#!/usr/bin/env ruby

require 'yaml'
require 'abbrev'
require 'trollop'
require 'highline'
require 'shellwords'
require 'sysexits'

require 'treequel'
require 'treequel/mixins'
require 'treequel/constants'


# A tool for displaying information about a directory's records and schema artifacts.
class Treequel::What
	extend Sysexits
	include Sysexits,
	        Treequel::Loggable,
	        Treequel::ANSIColorUtilities,
	        Treequel::Constants::Patterns,
	        Treequel::HashUtilities

	COLOR_SCHEME = HighLine::ColorScheme.new do |scheme|
		scheme[:header]	   = [ :bold, :yellow ]
		scheme[:subheader] = [ :bold, :white ]
		scheme[:key]	   = [ :white ]
		scheme[:value]	   = [ :bold, :white ]
		scheme[:error]	   = [ :red ]
		scheme[:warning]   = [ :yellow ]
		scheme[:message]   = [ :reset ]
	end


	### Run the utility with the given +args+.
	def self::run( args )
		HighLine.color_scheme = COLOR_SCHEME

		oparser = self.make_option_parser
		opts = Trollop.with_standard_exception_handling( oparser ) do
			oparser.parse( args )
		end

		pattern = oparser.leftovers.join( ' ' ) if oparser.leftovers

		self.new( opts ).run( pattern )
		exit :ok

	rescue => err
		Treequel.logger.fatal "Oops: %s: %s" % [ err.class.name, err.message ]
		Treequel.logger.debug { '  ' + err.backtrace.join("\n  ") }

		exit :software_error
	end


	### Create and configure a command-line option parser for the command.
	### @return [Trollop::Parser] the option parser
	def self::make_option_parser
		progname = File.basename( $0 )
		default_directory = Treequel.directory_from_config
		loglevels = Treequel::LOG_LEVELS.
			sort_by {|name,lvl| lvl }.
			collect {|name,lvl| name.to_s }.
			join( ', ' )

		return Trollop::Parser.new do
			banner "Usage: #{progname} [OPTIONS] [PATTERN]"

			text ''
			text %{Search for an object in an LDAP directory that matches PATTERN and } +
			     %{display some information about it.}
			text ''
			text %{The PATTERN can be the DN (or RDN relative to the base) of an entry, } +
			     %{a search filter, or the name of an artifact in the directory's schema, } +
			     %{such as an objectClass, matching rule, syntax, etc.}
			text ''
			text %{If no PATTERN is specified, general information about the directory is } +
			     %{output instead.}
			text ''

			text 'Options:'
			opt :ldapurl, "Specify the directory to connect to.",
				:default => default_directory.uri.to_s
			opt :debug, "Turn debugging on. Also sets the --loglevel to 'debug'."
			opt :loglevel, "Set the logging level. Must be one of: #{loglevels}",
				:default => Treequel::LOG_LEVEL_NAMES[ Treequel.logger.level ]
			opt :binddn, "The DN of the user to bind as. Defaults to anonymous binding.",
				:type => :string
		end
	end


	#################################################################
	###	I N S T A N C E   M E T H O D S
	#################################################################

	### Create a new instance of the command and set it up with the given
	### +options+.
	def initialize( options )
		Treequel.logger.formatter = Treequel::ColorLogFormatter.new( Treequel.logger )

		if options.debug
			$DEBUG = true
			$VERBOSE = true
			Treequel.logger.level = Logger::DEBUG
		elsif options.loglevel
			Treequel.logger.level = Treequel::LOG_LEVELS[ options.loglevel ]
		end

		@options   = options
		@prompt    = HighLine.new
		@directory = Treequel.directory( options.ldapurl )

		self.log.debug "Created new treewhat command object for %s" % [ @directory ]
	end


	######
	public
	######

	# The LDAP directory the command will connect to
	attr_reader :directory

	# The Trollop options hash the command will read its configuration from
	attr_reader :options

	# The HighLine object to use for prompting and displaying stuff
	attr_reader :prompt


	### Display an +object+ highlighted as a header.
	def print_header( object )
		self.prompt.say( self.prompt.color(object.to_s, :header) )
	end



	### Run the command with the specified +pattern+.
	def run( pattern=nil )
		self.log.debug "Running with pattern = %p" % [ pattern ]

		self.bind_to_directory if self.options.binddn

		case pattern

		# No argument
		when NilClass, ''
			self.show_directory_overview

		# DN/RDN or filter if it contains a '='
		when /=/
			self.show_entry( pattern )

		# Otherwise, try to find a schema item that matches
		else
			self.show_schema_artifact( pattern )
		end

	end


	### Prompt for a password and then bind to the command's directory using the binddn in
	### the options.
	def bind_to_directory
		binddn = self.options.binddn or
			raise ArgumentError, "no binddn in the options hash?!"
		self.log.debug "Attempting to bind to the directory as %s" % [ binddn ]

		pass = self.prompt.ask( "password: " ) {|q| q.echo = '*' }
		user = Treequel::Branch.new( self.directory, binddn )

		self.directory.bind_as( user, pass )
		self.log.debug "  bound as %s" % [ user ]

		return true
	end


	### Show general information about the directory if the user doesn't give a pattern on
	### the command line.
	def show_directory_overview
		pr  = self.prompt
		dir = self.directory

		self.print_header( dir.uri.to_s )
		pr.say( "\n" )
		pr.say( dir.schema.to_s )

	end



	#
	# 'Show entry' mode
	#

	### Fetch an entry from the directory and display it like Treequel's editing mode.
	def show_entry( pattern )
		dir = self.directory
		branch = Treequel::Branch.new( dir, pattern )

		if !branch.exists?
			branch = Treequel::Branch.new( dir, pattern + ',' + dir.base_dn )
		end

		if !branch.exists?
			branch = dir.filter( pattern ).first
		end

		if !branch
			self.prompt.say( self.prompt.color("No match.", :error) )
		end

		yaml = self.branch_as_yaml( branch )
		self.prompt.say( yaml )
	end


	### Return the specified Treequel::Branch object as YAML. If +include_operational+ is true,
	### include the entry's operational attributes. If +extra_objectclasses+ contains
	### one or more objectClass OIDs, include their MUST and MAY attributes when building the 
	### YAML representation of the branch.
	def branch_as_yaml( object, include_operational=false )
		object.include_operational_attrs = include_operational

		# Make sure the displayed entry has the MUST attributes
		entryhash = stringify_keys( object.must_attributes_hash )
		entryhash.merge!( object.entry || {} )
		entryhash['objectClass'] ||= []

		entryhash.delete( 'dn' ) # Special attribute, can't be edited

		yaml = entryhash.to_yaml
		yaml[ 5, 0 ] = self.prompt.color( "# #{object.dn}\n", :header )

		# Make comments out of MAY attributes that are unset
		mayhash = stringify_keys( object.may_attributes_hash )
		self.log.debug "MAY hash is: %p" % [ mayhash ]
		mayhash.delete_if {|attrname,val| entryhash.key?(attrname) }
		yaml << mayhash.to_yaml[5..-1].gsub( /\n\n/, "\n" ).gsub( /^/, '# ' )

		return yaml
	end




	#
	# 'Show schema artifact' mode
	#

	SCHEMA_ARTIFACT_TYPES = [
		:object_classes,
		:attribute_types,
		:ldap_syntaxes,
		:matching_rules,
		:matching_rule_uses,
	  ]

	### Find an artifact in the directory's schema that matches +pattern+, and display it
	### if it exists.
	def show_schema_artifact( pattern )
		pr        = self.prompt
		schema    = self.directory.schema
		artifacts = SCHEMA_ARTIFACT_TYPES.
			collect {|type| schema.send( type ).values.uniq }.flatten

		if match = find_exact_matching_artifact( artifacts, pattern )
			self.display_schema_artifact( match )
		elsif match = find_substring_matching_artifact( artifacts, pattern )
			pr.say( "No exact match. Falling back to substring match:" )
			self.display_schema_artifact( match )
		else
			pr.say( pr.color("No match.", :error) )
		end
	end


	### Display a schema artifact in a readable way.
	def display_schema_artifact( artifact )
		self.prompt.say( artifact.class.name.sub(/.*::/, '') + ' ' )
		self.prompt.say( artifact.to_s )
	end


	### Try to find an artifact in +artifacts+ whose name or oid matches +pattern+ exactly.
	### Returns the first matching artifact.
	def find_exact_matching_artifact( artifacts, pattern )
		self.log.debug "Trying to find an exact match for %p in %d artifacts." %
			[ pattern, artifacts.length ]
		return artifacts.find do |obj|
			(obj.respond_to?( :names ) && obj.names.map(&:to_s).include?(pattern) ) ||
			(obj.respond_to?( :name )  && obj.name.to_s == pattern ) ||
			(obj.respond_to?( :oid )   && obj.oid == pattern )
		end
	end


	### Try to find an artifact in +artifacts+ whose name or oid contains +pattern+.
	### Returns the first matching artifact.
	def find_substring_matching_artifact( artifacts, pattern )
		pattern = Regexp.new( Regexp.escape(pattern), Regexp::IGNORECASE )

		return artifacts.find do |obj|
			(obj.respond_to?( :names ) && obj.names.find {|name| name.to_s =~ pattern} ) ||
			(obj.respond_to?( :name )  && obj.name.to_s =~ pattern ) ||
			(obj.respond_to?( :oid )   && obj.oid =~ pattern )
		end
	end


end # class Treequel::What


Treequel::What.run( ARGV.dup )