#!/usr/bin/python3
#
# Copyright (c) 2016-2020 The Khronos Group Inc.
#
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Used for automatic reflow of spec sources to satisfy the agreed layout to
minimize git churn. Most of the logic has to do with detecting asciidoc
markup or block types that *shouldn't* be reflowed (tables, code) and
ignoring them. It's very likely there are many asciidoc constructs not yet
accounted for in the script, our usage of asciidoc markup is intentionally
somewhat limited.

Also used to insert identifying tags on explicit Valid Usage statements.

Usage: `reflow.py [-noflow] [-tagvu] [-nextvu #] [-overwrite] [-out dir] [-suffix str] files`

- `-noflow` acts as a passthrough, instead of reflowing text. Other
  processing may occur.
- `-tagvu` generates explicit VUID tag for Valid Usage statements which
  don't already have them.
- `-nextvu #` starts VUID tag generation at the specified # instead of
  the value wired into the `reflow.py` script.
- `-overwrite` updates in place (can be risky, make sure there are backups)
- `-out` specifies directory to create output file in, default 'out'
- `-suffix` specifies suffix to add to output files, default ''
- `files` are asciidoc source files from the spec to reflow.
"""
# For error and file-loading interfaces only
import argparse
import os
import re
import sys
from reflib import loadFile, logDiag, logWarn, setLogFile
from reflow_count import startVUID

from xrconventions import OpenXRConventions as APIConventions
conventions = APIConventions()

# Markup that always ends a paragraph
#   empty line or whitespace
#   [block options]
#   [[anchor]]
#   //                  comment
#   <<<<                page break
#   :attribute-setting
#   macro-directive::terms
#   +                   standalone list item continuation
#   label::             labelled list - label must be standalone
endPara = re.compile(r'^( *|\[.*\]|//.*|<<<<|:.*|[a-z]+::.*|\+|.*::)$')

# Special case of markup ending a paragraph, used to track the current
# command/structure. This allows for either OpenXR or Vulkan API path
# conventions. Nominally it should use the file suffix defined by the API
# conventions (conventions.file_suffix), except that XR uses '.txt' for
# generated API include files, not '.adoc' like its other includes.
includePat = re.compile(
        r'include::(?P<directory_traverse>((../){1,4}|\{INCS-VAR\}/|\{generated\}/)(generated/)?)(?P<generated_type>[\w]+)/(?P<category>\w+)/(?P<entity_name>[^./]+).txt[\[][\]]')

# Find the first pname: pattern in a Valid Usage statement
pnamePat = re.compile(r'pname:(?P<param>\w+)')

# Markup that's OK in a contiguous paragraph but otherwise passed through
#   .anything
#   === Section Titles
endParaContinue = re.compile(r'^(\..*|=+ .+)$')

# Markup for block delimiters whose contents *should* be reformatted
#   --   (exactly two)  (open block)
#   **** (4 or more)    (sidebar block - works best/only? in AsciiDoctor 2)
#   ==== (4 or more)    (example block)
#   ____ (4 or more)    (quote block)
blockReflow = re.compile(r'^(--|[*=_]{4,})$')

# Fake block delimiters for "common" VU statements
blockCommonReflow = '// Common Valid Usage\n'

# Markup for block delimiters whose contents should *not* be reformatted
#   |=== (3 or more)  (table)
#   ++++ (4 or more)  (passthrough block)
#   .... (4 or more)  (literal block)
#   //// (4 or more)  (comment block)
#   ---- (4 or more)  (listing block)
#   ```  (3 or more)  (listing block)
blockPassthrough = re.compile(r'^(\|={3,}|[`]{3}|[-.+/]{4,})$')

# Markup for introducing lists (hanging paragraphs)
#   * bullet
#     ** bullet
#     -- bullet
#   . bullet
#   :: bullet (no longer supported by asciidoctor 2)
#   {empty}:: bullet
#   1. list item
beginBullet = re.compile(r'^ *([-*.]+|\{empty\}::|::|[0-9]+[.]) ')

# Text that (may) not end sentences

# A single letter followed by a period, typically a middle initial.
endInitial = re.compile(r'^[A-Z]\.$')
# An abbreviation, which doesn't (usually) end a line.
endAbbrev = re.compile(r'(e\.g|i\.e|c\.f)\.$', re.IGNORECASE)

class ReflowState:
    """State machine for reflowing..

    Represents the state of the reflow operation"""
    def __init__(self,
                 filename,
                 margin = 76,
                 file = sys.stdout,
                 breakPeriod = True,
                 reflow = True,
                 nextvu = None):


        self.blockStack = [ None ]
        """The last element is a line with the asciidoc block delimiter that's currently in effect,
        such as '--', '----', '****', '======', or '+++++++++'.
        This affects whether or not the block contents should be formatted."""

        self.reflowStack = [ True ]
        """The last element is True or False if the current blockStack contents
        should be reflowed."""
        self.vuStack = [ False ]
        """the last element is True or False if the current blockStack contents
        are an explicit Valid Usage block."""

        self.margin = margin
        """margin to reflow text to."""

        self.para = []
        """list of lines in the paragraph being accumulated.
        When this is non-empty, there is a current paragraph."""

        self.lastTitle = False
        """true if the previous line was a document title line
        (e.g. :leveloffset: 0 - no attempt to track changes to this is made)."""

        self.leadIndent = 0
        """indent level (in spaces) of the first line of a paragraph."""

        self.hangIndent = 0
        """indent level of the remaining lines of a paragraph."""

        self.file = file
        """file pointer to write to."""

        self.filename = filename
        """base name of file being read from."""

        self.lineNumber = 0
        """line number being read from the input file."""

        self.breakPeriod = breakPeriod
        """True if justification should break to a new line after the end of a sentence."""

        self.breakInitial = True
        """True if justification should break to a new line after
        something that appears to be an initial in someone's name. **TBD**"""

        self.reflow = reflow
        """True if text should be reflowed, False to pass through unchanged."""

        self.vuPrefix = 'VUID'
        """Prefix of generated Valid Usage tags"""

        self.vuFormat = '{0}-{1}-{2}-{3:0>5d}'
        """Format string for generating Valid Usage tags.
        First argument is vuPrefix, second is command/struct name, third is parameter name, fourth is the tag number."""

        self.nextvu = nextvu
        """Integer to start tagging un-numbered Valid Usage statements with,
        or None if no tagging should be done."""

        self.apiName = ''
        """String name of a Vulkan structure or command for VUID tag generation,
        or None if one hasn't been included in this file yet."""

    def incrLineNumber(self):
        self.lineNumber = self.lineNumber + 1

    def printLines(self, lines):
        """Print an array of lines with newlines already present"""
        logDiag(':: printLines:', len(lines), 'lines: ', lines[0], end='')
        for line in lines:
            print(line, file=self.file, end='')

    def endSentence(self, word):
        """Return True if word ends with a sentence-period, False otherwise.

        Allows for contraction cases which won't end a line:

         - A single letter (if breakInitial is True)
         - Abbreviations: 'c.f.', 'e.g.', 'i.e.' (or mixed-case versions)"""
        if (word[-1:] != '.' or
            endAbbrev.search(word) or
                (self.breakInitial and endInitial.match(word))):
            return False

        return True

    def vuidAnchor(self, word):
        """Return True if word is a Valid Usage ID Tag anchor."""
        return (word[0:7] == '[[VUID-')

    def isOpenBlockDelimiter(self, line):
        """Returns True if line is an open block delimiter."""
        return line[0:2] == '--'

    def reflowPara(self):
        """Reflow the current paragraph, respecting the paragraph lead and
        hanging indentation levels.

        The algorithm also respects trailing '+' signs that indicate embedded newlines,
        and will not reflow a very long word immediately after a bullet point.

        Just return the paragraph unchanged if the -noflow argument was
        given."""
        if not self.reflow:
            return self.para

        logDiag('reflowPara lead indent = ', self.leadIndent,
                'hangIndent =', self.hangIndent,
                'para:', self.para[0], end='')

        # Total words processed (we care about the *first* word vs. others)
        wordCount = 0

        # Tracks the *previous* word processed. It must not be empty.
        prevWord = ' '

        #import pdb; pdb.set_trace()

        for line in self.para:
            line = line.rstrip()
            words = line.split()

            # logDiag('reflowPara: input line =', line)
            numWords = len(words) - 1

            for i in range(0, numWords + 1):
                word = words[i]
                wordLen = len(word)
                wordCount += 1

                endEscape = False
                if i == numWords and word == '+':
                    # Trailing ' +' must stay on the same line
                    endEscape = word
                    # logDiag('reflowPara last word of line =', word, 'prevWord =', prevWord, 'endEscape =', endEscape)
                else:
                    pass
                    # logDiag('reflowPara wordCount =', wordCount, 'word =', word, 'prevWord =', prevWord)

                if wordCount == 1:
                    # The first word of the paragraph is treated specially.
                    # The loop logic becomes trickier if all this code is
                    # done prior to looping over lines and words, so all the
                    # setup logic is done here.

                    outPara = []
                    outLine = ''.ljust(self.leadIndent) + word
                    outLineLen = self.leadIndent + wordLen

                    # If the paragraph begins with a bullet point, generate
                    # a hanging indent level if there isn't one already.
                    if beginBullet.match(self.para[0]):
                        bulletPoint = True
                        if len(self.para) > 1:
                            logDiag('reflowPara first line matches bullet point',
                                    'but indent already hanging @ input line',
                                    self.lineNumber)
                        else:
                            logDiag('reflowPara first line matches bullet point -'
                                    'single line, assuming hangIndent @ input line',
                                    self.lineNumber)
                            self.hangIndent = outLineLen + 1
                    else:
                        bulletPoint = False
                else:
                    # Possible actions to take with this word
                    #
                    # addWord - add word to current line
                    # closeLine - append line and start a new (null) one
                    # startLine - add word to a new line

                    # Default behavior if all the tests below fail is to add
                    # this word to the current line, and keep accumulating
                    # that line.
                    (addWord, closeLine, startLine) = (True, False, False)

                    # How long would this line be if the word were added?
                    newLen = outLineLen + 1 + wordLen

                    # Are we on the first word following a bullet point?
                    firstBullet = (wordCount == 2 and bulletPoint)

                    if endEscape:
                        # If the new word ends the input line with ' +',
                        # add it to the current line.

                        (addWord, closeLine, startLine) = (True, True, False)
                    elif self.vuidAnchor(word):
                        # If the new word is a Valid Usage anchor, break the
                        # line afterwards. Note that this should only happen
                        # immediately after a bullet point, but we don't
                        # currently check for this.
                        (addWord, closeLine, startLine) = (True, True, False)
                    elif newLen > self.margin:
                        if firstBullet:
                            # If the word follows a bullet point, add it to
                            # the current line no matter its length.

                            (addWord, closeLine, startLine) = (True, True, False)
                        else:
                            # The word overflows, so add it to a new line.

                            (addWord, closeLine, startLine) = (False, True, True)
                    elif (self.breakPeriod and
                          (wordCount > 2 or not firstBullet) and
                          self.endSentence(prevWord)):
                        # If the previous word ends a sentence and
                        # breakPeriod is set, start a new line.
                        # The complicated logic allows for leading bullet
                        # points which are periods (implicitly numbered lists).
                        # @@@ But not yet for explicitly numbered lists.

                        (addWord, closeLine, startLine) = (False, True, True)

                    # Add a word to the current line
                    if addWord:
                        if outLine:
                            outLine += ' ' + word
                            outLineLen = newLen
                        else:
                            # Fall through to startLine case if there's no
                            # current line yet.
                            startLine = True

                    # Add current line to the output paragraph. Force
                    # starting a new line, although we don't yet know if it
                    # will ever have contents.
                    if closeLine:
                        if outLine:
                            outPara.append(outLine + '\n')
                            outLine = None

                    # Start a new line and add a word to it
                    if startLine:
                        outLine = ''.ljust(self.hangIndent) + word
                        outLineLen = self.hangIndent + wordLen

                # Track the previous word, for use in breaking at end of
                # a sentence
                prevWord = word

        # Add this line to the output paragraph.
        if outLine:
            outPara.append(outLine + '\n')

        return outPara

    def emitPara(self):
        """Emit a paragraph, possibly reflowing it depending on the block context.

        Resets the paragraph accumulator."""
        if self.para != []:
            if self.vuStack[-1] and self.nextvu is not None:
                # If:
                #   - this paragraph is in a Valid Usage block,
                #   - VUID tags are being assigned,
                # Try to assign VUIDs

                if nestedVuPat.search(self.para[0]):
                    # Check for nested bullet points. These should not be
                    # assigned VUIDs, nor present at all, because they break
                    # the VU extractor.
                    logWarn(self.filename + ': Invalid nested bullet point in VU block:', self.para[0])
                elif self.vuPrefix not in self.para[0]:
                    # If:
                    #   - a tag is not already present, and
                    #   - the paragraph is a properly marked-up list item
                    # Then add a VUID tag starting with the next free ID.

                    # Split the first line after the bullet point
                    matches = vuPat.search(self.para[0])
                    if matches is not None:
                        logDiag('findRefs: Matched vuPat on line:', self.para[0], end='')
                        head = matches.group('head')
                        tail = matches.group('tail')

                        # Use the first pname: statement in the paragraph as
                        # the parameter name in the VUID tag. This won't always
                        # be correct, but should be highly reliable.
                        for vuLine in self.para:
                            matches = pnamePat.search(vuLine)
                            if matches is not None:
                                break

                        if matches is not None:
                            paramName = matches.group('param')
                        else:
                            paramName = 'None'
                            logWarn(self.filename,
                                    'No param name found for VUID tag on line:',
                                    self.para[0])

                        newline = (head + ' [[' +
                                   self.vuFormat.format(self.vuPrefix,
                                                        self.apiName,
                                                        paramName,
                                                        self.nextvu) + ']] ' + tail)

                        logDiag('Assigning', self.vuPrefix, self.apiName, self.nextvu,
                                ' on line:', self.para[0], '->', newline, 'END')

                        self.para[0] = newline
                        self.nextvu = self.nextvu + 1
                # else:
                #     There are only a few cases of this, and they're all
                #     legitimate. Leave detecting this case to another tool
                #     or hand inspection.
                #     logWarn(self.filename + ': Unexpected non-bullet item in VU block (harmless if following an ifdef):',
                #             self.para[0])

            if self.reflowStack[-1]:
                self.printLines(self.reflowPara())
            else:
                self.printLines(self.para)

        # Reset the paragraph, including its indentation level
        self.para = []
        self.leadIndent = 0
        self.hangIndent = 0

    def endPara(self, line):
        """'line' ends a paragraph and should itself be emitted.
        line may be None to indicate EOF or other exception."""
        logDiag('endPara line', self.lineNumber, ': emitting paragraph')

        # Emit current paragraph, this line, and reset tracker
        self.emitPara()

        if line:
            self.printLines( [ line ] )

    def endParaContinue(self, line):
        """'line' ends a paragraph (unless there's already a paragraph being
        accumulated, e.g. len(para) > 0 - currently not implemented)"""
        self.endPara(line)

    def endBlock(self, line, reflow = False, vuBlock = False):
        """'line' begins or ends a block.

        If beginning a block, tag whether or not to reflow the contents.

        vuBlock is True if the previous line indicates this is a Valid Usage block."""
        self.endPara(line)

        if self.blockStack[-1] == line:
            logDiag('endBlock line', self.lineNumber,
                    ': popping block end depth:', len(self.blockStack),
                    ':', line, end='')

            # Reset apiName at the end of an open block.
            # Open blocks cannot be nested, so this is safe.
            if self.isOpenBlockDelimiter(line):
                logDiag('reset apiName to empty at line', self.lineNumber)
                self.apiName = ''
            else:
                logDiag('NOT resetting apiName to empty at line', self.lineNumber)

            self.blockStack.pop()
            self.reflowStack.pop()
            self.vuStack.pop()
        else:
            # Start a block
            self.blockStack.append(line)
            self.reflowStack.append(reflow)
            self.vuStack.append(vuBlock)

            logDiag('endBlock reflow =', reflow, ' line', self.lineNumber,
                    ': pushing block start depth', len(self.blockStack),
                    ':', line, end='')

    def endParaBlockReflow(self, line, vuBlock):
        """'line' begins or ends a block. The paragraphs in the block *should* be
        reformatted (e.g. a NOTE)."""
        self.endBlock(line, reflow = True, vuBlock = vuBlock)

    def endParaBlockPassthrough(self, line):
        """'line' begins or ends a block. The paragraphs in the block should
        *not* be reformatted (e.g. a code listing)."""
        self.endBlock(line, reflow = False)

    def addLine(self, line):
        """'line' starts or continues a paragraph.

        Paragraphs may have "hanging indent", e.g.

        ```
          * Bullet point...
            ... continued
        ```

        In this case, when the higher indentation level ends, so does the
        paragraph."""
        logDiag('addLine line', self.lineNumber, ':', line, end='')

        # See https://stackoverflow.com/questions/13648813/what-is-the-pythonic-way-to-count-the-leading-spaces-in-a-string
        indent = len(line) - len(line.lstrip())

        # A hanging paragraph ends due to a less-indented line.
        if self.para != [] and indent < self.hangIndent:
            logDiag('addLine: line reduces indentation, emit paragraph')
            self.emitPara()

        # A bullet point (or something that looks like one) always ends the
        # current paragraph.
        if beginBullet.match(line):
            logDiag('addLine: line matches beginBullet, emit paragraph')
            self.emitPara()

        if self.para == []:
            # Begin a new paragraph
            self.para = [ line ]
            self.leadIndent = indent
            self.hangIndent = indent
        else:
            # Add a line to a paragraph. Increase the hanging indentation
            # level - once.
            if self.hangIndent == self.leadIndent:
                self.hangIndent = indent
            self.para.append(line)

def apiMatch(oldname, newname):
    """Returns whether oldname and newname match, up to an API suffix."""
    upper = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
    return oldname.rstrip(upper) == newname.rstrip(upper)

def reflowFile(filename, args):
    logDiag('reflow: filename', filename)

    lines = loadFile(filename)
    if lines is None:
        return

    # Output file handle and reflow object for this file. There are no race
    # conditions on overwriting the input, but it's not recommended unless
    # you have backing store such as git.

    if args.overwrite:
        outFilename = filename
    else:
        outFilename = args.outDir + '/' + os.path.basename(filename) + args.suffix

    try:
        fp = open(outFilename, 'w', encoding='utf8')
    except:
        logWarn('Cannot open output file', filename, ':', sys.exc_info()[0])
        return

    state = ReflowState(filename,
                        file = fp,
                        reflow = not args.noflow,
                        nextvu = args.nextvu)

    for line in lines:
        state.incrLineNumber()

        # Is this a title line (leading '= ' followed by text)?
        thisTitle = False

        # The logic here is broken. If we're in a non-reflowable block and
        # this line *doesn't* end the block, it should always be
        # accumulated.

        # Test for a blockCommonReflow delimiter comment first, to avoid
        # treating it solely as a end-Paragraph marker comment.
        if line == blockCommonReflow:
            # Starting or ending a pseudo-block for "common" VU statements.

            # Common VU statements use an Asciidoc variable as the apiName,
            # instead of inferring it from the most recent API include.
            state.apiName = '{refpage}'
            state.endParaBlockReflow(line, vuBlock = True)

        elif blockReflow.match(line):
            # Starting or ending a block whose contents may be reflowed.
            # Blocks cannot be nested.

            # Is this is an explicit Valid Usage block?
            vuBlock = (state.lineNumber > 1 and
                       lines[state.lineNumber-2] == '.Valid Usage\n')

            state.endParaBlockReflow(line, vuBlock)

        elif endPara.match(line):
            # Ending a paragraph. Emit the current paragraph, if any, and
            # prepare to begin a new paragraph.

            state.endPara(line)

            # If this is an include:: line starting the definition of a
            # structure or command, track that for use in VUID generation.

            matches = includePat.search(line)
            if matches is not None:
                generated_type = matches.group('generated_type')
                include_type = matches.group('category')
                if generated_type == 'api' and include_type in ('protos', 'structs'):
                    apiName = matches.group('entity_name')
                    if state.apiName != '':
                        # This happens when there are multiple API include
                        # lines in a single block. The style guideline is to
                        # always place the API which others are promoted to
                        # first. In virtually all cases, the promoted API
                        # will differ solely in the vendor suffix (or
                        # absence of it), which is benign.
                        if not apiMatch(state.apiName, apiName):
                            logWarn('Promoted API name mismatch at line',
                                    state.lineNumber,
                                    ':',
                                    'apiName:', apiName,
                                    'does not match state.apiName:',
                                    state.apiName)
                    else:
                        state.apiName = apiName

        elif endParaContinue.match(line):
            # For now, always just end the paragraph.
            # Could check see if len(para) > 0 to accumulate.

            state.endParaContinue(line)

            # If it's a title line, track that
            if line[0:2] == '= ':
                thisTitle = True

        elif blockPassthrough.match(line):
            # Starting or ending a block whose contents must not be reflowed.
            # These are tables, etc. Blocks cannot be nested.

            state.endParaBlockPassthrough(line)
        elif state.lastTitle:
            # The previous line was a document title line. This line
            # is the author / credits line and must not be reflowed.

            state.endPara(line)
        else:
            # Just accumulate a line to the current paragraph. Watch out for
            # hanging indents / bullet-points and track that indent level.

            state.addLine(line)

        state.lastTitle = thisTitle

    # Cleanup at end of file
    state.endPara(None)

    # Sanity check on block nesting
    if len(state.blockStack) > 1:
        logWarn('file', filename,
                'mismatched asciidoc block delimiters at EOF:',
                state.blockStack[-1])

    fp.close()

    # Update the 'nextvu' value
    if args.nextvu != state.nextvu:
        logWarn('Updated nextvu to', state.nextvu, 'after file', filename)
        args.nextvu = state.nextvu

def reflowAllAdocFiles(folder_to_reflow, args):
    for root, subdirs, files in os.walk(folder_to_reflow):
        for file in files:
            if file.endswith(conventions.file_suffix):
                file_path = os.path.join(root, file)
                reflowFile(file_path, args)
        for subdir in subdirs:
            sub_folder = os.path.join(root, subdir)
            print('Sub-folder = %s' % sub_folder)
            if subdir.lower() not in conventions.spec_no_reflow_dirs:
                print('   Parsing = %s' % sub_folder)
                reflowAllAdocFiles(sub_folder, args)
            else:
                print('   Skipping = %s' % sub_folder)

# Patterns used to recognize interesting lines in an asciidoc source file.
# These patterns are only compiled once.

# Explicit Valid Usage list item with one or more leading asterisks
# The re.DOTALL is needed to prevent vuPat.search() from stripping
# the trailing newline.
vuPat = re.compile(r'^(?P<head>  [*]+)( *)(?P<tail>.*)', re.DOTALL)

# Pattern matching leading nested bullet points
global nestedVuPat
nestedVuPat = re.compile(r'^  \*\*')

if __name__ == '__main__':
    parser = argparse.ArgumentParser()

    parser.add_argument('-diag', action='store', dest='diagFile',
                        help='Set the diagnostic file')
    parser.add_argument('-warn', action='store', dest='warnFile',
                        help='Set the warning file')
    parser.add_argument('-log', action='store', dest='logFile',
                        help='Set the log file for both diagnostics and warnings')
    parser.add_argument('-overwrite', action='store_true',
                        help='Overwrite input filenames instead of writing different output filenames')
    parser.add_argument('-out', action='store', dest='outDir',
                        default='out',
                        help='Set the output directory in which updated files are generated (default: out)')
    parser.add_argument('-tagvu', action='store_true',
                        help='Tag un-tagged Valid Usage statements starting at the value wired into reflow.py')
    parser.add_argument('-nextvu', action='store', dest='nextvu', type=int,
                        default=None,
                        help='Tag un-tagged Valid Usage statements starting at the specified base VUID instead of the value wired into reflow.py')
    parser.add_argument('-noflow', action='store_true', dest='noflow',
                        help='Do not reflow text. Other actions may apply.')
    parser.add_argument('-suffix', action='store', dest='suffix',
                        default='',
                        help='Set the suffix added to updated file names (default: none)')
    parser.add_argument('files', metavar='filename', nargs='*',
                        help='a filename to reflow text in')
    parser.add_argument('--version', action='version', version='%(prog)s 1.0')

    args = parser.parse_args()

    setLogFile(True,  True, args.logFile)
    setLogFile(True, False, args.diagFile)
    setLogFile(False, True, args.warnFile)

    if args.overwrite:
        logWarn("reflow.py: will overwrite all input files")

    if args.tagvu and args.nextvu is None:
        args.nextvu = startVUID

    if args.nextvu is not None:
        logWarn('Tagging untagged Valid Usage statements starting at', args.nextvu)

    # If no files are specified, reflow the entire specification chapters folder
    if not args.files:
        folder_to_reflow = conventions.spec_reflow_path
        logWarn('Reflowing all asciidoc files under', folder_to_reflow)
        reflowAllAdocFiles(folder_to_reflow, args)
    else:
        for file in args.files:
            reflowFile(file, args)

    if args.nextvu is not None and args.nextvu != startVUID:
        try:
            reflow_count_file_path = os.path.dirname(os.path.realpath(__file__))
            reflow_count_file_path += '/reflow_count.py'
            reflow_count_file = open(reflow_count_file_path, 'w', encoding='utf8')
            print('# The value to start tagging VU statements at, unless overridden by -nextvu\n', file=reflow_count_file, end='')
            count_string = 'startVUID = %d\n' % args.nextvu
            print(count_string, file=reflow_count_file, end='')
            reflow_count_file.close()
        except:
            logWarn('Cannot open output count file reflow_count.py', ':', sys.exc_info()[0])
