###
Iffy - parserless interactive fiction for the web
(c)2010 Jeremy Penner
###

#lazy enumeration
class Eni
	constructor: (@val, @fStarted) ->
	Value: () -> @val
	EniNext: () -> if not @fStarted then new Eni(@val, true)

EniEmpty = { EniNext: (-> null) }

class EniArray
	constructor: (@rg, @i) -> if not @i? then @i = -1
	Value: -> @rg[@i]
	EniNext: -> if @i + 1 < @rg.length then new EniArray(@rg, @i + 1)

class EniConcat
	constructor: (@eni1, @eni2) ->
	Value: -> @eni1.Value()
	EniNext: (rgarg...) ->
		eni1New = @eni1.EniNext(rgarg...)
		if eni1New?
			new EniConcat(eni1New, @eni2)
		else
			@eni2.EniNext(rgarg...)

class EniThunk
	constructor: (@thunk) ->
	# it is always illegal to call Value on this eni, as eninext will never return an eniThunk
	EniNext: (rgarg...) ->	
		# memoize generated eni
		if not @eni?
			@eni = @thunk(rgarg...)
		@eni.EniNext()

class EniCons
	constructor: (@value, @thunk, @fStarted) ->
	Value: -> @value
	EniNext: (rgarg...) ->
		if not @fStarted
			if not @eniNext?
				@eniNext = new EniCons(@value, @thunk, true)
			@eniNext
		else
			if not @eni?
				@eni = @thunk(this, rgarg...)
			@eni.EniNext()

class EniMap
	constructor: (@eni, @dg) ->
	Value: -> @dg(@eni.Value())
	EniNext: (rgarg...) -> 
		eniNext = @eni.EniNext()
		if eniNext? then new EniMap(eniNext, @dg, rgarg...)

class EniFilter
	constructor: (@eni, @dgFilter) ->
	Value: -> @eni.Value()
	EniNext: (rgarg...) ->
		eni = @eni.EniNext(rgarg...)
		while eni? and not @dgFilter(eni.Value(), eni, rgarg...)
			eni = eni.EniNext()
		eni

ArrayFromEni = (eni) ->
	rg = []
	while (eni = eni.EniNext())?
		rg.push(eni.Value())
	rg
	
# world state -- holds the state of the world after every 
NewWst = (obj, gst) ->
	Ctor = (@gst) ->
		@WstNext = (nev) ->
			CtorNext = (wstOld) ->
				@nev = nev
				@wstPrev = wstOld
				this
			CtorNext.prototype = this
			new CtorNext(this)
		@WstPrev = () -> @wstPrev
		this
	Ctor.prototype = obj
	new Ctor(gst)

class Respo
	constructor: (@enieniNev, @eniNev) ->
		if @enieniNev.eni.i < 0 and @eniNev?
			@eniNev = @eniNev
	@FromEnieniNev: (enieniNev) -> new Respo(enieniNev)
	Nev: () -> @eniNev.Value()
	Next: (nevgen) ->
		enieniNev = @enieniNev
		eniNev = @eniNev
		loop
			if not eniNev?
				enieniNev = enieniNev.EniNext()
				if enieniNev?
					eniNev = enieniNev.Value()
				else
					return null
			eniNev = eniNev.EniNext(nevgen, new Respo(enieniNev, eniNev))
			if eniNev? then return new Respo(enieniNev, eniNev)
		null
	ReplaceEniNev: (eniNevNew) -> new Respo(@enieniNev, eniNevNew)

class Nevgen
	constructor: (@gst, @wst, @eniWstResponding, @respo) ->
	@EniWst: (gst, wstInit) ->
		nevgen = new Nevgen(gst, wstInit, null, null)
		new EniCons(wstInit, nevgen.Thunk())
	Thunk: () ->
		(eniPrev) =>
			nevgen = this
			if not @eniWstResponding?
				nevgen = @RespondTo(@gst, @wst, eniPrev)
			nevgen = nevgen.Next()
			if nevgen?
				new EniCons(nevgen.wst, nevgen.Thunk())
			else
				EniEmpty
	Next: () ->
		nevgen = this
		while nevgen? and nevgen.wst == @wst
			nevgen = nevgen.NextI()
		nevgen
	NextI: () ->
		if @wst.nev.FEndsSection()
			return null
		if @respo?
			respoNext = @respo.Next(this)
			wst = @wst
			if respoNext? and respoNext.Nev().FCanRun(@gst, wst)
				wst = @gst.RunNev(wst, respoNext.Nev())
			new Nevgen(@gst, wst, @eniWstResponding, respoNext)
		else if @wst != @eniWstResponding.Value()
			@RespondTo(@gst, @wst, @eniWstResponding.EniNext())
	RespondTo: (gst, wst, eniWstResponding) ->
		new Nevgen(gst, wst, eniWstResponding, gst.story.RespoResponse(eniWstResponding.Value().nev, wst))
							
# game state -- holds all the information needed to display the current state of the game in our browser
class Gst
	constructor: (@story, @jDiv) ->
		@rgwstInit = [@story.WstInit(this)]
		@rgsection = [@story.SectionByName("start")]
		@rgwst = null
		@igenID = 0

	GoBackOneSection: () ->
		isectionRemove = @rgsection.length - 1
		@rgsection.splice(isectionRemove, 1)
		@rgwstInit.splice(isectionRemove, 1)
		@Display()
		
	PushSection: (section, wst) ->
		@rgsection.push(section)
		@rgwstInit.push(wst)
		@Display()
		
	SectionCurrent: () ->
		@rgsection[@rgsection.length - 1]
		
	Display: () ->
		@mpstId_dgOnClick = []
		@ClearMenu(true)
		@jDiv.empty()
		@jDiv.click(() => @ClearMenu())
		@jDiv.append("<div class='title'>
					<h1>#{@story.jStory.attr('title')}</h1>
						<h2>#{@story.jStory.attr('author')}</h2>
					  </div>")
		dgEnter = () -> $(this).addClass('hover')
		dgLeave = () -> $(this).removeClass('hover')
		
		# show "previous section" link
		if @rgsection.length > 1
			@jDiv.append("<div class='iffy-section-nav'>#{@Link("Previous section", () => @GoBackOneSection())}</div>")
		
		# show all nevs in section
		@rgwst = null
		@rgwst = @RgwstRun()
		for wst in @rgwst
			jDivNev = $("<div class='iffy-nev'/>")
			jDivNev.append(wst.nev.StHtmlDisplay(this, wst))
			@jDiv.append(jDivNev)
			jDivNev.hover(dgEnter, dgLeave)
			@wstLast = wst
		
		# show "next section" link
		stHtmlNav = @wstLast.nev.StHtmlNextSection(this, @wstLast)
		if stHtmlNav?
			@jDiv.append("<div class='iffy-section-nav'>#{stHtmlNav}</div>")

		for stId_dgOnClick in @mpstId_dgOnClick
			@jDiv.find("##{stId_dgOnClick[0]}").click(stId_dgOnClick[1])
	
	# only valid to call after the story has been run
	FWasRun: (nev) ->
		for wst in @rgwst
			if wst.nev.ID() == nev.ID()
				return true
		return false
		
	ShowMenu: (ev, dLink, rgverb) ->
		@ClearMenu(true)
		jMenu = $("<div class='iffy-menu'/>").hide()
		for verb in rgverb
			dgClick = ((verbT) => () => verbT.dgActivate(); @Display())(verb)
			jMenuItem = $("<a href='javascript:void(0)'>#{verb.stDisplay}</a><br/>").click(dgClick)
			jMenu.append(jMenuItem)
		
		jMenu.css({
			position: "absolute"
			top: ev.pageY
			left: ev.pageX
		})
		@jDiv.append(jMenu)

		@jMenu = jMenu
		@fMenuVisible = false
		jMenu.show('blind', {}, 300, () => @fMenuVisible = true)
	
	ClearMenu: (fForce) ->
		if @jMenu? and (fForce or @fMenuVisible)
			@jMenu.hide('blind', {}, 300, () -> $(this).remove())
			@jMenu = null
			@fMenuVisible = false
				
	RegOnClick: (dgOnClick) ->
		stId = "__gen#{@igenID++}"
		@mpstId_dgOnClick.push([stId, dgOnClick])
		stId

	Link: (stText, dgOnClick, stExtra) ->
		if not stExtra?
			stExtra = ""
		"<a href='javascript:void(0)' id='#{@RegOnClick(dgOnClick)}' #{stExtra}>#{stText}</a>"
		
	RgwstRun: () ->
		wst = @RunNev(@rgwstInit[@rgwstInit.length - 1], @SectionCurrent().NevByName("start"))
		eniWst = Nevgen.EniWst(this, wst)
		ArrayFromEni(eniWst)
	
	RunNev: (wst, nevResponse) ->
		wst = wst.WstNext(nevResponse)
		nevResponse.RunAction(this, wst)
		wst

	FWillNevRun: (wst, eniNevResponseNext, nevgen, respo, nevPretend, nevLater) ->
		wstNext = @RunNev(wst, nevPretend)

		ThunkWstContinue = (eniWstRespondingOld) ->
			() ->
				if eniWstRespondingOld?
					if eniWstRespondingOld.Value() == wst
						return new EniCons(wst, ThunkWstContinue(null))
					else
						return new EniCons(eniWstRespondingOld.Value(), ThunkWstContinue(eniWstRespondingOld.EniNext()))
				else
					return new EniConcat(new Eni(wstNext), eniWstNextPre)
		eniWstRespondingNew = ThunkWstContinue(nevgen.eniWstResponding)().EniNext()
		eniWstNextPre = new Nevgen(this, wstNext, eniWstRespondingNew, respo.ReplaceEniNev(eniNevResponseNext)).Thunk()()
		eniWstNext = eniWstNextPre.EniNext()
		while eniWstNext?
			if eniWstNext.Value().nev.ID() == nevLater.ID()
				return true
			eniWstNext = eniWstNext.EniNext()
		return false
		
	FilterStHtml: (stHtml, wst) ->
		for actor in @story.rgactor
			try
				stHtml = actor.FilterStHtml(stHtml, wst)
			catch error
				stHtml = stHtml + "<p class='error'>[[error interpreting markup: #{error}]]</p>"
		stHtml
	StHtmlUi: (wst) ->
		stHtmlUi = ""
		for actor in @story.rgactor
			if actor.StHtmlUi?
				stHtmlUiT = actor.StHtmlUi(wst)
				if stHtmlUiT?
					stHtmlUi += stHtmlUiT
		stHtmlUi
		
bind = (fn, me) -> ((args...) -> fn.apply(me, args))# argh new coffeescript won't let me use __bind :(

# narrative event -- the story is told as a sequence of these.  Contains the HTML to display when the
# narrative event happens, the preconditions to make sure the event should be allowed to occur, and
# the resultant effect on the state of the model of the world
class Nev
	@RgstelemReserved = ["cond", "set", "donext"]
	constructor: (@dNev) ->
	ID: () ->
		if not @id?
			rgstName = $(@dNev).parents("[name]").map(() -> $(this).attr("name")).get()
			rgstName.reverse()
			rgstName.push($(@dNev).attr("name"))
			@id = rgstName.join(".")
		@id
	FHasRun: (wst) ->
		while wst?.nev
			if wst.nev.ID() == @ID()
				return true
			wst = wst.WstPrev()
		return false
	FConds: (wst) ->
		for dCond in $("cond", @dNev)
			try
				if (!(new Function("wst", "with(wst) {return #{dCond.textContent};}")(wst)))
					return false
			catch error
				return false
		true
	FCanRun: (gst, wst) -> not @FHasRun(wst) and @FConds(wst)
	FEndsSection: () -> $(@dNev).attr("nextsection")?
	RunAction: (gst, wst) ->
		for dSet in $("set", @dNev)
			try
				new Function("wst", "wst.#{$(dSet).attr('var')} = #{dSet.textContent};")(wst)
			catch e
				alert("error setting #{$(dSet).attr('var')} to #{dSet.textContent}")
			
	StHtmlNextSection: (gst, wst) ->
		stSectionNext = $(@dNev).attr("nextsection")
		if stSectionNext?
			section = gst.story.SectionByName(stSectionNext)
			if section?
				gst.Link("Next section", () -> gst.PushSection(section, wst))
	StHtmlDisplay: (gst, wst) ->
		jdivTmp = $("<div/>")
		for dHTML in $(@dNev).contents()
			fReserved = false
			for stElemReserved in Nev.RgstelemReserved
				if ($.nodeName(dHTML, stElemReserved))
					fReserved = true
					break
			if not fReserved
				jdivTmp.append(document.importNode(dHTML, true))
		stHtml = jdivTmp[0].innerHTML
		"<div class='iffy-nev-ui'>#{gst.StHtmlUi(wst)}</div><div class='iffy-nev-text'>#{gst.FilterStHtml(stHtml, wst)}</div>"

#[word text to display] -- links to a word, usually a noun, that the player can interact with in some way.
#[word] == [word word]
# $(expr) inserts as a string the result of expr
# $[statements] executes some javascript (semicolons needed)
# [[ outputs [, ]] outputs ]

TemplateFromStNev = (st, wst) ->
	class Xpd
		constructor: (@st, @fExpr) ->
	
	JsStringLit = (st) ->
		"'" + st.replace(/'/g, "\\'").replace(/\r/g, "\\r").replace(/\n/g, "\\n").replace(/\t/, "\\t") + "'"
	
	rgxpd = []
	ich = 0
	ichLim = 0
	ichLimTok = 0
	
	PushText = (fExpr, dgSt) ->
		stTok = st.substring(ich, ichLim)
		if dgSt? then stTok = dgSt(stTok)
		if stTok then rgxpd.push(new Xpd(stTok, fExpr))
		ich = ichLimTok
		ichLim = ichLimTok
		
	Match = (dgPushNoTok, rgre_dg...) ->
		ire = 0
		ireMatched = -1
		ichMatchFirst = null
		for ire in [0...rgre_dg.length] by 2
			re = rgre_dg[ire]
			re.lastIndex = ichLimTok
			rgstMatched = re.exec(st)
			if rgstMatched?
				ichMatchT = re.lastIndex - rgstMatched[0].length
				if not ichMatchFirst? or ichMatchT < ichMatchFirst
					ichMatchFirst = ichMatchT
					stMatched = rgstMatched[0]
					ireMatched = ire
		reMatched = rgre_dg[re]
		if ireMatched >= 0
			ichLim = ichMatchFirst
			ichLimTok = ichMatchFirst + stMatched.length
			rgre_dg[ireMatched + 1]()
		else
			ichLim = ichLimTok = st.length
			if dgPushNoTok?
				dgPushNoTok()
			null
	
	MatchInText = () ->
		EndText = () -> 
			PushText(true, (st) -> JsStringLit(st.replace(/\[\[/g, "[").replace(/\]\]/g, "]")))
		Match(EndText,
			  /\[\[/g, () -> MatchInText,
			  /\]\]/g, () -> MatchInText,
			  /\[/g, () -> EndText(); MatchInWord,
			  /\$\[/g, () -> EndText(); MatchInStmts,
			  /\$\(/g, () -> EndText(); MatchInExpr)
	
	EndMatchBracket = (cbracketSquareNew, cbracketParenNew, dgPush) ->
		if cbracketSquareNew <= 0 && cbracketParenNew <= 0
			dgPush()
			MatchInText
		else
			MatchBracket(cbracketSquareNew, cbracketParenNew, dgPush)
	MatchBracket = (cbracketSquare, cbracketParen, dgPush) ->
		() -> Match(dgPush, # error?
					/"/g, () -> MatchString(MatchBracket(cbracketSquare, cbracketParen, dgPush)),
					/\[/g, () -> MatchBracket(cbracketSquare + 1, cbracketParen, dgPush),
					/\]/g, () -> EndMatchBracket(cbracketSquare - 1, cbracketParen, dgPush),
					/\(/g, () -> MatchBracket(cbracketSquare, cbracketParen + 1, dgPush),
					/\)/g, () -> EndMatchBracket(cbracketSquare, cbracketParen - 1, dgPush))
	
	MatchString = (matchAfter) ->
		() ->
			Match(null,
				  /\\\\/g, () -> MatchString(matchAfter),
				  /\\"/g, () -> MatchString(matchAfter),
				  /"/g, () -> matchAfter)
	StWord = (st) -> 
		rgstDisplay = /[ ]*([^ ]+)(.*)/.exec(st)
		stWord = rgstDisplay[1]
		if rgstDisplay[2]
			stDisplay = rgstDisplay[2]
		else
			stDisplay = rgstDisplay[1].replace(/_/g, " ")
			
		word = wst.gst.SectionCurrent().WordByName(wst.gst, stWord)
		if word? and (rgverb = word.Rgverb(wst)).length > 0
			JsStringLit(wst.gst.Link(stDisplay, ((ev) -> wst.gst.ShowMenu(ev, this, rgverb)), "class='iffy-word'"))
		else
			JsStringLit(stDisplay)
	MatchInWord = MatchBracket(1, 0, () -> PushText(true, StWord))
	MatchInExpr = MatchBracket(0, 1, () -> PushText(true))
	MatchInStmts = MatchBracket(1, 0, () -> PushText(false))

	BuildRgxpd = (dgMatch) ->
		while dgMatch?
			dgMatch = dgMatch()
	
	BuildRgxpd(MatchInText)
	
	rgstJs = ["var __p=[];with(wst){"]
	fExpr = false
	for xpd in rgxpd
		if xpd.fExpr != fExpr
			rgstJs.push(if fExpr then ");" else "__p.push(")
		else if fExpr
			rgstJs.push(",")
		fExpr = xpd.fExpr
		rgstJs.push(xpd.st)
	if fExpr then rgstJs.push(");")
	rgstJs.push("}return __p.join('');")
	new Function("wst",rgstJs.join(''))

class Word
	constructor: (@gst, @jWord) ->
	Rgverb: (wst) ->
		rgverb = []
		for dVerb in @jWord.find("verb")
			nev = new Nev(dVerb)
			if not @gst.FWasRun(nev) and not @gst.story.actorPlayer.FWillAttempt(wst, nev) and nev.FConds(wst)
				stDisplay = $(dVerb).attr("display") or $(dVerb).attr("name")
				dgActivate = ((dVerbT) => () => @gst.story.actorPlayer.RespondTo(wst.nev, new Nev(dVerbT)))(dVerb)
				rgverb.push(new Verb(stDisplay, dgActivate))
		rgverb
			
class Verb
	constructor: (@stDisplay, @dgActivate) ->
	
# actors drive the story by responding to nevs with more nevs
# ActorPlayer does its best to perform the actions that the player has told the game to perform.
class ActorPlayer
	constructor: (@story) ->
		@mpnevID_rgnev = {}
	RespondTo: (nev, nevResponse) ->
		nevResponse.player_nevIDRespondedTo = nev.ID();
		rgnev = @mpnevID_rgnev[nev.ID()]
		if rgnev?
			rgnev.splice(0, 0, nevResponse)
		else
			@mpnevID_rgnev[nev.ID()] = [nevResponse]
	RemoveResponse: (nevResponse) ->
		rgnev = @mpnevID_rgnev[nevResponse.player_nevIDRespondedTo]
		for nev, inev in rgnev
			if nev.ID() == nevResponse.ID()
				rgnev.splice(inev, 1)
				break

	FWillAttempt: (wst, nev) ->
		rgnev = @mpnevID_rgnev[wst.nev.ID()]
		if rgnev?
			for nevResponse in rgnev
				if nevResponse.ID() == nev.ID()
					return true
		return false
		
	EninevResponse: (nev, wst) ->
		rgnev = @mpnevID_rgnev[nev.ID()]
		if rgnev? then new EniArray(rgnev) else EniEmpty

	FilterStHtml: (stHtml, wst) ->
		TemplateFromStNev(stHtml, wst)(wst)

	StHtmlUi: (wst) ->
		if (wst.nev.player_nevIDRespondedTo?)
			wst.gst.Link("Undo", (() => @RemoveResponse(wst.nev); wst.gst.Display()), "class='iffy-undo'")
			
class ActorNext
	constructor: (@story) ->
		@mpnevID_rgnev = {}
		for section in @story.Rgsection()
			for dDoNext in section.jSection.find("donext")
				@add(new Nev($(dDoNext.parentNode)), section.NevByName($(dDoNext).attr("nev")))
	add: (nev, nevResponse) ->
		if not @mpnevID_rgnev[nev.ID()]?
			@mpnevID_rgnev[nev.ID()] = []
		@mpnevID_rgnev[nev.ID()].push(nevResponse)
	EninevResponse: (nev, wst) ->
		rgnev = @mpnevID_rgnev[nev.ID()]
		if rgnev? then new EniArray(rgnev) else EniEmpty

	FilterStHtml: (stHtml, wst) -> stHtml
class Story
	constructor: (@jStory) ->
		@actorPlayer = new ActorPlayer(this)
		@rgactor = [@actorPlayer, new ActorNext(this)]
	SectionByName: (stName) ->
		jSection = @jStory.find("section[name=#{stName}]")
		if jSection.length == 1 then new Section(this, jSection)
	Rgsection: () ->
		new Section(this, $(jSection)) for jSection in @jStory.find("section").toArray()
	RespoResponse: (nev, wst) ->
		Respo.FromEnieniNev(new EniMap(new EniArray(@rgactor), (actor) -> actor.EninevResponse(nev, wst)))
	WstInit: (gst) ->
		NewWst({}, gst)

class Section
	constructor: (@story, @jSection) ->

	NevByName: (stName) ->
		if stName?
			rgstName = stName.split('.')
			for dNev in @jSection.find("[name=#{rgstName[rgstName.length - 1]}]")
				istName = rgstName.length - 2
				dParent = dNev
				while dParent? and istName >= 0
					dParent = $(dParent).parent("[name=#{rgstName[istName]}]").get(0)
					istName--
				if dParent?
					return new Nev(dNev)
		null
	WordByName: (gst, stName) ->
		jWord = @jSection.find("word[name=#{stName}]")
		if jWord.length > 0 then new Word(gst, jWord)
	
Rgget = (rgurl, dgAfter, iurl, rgresult) ->
	if not iurl? then iurl = 0
	if not rgresult then rgresult = []
	if iurl == rgurl.length
		dgAfter(rgresult)
	else
		# $.get, called with javascript, results in a "syntax error" in FireFox if the result is not xml.  This is OK.
		$.get(rgurl[iurl], ((result) -> rgresult.push(result); Rgget(rgurl, dgAfter, iurl + 1, rgresult)), "text")

window.PlayStory = (url, jDiv) ->
	$.get(url, (domXml) ->
		story = new Story($("story", domXml))
		gst = new Gst(story, jDiv)
		rgurlExt = []
		for domLoad in $("loadmodule", domXml)
			rgurlExt.push($(domLoad).attr("url"))
		Rgget(rgurlExt, (rgscript) ->
			for script in rgscript
				eval(script)(gst)
			gst.Display()
		)			
	, "xml")