import bisect
import re
import token
import tokenize


class ChangeCollector(object):

    def __init__(self, text):
        self.text = text
        self.changes = []

    def add_change(self, start, end, new_text=None):
        if new_text is None:
            new_text = self.text[start:end]
        self.changes.append((start, end, new_text))

    def get_changed(self):
        if not self.changes:
            return None

        self.changes.sort(key=lambda x: x[:2])
        pieces = []
        last_changed = 0
        for change in self.changes:
            start, end, text = change
            pieces.append(self.text[last_changed:start] + text)
            last_changed = end
        if last_changed < len(self.text):
            pieces.append(self.text[last_changed:])
        result = ''.join(pieces)
        if result != self.text:
            return result


class SourceLinesAdapter(object):
    """Adapts source to Lines interface

    Note: The creation of this class is expensive.
    """

    def __init__(self, source_code):
        self.code = source_code
        self.starts = None
        self._initialize_line_starts()

    def _initialize_line_starts(self):
        self.starts = []
        self.starts.append(0)
        try:
            i = 0
            while True:
                i = self.code.index('\n', i) + 1
                self.starts.append(i)
        except ValueError:
            pass
        self.starts.append(len(self.code) + 1)

    def get_line(self, lineno):
        return self.code[self.starts[lineno - 1]:
                         self.starts[lineno] - 1]

    def length(self):
        return len(self.starts) - 1

    def get_line_number(self, offset):
        return bisect.bisect(self.starts, offset)

    def get_line_start(self, lineno):
        return self.starts[lineno - 1]

    def get_line_end(self, lineno):
        return self.starts[lineno] - 1


class ArrayLinesAdapter(object):

    def __init__(self, lines):
        self.lines = lines

    def get_line(self, line_number):
        return self.lines[line_number - 1]

    def length(self):
        return len(self.lines)


class LinesToReadline(object):

    def __init__(self, lines, start):
        self.lines = lines
        self.current = start

    def readline(self):
        if self.current  1 and striped.startswith('if') or striped.startswith('for'):
                bracs = 0
                for j in range(i, min(i + 5, lines.length() + 1)):
                    for c in lines.get_line(j):
                        if c == '#':
                            break
                        if c in '[(':
                            bracs += 1
                        if c in ')]':
                            bracs -= 1
                            if bracs < 0:
                                break
                    if bracs < 0:
                        break
                if bracs < 0:
                    continue
            return i
    return 1


_block_start_pattern = None


def get_block_start_patterns():
    global _block_start_pattern
    if not _block_start_pattern:
        pattern = '^\\s*(((def|class|if|elif|except|for|while|with)\\s)|'\
                  '((try|else|finally|except)\\s*:))'
        _block_start_pattern = re.compile(pattern, re.M)
    return _block_start_pattern


def count_line_indents(line):
    indents = 0
    for char in line:
        if char == ' ':
            indents += 1
        elif char == '\t':
            indents += 8
        else:
            return indents
    return 0


def get_string_pattern():
    start = r'(\b[uU]?[rR]?)?'
    longstr = r'%s"""(\\.|"(?!"")|\\\n|[^"\\])*"""' % start
    shortstr = r'%s"(\\.|\\\n|[^"\\])*"' % start
    return '|'.join([longstr, longstr.replace('"', "'"),
                     shortstr, shortstr.replace('"', "'")])


def get_comment_pattern():
    return r'#[^\n]*'