui.info  "Change your server location in knife.rb to the server's FQDN to avoid unwanted redirections."
      else
        ui.error "#{e.class.name}: #{e.message}"
      end
    end

    def humanize_http_exception(e)
      response = e.response
      case response
      when Net::HTTPUnauthorized
        ui.error "Failed to authenticate to #{server_url} as #{username} with key #{api_key}"
        ui.info "Response:  #{format_rest_error(response)}"
      when Net::HTTPForbidden
        ui.error "You authenticated successfully to #{server_url} as #{username} but you are not authorized for this action"
        ui.info "Response:  #{format_rest_error(response)}"
      when Net::HTTPBadRequest
        ui.error "The data in your request was invalid"
        ui.info "Response: #{format_rest_error(response)}"
      when Net::HTTPNotFound
        ui.error "The object you are looking for could not be found"
        ui.info "Response: #{format_rest_error(response)}"
      when Net::HTTPInternalServerError
        ui.error "internal server error"
        ui.info "Response: #{format_rest_error(response)}"
      when Net::HTTPBadGateway
        ui.error "bad gateway"
        ui.info "Response: #{format_rest_error(response)}"
      when Net::HTTPServiceUnavailable
        ui.error "Service temporarily unavailable"
        ui.info "Response: #{format_rest_error(response)}"
      when Net::HTTPNotAcceptable
        version_header = Chef::JSONCompat.from_json(response["x-ops-server-api-version"])
        client_api_version = version_header["request_version"]
        min_server_version = version_header["min_version"]
        max_server_version = version_header["max_version"]
        ui.error "The version of Chef that Knife is using is not supported by the Chef server you sent this request to"
        ui.info "The request that Knife sent was using API version #{client_api_version}"
        ui.info "The Chef server you sent the request to supports a min API verson of #{min_server_version} and a max API version of #{max_server_version}"
        ui.info "Please either update your Chef client or server to be a compatible set"
      else
        ui.error response.message
        ui.info "Response: #{format_rest_error(response)}"
      end
    end

    def username
      Chef::Config[:node_name]
    end

    def api_key
      Chef::Config[:client_key]
    end

    # Parses JSON from the error response sent by Chef Server and returns the
    # error message
    #--
    # TODO: this code belongs in Chef::REST
    def format_rest_error(response)
      Array(Chef::JSONCompat.from_json(response.body)["error"]).join('; ')
    rescue Exception
      response.body
    end

    def create_object(object, pretty_name=nil, &block)
      output = edit_data(object)

      if Kernel.block_given?
        output = block.call(output)
      else
        output.save
      end

      pretty_name ||= output

      self.msg("Created #{pretty_name}")

      output(output) if config[:print_after]
    end

    def delete_object(klass, name, delete_name=nil, &block)
      confirm("Do you really want to delete #{name}")

      if Kernel.block_given?
        object = block.call
      else
        object = klass.load(name)
        object.destroy
      end

      output(format_for_display(object)) if config[:print_after]

      obj_name = delete_name ? "#{delete_name}[#{name}]" : object
      self.msg("Deleted #{obj_name}")
    end

    # helper method for testing if a field exists
    # and returning the usage and proper error if not
    def test_mandatory_field(field, fieldname)
      if field.nil?
        show_usage
        ui.fatal("You must specify a #{fieldname}")
        exit 1
      end
    end

    def rest
      @rest ||= begin
        require 'chef/rest'
        Chef::REST.new(Chef::Config[:chef_server_url])
      end
    end

    def noauth_rest
      @rest ||= begin
        require 'chef/rest'
        Chef::REST.new(Chef::Config[:chef_server_url], false, false)
      end
    end

    def server_url
      Chef::Config[:chef_server_url]
    end

  end
end