import re, string

class TeXLexer:

	re_control_sequence = re.compile( r"^\\[a-zA-Z]+[ ]?|^\\[^a-zA-Z][ ]?" )

	def __init__( self, str ):
		self.str = str
		self.len = len(str)
		self.pos = 0
		self.token_stack = []

	def get_token( self ):
		if self.pos == self.len:
			return None

		if len(self.token_stack) > 0:
			return self.token_stack.pop()

		str = self.str[self.pos:]
		m = self.re_control_sequence.match(str)
		if m is not None:
			token = m.group()
			self.pos = self.pos + len(token)
			## consume trailing space
			if len(token) > 2 and token[-1] == ' ':
				token = token[:-1]
		else:
			token = str[0]
			self.pos = self.pos + 1

		return token

	def put_token( self, token ):
		self.token_stack.append( token )

	def peek( self ):
		token = self.get_token()
		self.put_token( token )
		return token

_common_token_dict = {
	r'\\'				: '\\',
	r'\$'				: r'$',
	r'\%'				: r'%',
	r'\#'				: r'#',
	r'\&'				: r'&',
#	r'\~'				: r'~',
	r'\{'				: r'{',
	r'\}'				: r'}',
	r'\_'				: r'_',
#	r'\^'				: r'^',

	r'~'				: r' ',
	r'\/'				: r'\r^',

	## special letters (p52)
#	r'\oe'				: r'',
#	r'\OE'				: r'',
	r'\ae'				: r'\ae',
	r'\AE'				: r'\AE',
	r'\aa'				: r'\oa',
	r'\AA'				: r'\oA',
	r'\o'				: r'\/o',
	r'\O'				: r'\/O',
#	r'\l'				: r'',
#	r'\L'				: r'',
	r'\ss'				: r'\ss',

	## ignore stray brackets
	r'{'				: r'',
	r'}'				: r'',
}

_text_token_dict = {
	## punctuation (p52)
	r'\`'				: r'\`',
	r"\'"				: r"\'",
	r'\^'				: r'\^',
	r'\"'				: r'\:',
	r'\~'				: r'\~',
	r'\c'				: r'\,',

	## non-math symbols (p438)
	r'\S'				: r'\sc',
	r'\P'				: r'\ps',
	r'\dag'				: r'\dg',
	r'\ddag'			: r'\dd',
}

_math_token_dict = {

	r'*'				: r'\**',

	## spacing
#	r' '				: r'',
	r'\ '				: r' ',
	r'\quad'			: r'\r1',	# 1 em
	r'\qquad'			: r'\r1\r1',	# 2 em
	r'\,'				: r'\r6',	# 3/18 em
#	r'\>'				: r'',		# 4/18 em
#	r'\;'				: r'',		# 5/18 em
	r'\!'				: r'\l6',	# -1/6 em

	## lowercase greek
	r'\alpha'			: r'\*a',
	r'\beta'			: r'\*b',
	r'\gamma'			: r'\*g',
	r'\delta'			: r'\*d',
	r'\epsilon'			: r'\*e',
#	r'\varepsilon'			: r'',
	r'\zeta'			: r'\*z',
	r'\eta'				: r'\*y',
	r'\theta'			: r'\*h',
	r'\vartheta'			: r'\+h', 
	r'\iota'			: r'\*i',
	r'\kappa'			: r'\*k',
	r'\lambda'			: r'\*l',
	r'\mu'				: r'\*m',
	r'\nu'				: r'\*n',
	r'\xi'				: r'\*c',
	r'\pi'				: r'\*p',
#	r'\varpi'			: r'',
	r'\rho'				: r'\*r',
#	r'\varrho'			: r'',
	r'\sigma'			: r'\*s',
	r'\varsigma'			: r'\ts',
	r'\tau'				: r'\*t',
	r'\upsilon'			: r'\*u',
	r'\phi'				: r'\*f',
	r'\varphi'			: r'\+f',
	r'\chi'				: r'\*x',
	r'\psi'				: r'\*q',
	r'\omega'			: r'\*w',

	## uppercase greek
	r'\Alpha'			: r'\*A',
	r'\Beta'			: r'\*B',
	r'\Gamma'			: r'\*G',
	r'\Delta'			: r'\*D',
	r'\Epsilon'			: r'\*E',
	r'\Zeta'			: r'\*Z',
	r'\Eta'				: r'\*Y',
	r'\Theta'			: r'\*H',
	r'\Iota'			: r'\*I',
	r'\Kappa'			: r'\*K',
	r'\Lambda'			: r'\*L',
	r'\Mu'				: r'\*M',
	r'\Nu'				: r'\*N',
	r'\Xi'				: r'\*C',
	r'\Pi'				: r'\*P',
	r'\Rho'				: r'\*R',
	r'\Sigma'			: r'\*S',
	r'\Tau'				: r'\*T',
	r'\Upsilon'			: r'\*U',
	r'\Phi'				: r'\*F',
	r'\Chi'				: r'\*X',
	r'\Psi'				: r'\*Q',
	r'\Omega'			: r'\*W',

	## miscellaneous
	r'\aleph'			: r'\Ah',
	r'\hbar'			: r'\hb',
	r'\ell'				: r'\#H0662',
	r'\wp'				: r'\wp',
	r'\Re'				: r'\Re',
	r'\Im'				: r'\Im',
	r'\partial'			: r'\pd',
	r'\infty'			: r'\if',
	r'\prime'			: r'\fm',
	r'\emptyset'			: r'\es',
	r'\nabla'			: r'\gr',
	r'\surd'			: r'\sr',
#	r'\top'				: r'',
#	r'\bot'				: r'',
	r'\|'				: r'\||',
	r'\angle'			: r'\/_',
#	r'\triangle'			: r'',
	r'\backslash'			: r'\\',
	r'\forall'			: r'\fa',
	r'\exists'			: r'\te',
	r'\neg'				: r'\no',
#	r'\flat'			: r'',
#	r'\natural'			: r'',
#	r'\sharp'			: r'',
	r'\clubsuit'			: r'\CL',
	r'\diamondsuit'			: r'\DI',
	r'\heartsuit'			: r'\HE',
	r'\spadesuit'			: r'\SP',

	## binary operations
	r'\pm'				: r'\+-',
	r'\mp'				: r'\-+',
#	r'\setminus'			: r'',
	r'\cdot'			: r'\md',
	r'\times'			: r'\mu',
	r'\ast'				: r'\**',
#	r'\star'			: r'',
#	r'\diamond'			: r'',
#	r'\circ'			: r'',
	r'\bullet'			: r'\bu',
	r'\div'				: r'\di',
	r'\cap'				: r'\ca',
	r'\cup'				: r'\cu',
#	r'\uplus'			: r'',
#	r'\sqcap'			: r'',
#	r'\sqcup'			: r'',
#	r'\triangleleft'		: r'',
#	r'\triangleright'		: r'',
#	r'\wr'				: r'',
#	r'\bigcirc'			: r'',
#	r'\bigtriangleup'		: r'',
#	r'\bigtriangledown'		: r'',
#	r'\vee'				: r'',
#	r'\wedge'			: r'',
	r'\oplus'			: r'\c+',
#	r'\ominus'			: r'',
	r'\otimes'			: r'\c*',
#	r'\oslash'			: r'',
#	r'\odot'			: r'',
	r'\dagger'			: r'\dg',
	r'\ddagger'			: r'\dd',
#	r'\amalg'			: r'',

	## relations
	r'\leq'				: r'\<=',
#	r'\prec'			: r'',
#	r'\preceq'			: r'',
	r'\ll'				: r'<<',
	r'\subset'			: r'\SB',
#	r'\subseteq'			: r'',
#	r'\sqsubseteq'			: r'',
	r'\in'				: r'\mo',
#	r'\vdash'			: r'',
#	r'\smile'			: r'',
#	r'\frown'			: r'',
	r'\geq'				: r'\>=',
#	r'\succ'			: r'',
#	r'\succeq'			: r'',
	r'\gg'				: r'>>',
	r'\supset'			: r'\SS',
#	r'\supseteq'			: r'',
#	r'\sqsupseteq'			: r'',
#	r'\ni'				: r'',
#	r'\dashv'			: r'',
	r'\mid'				: r'|',
	r'\parallel'			: r'\||',
	r'\equiv'			: r'\==',
	r'\sim'				: r'\ap',
	r'\simeq'			: r'\~-',
#	r'\asymp'			: r'',
	r'\approx'			: r'\~~',
	r'\cong'			: r'\=~',
#	r'\bowtie'			: r'',
	r'\propto'			: r'\pt',
#	r'\models'			: r'',
#	r'\doteq'			: r'',
	r'\perp'			: r'\pp',

	## arrows
	r'\leftarrow'			: r'\<-',
	r'\Leftarrow'			: r'\lA',
	r'\rightarrow'			: r'\->',
	r'\Rightarrow'			: r'\rA',
	r'\leftrightarrow'		: r'\<>',
	r'\Leftrightarrow'		: r'\hA',
#	r'\mapsto'			: r'',
#	r'\hookleftarrow'		: r'',
#	r'\leftharpoonup'		: r'',
#	r'\leftharpoondown'		: r'',
#	r'\rightleftharpoons'		: r'',
#	...
	r'\uparrow'			: r'\ua',
	r'\Uparrow'			: r'\uA',
	r'\downarrow'			: r'\da',
	r'\Downarrow'			: r'\dA',
#	r'\updownarrow'			: r'',
#	r'\Updownarrow'			: r'',
#	r'\nearrow'			: r'',
#	r'\searrow'			: r'',
#	r'\swarrow'			: r'',
#	r'\nwarrow'			: r'',

	## openings
	r'\lbrack'			: r'[',
	r'\lbrace'			: r'{',
	r'\langle'			: r'\la',
#	r'\lfloor'			: r'',
#	r'\lceil'			: r'',

	## closings
	r'\rbrack'			: r']',
	r'\rbrace'			: r'}',
	r'\rangle'			: r'\ra',
#	r'\rfloor'			: r'',
#	r'\rceil'			: r'',

	## alternate names
	r'\ne'				: r'\!=',
	r'\neq'				: r'\!=',
	r'\le'				: r'\<=',
	r'\ge'				: r'\>=',
	r'\to'				: r'\->',
	r'\gets'			: r'\<-',
#	r'\owns'			: r'',
	r'\land'			: r'\AN',
	r'\lor'				: r'\OR',
	r'\lnot'			: r'\no',
	r'\vert'			: r'|',
	r'\Vert'			: r'\||',

	## extensions
	r'\degree'			: r'\de',
	r'\deg'				: r'\de',
	r'\degr'			: r'\de',
	r'\arcdeg'			: r'\de',
}

def map_text_token( token ):
	if _text_token_dict.has_key(token):
		return _text_token_dict[token]
	else:
		return _common_token_dict.get( token, token )

def map_math_token( token ):
	if _math_token_dict.has_key(token):
		return _math_token_dict[token]
	else:
		return _common_token_dict.get( token, token )

def math_group( lexer ):
	output = ''
	bracketmode = 0
	while 1:
		token = lexer.get_token()
		if token is None:
			break

		if token == '{':
			bracketmode = 1
		elif token == '}':
			break
		else:
			output = output + map_math_token( token )
			if not bracketmode:
				break
	return output

font_code = [ r'\f0', r'\f1', r'\f2', r'\f3' ]

def tex2libplot( str ):
	output = ''
	mathmode = 0
	font_stack = []
	font = 1

	lexer = TeXLexer( str )
	while 1:
		token = lexer.get_token()
		if token is None:
			break

		append = ''

		if token == '$':
			mathmode = not mathmode
		elif token == '{':
			font_stack.append( font )
		elif token == '}':
			old_font = font_stack.pop()
			if old_font != font:
				font = old_font
				append = font_code[font]
		elif token == r'\rm':
			font = 1
			append = font_code[font]
		elif token == r'\it':
			font = 2
			append = font_code[font]
		elif token == r'\bf':
			font = 3
			append = font_code[font]
		elif not mathmode:
			append = map_text_token( token )
		elif token == '_':
			append = r'\sb' + math_group(lexer) + r'\eb'
			if lexer.peek() == '^':
				append = r'\mk' + append + r'\rt'
		elif token == '^':
			append = r'\sp' + math_group(lexer) + r'\ep'
			if lexer.peek() == '_':
				append = r'\mk' + append + r'\rt'
		else:
			append = map_math_token( token )

		output = output + append

	return output
