v20.1 HERETIC'S UNLIMITED EVENT PAGE CONDITION for PKMN Essentials 1.0

#==============================================================================
#
#           HERETIC'S UNLIMITED EVENT PAGE CONDITIONS [XP]
#           Version - 1.0
#           Monday, August 8th, 2016
#
#==============================================================================
#
#  ---  Overview  ---
#
#  This script will allow you to use Scripts as a Page Condition!  
#
#  This completely unlocks the functionality of Page Conditions, which now have
#  absolutely NO LIMITS!  For example, the Default Page Conditions allow
#  you to check a Game Variable, and the Page is only active if that
#  Game Variable is equal to or greater than what ever number you put there.
#  But, you could not check if the Game Variable was equal to or less than!
#  Now you can easily make Game Variable Less Than a Page Condition!
#
#  ---  Installation  ---
#
#  Place above Main and below Scene Debug.  Place below the SDK if used.
#
#  ---  Instructions  ---
#
#  Add a Comment to an Event says "Condition:" followed by a Script Condition.
#
#  Example 1:
#  @>Comment: Condition: $foo == $bar
#
#  Example 2:
#  @>Comment: Condition: $game_player.direction == 2 and $game_switches[12]
#
#  Example 3:
#  @>Comment: Condition: $game_player.moving? and $game_switches[12] and
#           : (not $game_system.map_interpreter.running? or $foo == $bar)
#
#  Example 4: (Not every line needs to be dedicated to evaluation.)
#  @>Comment: Condition: p = $game_player
#           : p.direction != 2
#
#  Example 5: (Comments within Comments work too, note the # Character)
#  @>Comment: Condition: p = $game_player
#           : # If Player is facing Down
#           : p.direction == 2
#
#  ---  Common Events  ----
#
#  This script does NOT affect Common Events, ONLY Map Events.
#
#  ---  Battle Event Pages  ---
#
#  This script does NOT affect Battle Event Page Conditions.  I wrote another
#  script for Battle Event Pages already.  
#
#  That script is called "Unlimited Battle Page Conditions" and is available
#  as one of my many scripts in Heretic's Collection.
#
#  ---  Multi Line Support  ---
#
#  You can extend your scripts to Multiple Lines of Comment Boxes!  The
#  Comment Box should be plenty big enough to hold your text!  Besides
#  that, you're using Script Calls, so if you can't fit your text into
#  one Box, you can write a Method that returns true or false and plug
#  that into your own script!
#
#  You can have Multiple Conditions also, each in their own Comment Box.
#
#
#  ---  Self Switches  ---
#
#  This script doesn't interfere with the use of Self Switches (ABCD).  Feel
#  free to combine both Self Switches and Script Conditions.
#
#
#  ---  Skipping Evaluation  ---
#
#  There may be certain conditions when you do NOT want a certain Page to
#  evaulate its Script Conditions.  For example, running an Event and you
#  don't want the Page to change until it is done doing its thing.  You
#  can turn Script Evaluation ON or OFF by either a Script Call or with
#  a Comment.  It is intended to use BOTH in conjunction with each other.
#  Basically, it gives you more control over when Scripts are evaluated.
#
#  To temporarily prevent a Page from executing its Script Conditions, simply
#  add a Comment to the Event's Page that reads:
#
#  @>Comment: \skip_eval
#
#  This is intended to be turned OFF with a Script Call or Move Route.
#
#  @>Script: $game_map.events[id].skip_eval = true / false
#  @>Set Move Route: This Event
#                  : $>Script: self.skip_eval = false
#                  : $>Script: skip_eval=(false)
#
#  NOTE: The Page MUST BE ACTIVE to change Skip Eval or else you will set
#        the Skip Eval on the WRONG PAGE.
#
#  NOTE: Once Skip Eval has been changed, it will retain the state you set
#        until the Map has been left entirely and transferred back to.  This
#        includes going into Battle Scenes.  The value of Skip Eval will be
#        remembered even after Battles are exited, but RESET if you leave
#        the Map and come back to this Map.
#
#
#  ---  Performance  ---
#
#  Each Script Condition is evaluated once per frame so don't go crazy using
#  too many Script Conditions, or at least make sure they evaluate quickly.
#  Script Conditions all evaluated on each Map.  Thus, if you have many maps
#  but only a few maps that use Script Conditions, don't worry too much.  You
#  may see performance issues if you use lots and lots of Script Conditions
#  on the same map.  This does end up being tons faster than using multiple
#  Parallel Events for very specific purposes however.
#
#
#  ---  Compatability  ---
#
#  This script may have some compatability issues with other scripts that
#  modify the RPG::Event::Page::Conditions class.  It has been tested with
#  More Self-Switches by Gameus / Game Guy and although only briefly tested
#  appears to work just fine.  This script works by replacing attr_accessor
#  methods with my custom definitions.  Instead of returning a property of
#  an object, it now uses self_switch_valid and self_switch_ch as getter
#  methods which consider if Script Conditions are being used.
#
#  It should also work just fine with Optimization Scripts as evaluation of
#  the Script Conditions is handled outside of Event and Game Map update
#  methods entirely.
#
#
#  ---  Legal  ---
#
#  You may distribute this script on websites in the scripts unaltered form.
#
#  You may use this script in Commercial or Non Commercial projects without
#  compensation as long as you give me credit for the use of my scripts.
#
#
#  ---  Config  ---
#
#  This script has no configurable Options.
#
#
#  ---  Version History  ---
#
#  Version 1.0 - Monday, August 8th, 2016
#  - Initial Release
#
#==============================================================================

#==============================================================================
# ** RPG - Main RPG Module
#==============================================================================
module RPG
  #----------------------------------------------------------------------------
  # ** Event - RPG::Event
  #----------------------------------------------------------------------------
  class Event
    #--------------------------------------------------------------------------
    # ** Page - RPG::Event::Page
    #--------------------------------------------------------------------------
    class Page
      #------------------------------------------------------------------------
      # ** Condition - RPG::Event::Page::Condition
      #------------------------------------------------------------------------
      class Condition
        #----------------------------------------------------------------------
        # * Public Instance Variables - RPG::Event::Page::Condition
        #----------------------------------------------------------------------
        attr_accessor :script_condition
        attr_accessor :map_id
        attr_accessor :event_id
        attr_accessor :skip_eval
        #----------------------------------------------------------------------
        # * Initialize - RPG::Event::Page::Condition
        #  - Adds Default Values for new Properties
        #----------------------------------------------------------------------
        alias script_condition_initialize initialize unless $@
        def initialize
          # Call Original or other Aliases
          script_condition_initialize
          # Container for Script Conditions
          @script_condition = nil
          # New Properties used for generating a Self Switches Hash Key
          @map_id = nil
          @event_id = nil
        end
        #----------------------------------------------------------------------
        # * Self Switch Valid - RPG::Event::Page::Condition
        #  - Replaces attr_reader with reader method
        #----------------------------------------------------------------------
        def self_switch_valid
          # Overrides @self_switch_valid value if a Script Condition exists
          return true if not @script_condition.nil?
          # Return Original Value (Self Switch is Checked in Edit Event)
          @self_switch_valid
        end
        #----------------------------------------------------------------------
        # * Self Switch Ch - RPG::Event::Page::Condition
        #  - Replaces attr_reader with reader method
        #  - Self Switch Channel is usually 'A' unless 'BCD' are specified
        #  - Checks both Self Switch and Script Condition to return Channel
        #----------------------------------------------------------------------
        def self_switch_ch
          # Use Self Switch Ch (ABCD) if Valid and Switch is OFF
          if @self_switch_valid
            # Hash Key for Self Switches
            key = [@map_id, @event_id, @self_switch_ch]
            # Use Self Switch Ch (ABCD) if Valid and Switch is OFF
            return @self_switch_ch if not $game_self_switches[key]
          end
          # If Script Condition Array has any Scripts
          if not @script_condition.nil? and @script_condition.size > 0
            # Iterate each Self Switch Script Condition
            for script in @script_condition
              # Create a Hash Key for Self Switches Hash with Script
              ss_key = [@map_id, @event_id, script]
              # Return the Script if Self Switch Script is OFF
              return script if not $game_self_switches[ss_key]
            end
            # Return Last Script in Array as Self Switch Channel
            return @script_condition.last
          end
          # Default Self Switch Channel (ABCD)
          @self_switch_ch
        end
      end
    end
  end
end

#==============================================================================
# ** Game_Event
#==============================================================================
class Game_Event < Game_Character
  #----------------------------------------------------------------------------
  # * Initialize - Game_Event
  #  - Checks each Page of Event for Script Conditions in Comments
  #        map_id : Map ID
  #         event : Game_Event stored in $data
  #----------------------------------------------------------------------------
  alias script_condition_initialize initialize unless $@
  #def initialize(map_id, event)
  def initialize(map_id, event, map = nil)
    super(map)
    # Default value and Shorthand
    script, sc = nil, $game_map.script_conditions
    # Iterate each of the Event's Pages
    event.pages.each {|page|
      # Store values in Condition Object for Self Switch Keys
      page.condition.map_id, page.condition.event_id = map_id, event.id
      # Iterate Each Command
      page.list.each {|command|
        # If Event Command is the first line of a Comment
        if command.code == 108
          # If Script is not nil (two Script Conditions in sequence)
          if not script.nil?
            # Modify Condition Object and Add to Hash for Evaluation
            add_script_condition(page.condition, script, map_id, event.id, sc)
            # Clear the String since it is now stored in the Condition Object
            script = nil
          end
          # Scan the Comment and look for \skip_eval Comments for this Page
          command.parameters[0].gsub(/^\\skip_eval/i) { 
            page.condition.skip_eval = true
          }
          # Use Regular Expression to look for "Condition:" and Capture String
          command.parameters[0].gsub(/^Condition:(.*)/){ script = $1.strip }
        # Else if Script and Event Command is a Comment, but not the first line
        elsif not script.nil? and command.code == 408
          # Append Script String with any text from this line of the Comment
          script += "\n" + command.parameters[0]
        # If Script String has contents
        elsif not script.nil?
          # Modify Condition Object and Add to Hash for Evaluation
          add_script_condition(page.condition, script, map_id, event.id, sc)
          # Clear the String since it is now stored in the Condition Object
          script = nil
          # Next Command (One Condition per Comment Box)
          next
        end
      }
    }
    # Call Original or other Aliases
    script_condition_initialize(map_id, event)
    
    moveto(event.x, event.y) if map
    refresh
  end
  #----------------------------------------------------------------------------
  # * Add Script Condition - Game_Event
  #  - Modifies the Condition Object with New Parameters for Script Evaluation
  #               c : RPG::Event::Page::Condition
  #          map_id : Map ID of Event
  #        event_id : Event ID
  #              sc : Shorthand for $game_map.script_conditions
  #----------------------------------------------------------------------------
  def add_script_condition(c, script, map_id, event_id, sc)
    # Loop to check for Syntax Errors
    begin
      # Evaluate the Script String and remember result
      result = eval(script)
    # Script Evaluated has a Syntax Error
    rescue
      # Display Warning to User
      script_condition_error(script, event_id, map_id)
      # Prevent Storing of Script Condition
      return
    end
    # Create a Boolean Value based on result for proper storage
    value = (result) ? true : false
    # Remember value of Script Evaluation in the Self Switch Hash
    $game_self_switches[[map_id, event_id, script]] = value    
    # Create Array if Nil
    c.script_condition = [] if c.script_condition.nil?
    # Push Script on to Script Condition Array
    c.script_condition << script
    # Add Script to Script Conditions Hash in Game Map with Event ID as Key
    sc[event_id] ? sc[event_id] << script : sc[event_id] = [script]
  end
  #----------------------------------------------------------------------------
  # * Eval Script Condition - Game_Event
  #  - Evaluates Script Conditions
  #       scripts : Array of Scripts for this Event's Conditions
  #----------------------------------------------------------------------------
  def eval_script_condition(scripts)
    # Default
    refresh_event = false
    # Iterate each Script in the Array
    for script in scripts
      # Run the Script and remember the result (Syntax already checked)
      result = eval(script)
      # Create a Boolean Value based on result for proper storage
      value = (result) ? true : false
      # If Stored Self Switch Value is not the same as the result
      if $game_self_switches[[$game_map.map_id, id, script]] != value
        # Store the Result in the Self Switches Hash
        $game_self_switches[[$game_map.map_id, id, script]] = value
        # Flag to Refresh this Event after running all Scripts if more than 1
        refresh_event = true
      end
    end
    # Refresh this Event if the Refresh Flag is set
    refresh if refresh_event
  end
  #----------------------------------------------------------------------------
  # * Script Condition Error - Game_Event
  #  - Prints a Warning and shows Script with a Syntax Error
  #        script : String of Script with Syntax Error
  #            id : Event ID with the Problem
  #        map_id : ID of Map with Event with Syntax Error in Condition
  #----------------------------------------------------------------------------
  def script_condition_error(script, id, map_id)
    # If running game from Editor
    if $DEBUG
      # Explain the Problem
      print "Warning: A Script Condition has a Syntax Error\n",
            "Event ID: ", id, "\nMap ID: ", map_id, "\n\n",
            "Condition: ", script, "\n\n",
            "Conditions should evaluate to true or false\n",
            "Example 1: Condition: $foo == $bar\n",
            "Example 2: Condition: $foo == $bar or $baz"
    end
  end
  #----------------------------------------------------------------------------
  # * Erased? - Game_Event
  #  - Returns true if Event is Erased
  #----------------------------------------------------------------------------
  def erased?
    return @erased
  end
  #----------------------------------------------------------------------------
  # * Skip Eval? - Game_Event
  #  - Getter method, returns Flag set in RPG::Event::Page::Condition
  #----------------------------------------------------------------------------
  def skip_eval?
    @page.condition.skip_eval if @page
  end
  #----------------------------------------------------------------------------
  # * Skip Eval= - Game_Event
  #  - Setter method, sets Flag set in RPG::Event::Page::Condition
  #----------------------------------------------------------------------------
  def skip_eval=(arg)
    @page.condition.skip_eval = (arg) ? true : false
  end
end

#==============================================================================
# ** Game_Map
#==============================================================================
class Game_Map
  #----------------------------------------------------------------------------
  # * Public Instance Variables - Game_Map
  #----------------------------------------------------------------------------
  attr_accessor     :script_conditions    # Holds Event Script Page Conditions
  #----------------------------------------------------------------------------
  # * Setup - Game_Event
  #  - Creates a Hash to hold Script Conditions for constant Evaluation
  #      map_id : Map ID from $data
  #----------------------------------------------------------------------------
  alias script_condition_setup setup unless $@
  def setup(map_id)
    # If Map ID is Valid and does not match current Map ID
    if map_id > 0 and map_id != @map_id
      # Create or Clear Hash
      @script_conditions = {}
    end
    # Call Original or other Aliases
    script_condition_setup(map_id)
  end
  #----------------------------------------------------------------------------
  # * Eval Script Conditions - Game_Map
  #  - Evaluates all Script Conditions in Hash and Refreshes Event if needed
  #----------------------------------------------------------------------------
  def eval_script_conditions
    # Check that Script Conditions exists
    return unless @script_conditions
    # Iterate any Script Condition
    @script_conditions.each {|id, scripts|
      # Get the Event
      event = @events[id]
      # If Event does not exist (typically event removed during game editing)
      if not event
        # Remove the Script Conditions from the Hash
        @script_conditions.delete(id)
        # Next Script
        next
      end
      # Skip this Event if Event has a Skip Eval flag
      next if event.skip_eval?
      # Evaluate Script Conditions (Array of Scripts) from within the Event
      event.eval_script_condition(scripts) unless event.erased?
    }
  end
end

#==============================================================================
# ** Game_Screen
#==============================================================================
class Game_Screen
  #----------------------------------------------------------------------------
  # * Update - Game_Screen
  #  - Calls to eval_script_conditions in the Map, so it will still evaluate
  #    even during Battle Scenes
  #  - Game_Screen is updated after important objects are updated for proper
  #    timing of changing Pages.  Thus, the Map, Events, Interpreter, Player
  #    and System are all updated before evaulating Script Conditions.  If
  #    the evaluations were run, for example, prior to updating either the
  #    Player or Map Interpreter, Page Changes would occur at improper times
  #    and most likely cause you a headache trying to figure out why thinggs
  #    did not work as you expect at the times you expect.
  #----------------------------------------------------------------------------
  alias script_condition_update update unless $@
  def update
    # Call Original or other Aliases
    script_condition_update
    # Update any Event Script Conditions
    $game_map.eval_script_conditions
  end
end