"""
Testing code.  This is not used in a PyPy translation.
It exports the same interface as the Python 're' module.
"""
import re, sys
from rpython.rlib.rsre import rsre_core, rsre_char
from rpython.rlib.rsre.rpy import get_code as _get_code
from rpython.rlib.unicodedata import unicodedb
from rpython.rlib.objectmodel import specialize
rsre_char.set_unicode_db(unicodedb)


I = IGNORECASE = re.I   # ignore case
L = LOCALE     = re.L   # assume current 8-bit locale
U = UNICODE    = re.U   # assume unicode locale
M = MULTILINE  = re.M   # make anchors look for newline
S = DOTALL     = re.S   # make dot match newline
X = VERBOSE    = re.X   # ignore whitespace and comments


def match(pattern, string, flags=0):
    return compile(pattern, flags).match(string)

def search(pattern, string, flags=0):
    return compile(pattern, flags).search(string)

def findall(pattern, string, flags=0):
    return compile(pattern, flags).findall(string)

def finditer(pattern, string, flags=0):
    return compile(pattern, flags).finditer(string)

def sub(pattern, repl, string, count=0):
    return compile(pattern).sub(repl, string, count)

def subn(pattern, repl, string, count=0):
    return compile(pattern).subn(repl, string, count)

def split(pattern, string, maxsplit=0):
    return compile(pattern).split(string, maxsplit)

@specialize.memo()
def compile(pattern, flags=0):
    code, flags, args = _get_code(pattern, flags, allargs=True)
    return RSREPattern(pattern, code, flags, *args)

escape = re.escape
error = re.error


class RSREPattern(object):

    def __init__(self, pattern, code, flags,
                 num_groups, groupindex, indexgroup):
        self._code = code
        self.pattern = pattern
        self.flags = flags
        self.groups = num_groups
        self.groupindex = groupindex
        self._indexgroup = indexgroup

    def match(self, string, pos=0, endpos=sys.maxint):
        return self._make_match(rsre_core.match(self._code, string,
                                                pos, endpos,
                                                flags=self.flags))

    def search(self, string, pos=0, endpos=sys.maxint):
        return self._make_match(rsre_core.search(self._code, string,
                                                 pos, endpos,
                                                 flags=self.flags))

    def findall(self, string, pos=0, endpos=sys.maxint):
        matchlist = []
        for match in self.finditer(string, pos, endpos):
            if self.groups == 0 or self.groups == 1:
                item = match.group(self.groups)
            else:
                item = match.groups("")
            matchlist.append(item)
        return matchlist

    def finditer(self, string, pos=0, endpos=sys.maxint):
        return iter(self.scanner(string, pos, endpos).search, None)

    def subn(self, repl, string, count=0):
        filter = repl
        if not callable(repl) and "\\" in repl:
            # handle non-literal strings; hand it over to the template compiler
            filter = re._subx(self, repl)
        start = 0
        sublist = []
        force_unicode = (isinstance(string, unicode) or
                         isinstance(repl, unicode))
        n = last_pos = 0
        while not count or n < count:
            match = rsre_core.search(self._code, string, start,
                                     flags=self.flags)
            if match is None:
                break
            if last_pos < match.match_start:
                sublist.append(string[last_pos:match.match_start])
            if not (last_pos == match.match_start
                             == match.match_end and n > 0):
                # the above ignores empty matches on latest position
                if callable(filter):
                    piece = filter(self._make_match(match))
                else:
                    piece = filter
                sublist.append(piece)
                last_pos = match.match_end
                n += 1
            elif last_pos >= len(string):
                break     # empty match at the end: finished
            #
            start = match.match_end
            if start == match.match_start:
                start += 1

        if last_pos < len(string):
            sublist.append(string[last_pos:])

        if n == 0:
            # not just an optimization -- see test_sub_unicode
            return string, n

        if force_unicode:
            item = u"".join(sublist)
        else:
            item = "".join(sublist)
        return item, n

    def sub(self, repl, string, count=0):
        item, n = self.subn(repl, string, count)
        return item

    def split(self, string, maxsplit=0):
        splitlist = []
        start = 0
        n = 0
        last = 0
        while not maxsplit or n < maxsplit:
            match = rsre_core.search(self._code, string, start,
                                     flags=self.flags)
            if match is None:
                break
            if match.match_start == match.match_end: # zero-width match
                if match.match_start == len(string): # at end of string
                    break
                start = match.match_end + 1
                continue
            splitlist.append(string[last:match.match_start])
            # add groups (if any)
            if self.groups:
                match1 = self._make_match(match)
                splitlist.extend(match1.groups(None))
            n += 1
            last = start = match.match_end
        splitlist.append(string[last:])
        return splitlist

    def scanner(self, string, start=0, end=sys.maxint):
        return SREScanner(self, string, start, end)

    def _make_match(self, res):
        if res is None:
            return None
        return RSREMatch(self, res)


class RSREMatch(object):

    def __init__(self, pattern, ctx):
        self.re = pattern
        self._ctx = ctx

    def span(self, groupnum=0):
#        if not isinstance(groupnum, (int, long)):
#            groupnum = self.re.groupindex[groupnum]

        return self._ctx.span(groupnum)

    def start(self, groupnum=0):
        return self.span(groupnum)[0]

    def end(self, groupnum=0):
        return self.span(groupnum)[1]

    def group(self, group=0):
        frm, to = self.span(group)
        if 0 <= frm <= to:
            return self._ctx._string[frm:to]
        else:
            return None

#    def group(self, *groups):
#        groups = groups or (0,)
#        result = []
#        for group in groups:
#            frm, to = self.span(group)
#            if 0 <= frm <= to:
#                result.append(self._ctx._string[frm:to])
#            else:
#                result.append(None)
#        if len(result) > 1:
#            return tuple(result)


    def groups(self, default=None):
        fmarks = self._ctx.flatten_marks()
        grps = []
        for i in range(1, self.re.groups+1):
            grp = self.group(i)
            if grp is None: grp = default
            grps.append(grp)
        return tuple(grps)

    def groupdict(self, default=None):
        d = {}
        for key, value in self.re.groupindex.iteritems():
            grp = self.group(value)
            if grp is None: grp = default
            d[key] = grp
        return d

    def expand(self, template):
        return re._expand(self.re, self, template)

    @property
    def regs(self):
        fmarks = self._ctx.flatten_marks()
        return tuple([(fmarks[i], fmarks[i+1])
                      for i in range(0, len(fmarks), 2)])

    @property
    def lastindex(self):
        self._ctx.flatten_marks()
        if self._ctx.match_lastindex < 0:
            return None
        return self._ctx.match_lastindex // 2 + 1

    @property
    def lastgroup(self):
        lastindex = self.lastindex
        if lastindex < 0 or lastindex >= len(self.re._indexgroup):
            return None
        return self.re._indexgroup[lastindex]

    @property
    def string(self):
        return self._ctx._string

    @property
    def pos(self):
        return self._ctx.match_start

    @property
    def endpos(self):
        return self._ctx.end


class SREScanner(object):
    def __init__(self, pattern, string, start, end):
        self.pattern = pattern
        self._string = string
        self._start = start
        self._end = end

    def _match_search(self, matcher):
        if self._start > len(self._string):
            return None
        match = matcher(self._string, self._start, self._end)
        if match is None:
            self._start += 1     # obscure corner case
        else:
            self._start = match.end()
            if match.start() == self._start:
                self._start += 1
        return match

    def match(self):
        return self._match_search(self.pattern.match)

    def search(self):
        return self._match_search(self.pattern.search)

class Scanner:
    # This class is copied directly from re.py.
    def __init__(self, lexicon, flags=0):
        from sre_constants import BRANCH, SUBPATTERN
        import sre_parse
        self.lexicon = lexicon
        # combine phrases into a compound pattern
        p = []
        s = sre_parse.Pattern()
        s.flags = flags
        for phrase, action in lexicon:
            p.append(sre_parse.SubPattern(s, [
                (SUBPATTERN, (len(p)+1, sre_parse.parse(phrase, flags))),
                ]))
        s.groups = len(p)+1
        p = sre_parse.SubPattern(s, [(BRANCH, (None, p))])
        self.scanner = compile(p)
    def scan(self, string):
        result = []
        append = result.append
        match = self.scanner.scanner(string).match
        i = 0
        while 1:
            m = match()
            if not m:
                break
            j = m.end()
            if i == j:
                break
            action = self.lexicon[m.lastindex-1][1]
            if callable(action):
                self.match = m
                action = action(self, m.group())
            if action is not None:
                append(action)
            i = j
        return result, string[i:]
