# pylint: disable=redefined-outer-name

from queue import Empty, Queue
from secrets import token_urlsafe
from pathlib import Path
from shutil import rmtree
from os.path import join
from os import mkdir, rename
from tempfile import TemporaryDirectory

import pytest
import watchdog

from inotify import InotifyObserver
from inotify import (
    InotifyFileCreatedEvent, InotifyFileModifiedEvent, InotifyFileMovedEvent,
    InotifyFileDeletedEvent, InotifyDirCreatedEvent, InotifyDirModifiedEvent,
    InotifyDirMovedEvent, InotifyDirDeletedEvent
)

watchdog.observers.inotify_buffer.InotifyBuffer.delay = 0


class InotifyContext:
    def __init__(self, workdir, subdir, subfile, observer):
        self.missing_events = 0
        self.workdir = workdir
        self.subdir = subdir
        self.subfile = subfile
        self.observer = observer

        self.event_to_queue = {
            InotifyFileCreatedEvent  : self.observer.create_queue,
            InotifyFileModifiedEvent : self.observer.modify_queue,
            InotifyFileMovedEvent    : self.observer.move_queue,
            InotifyFileDeletedEvent  : self.observer.delete_queue,
            InotifyDirCreatedEvent   : self.observer.create_queue,
            InotifyDirModifiedEvent  : self.observer.modify_queue,
            InotifyDirMovedEvent     : self.observer.move_queue,
            InotifyDirDeletedEvent   : self.observer.delete_queue
        }

    def create_random_file(self, dirname, extension):
        filename = self.join(f'{dirname}/{generate_name()}{extension}')
        Path(filename).touch()
        return filename

    def create_random_folder(self, basepath):
        dirname = self.join(f'{basepath}/{generate_name()}')
        mkdir(dirname)
        return dirname

    def join(self, path):
        return join(self.workdir, path)

    def check_event(self, event_type, path):
        self.missing_events += 1
        event = self.event_to_queue[event_type].get(timeout=0.1)
        assert isinstance(event, event_type)
        assert event.src_path == path
        return event

    def check_empty(self, event_type):
        with pytest.raises(Empty):
            self.event_to_queue[event_type].get(timeout=0.1)

    def check_any(self):
        attrs = self.observer.__dict__.values()
        total = sum([q.qsize() for q in attrs if isinstance(q, Queue)])
        return total+self.missing_events == len(self.observer.any_list)


class InotifyTestObserver(InotifyObserver):
    def __init__(self, path, patterns=None, exclude=None, recursive=False):
        self.any_list = []
        self.create_queue, self.modify_queue, self.move_queue, self.delete_queue = [Queue() for _ in range(4)]
        super().__init__(path, patterns, exclude, recursive)

    def on_any_event(self, event):
        self.any_list.append(event)

    def on_created(self, event):
        self.create_queue.put(event)

    def on_modified(self, event):
        self.modify_queue.put(event)

    def on_moved(self, event):
        self.move_queue.put(event)

    def on_deleted(self, event):
        self.delete_queue.put(event)

def generate_name():
    return token_urlsafe(16)

@pytest.fixture()
def context():
    with TemporaryDirectory() as workdir:
        subdir = join(workdir, generate_name())
        subfile = join(subdir, generate_name()+'.txt')
        mkdir(subdir)
        Path(subfile).touch()
        monitor = InotifyTestObserver(workdir, recursive=True)
        monitor.start()
        yield InotifyContext(workdir, subdir, subfile, monitor)

def test_create(context):
    newfile = context.create_random_file(context.workdir, '.txt')
    context.check_event(InotifyFileCreatedEvent, newfile)
    newdir = context.create_random_folder(context.workdir)
    context.check_event(InotifyDirCreatedEvent, newdir)
    assert context.check_any()

def test_modify(context):
    with open(context.subfile, 'w') as ofile:
        ofile.write('text')
    context.check_event(InotifyFileModifiedEvent, context.subfile)
    while True:
        try:
            context.observer.modify_queue.get(timeout=0.1)
            context.missing_events += 1
        except Empty:
            break
    rename(context.subfile, context.subfile+'_new')
    context.check_event(InotifyDirModifiedEvent, context.subdir)
    assert context.check_any()

def test_move(context):
    rename(context.subdir, context.subdir+'_new')
    context.check_event(InotifyDirMovedEvent, context.subdir)
    context.check_event(InotifyFileMovedEvent, context.subfile)
    assert context.check_any()

def test_delete(context):
    rmtree(context.subdir)
    context.check_event(InotifyFileDeletedEvent, context.subfile)
    context.check_event(InotifyDirDeletedEvent, context.subdir)
    assert context.check_any()

def test_path(context):
    context.observer.path = context.subdir
    context.create_random_folder(context.workdir)
    newfile = context.create_random_file(context.subdir, '.txt')
    context.check_event(InotifyFileCreatedEvent, newfile)
    context.observer.path = context.subdir
    assert context.check_any()

def test_patterns(context):
    context.observer.patterns = ['*.txt']
    context.create_random_file(context.subdir, '.bin')
    newfile = context.create_random_file(context.subdir, '.txt')
    context.check_event(InotifyFileCreatedEvent, newfile)
    context.check_empty(InotifyFileCreatedEvent)
    assert context.check_any()
    context.observer.patterns = None

def test_exclude(context):
    context.observer.exclude = ['*.txt']
    context.create_random_file(context.subdir, '.txt')
    newfile = context.create_random_file(context.subdir, '.bin')
    context.check_event(InotifyFileCreatedEvent, newfile)
    context.check_empty(InotifyFileCreatedEvent)
    assert context.check_any()
    context.observer.exclude = None

def test_stress(context):
    newfile = []
    for i in range(1024):
        newfile.append(context.create_random_file(context.subdir, '.txt'))
    for i in range(1024):
        context.check_event(InotifyFileCreatedEvent, newfile[i])
    assert context.check_any()