import json
import pathlib
import time
from typing import cast

import click
import filetype
from tqdm import tqdm
from watchdog.events import FileSystemEvent, FileSystemEventHandler
from watchdog.observers import Observer

from ..bg import remove
from ..session_factory import new_session
from ..sessions import sessions_names


@click.command(
    name="p",
    help="for a folder as input",
)
@click.option(
    "-m",
    "--model",
    default="u2net",
    type=click.Choice(sessions_names),
    show_default=True,
    show_choices=True,
    help="model name",
)
@click.option(
    "-a",
    "--alpha-matting",
    is_flag=True,
    show_default=True,
    help="use alpha matting",
)
@click.option(
    "-af",
    "--alpha-matting-foreground-threshold",
    default=240,
    type=int,
    show_default=True,
    help="trimap fg threshold",
)
@click.option(
    "-ab",
    "--alpha-matting-background-threshold",
    default=10,
    type=int,
    show_default=True,
    help="trimap bg threshold",
)
@click.option(
    "-ae",
    "--alpha-matting-erode-size",
    default=10,
    type=int,
    show_default=True,
    help="erode size",
)
@click.option(
    "-om",
    "--only-mask",
    is_flag=True,
    show_default=True,
    help="output only the mask",
)
@click.option(
    "-ppm",
    "--post-process-mask",
    is_flag=True,
    show_default=True,
    help="post process the mask",
)
@click.option(
    "-w",
    "--watch",
    default=False,
    is_flag=True,
    show_default=True,
    help="watches a folder for changes",
)
@click.option(
    "-bgc",
    "--bgcolor",
    default=None,
    type=(int, int, int, int),
    nargs=4,
    help="Background color (R G B A) to replace the removed background with",
)
@click.option("-x", "--extras", type=str)
@click.argument(
    "input",
    type=click.Path(
        exists=True,
        path_type=pathlib.Path,
        file_okay=False,
        dir_okay=True,
        readable=True,
    ),
)
@click.argument(
    "output",
    type=click.Path(
        exists=False,
        path_type=pathlib.Path,
        file_okay=False,
        dir_okay=True,
        writable=True,
    ),
)
def p_command(
    model: str,
    extras: str,
    input: pathlib.Path,
    output: pathlib.Path,
    watch: bool,
    **kwargs,
) -> None:
    try:
        kwargs.update(json.loads(extras))
    except Exception:
        pass

    session = new_session(model)

    def process(each_input: pathlib.Path) -> None:
        try:
            mimetype = filetype.guess(each_input)
            if mimetype is None:
                return
            if mimetype.mime.find("image") < 0:
                return

            each_output = (output / each_input.name).with_suffix(".png")
            each_output.parents[0].mkdir(parents=True, exist_ok=True)

            if not each_output.exists():
                each_output.write_bytes(
                    cast(
                        bytes,
                        remove(each_input.read_bytes(), session=session, **kwargs),
                    )
                )

                if watch:
                    print(
                        f"processed: {each_input.absolute()} -> {each_output.absolute()}"
                    )
        except Exception as e:
            print(e)

    inputs = list(input.glob("**/*"))
    if not watch:
        inputs = tqdm(inputs)

    for each_input in inputs:
        if not each_input.is_dir():
            process(each_input)

    if watch:
        observer = Observer()

        class EventHandler(FileSystemEventHandler):
            def on_any_event(self, event: FileSystemEvent) -> None:
                if not (
                    event.is_directory or event.event_type in ["deleted", "closed"]
                ):
                    process(pathlib.Path(event.src_path))

        event_handler = EventHandler()
        observer.schedule(event_handler, input, recursive=False)
        observer.start()

        try:
            while True:
                time.sleep(1)

        finally:
            observer.stop()
            observer.join()