import struct
import json
import sys


class BGIScript:
    def __init__(self, path: str):
        self.path = path
        with open(path, 'rb') as f:
            self.data = bytearray(f.read())
        self.read_header()
        self.get_instr_end()

    def read_header(self):
        self.header_size = struct.unpack('<L', self.data[28:32])[0]
        self.iPos = 28 + self.header_size

    def get_instr_end(self):
        finder = self.iPos
        self.len = len(self.data)
        self.last_pos = self.len
        while finder + 4 < self.len:
            d = struct.unpack('<L', self.data[finder:finder + 4])[0]
            if d == 0x1b:
                self.last_pos = finder
            finder += 4
        print(self.len)

    def extract_string(self):
        offset = struct.unpack('<L', self.data[self.iPos:self.iPos + 4])[0]
        self.iPos += 4
        start_pos = 28 + self.header_size + offset
        if start_pos < self.last_pos:
            return None
        pos = start_pos
        while True:
            if self.data[pos] == 0x00:
                break
            pos += 1
        data = self.data[start_pos:pos]
        try:
            data = data.decode('cp932')
        except UnicodeDecodeError:
            data = data.decode('utf-8')
            data = "utf8:" + data
        return start_pos, data
    
    def extract_value(self):
        offset = struct.unpack('<L', self.data[self.iPos:self.iPos + 4])[0]
        self.iPos += 4
        return offset

    def extract_values(self):
        strings = []
        while self.iPos < self.last_pos:
            ins = struct.unpack('<L', self.data[self.iPos:self.iPos + 4])[0]
            self.iPos += 4
            if ins == 0x03:
                string = self.extract_string()
                if string is not None:
                    strings.append(string)
            elif ins in [0x00, 0x01, 0x02, 0x08, 0x09, 0x0a, 0x19, 0x3f]:
                val = self.extract_value()
        return dict(strings)


base = sys.argv[1]
json_f = f"{base}.json"
if len(sys.argv) > 2:
    json_f = sys.argv[2]
scr = BGIScript(base)
print(scr.header_size)
print(scr.iPos)
print(scr.last_pos)
with open(json_f, "w", encoding="utf-8") as f:
    json.dump(scr.extract_values(), f, ensure_ascii=False, indent=2)