"""
This example implements Matrix bot that generates a pixelized noise image with
specified maximum R, G and B values.

It uses environment variables to specify authorization data. Use Ctrl+C to stop
the bot.
"""

import asyncio
from io import BytesIO
import os
import time
import logging
import random
from PIL import Image, ImageFilter

from mab import *

from _environment import check_environment

async def on_gen_command(data: EventContext) -> None:
    """This callback is called when `!gen R G B` command is received."""
    # convert R, G and B to floats
    try:
        r, g, b = [float(v) for v in data[CTX_CMD_ARGS]]
    except:
        await data.bot.send.text(data.room, "Invalid arguments")
        return
    await data.bot.send.text(data.room, "Generating the noise...")
    # create the basic noise
    img = Image.new("RGB", (16, 16))
    for x in range(img.width):
        for y in range(img.height):
            col = (random.random() * r, random.random() * g, random.random() * b)
            img.putpixel(
                (x, y),
                tuple(int(c * 255) for c in col)
            )
    # pixelized upscale
    img = img.resize((2048, 2048), resample=Image.Resampling.NEAREST)
    # save to buffer
    buf = BytesIO()
    img.save(buf, format="PNG")
    buf.seek(0)
    buf = buf.read()
    # send
    await data.bot.send.image_bytes(data.room, buf, "noise.png")

async def on_image(ctx: EventContext) -> None:
    """This callback is called when an image is received."""
    # download
    s = time.time()
    data = await ctx.bot.download.file(ctx)
    took_time = time.time() - s
    # convert to Image
    with BytesIO(data) as buf:
        img = Image.open(buf)
        # apply effects
        blur = ImageFilter.GaussianBlur(
            radius=min(img.size[0] // 10, 5)
        )
        img = img.filter(blur)
    # save to buffer
    buf = BytesIO()
    img.save(buf, format="PNG")
    buf.seek(0)
    buf = buf.read()
    # send
    await ctx.bot.send.image_bytes(
        ctx.room,
        buf,
        "blurred.png",
        text="Download and decryption took %.4f seconds" % took_time
    )

async def on_wrong_message(data: EventContext) -> None:
    """This callback is called when a wrong message is received."""
    await data.bot.send.text(
        data.room,
        "Text me something like <code>!gen 0.1 0.7 1.0</code> or send an image to blur"
    )

async def main() -> None:
    """Application entry point"""
    logging.basicConfig(level=logging.INFO)
    logging.getLogger("nio").setLevel(logging.CRITICAL+1)
    check_environment()

    config = MatrixBotConfig(
        matrix_homeserver_url=os.environ["MATRIX_HOMESERVER"],
        matrix_username_localpart=os.environ["MATRIX_USERNAME"],
        storage_directory="session_storage"
    )
    bot = MatrixBot(config)
    command_filter = MessageTypeFilter(MessageType.TEXT) & BodyCommandFilter(
        verbs=["gen"],
        min_args=3,
        max_args=3
    )

    # callback for message that
    # 1. are sent not by this bot
    # 2. do match the command filter
    bot.add_callback(
        ~SenderIsBotFilter() & command_filter,
        on_gen_command)

    # callback for new image message
    bot.add_callback(
        ~SenderIsBotFilter() & MessageTypeFilter(MessageType.IMAGE) & NewMessageFilter(),
        on_image
    )
    
    # callback for message that
    # 1. are sent not by this bot
    # 2. are new messages (not edits)
    bot.add_callback(
        ~SenderIsBotFilter() & BodyExistsFilter() & NewMessageFilter(),
        on_wrong_message
    )

    # run until Ctrl+C
    try:
        await bot.run()
    except asyncio.CancelledError:
        pass

if __name__ == "__main__":
    asyncio.run(main())