#!/usr/bin/env python
"""Pretty-print the structure of an Android OAT file.

Parses an ``.oat`` file with ``lief.OAT.parse`` and renders a summary
of the file (header, embedded DEX files, classes, methods) selected
by command-line flags.

Example:

    $ python oat_reader.py -a boot.oat
"""

import argparse
import shutil
import sys
import traceback

import lief
from lief import OAT

EXIT_STATUS = 0
_term_size = shutil.get_terminal_size((100, 100))
terminal_columns = _term_size.columns
terminal_rows = _term_size.lines


class exceptions_handler(object):
    func = None

    def __init__(self, exceptions, on_except_callback=None):
        self.exceptions = exceptions
        self.on_except_callback = on_except_callback

    def __call__(self, *args, **kwargs):
        if self.func is None:
            self.func = args[0]
            return self
        try:
            return self.func(*args, **kwargs)
        except self.exceptions as e:
            global EXIT_STATUS
            print("{} raised: {}".format(self.func.__name__, e))
            EXIT_STATUS = 1
            if self.on_except_callback is not None:
                self.on_except_callback(e)
            else:
                print("-" * 60)
                print("Exception in {}: {}".format(self.func.__name__, e))
                exc_type, exc_value, exc_traceback = sys.exc_info()
                traceback.print_tb(exc_traceback)
                print("-" * 60)


@exceptions_handler(Exception)
def print_information(binary):
    print("== Information ==")

    android_version = lief.OAT.android_version(binary.header.version)
    code_name = lief.Android.code_name(android_version)
    version = lief.Android.version_string(android_version)

    print(
        "Version: {} - Android {} {}".format(binary.header.version, version, code_name)
    )
    print("Number of dex files: {}".format(len(binary.oat_dex_files)))
    print("Number of classes: {}".format(len(binary.classes)))
    print("Number of methods: {}".format(len(binary.methods)))
    print("")


@exceptions_handler(Exception)
def print_header(binary):
    print("== Header ==")
    print(binary.header)


@exceptions_handler(Exception)
def print_dex_files(binary):
    print("== Dex files ==")
    for oat_dex in binary.oat_dex_files:
        print(oat_dex)


@exceptions_handler(Exception)
def print_classes(binary):
    print("== Classes ==")
    for cls in binary.classes:
        print(cls)


@exceptions_handler(Exception)
def print_methods(binary):
    print("== Methods ==")
    for m in binary.methods:
        print(m)


def main():
    parser = argparse.ArgumentParser(usage="%(prog)s [options] oat files")
    parser.add_argument(
        "-a", "--all", action="store_true", dest="show_all", help="Show all information"
    )

    parser.add_argument(
        "-H", "--header", action="store_true", dest="show_header", help="Display header"
    )

    parser.add_argument(
        "-c",
        "--classes",
        action="store_true",
        dest="show_classes",
        help="Display classes",
    )

    parser.add_argument(
        "-d", "--dex", action="store_true", dest="show_dex", help="Display Dex files"
    )

    parser.add_argument(
        "-m",
        "--methods",
        action="store_true",
        dest="show_methods",
        help="Display Methods",
    )

    parser.add_argument(
        "-x",
        "--extract",
        action="store_true",
        dest="extract_dex",
        help="Extract DEX files",
    )

    parser.add_argument("binary", metavar="<oat-file>", help="Target OAT File")

    # Logging setup
    logger_group = parser.add_argument_group("Logger")
    verbosity = logger_group.add_mutually_exclusive_group()

    verbosity.add_argument(
        "--debug",
        dest="main_verbosity",
        action="store_const",
        const=lief.logging.LEVEL.DEBUG,
    )

    verbosity.add_argument(
        "--trace",
        dest="main_verbosity",
        action="store_const",
        const=lief.logging.LEVEL.TRACE,
    )

    verbosity.add_argument(
        "--info",
        dest="main_verbosity",
        action="store_const",
        const=lief.logging.LEVEL.INFO,
    )

    verbosity.add_argument(
        "--warn",
        dest="main_verbosity",
        action="store_const",
        const=lief.logging.LEVEL.WARN,
    )

    verbosity.add_argument(
        "--err",
        dest="main_verbosity",
        action="store_const",
        const=lief.logging.LEVEL.ERROR,
    )

    verbosity.add_argument(
        "--critical",
        dest="main_verbosity",
        action="store_const",
        const=lief.logging.LEVEL.CRITICAL,
    )

    parser.set_defaults(main_verbosity=lief.logging.LEVEL.WARN)

    args = parser.parse_args()

    lief.logging.set_level(args.main_verbosity)

    binary = OAT.parse(args.binary)
    if binary is None:
        print(f"Error: failed to parse '{args.binary}' as OAT", file=sys.stderr)
        return 1

    print_information(binary)

    if args.show_header or args.show_all:
        print_header(binary)

    if (args.show_dex or args.show_all) and len(binary.oat_dex_files) > 0:
        print_dex_files(binary)

    if args.show_classes and len(binary.classes) > 0:
        print_classes(binary)

    if args.show_methods and len(binary.methods) > 0:
        print_methods(binary)

    return EXIT_STATUS


if __name__ == "__main__":
    sys.exit(main())