#!/usr/bin/env python3

"""
matrix-redact: Delete all messages and media a user has sent in a matrix room.
"""

import random
import math
import asyncio
import argparse
import getpass
import sys
import subprocess
from nio import(
        AsyncClient,
        MatrixRoom,
        LoginResponse,
        RoomInfo,
        MessageDirection,
        RedactedEvent,
        RoomMessagesError,
        RoomRedactError,
        responses
)
from typing import Optional


async def select_room(client: AsyncClient, sync_response) -> MatrixRoom:
    rooms = []
    for room_id, room in client.rooms.items():
        if room_id in sync_response.rooms.join:
            rooms.append({
                "room_id": room_id,
                "display_name": room.display_name,
            })
            print(f"{rooms[-1]['room_id']} | {rooms[-1]['display_name']}")

    selection = input("\nManually type the full room ID to which redaction will be performed: ")
    for room in rooms:
        if room['room_id'] == selection:
            print(f"{selection} will be redacted")
            return room
    print(f"{selection} is invalid. ")
    return None

async def client_login() -> Optional[AsyncClient]:
    uid = input("Full user ID (eg. @user:matrix.server.com): ")
    upass = getpass.getpass(f"Enter the password for {uid}: ")
    user, hserv = uid[1:].split(':', 1)
    client = AsyncClient(f"https://{hserv}", uid)

    if not isinstance(await client.login(upass), LoginResponse):
        print("could not login, returning None")
        return None
    print("login was successful, returning client.")
    return client

async def redact_room(client: AsyncClient, room: MatrixRoom) -> None:
    print(f"\nAll events sent by '{client.user_id}' in " +
          f"'{room['room_id']}' ({room['display_name']}) will be deleted.")
    if not input("\n\nIs this room correct? (Type 'Continue') to proceed: ") == "Continue":
        return None

    sync_resp = await client.sync(timeout=30000, full_state=True)
    start_token = sync_resp.rooms.join[room['room_id']].timeline.prev_batch
    current_token = start_token

    # BUG: This loops if messages are already redacted.
    # NOTE: I wonder if we need to continuously sync? So perhaps it is necessary that we modularize fetching room events

# TODO: if response = 429 (ratelimited), should pausae.
    events_redacted = 0
    while True:
        try:
            print(f"getting messages in {room['room_id']}")
            resp = await client.room_messages(
                    room['room_id'],
                    current_token,
                    limit=500,
                    direction=MessageDirection.back,
            )
        except Exception as e:
            print(f"could not get room message: {e}")
            break
        if isinstance(resp, RoomMessagesError):
            print(f"Could not get room message: {resp}")
            break
        current_token = resp.end
        if len(resp.chunk) == 0:
            print("no more messages to fetch.")
            break

        for event in resp.chunk:
            if event.sender == client.user_id:
                event_id = event.event_id
            try:
                redact_resp = await client.room_redact(
                        room['room_id'],
                        event_id,
                        reason="test test test"
                )

                if isinstance(redact_resp, RoomRedactError):
                    print(f"Could not redact event {event_id} in {room['room_id']}.")
                else:
                    print(f"Successfuly redacted event {event_id} in {room['room_id']}.")
                    events_redacted += 1
                await asyncio.sleep(5)
            except Exception as e:
                print(f"Error redacting event {event_id}: {e}")

    if events_redacted:
        print(f"Total messages redacted: {events_redacted}")
    else:
        print("could not redact any messages.")

    # NOTE: need to ensure event belongs to correct user ID (ie. client.user_id)

    # https://github.com/8go/matrix-commander/blob/master/matrix_commander/matrix_commander.py#L6241
    # https://github.com/8go/matrix-commander/blob/master/matrix_commander/matrix_commander.py#L4314
    # https://github.com/8go/matrix-commander/blob/master/matrix_commander/matrix_commander.py#L4402
    # https://github.com/8go/matrix-commander/blob/master/matrix_commander/matrix_commander.py#L4188f

async def main(args) -> None:
    print("\n" + "="*80)
    print("WARNING: THIS PROGRAM PERFORMS A PERMANENT DESTRUCTIVE ACTION IN A PROVIDED MATRIX ROOM.")
    print("""
          This program will (applies only to a provided room and user ID):
          - Delete all user-uploaded media (images, files, etc.)
          - Delete all messages you've sent
          - Delete any other content you've posted
          - Operate *irreversibly* on the room ID you provide
          - Act as the logged-in user on the specified homeserver

          THIS ACTION IS DESTRUCTIVE AND CANNOT BE UNDONE.

          Make absolutely sure you understand what this program does before proceeding.
          We take zero liability for any misuse of this program.
          """)

    confirmation = input("Type 'YES I UNDERSTAND' to continue: ")
    if confirmation != "YES I UNDERSTAND":
        print("Exiting.")
        sys.exit(1)

    x = random.randint(2, 12)
    a = random.randint(2, 12)
    b = a * x

    print(f"Solve this: {a} * x = {b}")
    if int(input("Answer: ").strip()) != x:
        print("Incorrect math solution. Exiting.")
        sys.exit(1)

    client = None
    try:
        client = await client_login()
        if not client:
            print("Could not login.")
            sys.exit(1)

        sync_resp = await client.sync(timeout=30000, full_state=True)
        room = await select_room(client, sync_resp)

        if room:
            await redact_room(client, room)

    except Exception as e:
        print(f"Error: {e}")
    finally:
        if client:
            print("logging out.")
            await client.logout()
            await client.close()

if __name__ == "__main__":
    parser = argparse.ArgumentParser(
            description="matrix-mcnt: Matrix Unread Message Count"
    )

    asyncio.run(main(parser.parse_args()))