# I confess that this world model heavily borrows from INSTEAD engine. - A.Y.

require('./salet.coffee')
obj = require('./obj.coffee')
markdown = require('./markdown.coffee')
cycle = require('./cycle.coffee')

assert = (msg, assertion) -> console.assert assertion, msg

Function.prototype.fcall = Function.prototype.call;
Boolean.prototype.fcall = () ->
  return this
String.prototype.fcall = () ->
  return this

way_to = (content, ref) ->
  return "<a href='#{ref}' class='way' id='waylink-#{ref}'>#{content}</a>"

Array::remove = (e) -> @[t..t] = [] if (t = @indexOf(e)) > -1

class SaletRoom
  constructor: (spec) ->
    for index, value of spec
      this[index] = value
    return this
  visited: 0
  title: "Room"
  objects: {}

  # room illustration image, VN-style. Can be a GIF or WEBM. Can be a function.
  pic: false

  canView: true
  canChoose: true
  priority: 1
  displayOrder: 1
  tags: []
  choices: ""
  optionText: "Choice"

  dsc: false # room description
  extendSection: false
  distance: Infinity # distance to the destination
  clear: true # clear the screen on entering the room?

  entering: (system, from) =>

  ###
    I call SaletRoom.exit every time the player exits to another room.
    Unlike @after this gets called after the section is closed.
    It's a styling difference.
  ###
  exit: (system, to) =>
    return true

  ###
    I call SaletRoom.enter every time the player enters this room but before the section is opened.
    Unlike @before this gets called before the current section is opened.
    It's a styling difference.

    The upstream Undum version does not allow you to redefine @enter function easily but allows custom @exit one.
    It was renamed as @entering to achieve API consistency.
  ###
  enter: (system, from) =>
    return true

  ###
    Salet's Undum version calls Situation.entering every time a situation is entered, and
    passes it three arguments; The character object, the system object,
    and a string referencing the previous situation, or null if there is
    none (ie, for the starting situation).

    My version of `enter` splits the location description from the effects.
    Also if f == this.name (we're in the same location) the `before` and `after` callbacks are ignored.
  ###
  entering: (system, f) =>
    if @clear and f?
      system.view.clearContent()

    if f != @name and f?
      @visited++
      if system.rooms[f].exit?
        system.rooms[f].exit system, @name

    if @enter
      @enter system, f

    room_content = ""
    if not @extendSection
      classes = if @classes then ' ' + @classes.join(' ') else ''
      room = document.getElementById('current-room')
      if room?
        room.removeAttribute('id')
      # Javascript DOM manipulation functions like jQuery's append() or document.createElement
      # don't work like a typical printLn - they create *DOM nodes*.
      # You can't leave an unclosed tag just like that. So we have to buffer the output.
      room_content = "<section id='current-room' data-room='#{@name}' class='room-#{@name}#{classes}'>"

    if f != @name and @before?
      room_content += markdown(@before.fcall(this, system, f))

    room_content += @look system, f

    if f != @name and @after?
      room_content += markdown(@after.fcall(this, system, f))

    if not @extendSection
      room_content += "</section>"

    system.view.write(room_content)

    if @choices
      system.view.writeChoices(system, system.getSituationIdChoices(@choices, @maxChoices))

  ###
    An internal function to get the room's description and the descriptions of
    every object in this room.
  ###
  look: (system, f) =>
    system.view.updateWays(system, @ways, @name)
    retval = ""

    if @pic
      retval += '<div class="pic">'+system.view.pictureTag(@pic.fcall(this, system, f))+'</div>'

    # Print the room description
    if @dsc
      dsc = @dsc.fcall(this, system, f).toString()
      retval += markdown(dsc)

    for name, thing of @objects
      retval += thing.look()

    return retval

  ###
    Puts an object in this room.
  ###
  take: (thing) =>
    @objects[thing.name] = thing
    # BUG: for some really weird reason if the call is made in init function or
    # during the initialization, this ALSO puts the thing in the start room.
    salet.rooms["start"].objects = {}

  drop: (name) =>
    delete @objects[name]

  ###
    Object action. A function or a string which comes when you click on the object link.
    You could interpret this as an EXAMINE verb or USE one, it's your call.
  ###
  act: (system, action) =>
    if (link = action.match(/^_(act|cycle)_(.+)$/)) #object action
      for name, thing of @objects
        if name == link[2]
          if link[1] == "act"
            # If it's takeable, the player can take this object.
            # If not, we check the "act" function.
            if thing.takeable
              system.character.inventory.push thing
              @drop name
              system.view.clearContent()
              @entering.fcall(this, system, @name)
              return system.view.write(thing.take.fcall(thing, system).toString())
            if thing.act
              return system.view.write(thing.act.fcall(thing, system).toString())
          elseif link[1] == "cycle"
            # TODO object cyclewriter
      # the loop is done but no return came - match not found
      console.error("Could not find #{link[1]} in current room.")

    # we're done with objects, now check the regular actions
    actionClass = action.match(/^_(\w+)_(.+)$/)
    that = this

    responses = {
      writer: (ref) ->
        content = that.writers[ref].fcall(that, system, action)
        output = markdown(content)
        system.view.write(output)
      replacer: (ref) ->
        content = that.writers[ref].fcall(that, system, action)
        system.view.replace(content, '#'+ref)
      inserter: (ref) ->
        content = that.writers[ref].fcall(that, system, action)
        output = markdown(content)
        system.view.write(output, '#'+ref)
    }

    if (actionClass)
      # Matched a special action class
      [responder, ref] = [actionClass[1], actionClass[2]]

      if(!@writers.hasOwnProperty(actionClass[2]))
        throw new Error("Tried to call undefined writer: #{action}");
      responses[responder](ref);
    else if (@actions.hasOwnProperty(action))
      @actions[action].call(this, system, action);
    else
      throw new Error("Tried to call undefined action: #{action}");

  # Marks every room in the game with distance to this room
  destination: () =>
    @distance = 0

    candidates = [this]
    while candidates.length > 0
      current_room = candidates.shift()
      if current_room.ways
        for node in current_room.ways
          if node.distance == Infinity
            node.distance = current_room.distance + 1
            candidates.push(node)

  register: (salet) =>
    if not @name?
      console.error("Situation has no name")
      return this
    salet.rooms[@name] = this
    return this

  writers:
    cyclewriter: (salet) ->
      cycle(this.cycle, this.name, salet.character)

room = (name, salet, spec) ->
  spec ?= {}
  spec.name = name
  return new SaletRoom(spec).register(salet)

module.exports = room