#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import os
import json

from ast_parser import AST_Parser


def create_paths_list(dirname, filenames):
    paths = []
    for basename in filenames:
        path = dirname + basename
        paths.append(path)
    return paths


def read_files(paths):
    content = []
    for path in paths:
        file_info = read_file(path)
        content.append(file_info)
    return content


def read_file(path):
    with open(path) as f:
        file_content = f.read()
        item = {"path": path,
                "sourcecode": file_content}
    return item


def write_json(header, key):
    outpath = header["outpath"] + "." + key + ".json"
    with open(outpath, "w+") as f:
        json.dump(header[key], f, indent=4)


def prepare_header(header, out_dir):
    basename = os.path.basename(header.get("path"))
    outpath = out_dir + basename
    header["outpath"] = outpath
    return header


def create_simple_ast(ast):
    elems = {"functions": "",
             "structs": "",
             "enums": ""}
    elems["functions"] = extract_functions_from_ast(ast)
    elems["structs"] = extract_structs_from_ast(ast)
    elems["enums"] = extract_enums_from_ast(ast)
    return elems


# extracts top level functions only (is there anything else in C?)
def extract_functions_from_ast(ast):
    functions = []
    for child in ast["children"]:
        if child["kind"] == "CursorKind.FUNCTION_DECL":
            functions.append(simple_ast_functions(child))
    return functions


def simple_ast_functions(func_ast):
    simple_func = {"name": "",
                   "return_type": "",
                   "arguments": []}

    simple_func["name"] = func_ast["name"]
    simple_func["return_type"] = func_ast["result_type"]
    arguments = []
    # check if func has args
    if "children" in func_ast:
        for arg_ast in func_ast["children"]:
            arg_simple = None
            if arg_ast["kind"] == "CursorKind.PARM_DECL":
                arg_simple = {"name": "",
                              "type": ""}
                arg_simple["name"] = arg_ast["name"]
                arg_simple["type"] = arg_ast["type"]
            if arg_simple:
                arguments.append(arg_simple)

    if arguments:
        simple_func["arguments"] = arguments
    return simple_func


# only typedef enums
def extract_enums_from_ast(ast):
    enums = []
    for typedef in ast["children"]:
        if typedef["kind"] == "CursorKind.TYPEDEF_DECL":
            typename = typedef["type"]
            if "children" in typedef:
                for enum in typedef["children"]:
                    if enum["kind"] == "CursorKind.ENUM_DECL":
                        enums.append(simple_ast_enums(enum, typename))

    return enums


def simple_ast_enums(enum_ast, typename):
    simple_enum = {"name": typename,
                   "items": []}

    items = []
    if "children" in enum_ast:
        for item in enum_ast["children"]:
            if item["kind"] == "CursorKind.ENUM_CONSTANT_DECL":
                simple_item = {"name": "",
                               "value": ""}
                simple_item["name"] = item["name"]
                simple_item["value"] = item["value"]
                items.append(simple_item)

    if items:
        simple_enum["items"] = items

    return simple_enum


# only typedef structs
def extract_structs_from_ast(ast):
    structs = []
    for typedef in ast["children"]:
        if typedef["kind"] == "CursorKind.TYPEDEF_DECL":
            typename = typedef["type"]
            if "children" in typedef:
                for struct in typedef["children"]:
                    if struct["kind"] == "CursorKind.STRUCT_DECL":
                        structs.append(simple_ast_structs(struct, typename))

    return structs

def simple_ast_structs(struct_ast, typename):
    simple_struct = {"name" : typename,
                     "fields" : []}

    fields = []
    if "children" in struct_ast:
        for field in struct_ast["children"]:
            if field["kind"] == "CursorKind.FIELD_DECL":
                simple_field = {"name": "",
                                "type": ""}
                simple_field["name"] = field["name"]
                simple_field["type"] = field["type"]
                fields.append(simple_field)

    if fields:
        simple_struct["fields"] = fields

    return simple_struct


def main():
    input()
    parser = AST_Parser("/opt/local/libexec/llvm-9.0/lib/libclang.dylib")
    # Input
    prefix = r"/Users/heck/local-default/"
    filenames = ["pEpEngine.h",
                 "keymanagement.h"]
    # Output
    out_dir = "data/output/"
    if not os.path.isdir(out_dir):
        os.makedirs(out_dir)

    in_dir = prefix + r"include/pEp/"
    paths = create_paths_list(in_dir, filenames)
    headers = read_files(paths)

    for header in headers:
        header = prepare_header(header, out_dir)
        print("processing path: " + header.get("path") + "...")
        header["ast"] = parser.parse(header["path"], header["sourcecode"])
        write_json(header, "ast")

        header["simple_ast"] = create_simple_ast(header["ast"])
        write_json(header, "simple_ast")


if __name__ == "__main__":
    main()