require 'yaml'

module Beaker
  module Options
    #An Object that parses, merges and normalizes all supported Beaker options and arguments
    class Parser
      GITREPO      = 'git://github.com/puppetlabs'
      #These options can have the form of arg1,arg2 or [arg] or just arg,
      #should default to []
      LONG_OPTS    = [:helper, :load_path, :tests, :pre_suite, :post_suite, :install, :modules]
      #These options expand out into an array of .rb files
      RB_FILE_OPTS = [:tests, :pre_suite, :post_suite]

      PARSE_ERROR = Psych::SyntaxError

      #The OptionsHash of all parsed options
      attr_accessor :options

      # Raises an ArgumentError with associated message
      # @param [String] msg The error message to be reported
      # @raise [ArgumentError] Takes the supplied message and raises it as an ArgumentError
      def parser_error msg = ""
        raise ArgumentError, msg.to_s
      end

      # Returns the git repository used for git installations
      # @return [String] The git repository
      def repo
        GITREPO
      end

      # Returns a description of Beaker's supported arguments
      # @return [String] The usage String
      def usage
       @command_line_parser.usage
      end

      # Normalizes argument into an Array.  Argument can either be converted into an array of a single value,
      # or can become an array of multiple values by splitting arg over ','.  If argument is already an
      # array that array is returned untouched.
      # @example
      #   split_arg([1, 2, 3]) == [1, 2, 3]
      #   split_arg(1) == [1]
      #   split_arg("1,2") == ["1", "2"]
      #   split_arg(nil) == []
      # @param [Array, String] arg Either an array or a string to be split into an array
      # @return [Array] An array of the form arg, [arg], or arg.split(',')
      def split_arg arg
        arry = []
        if arg.is_a?(Array)
          arry += arg
        elsif arg =~ /,/
          arry += arg.split(',')
        else
          arry << arg
        end
        arry
      end

      # Generates a list of files based upon a given path or list of paths.
      #
      # Looks recursively for .rb files in paths.
      #
      # @param [Array] paths Array of file paths to search for .rb files
      # @return [Array] An Array of fully qualified paths to .rb files
      # @raise [ArgumentError] Raises if no .rb files are found in searched directory or if
      #                         no .rb files are found overall
      def file_list(paths)
        files = []
        if not paths.empty?
          paths.each do |root|
            if File.file?(root)
              files << root
            elsif File.directory?(root) #expand and explore
              discover_files = Dir.glob(
                File.join(root, "**/*.rb")
              ).select { |f| File.file?(f) }
              if discover_files.empty?
                parser_error "empty directory used as an option (#{root})!"
              end
              files += discover_files.sort_by {|file| [file.count("/"), file]}
            else #not a file, not a directory, not nothin'
              parser_error "#{root} used as a file option but is not a file or directory!"
            end
          end
        end
        if files.empty?
          parser_error "no .rb files found in #{paths.to_s}"
        end
        files
      end

      #Converts array of paths into array of fully qualified git repo URLS with expanded keywords
      #
      #Supports the following keywords
      #  PUPPET
      #  FACTER
      #  HIERA
      #  HIERA-PUPPET
      #@example
      #  opts = ["PUPPET/3.1"]
      #  parse_git_repos(opts) == ["#{GITREPO}/puppet.git#3.1"]
      #@param [Array] git_opts An array of paths
      #@return [Array] An array of fully qualified git repo URLs with expanded keywords
      def parse_git_repos(git_opts)
        git_opts.map! { |opt|
          case opt
            when /^PUPPET\//
              opt = "#{GITREPO}/puppet.git##{opt.split('/', 2)[1]}"
            when /^FACTER\//
              opt = "#{GITREPO}/facter.git##{opt.split('/', 2)[1]}"
            when /^HIERA\//
              opt = "#{GITREPO}/hiera.git##{opt.split('/', 2)[1]}"
            when /^HIERA-PUPPET\//
              opt = "#{GITREPO}/hiera-puppet.git##{opt.split('/', 2)[1]}"
          end
          opt
        }
        git_opts
      end

      #Add the 'default' role to the host determined to be the default.  If a host already has the role default then
      #do nothing.  If more than a single host has the role 'default', raise error.
      #Default host determined to be 1) the only host in a single host configuration, 2) the host with the role 'master'
      #defined.
      #@param [Hash] hosts A hash of hosts, each identified by a String name.  Each named host will have an Array of roles
      def set_default_host!(hosts)
        default = []
        master = []
        default_host_name = nil

        #look through the hosts and find any hosts with role 'default' and any hosts with role 'master'
        hosts.each_key do |name|
          host = hosts[name]
          if host[:roles].include?('default')
            default << name
          elsif host[:roles].include?('master')
            master << name
          end
        end

        if not default.empty?
          #we already have a default set, do nothing
          if default.length > 1
            parser_error "Only one host may have the role 'default', default roles assigned to #{default}"
          end
        else
          #no default set, let's make one
          if not master.empty? and master.length == 1
            default_host_name = master[0]
          elsif hosts.length == 1
            default_host_name = hosts.keys[0]
          end
          if default_host_name
            hosts[default_host_name][:roles] << 'default'
          end
        end
      end

      #Constructor for Parser
      #
      def initialize
         @command_line_parser = Beaker::Options::CommandLineParser.new
         @presets = Beaker::Options::Presets.new
      end

      # Parses ARGV or provided arguments array, file options, hosts options and combines with environment variables and
      # preset defaults to generate a Hash representing the Beaker options for a given test run
      #
      # Order of priority is as follows:
      #   1.  environment variables are given top priority
      #   2.  ARGV or provided arguments array
      #   3.  the 'CONFIG' section of the hosts file
      #   4.  options file values
      #   5.  default or preset values are given the lowest priority
      #
      # @param [Array] args ARGV or a provided arguments array
      # @raise [ArgumentError] Raises error on bad input
      def parse_args(args = ARGV)
        @options = @presets.presets
        cmd_line_options = @command_line_parser.parse(args)
        cmd_line_options[:command_line] = ([$0] + args).join(' ')
        file_options = Beaker::Options::OptionsFileParser.parse_options_file(cmd_line_options[:options_file])

        # merge together command line and file_options
        #   overwrite file options with command line options
        cmd_line_and_file_options = file_options.merge(cmd_line_options)

        # merge command line and file options with defaults
        #   overwrite defaults with command line and file options
        @options = @options.merge(cmd_line_and_file_options)

        if not @options[:help] and not @options[:beaker_version_print]
          #read the hosts file that contains the node configuration and hypervisor info
          hosts_options = Beaker::Options::HostsFileParser.parse_hosts_file(@options[:hosts_file])

          # merge in host file vars
          #   overwrite options (default, file options, command line) with host file options
          @options = @options.merge(hosts_options)

          # re-merge the command line options
          #   overwrite options (default, file options, hosts file ) with command line arguments
          @options = @options.merge(cmd_line_options)

          # merge in env vars
          #   overwrite options (default, file options, command line, hosts file) with env
          env_vars = @presets.env_vars

          @options = @options.merge(env_vars)

          normalize_args
        end

        @options
      end

      # Determine is a given file exists and is a valid YAML file
      # @param [String] f The YAML file path to examine
      # @param [String] msg An options message to report in case of error
      # @raise [ArgumentError] Raise if file does not exist or is not valid YAML
      def check_yaml_file(f, msg = "")
        if not File.file?(f)
          parser_error "#{f} does not exist (#{msg})"
        end
        begin
          YAML.load_file(f)
        rescue PARSE_ERROR => e
          parser_error "#{f} is not a valid YAML file (#{msg})\n\t#{e}"
        end
      end

      #Validate all merged options values for correctness
      #
      #Currently checks:
      #  - each host has a valid platform
      #  - if a keyfile is provided then use it
      #  - paths provided to --test, --pre-suite, --post-suite provided lists of .rb files for testing
      #  - --fail-mode is one of 'fast', 'stop' or nil
      #  - if using blimpy hypervisor an EC2 YAML file exists
      #  - if using the aix, solaris, or vcloud hypervisors a .fog file exists
      #  - that one and only one master is defined per set of hosts
      #  - that solaris/windows/aix hosts are agent only for PE tests OR
      #  - sets the default host based upon machine definitions
      #  - if an ssh user has been defined make it the host user
      #
      #@raise [ArgumentError] Raise if argument/options values are invalid
      def normalize_args

        @options['HOSTS'].each_key do |name|
          if not @options['HOSTS'][name]['platform']
            parser_error "Host #{name} does not have a platform specified"
          else
            @options['HOSTS'][name]['platform'] = Platform.new(@options['HOSTS'][name]['platform'])
          end
        end

        #use the keyfile if present
        if @options.has_key?(:keyfile)
          @options[:ssh][:keys] = [@options[:keyfile]]
        end

        #split out arguments - these arguments can have the form of arg1,arg2 or [arg] or just arg
        #will end up being normalized into an array
        LONG_OPTS.each do |opt|
          if @options.has_key?(opt)
            @options[opt] = split_arg(@options[opt])
            if RB_FILE_OPTS.include?(opt) && (not @options[opt] == [])
              @options[opt] = file_list(@options[opt])
            end
            if opt == :install
              @options[:install] = parse_git_repos(@options[:install])
            end
          else
            @options[opt] = []
          end
        end

        #check for valid fail mode
        if @options[:fail_mode] !~ /stop|fast|slow/
          parser_error "--fail-mode must be one of fast or slow, not '#{@options[:fail_mode]}'"
        end

        #check for valid preserve_hosts option
        if @options[:preserve_hosts] !~ /always|onfail|onpass|never/
          parser_error "--preserve_hosts must be one of always, onfail, onpass or never, not '#{@options[:preserve_hosts]}'"
        end

        #check for config files necessary for different hypervisors
        hypervisors = []
        @options[:HOSTS].each_key do |name|
          hypervisors << @options[:HOSTS][name][:hypervisor].to_s
        end
        hypervisors.uniq!
        hypervisors.each do |visor|
          if ['blimpy'].include?(visor)
            check_yaml_file(@options[:ec2_yaml], "required by #{visor}")
          end
          if ['aix', 'solaris', 'vcloud'].include?(visor)
            check_yaml_file(@options[:dot_fog], "required by #{visor}")
          end
        end

        #check that roles of hosts make sense
        # - must be one and only one master
        roles = []
        @options[:HOSTS].each_key do |name|
          roles << @options[:HOSTS][name][:roles]
        end
        master = 0
        roles.each do |role_array|
          if role_array.include?('master')
            master += 1
          end
          if role_array.include?('frictionless') and !(role_array & ['master', 'database', 'dashboard', 'console']).empty?
            parser_error "Only agent nodes may have the role 'frictionless', fix #{@options[:hosts_file]}"
          end
        end
        if master > 1
          parser_error "Only one host/node may have the role 'master', fix #{@options[:hosts_file]}"
        end

        #check that windows/el-4 boxes are only agents (solaris can be a master in foss cases)
        @options[:HOSTS].each_key do |name|
          host = @options[:HOSTS][name]
          if host[:platform] =~ /windows|el-4/
            test_host_roles(name, host)
          end
        end

        normalize_and_validate_tags()
        resolve_symlinks()

        #set the default role
        set_default_host!(@options[:HOSTS])

        #check to see if a custom user account has been provided, if so use it
        @options[:HOSTS].each_key do |name|
          host = @options[:HOSTS][name]
          if host[:ssh] && host[:ssh][:user]
            host[:user] = host[:ssh][:user]
          end
        end

      end

      # Takes tag arguments given at this point, which are strings, converts
      # them into the proper format (an array of strings) for Beaker use,
      # and lastly, validates them.
      #
      # @return nil
      # @api public
      def normalize_and_validate_tags()
        @options[:tag_includes] ||= ''
        @options[:tag_excludes] ||= ''
        @options[:tag_includes] = @options[:tag_includes].split(',') if @options[:tag_includes].respond_to?(:split)
        @options[:tag_excludes] = @options[:tag_excludes].split(',') if @options[:tag_excludes].respond_to?(:split)
        @options[:tag_includes].map!(&:downcase)
        @options[:tag_excludes].map!(&:downcase)

        #check that a tag is not both included & excluded sets
        @options[:tag_includes].each do |included_tag|
          @options[:tag_excludes].each do |excluded_tag|
            parser_error "tag '#{included_tag}' cannot be in both the included and excluded tag sets" \
              if included_tag == excluded_tag
          end
        end
      end

      # resolves all file symlinks that require it.
      #
      # @note doing it here allows us to not need duplicate logic, which we
      #   would need if we were doing it in the parser (--hosts & --config)
      #
      # @return nil
      # @api public
      def resolve_symlinks()
        @options[:hosts_file] = File.realpath(@options[:hosts_file]) if @options[:hosts_file]
      end

      private

      # @api private
      def test_host_roles(host_name, host_hash)
        host_roles = host_hash[:roles]
        if !(host_roles & ['master', 'database', 'dashboard']).empty?
          parser_error "#{host_hash[:platform].to_s} box '#{host_name}' may not have roles 'master', 'dashboard', or 'database'; it has roles #{host_roles.to_s}"
        end
      end

    end
  end
end