#!/usr/bin/env python3
# encoding: utf-8
# Thomas Nagy, 2006-2018 (ita)

"""
TeX/LaTeX/PDFLaTeX/XeLaTeX support

Example::

	def configure(conf):
		conf.load('tex')
		if not conf.env.LATEX:
			conf.fatal('The program LaTex is required')

	def build(bld):
		bld(
			features = 'tex',
			type     = 'latex', # pdflatex or xelatex
			source   = 'document.ltx', # mandatory, the source
			outs     = 'ps', # 'pdf' or 'ps pdf'
			deps     = 'crossreferencing.lst', # to give dependencies directly
			prompt   = 1, # 0 for the batch mode
		)

Notes:

- To configure with a special program, use::

     $ PDFLATEX=luatex waf configure

- This tool does not use the target attribute of the task generator
  (``bld(target=...)``); the target file name is built from the source
  base name and the output type(s)
"""

import os, re
from waflib import Utils, Task, Errors, Logs, Node
from waflib.TaskGen import feature, before_method

re_bibunit = re.compile(r'\\(?P<type>putbib)\[(?P<file>[^\[\]]*)\]',re.M)
def bibunitscan(self):
	"""
	Parses TeX inputs and try to find the *bibunit* file dependencies

	:return: list of bibunit files
	:rtype: list of :py:class:`waflib.Node.Node`
	"""
	node = self.inputs[0]

	nodes = []
	if not node:
		return nodes

	code = node.read()
	for match in re_bibunit.finditer(code):
		path = match.group('file')
		if path:
			found = None
			for k in ('', '.bib'):
				# add another loop for the tex include paths?
				Logs.debug('tex: trying %s%s', path, k)
				fi = node.parent.find_resource(path + k)
				if fi:
					found = True
					nodes.append(fi)
					# no break
			if not found:
				Logs.debug('tex: could not find %s', path)

	Logs.debug('tex: found the following bibunit files: %s', nodes)
	return nodes

exts_deps_tex = ['', '.ltx', '.tex', '.bib', '.pdf', '.png', '.eps', '.ps', '.sty']
"""List of typical file extensions included in latex files"""

exts_tex = ['.ltx', '.tex']
"""List of typical file extensions that contain latex"""

re_tex = re.compile(r'\\(?P<type>usepackage|RequirePackage|include|bibliography([^\[\]{}]*)|putbib|includegraphics|input|import|bringin|lstinputlisting)(\[[^\[\]]*\])?{(?P<file>[^{}]*)}',re.M)
"""Regexp for expressions that may include latex files"""

g_bibtex_re = re.compile('bibdata', re.M)
"""Regexp for bibtex files"""

g_glossaries_re = re.compile('\\@newglossary', re.M)
"""Regexp for expressions that create glossaries"""

class tex(Task.Task):
	"""
	Compiles a tex/latex file.

	.. inheritance-diagram:: waflib.Tools.tex.latex waflib.Tools.tex.xelatex waflib.Tools.tex.pdflatex
	"""

	bibtex_fun, _ = Task.compile_fun('${BIBTEX} ${BIBTEXFLAGS} ${SRCFILE}', shell=False)
	bibtex_fun.__doc__ = """
	Execute the program **bibtex**
	"""

	makeindex_fun, _ = Task.compile_fun('${MAKEINDEX} ${MAKEINDEXFLAGS} ${SRCFILE}', shell=False)
	makeindex_fun.__doc__ = """
	Execute the program **makeindex**
	"""

	makeglossaries_fun, _ = Task.compile_fun('${MAKEGLOSSARIES} ${SRCFILE}', shell=False)
	makeglossaries_fun.__doc__ = """
	Execute the program **makeglossaries**
	"""

	def exec_command(self, cmd, **kw):
		"""
		Executes TeX commands without buffering (latex may prompt for inputs)

		:return: the return code
		:rtype: int
		"""
		if self.env.PROMPT_LATEX:
			# capture the outputs in configuration tests
			kw['stdout'] = kw['stderr'] = None
		return super(tex, self).exec_command(cmd, **kw)

	def scan_aux(self, node):
		"""
		Recursive regex-based scanner that finds included auxiliary files.
		"""
		nodes = [node]
		re_aux = re.compile(r'\\@input{(?P<file>[^{}]*)}', re.M)

		def parse_node(node):
			code = node.read()
			for match in re_aux.finditer(code):
				path = match.group('file')
				found = node.parent.find_or_declare(path)
				if found and found not in nodes:
					Logs.debug('tex: found aux node %r', found)
					nodes.append(found)
					parse_node(found)
		parse_node(node)
		return nodes

	def scan(self):
		"""
		Recursive regex-based scanner that finds latex dependencies. It uses :py:attr:`waflib.Tools.tex.re_tex`

		Depending on your needs you might want:

		* to change re_tex::

			from waflib.Tools import tex
			tex.re_tex = myregex

		* or to change the method scan from the latex tasks::

			from waflib.Task import classes
			classes['latex'].scan = myscanfunction
		"""
		node = self.inputs[0]

		nodes = []
		names = []
		seen = []
		if not node:
			return (nodes, names)

		def parse_node(node):
			if node in seen:
				return
			seen.append(node)
			code = node.read()
			for match in re_tex.finditer(code):

				multibib = match.group('type')
				if multibib and multibib.startswith('bibliography'):
					multibib = multibib[len('bibliography'):]
					if multibib.startswith('style'):
						continue
				else:
					multibib = None

				for path in match.group('file').split(','):
					if path:
						add_name = True
						found = None
						for k in exts_deps_tex:

							# issue 1067, scan in all texinputs folders
							for up in self.texinputs_nodes:
								Logs.debug('tex: trying %s%s', path, k)
								found = up.find_resource(path + k)
								if found:
									break


							for tsk in self.generator.tasks:
								if not found or found in tsk.outputs:
									break
							else:
								nodes.append(found)
								add_name = False
								for ext in exts_tex:
									if found.name.endswith(ext):
										parse_node(found)
										break

							# multibib stuff
							if found and multibib and found.name.endswith('.bib'):
								try:
									self.multibibs.append(found)
								except AttributeError:
									self.multibibs = [found]

							# no break, people are crazy
						if add_name:
							names.append(path)
		parse_node(node)

		for x in nodes:
			x.parent.get_bld().mkdir()

		Logs.debug("tex: found the following : %s and names %s", nodes, names)
		return (nodes, names)

	def check_status(self, msg, retcode):
		"""
		Checks an exit status and raise an error with a particular message

		:param msg: message to display if the code is non-zero
		:type msg: string
		:param retcode: condition
		:type retcode: boolean
		"""
		if retcode != 0:
			raise Errors.WafError('%r command exit status %r' % (msg, retcode))

	def info(self, *k, **kw):
		try:
			info = self.generator.bld.conf.logger.info
		except AttributeError:
			info = Logs.info
		info(*k, **kw)

	def bibfile(self):
		"""
		Parses *.aux* files to find bibfiles to process.
		If present, execute :py:meth:`waflib.Tools.tex.tex.bibtex_fun`
		"""
		for aux_node in self.aux_nodes:
			try:
				ct = aux_node.read()
			except EnvironmentError:
				Logs.error('Error reading %s: %r', aux_node.abspath())
				continue

			if g_bibtex_re.findall(ct):
				self.info('calling bibtex')

				self.env.env = {}
				self.env.env.update(os.environ)
				self.env.env.update({'BIBINPUTS': self.texinputs(), 'BSTINPUTS': self.texinputs()})
				self.env.SRCFILE = aux_node.name[:-4]
				self.check_status('error when calling bibtex', self.bibtex_fun())

		for node in getattr(self, 'multibibs', []):
			self.env.env = {}
			self.env.env.update(os.environ)
			self.env.env.update({'BIBINPUTS': self.texinputs(), 'BSTINPUTS': self.texinputs()})
			self.env.SRCFILE = node.name[:-4]
			self.check_status('error when calling bibtex', self.bibtex_fun())

	def bibunits(self):
		"""
		Parses *.aux* file to find bibunit files. If there are bibunit files,
		runs :py:meth:`waflib.Tools.tex.tex.bibtex_fun`.
		"""
		try:
			bibunits = bibunitscan(self)
		except OSError:
			Logs.error('error bibunitscan')
		else:
			if bibunits:
				fn  = ['bu' + str(i) for i in range(1, len(bibunits) + 1)]
				if fn:
					self.info('calling bibtex on bibunits')

				for f in fn:
					self.env.env = {'BIBINPUTS': self.texinputs(), 'BSTINPUTS': self.texinputs()}
					self.env.SRCFILE = f
					self.check_status('error when calling bibtex', self.bibtex_fun())

	def makeindex(self):
		"""
		Searches the filesystem for *.idx* files to process. If present,
		runs :py:meth:`waflib.Tools.tex.tex.makeindex_fun`
		"""
		self.idx_node = self.inputs[0].change_ext('.idx')
		try:
			idx_path = self.idx_node.abspath()
			os.stat(idx_path)
		except OSError:
			self.info('index file %s absent, not calling makeindex', idx_path)
		else:
			self.info('calling makeindex')

			self.env.SRCFILE = self.idx_node.name
			self.env.env = {}
			self.check_status('error when calling makeindex %s' % idx_path, self.makeindex_fun())

	def bibtopic(self):
		"""
		Lists additional .aux files from the bibtopic package
		"""
		p = self.inputs[0].parent.get_bld()
		if os.path.exists(os.path.join(p.abspath(), 'btaux.aux')):
			self.aux_nodes += p.ant_glob('*[0-9].aux')

	def makeglossaries(self):
		"""
		Lists additional glossaries from .aux files. If present, runs the makeglossaries program.
		"""
		src_file = self.inputs[0].abspath()
		base_file = os.path.basename(src_file)
		base, _ = os.path.splitext(base_file)
		for aux_node in self.aux_nodes:
			try:
				ct = aux_node.read()
			except EnvironmentError:
				Logs.error('Error reading %s: %r', aux_node.abspath())
				continue

			if g_glossaries_re.findall(ct):
				if not self.env.MAKEGLOSSARIES:
					raise Errors.WafError("The program 'makeglossaries' is missing!")
				Logs.warn('calling makeglossaries')
				self.env.SRCFILE = base
				self.check_status('error when calling makeglossaries %s' % base, self.makeglossaries_fun())
				return

	def texinputs(self):
		"""
		Returns the list of texinput nodes as a string suitable for the TEXINPUTS environment variables

		:rtype: string
		"""
		return os.pathsep.join([k.abspath() for k in self.texinputs_nodes]) + os.pathsep

	def run(self):
		"""
		Runs the whole TeX build process

		Multiple passes are required depending on the usage of cross-references,
		bibliographies, glossaries, indexes and additional contents
		The appropriate TeX compiler is called until the *.aux* files stop changing.
		"""
		env = self.env

		if not env.PROMPT_LATEX:
			env.append_value('LATEXFLAGS', '-interaction=batchmode')
			env.append_value('PDFLATEXFLAGS', '-interaction=batchmode')
			env.append_value('XELATEXFLAGS', '-interaction=batchmode')

		# important, set the cwd for everybody
		self.cwd = self.inputs[0].parent.get_bld()

		self.info('first pass on %s', self.__class__.__name__)

		# Hash .aux files before even calling the LaTeX compiler
		cur_hash = self.hash_aux_nodes()

		self.call_latex()

		# Find the .aux files again since bibtex processing can require it
		self.hash_aux_nodes()

		self.bibtopic()
		self.bibfile()
		self.bibunits()
		self.makeindex()
		self.makeglossaries()

		for i in range(10):
			# There is no need to call latex again if the .aux hash value has not changed
			prev_hash = cur_hash
			cur_hash = self.hash_aux_nodes()
			if not cur_hash:
				Logs.error('No aux.h to process')
			if cur_hash and cur_hash == prev_hash:
				break

			# run the command
			self.info('calling %s', self.__class__.__name__)
			self.call_latex()

	def hash_aux_nodes(self):
		"""
		Returns a hash of the .aux file contents

		:rtype: string or bytes
		"""
		try:
			self.aux_nodes
		except AttributeError:
			try:
				self.aux_nodes = self.scan_aux(self.inputs[0].change_ext('.aux'))
			except IOError:
				return None
		return Utils.h_list([Utils.h_file(x.abspath()) for x in self.aux_nodes])

	def call_latex(self):
		"""
		Runs the TeX compiler once
		"""
		self.env.env = {}
		self.env.env.update(os.environ)
		self.env.env.update({'TEXINPUTS': self.texinputs()})
		self.env.SRCFILE = self.inputs[0].abspath()
		self.check_status('error when calling latex', self.texfun())

class latex(tex):
	"Compiles LaTeX files"
	texfun, vars = Task.compile_fun('${LATEX} ${LATEXFLAGS} ${SRCFILE}', shell=False)

class pdflatex(tex):
	"Compiles PdfLaTeX files"
	texfun, vars =  Task.compile_fun('${PDFLATEX} ${PDFLATEXFLAGS} ${SRCFILE}', shell=False)

class xelatex(tex):
	"XeLaTeX files"
	texfun, vars = Task.compile_fun('${XELATEX} ${XELATEXFLAGS} ${SRCFILE}', shell=False)

class dvips(Task.Task):
	"Converts dvi files to postscript"
	run_str = '${DVIPS} ${DVIPSFLAGS} ${SRC} -o ${TGT}'
	color   = 'BLUE'
	after   = ['latex', 'pdflatex', 'xelatex']

class dvipdf(Task.Task):
	"Converts dvi files to pdf"
	run_str = '${DVIPDF} ${DVIPDFFLAGS} ${SRC} ${TGT}'
	color   = 'BLUE'
	after   = ['latex', 'pdflatex', 'xelatex']

class pdf2ps(Task.Task):
	"Converts pdf files to postscript"
	run_str = '${PDF2PS} ${PDF2PSFLAGS} ${SRC} ${TGT}'
	color   = 'BLUE'
	after   = ['latex', 'pdflatex', 'xelatex']

@feature('tex')
@before_method('process_source')
def apply_tex(self):
	"""
	Creates :py:class:`waflib.Tools.tex.tex` objects, and
	dvips/dvipdf/pdf2ps tasks if necessary (outs='ps', etc).
	"""
	if not getattr(self, 'type', None) in ('latex', 'pdflatex', 'xelatex'):
		self.type = 'pdflatex'

	outs = Utils.to_list(getattr(self, 'outs', []))

	# prompt for incomplete files (else the batchmode is used)
	try:
		self.generator.bld.conf
	except AttributeError:
		default_prompt = False
	else:
		default_prompt = True
	self.env.PROMPT_LATEX = getattr(self, 'prompt', default_prompt)

	deps_lst = []

	if getattr(self, 'deps', None):
		deps = self.to_list(self.deps)
		for dep in deps:
			if isinstance(dep, str):
				n = self.path.find_resource(dep)
				if not n:
					self.bld.fatal('Could not find %r for %r' % (dep, self))
				if not n in deps_lst:
					deps_lst.append(n)
			elif isinstance(dep, Node.Node):
				deps_lst.append(dep)

	for node in self.to_nodes(self.source):
		if self.type == 'latex':
			task = self.create_task('latex', node, node.change_ext('.dvi'))
		elif self.type == 'pdflatex':
			task = self.create_task('pdflatex', node, node.change_ext('.pdf'))
		elif self.type == 'xelatex':
			task = self.create_task('xelatex', node, node.change_ext('.pdf'))

		task.env = self.env

		# add the manual dependencies
		if deps_lst:
			for n in deps_lst:
				if not n in task.dep_nodes:
					task.dep_nodes.append(n)

		# texinputs is a nasty beast
		if hasattr(self, 'texinputs_nodes'):
			task.texinputs_nodes = self.texinputs_nodes
		else:
			task.texinputs_nodes = [node.parent, node.parent.get_bld(), self.path, self.path.get_bld()]
			lst = os.environ.get('TEXINPUTS', '')
			if self.env.TEXINPUTS:
				lst += os.pathsep + self.env.TEXINPUTS
			if lst:
				lst = lst.split(os.pathsep)
			for x in lst:
				if x:
					if os.path.isabs(x):
						p = self.bld.root.find_node(x)
						if p:
							task.texinputs_nodes.append(p)
						else:
							Logs.error('Invalid TEXINPUTS folder %s', x)
					else:
						Logs.error('Cannot resolve relative paths in TEXINPUTS %s', x)

		if self.type == 'latex':
			if 'ps' in outs:
				tsk = self.create_task('dvips', task.outputs, node.change_ext('.ps'))
				tsk.env.env = dict(os.environ)
			if 'pdf' in outs:
				tsk = self.create_task('dvipdf', task.outputs, node.change_ext('.pdf'))
				tsk.env.env = dict(os.environ)
		elif self.type == 'pdflatex':
			if 'ps' in outs:
				self.create_task('pdf2ps', task.outputs, node.change_ext('.ps'))
	self.source = []

def configure(self):
	"""
	Find the programs tex, latex and others without raising errors.
	"""
	v = self.env
	for p in 'tex latex pdflatex xelatex bibtex dvips dvipdf ps2pdf makeindex pdf2ps makeglossaries'.split():
		try:
			self.find_program(p, var=p.upper())
		except self.errors.ConfigurationError:
			pass
	v.DVIPSFLAGS = '-Ppdf'

