# This file is used to process section data generated by `objdump -s`
import re


class SectionTable(object):

    class Section(object):
        SECTION_START_PATTERN = re.compile("Contents of section (.+?):")
        DATA_PATTERN = re.compile("([0-9a-f]{4,8})")

        def __init__(self, name, start_address, data):
            self.name = name
            self.start_address = start_address
            self.data = data

        def __contains__(self, item):
            if (item["region"] == self.name or item["region"] == "any") \
                    and (self.start_address <= item["address"] < (self.start_address + len(self.data))):
                return True
            else:
                return False

        def __getitem__(self, item):
            if isinstance(item, int):
                return self.data[item - self.start_address]
            elif isinstance(item, slice):
                start = item.start if item.start is None else item.start - self.start_address
                stop = item.stop if item.stop is None else item.stop - self.start_address
                return self.data[start:stop]
            return self.data[item]

        def __str__(self):
            return "%s [%08x - %08x]" % (self.name, self.start_address, self.start_address+len(self.data))

        __repr__ = __str__

        @classmethod
        def parse_raw_data(cls, raw_data):
            name = ""
            data = ""
            start_address = 0
            # first find start line
            for i, line in enumerate(raw_data):
                if line.find("Contents of section ") != -1:  # do strcmp first to speed up
                    match = cls.SECTION_START_PATTERN.search(line)
                    if match is not None:
                        name = match.group(1)
                        raw_data = raw_data[i+1:]
                        break
            else:
                # do some error handling
                raw_data = [""]  # add a dummy first data line
                pass

            def process_data_line(line_to_process):
                # first remove the ascii part
                hex_part = line_to_process.split("  ")[0]
                # process rest part
                data_list = cls.DATA_PATTERN.findall(hex_part)
                try:
                    _address = int(data_list[0], base=16)
                except IndexError:
                    _address = -1

                def hex_to_str(hex_data):
                    if len(hex_data) % 2 == 1:
                        hex_data = "0" + hex_data  # append zero at the beginning
                    _length = len(hex_data)
                    return "".join([chr(int(hex_data[_i:_i+2], base=16))
                                    for _i in range(0, _length, 2)])
                    pass

                return _address, "".join([hex_to_str(x) for x in data_list[1:]])

            # handle first line:
            address, _data = process_data_line(raw_data[0])
            if address != -1:
                start_address = address
                data += _data
                raw_data = raw_data[1:]
                for i, line in enumerate(raw_data):
                    address, _data = process_data_line(line)
                    if address == -1:
                        raw_data = raw_data[i:]
                        break
                    else:
                        data += _data
            else:
                # do error handling
                raw_data = []
                pass
            return cls(name, start_address, data) if start_address != -1 else None,\
                None if len(raw_data) == 0 else raw_data
            pass

    def __init__(self, file_name):
        with open(file_name, "rb") as f:
            raw_data = f.readlines()
        self.table = []
        while raw_data:
            section, raw_data = self.Section.parse_raw_data(raw_data)
            self.table.append(section)

    def get_unsigned_int(self, region, address, size=4, endian="LE"):
        if address % 4 != 0 or size % 4 != 0:
            print "warning: try to access without 4 bytes aligned"
        key = {"address": address, "region": region}
        for section in self.table:
            if key in section:
                tmp = section[address:address+size]
                value = 0
                for i in range(size):
                    if endian == "LE":
                        value += ord(tmp[i]) << (i*8)
                    elif endian == "BE":
                        value += ord(tmp[i]) << ((size - i - 1) * 8)
                    else:
                        print "only support LE or BE for parameter endian"
                        assert False
                break
        else:
            value = None
        return value

    def get_string(self, region, address):
        value = None
        key = {"address": address, "region": region}
        for section in self.table:
            if key in section:
                value = section[address:]
                for i, c in enumerate(value):
                    if c == '\0':
                        value = value[:i]
                        break
                break
        return value
    pass


def main():
    pass


if __name__ == '__main__':
    main()