#!/usr/bin/env python

# $Id$
#
# Copyright (C) 2013  Internet Systems Consortium ("ISC")
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

import os
import sys
import getopt
import base64
import textwrap

from lxml.etree import Element, SubElement, ElementTree

space4 = " " * 4
space6 = " " * 6
space8 = " " * 8
star78 = "*" * 78

wiki_wrapper = textwrap.TextWrapper()
conf_wrapper = textwrap.TextWrapper(initial_indent = "# ", subsequent_indent = "# ")
xml6_wrapper = textwrap.TextWrapper(initial_indent = space6, subsequent_indent = space6)
xml8_wrapper = textwrap.TextWrapper(initial_indent = space8, subsequent_indent = space8)

class Option(object):

  def __init__(self, name, value, doc):
    self.name = name
    self.value = value
    self.doc = doc

  @property
  def width(self):
    return len(self.name)

  def to_xml(self):
    x = Element("option", name = self.name)
    if self.value is not None:
      x.set("value", self.value)
    for d in self.doc:
      SubElement(x, "doc").text = "\n" + xml8_wrapper.fill(d) + "\n" + space6
    return x

  def to_wiki(self, f):
    f.write("\n== %s == #%s\n" % (self.name, self.name))
    for d in self.doc:
      f.write("\n%s\n" % wiki_wrapper.fill(d))
    if self.value is None:
      f.write("\n%s\n" % wiki_wrapper.fill("No default value."))
    else:
      f.write("\n{{{\n#!ini\n%s = %s\n}}}\n" % (self.name, self.value))

  def to_conf(self, f, width):
    for i, d in enumerate(self.doc):
      f.write("%s\n%s\n" % ("" if i == 0 else "#", conf_wrapper.fill(d)))
    if self.value is None:
      f.write("\n#%-*s = ???\n" % (width - 1, self.name))
    else:
      f.write("\n%-*s = %s\n" % (width, self.name, self.value))

class Section(object):

  def __init__(self, name):
    self.name = name
    self.doc = []
    self.options = []

  @property
  def width(self):
    return max(o.width for o in self.options)

  @classmethod
  def from_xml(cls, elt):
    self = cls(name = elt.get("name"))
    for x in elt.iterchildren("doc"):
      self.doc.append(" ".join(x.text.split()))
    for x in elt.iterchildren("option"):
      self.options.append(Option(name = x.get("name"), value = x.get("value"),
                                 doc = [" ".join(d.text.split())
                                        for d in x.iterchildren("doc")]))
    return self

  def to_xml(self):
    x = Element("section", name = self.name)
    for d in self.doc:
      SubElement(x, "doc").text = "\n" + xml6_wrapper.fill(d) + "\n" + space4
    x.extend(o.to_xml() for o in self.options)
    return x

  def to_wiki(self, f):
    f.write("\n= [%s] section = #%s\n" % (self.name, self.name))
    for d in self.doc:
      f.write("\n%s\n" % wiki_wrapper.fill(d))
    for o in self.options:
      o.to_wiki(f)

  def to_conf(self, f, width):
    f.write("\n" + "#" * 78 + "\n\n[" + self.name + "]\n")
    if self.doc:
      f.write("\n##")
      for i, d in enumerate(self.doc):
        f.write("%s\n%s\n" % ("" if i == 0 else "#", conf_wrapper.fill(d)))
      f.write("##\n")
    for o in self.options:
      o.to_conf(f, width)

def wiki_header(f):
  f.write("\n".join((
    "{{{",
    "#!comment",
    "",
    star78,
    "THIS PAGE WAS GENERATED AUTOMATICALLY, DO NOT EDIT.",
    "",
    "Generated from " + ident,
    "            by $Id$",
    star78,
    "",
    "}}}",
    "")))
  if toc is not None:
    f.write("[[TracNav(%s)]]\n" % toc)
  f.write("[[PageOutline]]\n")

def conf_header(f):
  f.write("\n".join((
    "# Automatically generated.  Edit as needed, but be careful of overwriting.",
    "#",
    "# Generated from " + ident,
    "#             by $Id$",
    "")))

# We use clunky getopt instead of shiny argparse because ordering of
# operations matters here, and most options may be repeated.  No doubt
# there's a way to do this with argparse, but it's not obvious that
# it's worth the time it would take to figure it out.

sections = []
section_map = None
option_map = None
ident = None
toc = None

try:
  opts, argv = getopt.getopt(sys.argv[1:], "h",
                             ["help",
                              "read-xml=",
                              "write-xml=",
                              "write-wiki=",
                              "write-conf=",
                              "set=",
                              "pwgen=",
                              "toc=",
                              "autoconf"])
except getopt.GetoptError, e:
  sys.exit("%s: %s" % (sys.argv[0], e))

for o, a in opts:

  if o in ("-h", "--help"):
    sys.exit("Use the Source, Luke")

  elif o == "--read-xml":
    option_map = None
    root = ElementTree(file = a).getroot()
    ident = root.get("ident")
    sections.extend(Section.from_xml(x) for x in root)
    option_map = {}
    section_map = {}
    for section in sections:
      if section.name in section_map:
        sys.exit("Duplicate section %s" % section.name)
      section_map[section.name] = section
      for option in section.options:
        name = (section.name, option.name)
        if name in option_map:
          sys.exit("Duplicate option %s::%s" % name)
        option_map[name] = option

  elif o == "--set":
    try:
      name, value = a.split("=", 1)
      section, option = name.split("::")
    except ValueError:
      sys.exit("Couldn't parse --set specification \"%s\"" % a)
    name = (section, option)
    if name not in option_map:
      sys.exit("Couldn't find option %s::%s" % name)
    option_map[name].value = value

  elif o == "--pwgen":
    try:
      section, option = a.split("::")
    except ValueError:
      sys.exit("Couldn't parse --pwgen specification \"%s\"" % a)
    name = (section, option)
    if name not in option_map:
      sys.exit("Couldn't find option %s::%s" % name)
    option_map[name].value = base64.urlsafe_b64encode(os.urandom(66))

  elif o == "--autoconf":
    try:
      import rpki.autoconf
      for option in section_map["autoconf"].options:
        try:
          option.value = getattr(rpki.autoconf, option.name)
        except AttributeError:
          pass
    except ImportError:
      sys.exit("rpki.autoconf module is not available")
    except KeyError:
      sys.exit("Couldn't find autoconf section")

  elif o == "--write-xml":
    x = Element("configuration", ident = ident)
    x.extend(s.to_xml() for s in sections)
    ElementTree(x).write(a, pretty_print = True, encoding = "us-ascii")

  elif o == "--write-wiki":
    if "%" in a:
      for section in sections:
        with open(a % section.name, "w") as f:
          wiki_header(f)
          section.to_wiki(f)
    else:
      with open(a, "w") as f:
        for i, section in enumerate(sections):
          if i == 0:
            wiki_header(f)
          else:
            f.write("\f\n")
          section.to_wiki(f)

  elif o == "--write-conf":
    with open(a, "w") as f:
      conf_header(f)
      width = max(s.width for s in sections)
      for section in sections:
        section.to_conf(f, width)

  elif o == "--toc":
    toc = a

if argv:
  sys.exit("%s: Unexpected argument%s: %s" % (sys.argv[0], "" if len(argv) == 1 else "s", " ".join(argv)))