"""Generic output formatting.

Formatter objects transform an abstract flow of formatting events into
specific output events on writer objects. Formatters manage several stack
structures to allow various properties of a writer object to be changed and
restored; writers need not be able to handle relative changes nor any sort
of ``change back'' operation. Specific writer properties which may be
controlled via formatter objects are horizontal alignment, font, and left
margin indentations. A mechanism is provided which supports providing
arbitrary, non-exclusive style settings to a writer as well. Additional
interfaces facilitate formatting events which are not reversible, such as
paragraph separation.

Writer objects encapsulate device interfaces. Abstract devices, such as
file formats, are supported as well as physical devices. The provided
implementations all work with abstract devices. The interface makes
available mechanisms for setting the properties which formatter objects
manage and inserting data into the output.
"""

import sys
import warnings
warnings.warn('the formatter module is deprecated', DeprecationWarning,
 stacklevel=2)


AS_IS = None


class NullFormatter:
 """A formatter which does nothing.

 If the writer parameter is omitted, a NullWriter instance is created.
 No methods of the writer are called by NullFormatter instances.

 Implementations should inherit from this class if implementing a writer
 interface but don't need to inherit any implementation.

 """

 def __init__(self, writer=None):
 if writer is None:
 writer = NullWriter()
 self.writer = writer
 def end_paragraph(self, blankline): pass
 def add_line_break(self): pass
 def add_hor_rule(self, *args, **kw): pass
 def add_label_data(self, format, counter, blankline=None): pass
 def add_flowing_data(self, data): pass
 def add_literal_data(self, data): pass
 def flush_softspace(self): pass
 def push_alignment(self, align): pass
 def pop_alignment(self): pass
 def push_font(self, x): pass
 def pop_font(self): pass
 def push_margin(self, margin): pass
 def pop_margin(self): pass
 def set_spacing(self, spacing): pass
 def push_style(self, *styles): pass
 def pop_style(self, n=1): pass
 def assert_line_data(self, flag=1): pass


class AbstractFormatter:
 """The standard formatter.

 This implementation has demonstrated wide applicability to many writers,
 and may be used directly in most circumstances. It has been used to
 implement a full-featured World Wide Web browser.

 """

 # Space handling policy: blank spaces at the boundary between elements
 # are handled by the outermost context. "Literal" data is not checked
 # to determine context, so spaces in literal data are handled directly
 # in all circumstances.

 def __init__(self, writer):
 self.writer = writer # Output device
 self.align = None # Current alignment
 self.align_stack = [] # Alignment stack
 self.font_stack = [] # Font state
 self.margin_stack = [] # Margin state
 self.spacing = None # Vertical spacing state
 self.style_stack = [] # Other state, e.g. color
 self.nospace = 1 # Should leading space be suppressed
 self.softspace = 0 # Should a space be inserted
 self.para_end = 1 # Just ended a paragraph
 self.parskip = 0 # Skipped space between paragraphs?
 self.hard_break = 1 # Have a hard break
 self.have_label = 0

 def end_paragraph(self, blankline):
 if not self.hard_break:
 self.writer.send_line_break()
 self.have_label = 0
 if self.parskip < blankline and not self.have_label:
 self.writer.send_paragraph(blankline - self.parskip)
 self.parskip = blankline
 self.have_label = 0
 self.hard_break = self.nospace = self.para_end = 1
 self.softspace = 0

 def add_line_break(self):
 if not (self.hard_break or self.para_end):
 self.writer.send_line_break()
 self.have_label = self.parskip = 0
 self.hard_break = self.nospace = 1
 self.softspace = 0

 def add_hor_rule(self, *args, **kw):
 if not self.hard_break:
 self.writer.send_line_break()
 self.writer.send_hor_rule(*args, **kw)
 self.hard_break = self.nospace = 1
 self.have_label = self.para_end = self.softspace = self.parskip = 0

 def add_label_data(self, format, counter, blankline = None):
 if self.have_label or not self.hard_break:
 self.writer.send_line_break()
 if not self.para_end:
 self.writer.send_paragraph((blankline and 1) or 0)
 if isinstance(format, str):
 self.writer.send_label_data(self.format_counter(format, counter))
 else:
 self.writer.send_label_data(format)
 self.nospace = self.have_label = self.hard_break = self.para_end = 1
 self.softspace = self.parskip = 0

 def format_counter(self, format, counter):
 label = ''
 for c in format:
 if c == '1':
 label = label + ('%d' % counter)
 elif c in 'aA':
 if counter > 0:
 label = label + self.format_letter(c, counter)
 elif c in 'iI':
 if counter > 0:
 label = label + self.format_roman(c, counter)
 else:
 label = label + c
 return label

 def format_letter(self, case, counter):
 label = ''
 while counter > 0:
 counter, x = divmod(counter-1, 26)
 # This makes a strong assumption that lowercase letters
 # and uppercase letters form two contiguous blocks, with
 # letters in order!
 s = chr(ord(case) + x)
 label = s + label
 return label

 def format_roman(self, case, counter):
 ones = ['i', 'x', 'c', 'm']
 fives = ['v', 'l', 'd']
 label, index = '', 0
 # This will die of IndexError when counter is too big
 while counter > 0:
 counter, x = divmod(counter, 10)
 if x == 9:
 label = ones[index] + ones[index+1] + label
 elif x == 4:
 label = ones[index] + fives[index] + label
 else:
 if x >= 5:
 s = fives[index]
 x = x-5
 else:
 s = ''
 s = s + ones[index]*x
 label = s + label
 index = index + 1
 if case == 'I':
 return label.upper()
 return label

 def add_flowing_data(self, data):
 if not data: return
 prespace = data[:1].isspace()
 postspace = data[-1:].isspace()
 data = " ".join(data.split())
 if self.nospace and not data:
 return
 elif prespace or self.softspace:
 if not data:
 if not self.nospace:
 self.softspace = 1
 self.parskip = 0
 return
 if not self.nospace:
 data = ' ' + data
 self.hard_break = self.nospace = self.para_end = \
 self.parskip = self.have_label = 0
 self.softspace = postspace
 self.writer.send_flowing_data(data)

 def add_literal_data(self, data):
 if not data: return
 if self.softspace:
 self.writer.send_flowing_data(" ")
 self.hard_break = data[-1:] == '\n'
 self.nospace = self.para_end = self.softspace = \
 self.parskip = self.have_label = 0
 self.writer.send_literal_data(data)

 def flush_softspace(self):
 if self.softspace:
 self.hard_break = self.para_end = self.parskip = \
 self.have_label = self.softspace = 0
 self.nospace = 1
 self.writer.send_flowing_data(' ')

 def push_alignment(self, align):
 if align and align != self.align:
 self.writer.new_alignment(align)
 self.align = align
 self.align_stack.append(align)
 else:
 self.align_stack.append(self.align)

 def pop_alignment(self):
 if self.align_stack:
 del self.align_stack[-1]
 if self.align_stack:
 self.align = align = self.align_stack[-1]
 self.writer.new_alignment(align)
 else:
 self.align = None
 self.writer.new_alignment(None)

 def push_font(self, font):
 size, i, b, tt = font
 if self.softspace:
 self.hard_break = self.para_end = self.softspace = 0
 self.nospace = 1
 self.writer.send_flowing_data(' ')
 if self.font_stack:
 csize, ci, cb, ctt = self.font_stack[-1]
 if size is AS_IS: size = csize
 if i is AS_IS: i = ci
 if b is AS_IS: b = cb
 if tt is AS_IS: tt = ctt
 font = (size, i, b, tt)
 self.font_stack.append(font)
 self.writer.new_font(font)

 def pop_font(self):
 if self.font_stack:
 del self.font_stack[-1]
 if self.font_stack:
 font = self.font_stack[-1]
 else:
 font = None
 self.writer.new_font(font)

 def push_margin(self, margin):
 self.margin_stack.append(margin)
 fstack = [m for m in self.margin_stack if m]
 if not margin and fstack:
 margin = fstack[-1]
 self.writer.new_margin(margin, len(fstack))

 def pop_margin(self):
 if self.margin_stack:
 del self.margin_stack[-1]
 fstack = [m for m in self.margin_stack if m]
 if fstack:
 margin = fstack[-1]
 else:
 margin = None
 self.writer.new_margin(margin, len(fstack))

 def set_spacing(self, spacing):
 self.spacing = spacing
 self.writer.new_spacing(spacing)

 def push_style(self, *styles):
 if self.softspace:
 self.hard_break = self.para_end = self.softspace = 0
 self.nospace = 1
 self.writer.send_flowing_data(' ')
 for style in styles:
 self.style_stack.append(style)
 self.writer.new_styles(tuple(self.style_stack))

 def pop_style(self, n=1):
 del self.style_stack[-n:]
 self.writer.new_styles(tuple(self.style_stack))

 def assert_line_data(self, flag=1):
 self.nospace = self.hard_break = not flag
 self.para_end = self.parskip = self.have_label = 0


class NullWriter:
 """Minimal writer interface to use in testing & inheritance.

 A writer which only provides the interface definition; no actions are
 taken on any methods. This should be the base class for all writers
 which do not need to inherit any implementation methods.

 """
 def __init__(self): pass
 def flush(self): pass
 def new_alignment(self, align): pass
 def new_font(self, font): pass
 def new_margin(self, margin, level): pass
 def new_spacing(self, spacing): pass
 def new_styles(self, styles): pass
 def send_paragraph(self, blankline): pass
 def send_line_break(self): pass
 def send_hor_rule(self, *args, **kw): pass
 def send_label_data(self, data): pass
 def send_flowing_data(self, data): pass
 def send_literal_data(self, data): pass


class AbstractWriter(NullWriter):
 """A writer which can be used in debugging formatters, but not much else.

 Each method simply announces itself by printing its name and
 arguments on standard output.

 """

 def new_alignment(self, align):
 print("new_alignment(%r)" % (align,))

 def new_font(self, font):
 print("new_font(%r)" % (font,))

 def new_margin(self, margin, level):
 print("new_margin(%r, %d)" % (margin, level))

 def new_spacing(self, spacing):
 print("new_spacing(%r)" % (spacing,))

 def new_styles(self, styles):
 print("new_styles(%r)" % (styles,))

 def send_paragraph(self, blankline):
 print("send_paragraph(%r)" % (blankline,))

 def send_line_break(self):
 print("send_line_break()")

 def send_hor_rule(self, *args, **kw):
 print("send_hor_rule()")

 def send_label_data(self, data):
 print("send_label_data(%r)" % (data,))

 def send_flowing_data(self, data):
 print("send_flowing_data(%r)" % (data,))

 def send_literal_data(self, data):
 print("send_literal_data(%r)" % (data,))


class DumbWriter(NullWriter):
 """Simple writer class which writes output on the file object passed in
 as the file parameter or, if file is omitted, on standard output. The
 output is simply word-wrapped to the number of columns specified by
 the maxcol parameter. This class is suitable for reflowing a sequence
 of paragraphs.

 """

 def __init__(self, file=None, maxcol=72):
 self.file = file or sys.stdout
 self.maxcol = maxcol
 NullWriter.__init__(self)
 self.reset()

 def reset(self):
 self.col = 0
 self.atbreak = 0

 def send_paragraph(self, blankline):
 self.file.write('\n'*blankline)
 self.col = 0
 self.atbreak = 0

 def send_line_break(self):
 self.file.write('\n')
 self.col = 0
 self.atbreak = 0

 def send_hor_rule(self, *args, **kw):
 self.file.write('\n')
 self.file.write('-'*self.maxcol)
 self.file.write('\n')
 self.col = 0
 self.atbreak = 0

 def send_literal_data(self, data):
 self.file.write(data)
 i = data.rfind('\n')
 if i >= 0:
 self.col = 0
 data = data[i+1:]
 data = data.expandtabs()
 self.col = self.col + len(data)
 self.atbreak = 0

 def send_flowing_data(self, data):
 if not data: return
 atbreak = self.atbreak or data[0].isspace()
 col = self.col
 maxcol = self.maxcol
 write = self.file.write
 for word in data.split():
 if atbreak:
 if col + len(word) >= maxcol:
 write('\n')
 col = 0
 else:
 write(' ')
 col = col + 1
 write(word)
 col = col + len(word)
 atbreak = 1
 self.col = col
 self.atbreak = data[-1].isspace()


def test(file = None):
 w = DumbWriter()
 f = AbstractFormatter(w)
 if file is not None:
 fp = open(file)
 elif sys.argv[1:]:
 fp = open(sys.argv[1])
 else:
 fp = sys.stdin
 try:
 for line in fp:
 if line == '\n':
 f.end_paragraph(1)
 else:
 f.add_flowing_data(line)
 finally:
 if fp is not sys.stdin:
 fp.close()
 f.end_paragraph(0)


if __name__ == '__main__':
 test()