#!/usr/bin/env python

import sys;
import os;
import re;
from sets import Set

filename = sys.argv[1]

filename_base = os.path.basename(filename)
(filename_name, filename_ext) = os.path.splitext(filename_base)

c_stdlib_headers = Set(["assert.h",  "limits.h",  "signal.h",  "stdlib.h", "ctype.h", "locale.h",  "stdarg.h", "string.h", "errno.h", "math.h", "stddef.h", "time.h", "float.h",  "setjmp.h", "stdio.h", "iso646.h", "wchar.h", "wctype.h", "complex.h", "inttypes.h", "stdint.h", "tgmath.h", "fenv.h", "stdbool.h"])

cpp_stdlib_headers = Set(["algorithm", "fstream", "list", "regex", "typeindex", "array", "functional", "locale", "set", "typeinfo", "atomic", "future", "map", "sstream", "type_traits", "bitset", "initializer_list", "memory", "stack", "unordered_map", "chrono", "iomanip", "mutex", "stdexcept", "unordered_set", "codecvt", "ios", "new", "streambuf", "utility", "complex", "iosfwd", "numeric", "string", "valarray", "condition_variable", "iostream", "ostream", "strstream", "vector", "deque", "istream", "queue", "system_error", "exception", "iterator", "random", "thread", "forward_list", "limits", "ratio", "tuple", "cassert", "ciso646", "csetjmp", "cstdio", "ctime", "cctype", "climits", "csignal", "cstdlib", "cwchar", "cerrno", "clocale", "cstdarg", "cstring", "cwctype", "cfloat", "cmath", "cstddef"])

class HeaderType:
    PRAGMA_ONCE, CORRESPONDING_HEADER, C_STDLIB, CPP_STDLIB, BOOST, QT, OTHER, SWIFTEN, SWIFT_CONTROLLERS, SWIFTOOLS, SWIFT = range(11)

def findHeaderBlock(lines):
  start = False
  end = False

  for idx, line in enumerate(lines):
    if not start and line.startswith("#"):
      start = idx
    elif start and (not end) and (not line.startswith("#")) and line.strip():
      end = idx-1
      break
  return (start, end)

def lineToFileName(line):
  match = re.match( r'#include "(.*)"', line)
  if match:
    return match.group(1)
  match = re.match( r'#include <(.*)>', line)
  if match:
    return match.group(1)
  return False

def fileNameToHeaderType(name):
  if name.endswith(filename_name + ".h"):
    return HeaderType.CORRESPONDING_HEADER

  if name in c_stdlib_headers:
    return HeaderType.C_STDLIB
  
  if name in cpp_stdlib_headers:
    return HeaderType.CPP_STDLIB

  if name.startswith("boost"):
    return HeaderType.BOOST

  if name.startswith("Q"):
    return HeaderType.QT

  if name.startswith("Swiften"):
    return HeaderType.SWIFTEN

  if name.startswith("Swift/Controllers"):
    return HeaderType.SWIFT_CONTROLLERS

  if name.startswith("SwifTools"):
    return HeaderType.SWIFTOOLS

  if name.startswith("Swift"):
    return HeaderType.SWIFT

  return HeaderType.OTHER

def serializeHeaderGroups(groups):
  headerList = []
  for group in range(0, HeaderType.SWIFT + 1):
    if group in groups:
      headers = sorted(groups[group])
      headerList.extend(headers)
      headerList.extend(["\n"])
  headerList.pop()
  return headerList

def cleanHeaderFile(content, headerStart, headerEnd, headerGroups):
  del content[headerStart:headerEnd]
  newHeaders = serializeHeaderGroups(headerGroups)
  content[headerStart:1] = newHeaders

  for line in content:
    print line,

def cleanImplementationFile(content, headerStart, headerEnd, headerGroups):
  del content[headerStart:headerEnd]
  newHeaders = serializeHeaderGroups(headerGroups)
  content[headerStart:1] = newHeaders

  for line in content:
    print line,


containsIf = False

with open(filename) as f:
  content = f.readlines()

(headerStart, headerEnd) = findHeaderBlock(content)

headerGroups = {}

for line in content[headerStart:headerEnd]:
  if line.strip():
    if line.strip().startswith("#if "):
      containsIf = True
      break

    if line.strip().startswith("#pragma once"):
      headerType = HeaderType.PRAGMA_ONCE
    else:
      headerType = fileNameToHeaderType(lineToFileName(line))
    
    filename = lineToFileName(line)
    if headerType in headerGroups:
      headerGroups[headerType].append(line)
    else:
      headerGroups[headerType] = [line]

if containsIf:
  print "Cannot format headers containing preprocessor if statements"
  exit(1)

if filename_base.endswith(".h"):
  if not HeaderType.PRAGMA_ONCE in headerGroups:
    print "Missing #pragma once!"
    exit(2)
  cleanHeaderFile(content, headerStart, headerEnd, headerGroups)
elif filename_base.endswith(".cpp"):
  cleanImplementationFile(content, headerStart, headerEnd, headerGroups)