#!/usr/bin/env python

"""Updates the README.rst file as the include directive is disabled on GitHub."""
__date__     = "Thu Apr  3 23:06:18 CEST 2014"
__author__ = "Anthony Scemama <scemama@irsamc.ups-tlse.fr>"


README="README.rst"
Assum_key="Assumptions\n===========\n"
Needed_key="Needed Modules\n==============\n"
Doc_key="Documentation\n=============\n"
Sentinel="@@$%&@@"
URL="http://github.com/LCPQ/quantum_package/tree/master/src/"

import os
import subprocess

header = """
.. Do not edit this section. It was auto-generated from the
.. NEEDED_MODULES file.

"""

try:
# subprocess.check_output("git status".split())
# has_git = True
  pass
except OSError:
  has_git = False

def fetch_splitted_data():
    """Read the README.rst file and split it in strings:
    * The description
    * The assumptions
    * The documentation 
    * The needed modules
    The result is given as a list of strings
    """

    file = open(README,'r')
    data = file.read()
    file.close()

    # Place sentinels
    data = data.replace(Assum_key,Sentinel+Assum_key)
    data = data.replace(Doc_key,Sentinel+Doc_key)
    data = data.replace(Needed_key,Sentinel+Needed_key)
    
    # Now Split data using the sentinels
    result = data.split(Sentinel)

    return result


def update_assumptions(data):
    """Read the ASSUMPTIONS.rst file, and replace the data with it."""

    try:
        file = open('ASSUMPTIONS.rst','r')
    except IOError:
        file = open('ASSUMPTIONS.rst','w')
        assumptions = ""
    else:
        assumptions = file.read()
    file.close()

    if assumptions.strip() != "":
        assumptions = Assum_key + header + assumptions + '\n\n'

    has_assumptions = False
    for i in range(len(data)):
        if data[i].startswith(Assum_key):
            has_assumptions = True
            data[i] = assumptions

    if not has_assumptions:
        data.insert(1,assumptions)

    return data


def update_needed(data):
    """Read the NEEDED_MODULES file, and replace the data with it.
    Create the links to the GitHub pages."""

    file = open('NEEDED_MODULES','r')
    modules = file.read()
    file.close()

    if modules.strip() != "":
        modules = [ '* `%s <%s%s>`_'%(x,URL,x) for x in  modules.split() ]
        modules = "\n".join(modules)
        modules = Needed_key + header + modules + '\n\n'

    has_modules = False
    for i in range(len(data)):
        if data[i].startswith(Needed_key):
            has_modules = True
            data[i] = modules

    if not has_modules:
        data.append(modules)

    return data


def update_documentation(data):
  """Reads the BEGIN_DOC ... END_DOC blocks and builds the documentation"""

  # If the file does not exist, don't do anything
  try:
    file = open('tags','r')
  except:
    return
  tags = file.readlines()
  file.close()

  def extract_doc(item):
    """Extracts the documentation contained in IRPF90_man file"""
    file = open("IRPF90_man/%s.l"%(item),'r')
    lines = file.readlines()
    file.close()
    result = []
    inside = False
    for line in lines:
      if not inside:
        inside = line.startswith(".SH Description")
      else:
        if line.startswith(".SH"):
          break
        result.append("  "+line.strip())

    if result == []:
      result = ["  Undocumented"]
    return "\n".join(result)+'\n'
            
        
  
  items = []
  dirname = os.path.basename(os.getcwd())
  command = "git ls-tree --full-tree --name-only HEAD:src/%s"
  command = command%(dirname)
  try:
    if dirname != 'src':
      p = subprocess.Popen(command.split(),stdout=subprocess.PIPE)
      tracked_files = p.stdout.read()
    else:
      tracked_files = ""
    tracked_files = tracked_files.splitlines()
  except:
    tracked_files = []
  for filename in tracked_files:
      if filename.endswith('.irp.f'):
          # Search for providers, subroutines and functions in each file using
          # the tags file
          search = "\t"+filename+"\t"
          tmp = filter(lambda line: search in line, tags)

          # Search for the documentation in the IRPF90_man directory
          for item in tmp :
              item, _, line = item.strip().split('\t')
              doc = extract_doc(item)
              items.append( (item, filename, doc, line) )

  dirname = os.path.basename(os.getcwd())
  # Write the documentation in the README
  template = "`%(item)s <%(url)s%(dirname)s/%(filename)s#L%(line)s>`_\n%(doc)s\n"

  documentation = Doc_key + header 
  url = URL
  for item, filename, doc, line in items:
    documentation += template%locals()
  documentation += '\n\n'

  has_doc = False
  for i in range(len(data)):
      if data[i].startswith(Doc_key):
          has_doc = True
          data[i] = documentation

  if not has_doc:
      data.append(documentation)

  return data


def git_add():
    """Executes:
    git add README.rst
    if git is present on the machine."""
    command = "git add "+README
    os.system(command+" &> /dev/null")


def main():
    if not has_git:
        return
    data = fetch_splitted_data()
    data = update_assumptions(data)
    data = update_documentation(data)
    data = update_needed(data)
    output = ''.join(data)
    
    file = open(README,'w')
    file.write(output)
    file.close()

    git_add()


if __name__ == '__main__':
    try:
      main()
    except:
      pass