#!/usr/bin/env python

"""
Generate function define macros.
"""

from __future__ import print_function
import string
import sys
import os


# type -> (<c type if used as parameter>, <c type if used as ret type>,
#          <function to get value from array>,
#          <function to set value to the ret_object>,
#          <function to set value to array>,
#          <default_ret_value>)
type_table = {
    "string": ("const char*",
               "char*",
               "json_array_get_string_or_null_element",
               "searpc_set_string_to_ret_object",
               "json_array_add_string_or_null_element",
               "NULL"),
    "int": ("int",
            "int",
            "json_array_get_int_element",
            "searpc_set_int_to_ret_object",
            "json_array_add_int_element",
            "-1"),
    "int64": ("gint64",
              "gint64",
              "json_array_get_int_element",
              "searpc_set_int_to_ret_object",
              "json_array_add_int_element",
              "-1"),
    "object": ("GObject*",
               "GObject*",
               "",
               "searpc_set_object_to_ret_object",
               "",
               "NULL"),
    "objlist": ("GList*",
                "GList*",
                "",
                "searpc_set_objlist_to_ret_object",
                "",
                "NULL"),
    "json": ("const json_t*",
             "json_t*",
             "json_array_get_json_or_null_element",
             "searpc_set_json_to_ret_object",
             "json_array_add_json_or_null_element",
             "NULL"),
}

marshal_template = r"""
static char *
${marshal_name} (void *func, json_t *param_array, gsize *ret_len)
{
    GError *error = NULL;
${get_parameters}
    ${func_call}

    json_t *object = json_object ();
    ${convert_ret}
    return searpc_marshal_set_ret_common (object, ret_len, error);
}
"""

def generate_marshal(ret_type, arg_types):
    ret_type_item = type_table[ret_type]
    ret_type_in_c = ret_type_item[1]

    template = string.Template(marshal_template)

    if len(arg_types) == 0:
        marshal_name = "marshal_" + ret_type + "__void"
    else:
        marshal_name = "marshal_" + ret_type + "__" + ('_'.join(arg_types))
    get_parameters = ""
    for i, arg_type in enumerate(arg_types):
        type_item = type_table[arg_type]
        stmt = "    %s param%d = %s (param_array, %d);\n" %(
            type_item[0], i+1, type_item[2], i+1)
        get_parameters += stmt

    # func_prototype should be something like
    # GList* (*)(const char*, int, GError **)
    func_prototype = ret_type_in_c + " (*)("
    for arg_type in arg_types:
        func_prototype += type_table[arg_type][0] + ", "
    func_prototype += "GError **)"

    func_args = ""
    for i in range(1, len(arg_types)+1):
        func_args += "param%d, " % (i)
    func_args += "&error"

    func_call = "%s ret = ((%s)func) (%s);" % (ret_type_in_c, func_prototype,
                                              func_args)

    convert_ret = "%s (object, ret);" % ret_type_item[3]

    return template.substitute(marshal_name=marshal_name,
                               get_parameters=get_parameters,
                               func_call=func_call,
                               convert_ret=convert_ret)

def write_file(f, s):
    f.write(s)
    f.write('\n')

def gen_marshal_functions(f):
    for item in func_table:
        write_file(f, generate_marshal(item[0], item[1]))


marshal_register_item = r"""
    {
        searpc_server_register_marshal (${signature_name}(), ${marshal_name});
    }
"""

def generate_marshal_register_item(ret_type, arg_types):
    if len(arg_types) == 0:
        marshal_name = "marshal_" + ret_type + "__void"
    else:
        marshal_name = "marshal_" + ret_type + "__" + ('_'.join(arg_types))

    if len(arg_types) == 0:
        signature_name = "searpc_signature_" + ret_type + "__void"
    else:
        signature_name = "searpc_signature_" + ret_type + "__" + (
            '_'.join(arg_types))

    return string.Template(marshal_register_item).substitute(
        marshal_name=marshal_name,
        signature_name=signature_name)

def gen_marshal_register_function(f):
    write_file(f, "static void register_marshals()""")
    write_file(f,  "{")
    for item in func_table:
        write_file(f, generate_marshal_register_item(item[0], item[1]))
    write_file(f,  "}")

signature_template = r"""
inline static gchar *
${signature_name}()
{
    return searpc_compute_signature (${args});
}
"""

def generate_signature(ret_type, arg_types):
    ret_type_item = type_table[ret_type]
    ret_type_in_c = ret_type_item[1]

    if len(arg_types) == 0:
        signature_name = "searpc_signature_" + ret_type + "__void"
    else:
        signature_name = "searpc_signature_" + ret_type + "__" + (
            '_'.join(arg_types))

    args = "\"" + ret_type + "\"" + ", " + str(len(arg_types))
    for arg_type in arg_types:
        args += ", " + "\"" + arg_type + "\""

    template = string.Template(signature_template)
    return template.substitute(signature_name=signature_name, args=args)

def gen_signature_list():
    with open('searpc-signature.h', 'w') as f:
        for item in func_table:
            write_file(f, generate_signature(item[0], item[1]))

if __name__ == "__main__":
    import argparse
    parser = argparse.ArgumentParser(description='Generate function signatures and marshals for using Searpc')
    parser.add_argument('rpc_mod_file', nargs='?', help='the RPC module file name (default: rpc_table)')
    args = parser.parse_args()

    sys.path.append(os.getcwd())

    # load function table
    if args.rpc_mod_file:
        abspath = os.path.abspath(args.rpc_mod_file)
        with open(abspath, 'r') as fp:
            exec(fp.read())
        print("loaded func_table from %s" % abspath)
    else:
        # load from default rpc_table.py
        from rpc_table import func_table

    # gen code
    with open('searpc-marshal.h', 'w') as marshal:
        gen_marshal_functions(marshal)
        gen_marshal_register_function(marshal)
    gen_signature_list()