from pwn import remote, log
import ctypes
import sys
import re

# Set up the connection
host = 'challs.glacierctf.com'
port = 13386

p = remote(host, port)

# Load the C library (Liquids/glibc)
# This is required to match the server's random number generation.
# Note: This usually requires running on Linux to match a Linux server.
try:
    libc = ctypes.CDLL('libc.so.6')
except OSError:
    # Fallback for Mac/others, though values might differ from the Linux server
    libc = ctypes.CDLL(None) 
    log.warning("Could not explicitly load libc.so.6. Using default system libc. If on Windows/Mac, numbers might not match server.")

def solve():
    # 1. Wait for the initial prompt '>'
    p.recvuntil(b'>')
    
    # 2. "Write time" -> Send the command to get the seed info
    log.info("Sending 'time' command...")
    p.sendline(b'time')

    # 3. Wait for ':' (The prompt for timezone)
    p.recvuntil(b':')

    # 4. Write "Europe/Berlin"
    log.info("Sending timezone 'Europe/Berlin'...")
    p.sendline(b'Europe/Berlin')

    # 5. Receive the output containing the seed
    # We expect:
    # THIS IS THE STRING: 20251122201640
    # THIS IS THE SEED: 351401000
    response = p.recvuntil(b'>', drop=True).decode() # Read until next prompt/menu
    print(f"\nServer Response:\n{response}\n")

    # 6. Parse the seed using Regex
    # Looking for: "THIS IS THE SEED: <number>"
    match = re.search(r'THIS IS THE SEED:\s*(\d+)', response)
    
    if match:
        seed = int(match.group(1))
        log.success(f"Extracted Seed: {seed}")
    else:
        log.error("Could not find seed in server response!")
        return

    # 7. Initialize srand with the extracted seed
    libc.srand(seed)
    log.info("Initialized local C library with seed.")

    # 8. Generate the number
    # This should match the server's next rand() call
    generated_number = libc.rand()
    log.success(f"Predicted Random Number: {generated_number}")

    # 9. "Write solve" -> Send the solve command
    log.info("Sending 'solve' command...")
    p.sendline(b'solve')

    # 10. Wait for ':' (The prompt for the random number)
    p.recvuntil(b':')

    # 11. Send the generated number
    log.info(f"Sending predicted number: {generated_number}")
    p.sendline(str(generated_number).encode())

    # 12. Switch to interactive mode to see the flag/result
    p.interactive()

if __name__ == "__main__":
    solve()