# repoman: Checks
# Copyright 2007 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id$

"""This module contains functions used in Repoman to ascertain the quality
and correctness of an ebuild."""

import re
import time
import repoman.errors as errors

class LineCheck(object):
	"""Run a check on a line of an ebuild."""
	"""A regular expression to determine whether to ignore the line"""
	ignore_line = False

	def new(self, pkg):
		pass

	def check_eapi(self, eapi):
		""" returns if the check should be run in the given EAPI (default is True) """
		return True

	def check(self, num, line):
		"""Run the check on line and return error if there is one"""
		if self.re.match(line):
			return self.error

	def end(self):
		pass

class PhaseCheck(LineCheck):
	""" basic class for function detection """

	ignore_line = re.compile(r'(^\s*#)')
	func_end_re = re.compile(r'^\}$')
	in_phase = ''

	def __init__(self):
		self.phases = ('pkg_pretend', 'pkg_setup', 'src_unpack', 'src_prepare', 'src_configure', 'src_compile',
			'src_test', 'src_install', 'pkg_preinst', 'pkg_postinst', 'pkg_prerm', 'pkg_postrm', 'pkg_config')
		phase_re = '('
		for phase in self.phases:
			phase_re += phase + '|'
		phase_re = phase_re[:-1] + ')'
		self.phases_re = re.compile(phase_re)

	def check(self, num, line):
		m = self.phases_re.match(line)
		if m is not None:
			self.in_phase = m.group(1)
		if self.in_phase != '' and \
				self.func_end_re.match(line) is not None:
			self.in_phase = ''

		return self.phase_check(num, line)

	def phase_check(self, num, line):
		""" override this function for your checks """
		pass

class EbuildHeader(LineCheck):
	"""Ensure ebuilds have proper headers
		Copyright header errors
		CVS header errors
		License header errors
	
	Args:
		modification_year - Year the ebuild was last modified
	"""

	repoman_check_name = 'ebuild.badheader'

	gentoo_copyright = r'^# Copyright ((1999|200\d)-)?%s Gentoo Foundation$'
	# Why a regex here, use a string match
	# gentoo_license = re.compile(r'^# Distributed under the terms of the GNU General Public License v2$')
	gentoo_license = r'# Distributed under the terms of the GNU General Public License v2'
	cvs_header = re.compile(r'^#\s*\$Header.*\$$')

	def new(self, pkg):
		self.modification_year = str(time.gmtime(pkg.mtime)[0])
		self.gentoo_copyright_re = re.compile(
			self.gentoo_copyright % self.modification_year)

	def check(self, num, line):
		if num > 2:
			return
		elif num == 0:
			if not self.gentoo_copyright_re.match(line):
				return errors.COPYRIGHT_ERROR
		elif num == 1 and line.strip() != self.gentoo_license:
			return errors.LICENSE_ERROR
		elif num == 2:
			if not self.cvs_header.match(line):
				return errors.CVS_HEADER_ERROR


class EbuildWhitespace(LineCheck):
	"""Ensure ebuilds have proper whitespacing"""

	repoman_check_name = 'ebuild.minorsyn'

	ignore_line = re.compile(r'(^$)|(^(\t)*#)')
	leading_spaces = re.compile(r'^[\S\t]')
	trailing_whitespace = re.compile(r'.*([\S]$)')	

	def check(self, num, line):
		if self.leading_spaces.match(line) is None:
			return errors.LEADING_SPACES_ERROR
		if self.trailing_whitespace.match(line) is None:
			return errors.TRAILING_WHITESPACE_ERROR

class EbuildBlankLine(LineCheck):
	repoman_check_name = 'ebuild.minorsyn'
	blank_line = re.compile(r'^$')

	def new(self, pkg):
		self.line_is_blank = False

	def check(self, num, line):
		if self.line_is_blank and self.blank_line.match(line):
			return 'Useless blank line on line: %d'
		if self.blank_line.match(line):
			self.line_is_blank = True
		else:
			self.line_is_blank = False

	def end(self):
		if self.line_is_blank:
			yield 'Useless blank line on last line'

class EbuildQuote(LineCheck):
	"""Ensure ebuilds have valid quoting around things like D,FILESDIR, etc..."""

	repoman_check_name = 'ebuild.minorsyn'
	_message_commands = ["die", "echo", "eerror",
		"einfo", "elog", "eqawarn", "ewarn"]
	_message_re = re.compile(r'\s(' + "|".join(_message_commands) + \
		r')\s+"[^"]*"\s*$')
	_ignored_commands = ["local", "export"] + _message_commands
	ignore_line = re.compile(r'(^$)|(^\s*#.*)|(^\s*\w+=.*)' + \
		r'|(^\s*(' + "|".join(_ignored_commands) + r')\s+)')
	var_names = ["D", "DISTDIR", "FILESDIR", "S", "T", "ROOT", "WORKDIR"]

	# variables for games.eclass
	var_names += ["Ddir", "GAMES_PREFIX_OPT", "GAMES_DATADIR",
		"GAMES_DATADIR_BASE", "GAMES_SYSCONFDIR", "GAMES_STATEDIR",
		"GAMES_LOGDIR", "GAMES_BINDIR"]

	var_names = "(%s)" % "|".join(var_names)
	var_reference = re.compile(r'\$(\{'+var_names+'\}|' + \
		var_names + '\W)')
	missing_quotes = re.compile(r'(\s|^)[^"\'\s]*\$\{?' + var_names + \
		r'\}?[^"\'\s]*(\s|$)')
	cond_begin =  re.compile(r'(^|\s+)\[\[($|\\$|\s+)')
	cond_end =  re.compile(r'(^|\s+)\]\]($|\\$|\s+)')
	
	def check(self, num, line):
		if self.var_reference.search(line) is None:
			return
		# There can be multiple matches / violations on a single line. We
		# have to make sure none of the matches are violators. Once we've
		# found one violator, any remaining matches on the same line can
		# be ignored.
		pos = 0
		while pos <= len(line) - 1:
			missing_quotes = self.missing_quotes.search(line, pos)
			if not missing_quotes:
				break
			# If the last character of the previous match is a whitespace
			# character, that character may be needed for the next
			# missing_quotes match, so search overlaps by 1 character.
			group = missing_quotes.group()
			pos = missing_quotes.end() - 1

			# Filter out some false positives that can
			# get through the missing_quotes regex.
			if self.var_reference.search(group) is None:
				continue

			# Filter matches that appear to be an
			# argument to a message command.
			# For example: false || ewarn "foo $WORKDIR/bar baz"
			message_match = self._message_re.search(line)
			if message_match is not None and \
				message_match.start() < pos and \
				message_match.end() > pos:
				break

			# This is an attempt to avoid false positives without getting
			# too complex, while possibly allowing some (hopefully
			# unlikely) violations to slip through. We just assume
			# everything is correct if the there is a ' [[ ' or a ' ]] '
			# anywhere in the whole line (possibly continued over one
			# line).
			if self.cond_begin.search(line) is not None:
				continue
			if self.cond_end.search(line) is not None:
				continue

			# Any remaining matches on the same line can be ignored.
			return errors.MISSING_QUOTES_ERROR


class EbuildAssignment(LineCheck):
	"""Ensure ebuilds don't assign to readonly variables."""

	repoman_check_name = 'variable.readonly'

	readonly_assignment = re.compile(r'^\s*(export\s+)?(A|CATEGORY|P|PV|PN|PR|PVR|PF|D|WORKDIR|FILESDIR|FEATURES|USE)=')
	line_continuation = re.compile(r'([^#]*\S)(\s+|\t)\\$')
	ignore_line = re.compile(r'(^$)|(^(\t)*#)')

	def __init__(self):
		self.previous_line = None

	def check(self, num, line):
		match = self.readonly_assignment.match(line)
		e = None
		if match and (not self.previous_line or not self.line_continuation.match(self.previous_line)):
			e = errors.READONLY_ASSIGNMENT_ERROR
		self.previous_line = line
		return e


class EbuildNestedDie(LineCheck):
	"""Check ebuild for nested die statements (die statements in subshells"""
	
	repoman_check_name = 'ebuild.nesteddie'
	nesteddie_re = re.compile(r'^[^#]*\s\(\s[^)]*\bdie\b')
	
	def check(self, num, line):
		if self.nesteddie_re.match(line):
			return errors.NESTED_DIE_ERROR


class EbuildUselessDodoc(LineCheck):
	"""Check ebuild for useless files in dodoc arguments."""
	repoman_check_name = 'ebuild.minorsyn'
	uselessdodoc_re = re.compile(
		r'^\s*dodoc(\s+|\s+.*\s+)(ABOUT-NLS|COPYING|LICENSE)($|\s)')

	def check(self, num, line):
		match = self.uselessdodoc_re.match(line)
		if match:
			return "Useless dodoc '%s'" % (match.group(2), ) + " on line: %d"


class EbuildUselessCdS(LineCheck):
	"""Check for redundant cd ${S} statements"""
	repoman_check_name = 'ebuild.minorsyn'
	method_re = re.compile(r'^\s*src_(prepare|configure|compile|install|test)\s*\(\)')
	cds_re = re.compile(r'^\s*cd\s+("\$(\{S\}|S)"|\$(\{S\}|S))\s')

	def __init__(self):
		self.check_next_line = False

	def check(self, num, line):
		if self.check_next_line:
			self.check_next_line = False
			if self.cds_re.match(line):
				return errors.REDUNDANT_CD_S_ERROR
		elif self.method_re.match(line):
			self.check_next_line = True

class EapiDefinition(LineCheck):
	""" Check that EAPI is defined before inherits"""
	repoman_check_name = 'EAPI.definition'

	eapi_re = re.compile(r'^EAPI=')
	inherit_re = re.compile(r'^\s*inherit\s')

	def new(self, pkg):
		self.inherit_line = None

	def check(self, num, line):
		if self.eapi_re.match(line) is not None:
			if self.inherit_line is not None:
				return errors.EAPI_DEFINED_AFTER_INHERIT
		elif self.inherit_re.match(line) is not None:
			self.inherit_line = line

class EbuildPatches(LineCheck):
	"""Ensure ebuilds use bash arrays for PATCHES to ensure white space safety"""
	repoman_check_name = 'ebuild.patches'
	re = re.compile(r'^\s*PATCHES=[^\(]')
	error = errors.PATCHES_ERROR

class EbuildQuotedA(LineCheck):
	"""Ensure ebuilds have no quoting around ${A}"""

	repoman_check_name = 'ebuild.minorsyn'
	a_quoted = re.compile(r'.*\"\$(\{A\}|A)\"')

	def check(self, num, line):
		match = self.a_quoted.match(line)
		if match:
			return "Quoted \"${A}\" on line: %d"

class InheritAutotools(LineCheck):
	"""
	Make sure appropriate functions are called in
	ebuilds that inherit autotools.eclass.
	"""

	repoman_check_name = 'inherit.autotools'
	ignore_line = re.compile(r'(^|\s*)#')
	_inherit_autotools_re = re.compile(r'^\s*inherit\s(.*\s)?autotools(\s|$)')
	_autotools_funcs = (
		"eaclocal", "eautoconf", "eautoheader",
		"eautomake", "eautoreconf", "_elibtoolize")
	_autotools_func_re = re.compile(r'\b(' + \
		"|".join(_autotools_funcs) + r')\b')
	# Exempt eclasses:
	# git - An EGIT_BOOTSTRAP variable may be used to call one of
	#       the autotools functions.
	# subversion - An ESVN_BOOTSTRAP variable may be used to call one of
	#       the autotools functions.
	_exempt_eclasses = frozenset(["git", "subversion"])

	def new(self, pkg):
		self._inherit_autotools = None
		self._autotools_func_call = None
		self._disabled = self._exempt_eclasses.intersection(pkg.inherited)

	def check(self, num, line):
		if self._disabled:
			return
		if self._inherit_autotools is None:
			self._inherit_autotools = self._inherit_autotools_re.match(line)
		if self._inherit_autotools is not None and \
			self._autotools_func_call is None:
			self._autotools_func_call = self._autotools_func_re.search(line)

	def end(self):
		if self._inherit_autotools and self._autotools_func_call is None:
			yield 'no eauto* function called'

class IUseUndefined(LineCheck):
	"""
	Make sure the ebuild defines IUSE (style guideline
	says to define IUSE even when empty).
	"""

	repoman_check_name = 'IUSE.undefined'
	_iuse_def_re = re.compile(r'^IUSE=.*')

	def new(self, pkg):
		self._iuse_def = None

	def check(self, num, line):
		if self._iuse_def is None:
			self._iuse_def = self._iuse_def_re.match(line)

	def end(self):
		if self._iuse_def is None:
			yield 'IUSE is not defined'

class EMakeParallelDisabled(PhaseCheck):
	"""Check for emake -j1 calls which disable parallelization."""
	repoman_check_name = 'upstream.workaround'
	re = re.compile(r'^\s*emake\s+.*-j\s*1\b')
	error = errors.EMAKE_PARALLEL_DISABLED

	def phase_check(self, num, line):
		if self.in_phase == 'src_compile' or self.in_phase == 'src_install':
			if self.re.match(line):
				return self.error

class EMakeParallelDisabledViaMAKEOPTS(LineCheck):
	"""Check for MAKEOPTS=-j1 that disables parallelization."""
	repoman_check_name = 'upstream.workaround'
	re = re.compile(r'^\s*MAKEOPTS=(\'|")?.*-j\s*1\b')
	error = errors.EMAKE_PARALLEL_DISABLED_VIA_MAKEOPTS

class DeprecatedBindnowFlags(LineCheck):
	"""Check for calls to the deprecated bindnow-flags function."""
	repoman_check_name = 'ebuild.minorsyn'
	re = re.compile(r'.*\$\(bindnow-flags\)')
	error = errors.DEPRECATED_BINDNOW_FLAGS

class WantAutoDefaultValue(LineCheck):
	"""Check setting WANT_AUTO* to latest (default value)."""
	repoman_check_name = 'ebuild.minorsyn'
	_re = re.compile(r'^WANT_AUTO(CONF|MAKE)=(\'|")?latest')

	def check(self, num, line):
		m = self._re.match(line)
		if m is not None:
			return 'WANT_AUTO' + m.group(1) + \
				' redundantly set to default value "latest" on line: %d'

class SrcCompileEconf(PhaseCheck):
	repoman_check_name = 'ebuild.minorsyn'
	configure_re = re.compile(r'\s(econf|./configure)')

	def check_eapi(self, eapi):
		return eapi not in ('0', '1')

	def phase_check(self, num, line):
		if self.in_phase == 'src_compile':
			m = self.configure_re.match(line)
			if m is not None:
				return ("'%s'" % m.group(1)) + \
					" call should be moved to src_configure from line: %d"

class SrcUnpackPatches(PhaseCheck):
	repoman_check_name = 'ebuild.minorsyn'
	src_prepare_tools_re = re.compile(r'\s(e?patch|sed)\s')

	def new(self, pkg):
		if pkg.metadata['EAPI'] not in ('0', '1'):
			self.eapi = pkg.metadata['EAPI']
		else:
			self.eapi = None
		self.in_src_unpack = None

	def check_eapi(self, eapi):
		return eapi not in ('0', '1')

	def phase_check(self, num, line):
		if self.in_phase == 'src_unpack':
			m = self.src_prepare_tools_re.search(line)
			if m is not None:
				return ("'%s'" % m.group(1)) + \
					" call should be moved to src_prepare from line: %d"

# EAPI-3 checks
class Eapi3IncompatibleFuncs(LineCheck):
	repoman_check_name = 'EAPI.incompatible'
	ignore_line = re.compile(r'(^\s*#)')
	banned_commands_re = re.compile(r'^\s*(dosed|dohard)')

	def new(self, pkg):
		self.eapi = pkg.metadata['EAPI']

	def check_eapi(self, eapi):
		return self.eapi not in ('0', '1', '2')

	def check(self, num, line):
		m = self.banned_commands_re.match(line)
		if m is not None:
			return ("'%s'" % m.group(1)) + \
				" has been banned in EAPI=3 on line: %d"

class Eapi3GoneVars(LineCheck):
	repoman_check_name = 'EAPI.incompatible'
	ignore_line = re.compile(r'(^\s*#)')
	undefined_vars_re = re.compile(r'.*\$(\{(AA|KV)\}|(AA|KV))')

	def new(self, pkg):
		self.eapi = pkg.metadata['EAPI']

	def check_eapi(self, eapi):
		return self.eapi not in ('0', '1', '2')

	def check(self, num, line):
		m = self.undefined_vars_re.match(line)
		if m is not None:
			return ("variable '$%s'" % m.group(1)) + \
				" is gone in EAPI=3 on line: %d"


_constant_checks = tuple((c() for c in (
	EbuildHeader, EbuildWhitespace, EbuildBlankLine, EbuildQuote,
	EbuildAssignment, EbuildUselessDodoc,
	EbuildUselessCdS, EbuildNestedDie,
	EbuildPatches, EbuildQuotedA, EapiDefinition,
	IUseUndefined, InheritAutotools,
	EMakeParallelDisabled, EMakeParallelDisabledViaMAKEOPTS,
	DeprecatedBindnowFlags, SrcUnpackPatches, WantAutoDefaultValue,
	SrcCompileEconf, Eapi3IncompatibleFuncs, Eapi3GoneVars)))

_here_doc_re = re.compile(r'.*\s<<[-]?(\w+)$')

def run_checks(contents, pkg):
	checks = _constant_checks
	here_doc_delim = None

	for lc in checks:
		lc.new(pkg)
	for num, line in enumerate(contents):

		# Check if we're inside a here-document.
		if here_doc_delim is not None:
			if here_doc_delim.match(line):
				here_doc_delim = None
		if here_doc_delim is None:
			here_doc = _here_doc_re.match(line)
			if here_doc is not None:
				here_doc_delim = re.compile(r'^\s*%s$' % here_doc.group(1))

		if here_doc_delim is None:
			# We're not in a here-document.
			for lc in checks:
				if lc.check_eapi(pkg.metadata['EAPI']):
					ignore = lc.ignore_line
					if not ignore or not ignore.match(line):
						e = lc.check(num, line)
						if e:
							yield lc.repoman_check_name, e % (num + 1)

	for lc in checks:
		i = lc.end()
		if i is not None:
			for e in i:
				yield lc.repoman_check_name, e