#!/usr/bin/python

"""Modify a dependency listed in a package.json file"""

# Copyright 2013 T.C. Hollingsworth <tchollingsworth@gmail.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.

import json
import optparse
import os
import re
import shutil
import sys

RE_VERSION = re.compile(r'\s*v?([<>=~^]{0,2})\s*([0-9][0-9\.\-]*)\s*')

p = optparse.OptionParser(
        description='Modifies dependency entries in package.json files')

p.add_option('-r', '--remove', action='store_true')
p.add_option('--dev', action='store_const', const='devDependencies', 
             dest='deptype', help='affect devDependencies')
p.add_option('--optional', action='store_const', const='optionalDependencies', 
             dest='deptype', help='affect optionalDependencies')
p.add_option('--caret', action='store_true',
             help='convert all or specified dependencies to use the caret operator')

options, args = p.parse_args()

if not os.path.exists('package.json~'):
    shutil.copy2('package.json', 'package.json~')

md = json.load(open('package.json'))

deptype = options.deptype if options.deptype is not None else 'dependencies'

if deptype not in md:
    md[deptype] = {}

# convert alternate JSON dependency representations to a dictionary
if not options.caret and not isinstance(md[deptype], dict):
    if isinstance(md[deptype], list):
        deps = md[deptype]
        md[deptype] = {}
        for dep in deps:
            md[deptype][dep] = '*'
    elif isinstance(md[deptype], basestring):
        md[deptype] = { md[deptype] : '*' }

if options.remove:
    dep = args[0]
    del md[deptype][dep]
elif options.caret:
    if not isinstance(md[deptype], dict):
        sys.stderr.write('All dependencies are unversioned.  Unable to apply ' +
                         'caret operator.\n')
        sys.exit(2)
        
    deps = args if len(args) > 0 else md[deptype].keys()
    for dep in deps:
        if md[deptype][dep][0] == '^':
            continue
        elif md[deptype][dep][0] in ('~','0','1','2','3','4','5','6','7','8','9'):
            ver = re.match(RE_VERSION, md[deptype][dep]).group(2)
            md[deptype][dep] = '^' + ver
        else:
            sys.stderr.write('Attempted to convert non-numeric or tilde ' +
                'dependency to caret.  This is not permitted.\n')
            sys.exit(1)
else:
    dep = args[0]

    if len(args) > 1:
        ver = args[1]
    else:
        ver = '*'

    md[deptype][dep] = ver

fh = open('package.json', 'w')
data = json.JSONEncoder(indent=4).encode(md)
fh.write(data)
fh.close()