import logging

from tfw.internals.networking import Scope
from tfw.internals.inotify import InotifyObserver

from .file_manager import FileManager

LOG = logging.getLogger(__name__)

BUILD_ARTIFACTS = (
    "*.a",
    "*.class",
    "*.dll",
    "*.dylib",
    "*.elf",
    "*.exe",
    "*.jar",
    "*.ko",
    "*.la",
    "*.lib",
    "*.lo",
    "*.o",
    "*.obj",
    "*.out",
    "*.py[cod]",
    "*.so",
    "*.so.*",
    "*.tar.gz",
    "*.zip",
    "*__pycache__*"
)


class IdeHandler:
    keys = ['ide']
    type_id = 'ControlEventHandler'

    def __init__(self, *, patterns, initial_file=None):
        self.connector = None
        self.filemanager = FileManager(patterns)
        self._initial_file = initial_file or ''

        self.monitor = InotifyObserver(
            path=self.filemanager.parents,
            exclude=BUILD_ARTIFACTS
        )
        self.monitor.on_modified = self._reload_frontend
        self.monitor.start()

        self.commands = {
            'ide.read'  : self.read,
            'ide.write' : self.write
        }

    def _reload_frontend(self, event):  # pylint: disable=unused-argument
        self.send_message({'key': 'ide.reload'})

    @property
    def initial_file(self):
        if not self.filemanager.is_allowed(self._initial_file):
            self._initial_file = self.filemanager.files[0]
        return self._initial_file

    def send_message(self, message):
        self.connector.send_message(message, scope=Scope.WEBSOCKET)

    def handle_event(self, message, _):
        try:
            self.commands[message['key']](message)
            message['files'] = self.filemanager.files
            self.send_message(message)
        except KeyError:
            LOG.error('IGNORING MESSAGE: Invalid message received: %s', message)

    def read(self, message):
        if 'patterns' in message:
            self.filemanager.patterns = message['patterns']
        try:
            message['filename'] = self.filemanager.find_file(
                message.get('filename') or self.initial_file
            )
            message['content'] = self.filemanager.read_file(message['filename'])
        except (PermissionError, ValueError):
            message['content'] = 'You have no permission to open that file :('
        except FileNotFoundError:
            message['content'] = 'This file does not exist :('
        except Exception: # pylint: disable=broad-except
            message['content'] = 'Failed to read file :('
            LOG.exception('Error reading file!')

    def write(self, message):
        try:
            self.filemanager.write_file(message['filename'], message['content'])
        except KeyError:
            LOG.error('You must provide a filename to write!')
        except Exception: # pylint: disable=broad-except
            LOG.exception('Error writing file!')
        del message['content']

    def cleanup(self):
        self.monitor.stop()