#!/usr/bin/env python

'''
A program to create a *.lic file from scratch.
'''


import sys
import os
import getopt
import glob
import fnmatch
import xml.etree.cElementTree as etree

try:
    from anuga.utilities.system_tools import compute_checksum
except ImportError:
    print("Can't import 'anuga.utilities.system_tools'?")
    print('Please ensure PYTHONPATH environment variable is correct.')
    print("It's currently: %s" % os.getenv('PYTHONPATH'))
    sys.exit(10)


# default XML encoding
DefaultEncoding = 'iso-8859-1'

Datafile_Template = '''  <datafile>
    <filename></filename>
    <checksum>-1</checksum>
    <publishable>Yes</publishable>
    <accountable>ANUGA developer</accountable>
    <source>Generated by ANUGA development team</source>
    <IP_owner>Geoscience Australia</IP_owner>
    <IP_info>For use with the ANUGA test suite</IP_info>
  </datafile>

'''

# dictionary to map yes/no chars to a string
YesNoDict = {'y': 'Yes',
             'n': 'No'}


def create_file(lfile, fnames, arg_author='',
                arg_publishable='', arg_accountable='',
                arg_source='', arg_ipowner='', arg_ipinfo=''):
    '''Create licence file 'lfile' that controls files in 'fnames'.'''

    # get username from the environment
    username = os.getenv('USERNAME')

    # see if there is already a licence file
    if os.path.exists(lfile):
        print("Sorry, licence file '%s' already exists" % lfile)
        return False

    # create initial XML template
    root = etree.Element('ga_license_file')
    root.text = '\n  '
    metadata = etree.SubElement(root, 'metadata')
    metadata.text = '\n    '
    metadata.tail = '\n  '
    author = etree.SubElement(metadata, 'author')
    author.tail = '\n  '
    if arg_author:
        author.text = arg_author
    else:
        author.text = username

    # add each controlled file to XML tree
    prev_f_tree = None
    already_done = []       # list of handled files
    for f in fnames:
        # check we haven't already handled this file
        if f in already_done:
            print("Have already seen file '%s': ignored" % f)
            continue
        already_done.append(f)

        # get new XML sub-tree for this file
        f_tree = etree.fromstring(Datafile_Template)

        # update  filename and checksum text
        f_tree.find('filename').text = f
        f_tree.find('checksum').text = str(compute_checksum(f))

        # update other tags user has overridden
        if arg_publishable:
            f_tree.find('publishable').text = arg_publishable
        if arg_accountable:
            f_tree.find('accountable').text = arg_accountable
        else:
            f_tree.find('accountable').text = username
        if arg_source:
            f_tree.find('source').text = arg_source
        if arg_ipowner:
            f_tree.find('IP_owner').text = arg_ipowner
        if arg_ipinfo:
            f_tree.find('IP_info').text = arg_ipinfo

        # fix element layout
        f_tree.tail = '\n'
        if prev_f_tree:
            prev_f_tree.tail = '\n  '
        prev_f_tree = f_tree

        # plug new sub-tree into top-level XML
        root.append(f_tree)

    # write new licence data to file
    root = etree.ElementTree(root)
    root.write(lfile, DefaultEncoding)


def usage(msg=None):
    if msg:
        print(msg)

    print('usage: create_lic_file.py <options> <lic_file> [<filename> ...]')
    print('where <options>  is zero or more of:')
    print('                  --author <name>')
    print('                  -w <name>             '
          '- name of the author')
    print('                  --publishable [Yes|No]')
    print('                  -p [Yes|No]           '
          '- is document publishable (Yes is default)')
    print('                  --accountable <name>')
    print('                  -a <name>             '
          '- name of person accountable for file')
    print('                  --source <string>')
    print('                  -s <string>           '
          '- source of controlled file')
    print('                  --owner <name>')
    print('                  -o <name>             '
          '- IP owner name')
    print('                  --info <string>')
    print('                  -i <string>           '
          '- IP extra information')
    print('      <lic_file> is the name of the licence file to create.')
    print('      <filename> is one or more files to control.')


def main(argv):
    # parse command line args
    try:
        opts, args = getopt.gnu_getopt(argv, 'hw:p:a:s:o:i:',
                                       ['help', 'author=', 'publishable=',
                                        'accountable=', 'source=', 'owner=',
                                        'info='])
    except:
        usage()
        return 10

    arg_author = None
    arg_publishable = None
    arg_accountable = None
    arg_source = None
    arg_ipowner = None
    arg_ipinfo = None

    for (opt, opt_arg) in opts:
        if opt in ['-h', '--help']:
            usage()
            return 10
        elif opt in ['-w', '--author']:
            arg_author = opt_arg
        elif opt in ['-p', '--publishable']:
            try:
                arg_publishable = YesNoDict[opt_arg.lower()[0]]
            except KeyError:
                print("Bad %s arg: '%s' "
                      "(expected a string starting 'y', 'n', 'Y' or 'N')"
                      % (opt, opt_arg))
        elif opt in ['-a', '--accountable']:
            arg_accountable = opt_arg
        elif opt in ['-s', '--source']:
            arg_source = opt_arg
        elif opt in ['-o', '--owner']:
            arg_ipowner = opt_arg
        elif opt in ['-i', '--info']:
            arg_ipinfo = opt_arg

    if len(args) < 2:
        usage()
        return 10
    lic_file = args[0]
    filenames = args[1:]

    create_file(lic_file, filenames,
                arg_author=arg_author, arg_publishable=arg_publishable,
                arg_accountable=arg_accountable,
                arg_source=arg_source,  arg_ipowner=arg_ipowner,
                arg_ipinfo=arg_ipinfo)

sys.exit(main(sys.argv[1:]))