piqic-python

#!/usr/bin/env python

import os
import sys
import json
import pprint

import piq


# variant item, tag, value
def vi(variant):
    return variant.items()[0]
def vt(variant):
    return vi(variant)[0]
def vv(variant):
    return vi(variant)[1]


class Piqi(object):
    typedef_list = []
    index = {}

    def __init__(self, piqi_json):
        self.typedef_list = piqi_json.get('typedef', [])

        self.index = {}
        for x in self.typedef_list:
            type_tag, typedef = vi(x)
            name = typedef['name']
            self.index[name] = (type_tag, typedef)


def print_iolist(l):
    def print_iolist_item(x):
        if isinstance(x, basestring):
            sys.stdout.write(x)
        elif isinstance(x, list):
            print_iolist(x)
        else:
            assert False
    for x in l:
        print_iolist_item(x)


def gen_types_piqi(piqi):
    return [gen_types_typedef(piqi, x) for x in piqi.typedef_list]


def gen_types_typedef(piqi, x):
    tag, value = vi(x)

    name = value['name']

    # TODO: snake to CamelCase
    pyname = gen_name(name)

    # TODO, FIXME: unalias
    piqi_class = 'Piqi.' + tag.capitalize()

    return [
        'class ', pyname, '(', piqi_class, '): pass\n'
    ]


def gen_parse_piqi(piqi):
    return [gen_parse_typedef(piqi, x) for x in piqi.typedef_list]


def gen_parse_typedef(piqi, x):
    tag, value = vi(x)

    name = value['name']
    pyname = gen_name(name)

    return [
        'def parse_', pyname, '(x, **kwargs):\n'
        '    return parse(x, "', name, '", **kwargs)\n'
    ]


def gen_name(x):
    return x.replace('-', '_')


def parse_piqi_bundle(json_data):
    return json_data


def main():
    filename = sys.argv[1]

    piqi_executable = os.environ.get('PIQI', 'piqi')
    command = piqi_executable + ' compile -t json ' + filename

    data = os.popen(command).read()
    piqi_bundle_json = json.loads(data)

    # TODO, XXX: support imported specs? potentially, via nested classes each
    # corresponding to a piqi module
    piqi_json = piqi_bundle_json['piqi'][0]
    piqi = Piqi(piqi_json)

    code = [
        'import piqi\n',
        '\n',
        'typedef_index =\\\n', pprint.pformat(piqi.index), '\n'
        '\n',

        # TODO, XXX: do we actually need to type each parsed value to its own
        # class? We can do it if necessary by including classes in the index
        #
        #gen_types_piqi(piqi),
        #'\n',

        'def parse(x, typename, format="piq"):\n',
        '    return piqi.parse(x, __name__, typename, format)\n',
        '\n',
        gen_parse_piqi(piqi),
    ]
    print_iolist(code)


if __name__ == '__main__':
    main()