from pathlib import Path

from pyramid.config import Configurator
from pyramid.path import AssetResolver
from watchdog.observers import Observer
from watchdog.events import FileSystemEventHandler

from flatfilecms.resources import Root, root_factory, roots


class PagesEventHandler(FileSystemEventHandler):
    def __init__(self, root_path):
        super(PagesEventHandler, self).__init__()
        self.root_path = root_path
        self.abspath = AssetResolver().resolve(root_path).abspath()

    def find_dir(self, path):
        folder = roots.setdefault(self.root_path, Root(self.root_path))
        path = path.relative_to(self.abspath)
        for name in path.parts[:-1]:
            folder = folder[name]
        return folder

    def on_created(self, event):
        super(PagesEventHandler, self).on_created(event)
        path = Path(
            event.dest_path if hasattr(event, 'dest_path') else event.src_path)
        folder = self.find_dir(path)
        if event.is_directory:
            folder.create_dir(path)
        else:
            folder.create_file(path)

    def on_deleted(self, event):
        super(PagesEventHandler, self).on_deleted(event)
        path = Path(event.src_path)
        folder = self.find_dir(path)
        name = path.stem
        if path.suffix not in ['.md', '.yaml', '.j2', '.jinja2'] \
           and path.name != 'index.html':
            name = path.name
        del folder[name]

    def on_moved(self, event):
        super(PagesEventHandler, self).on_moved(event)
        self.on_deleted(event)
        self.on_created(event)


def main(global_config, **settings):
    """ This function returns a Pyramid WSGI application.
    """
    from pyramid.settings import asbool
    watchdog = asbool(settings.get('watchdog', 'false'))
    settings['watchdog'] = watchdog
    settings.setdefault('pages_path', 'pages')
    settings.setdefault('data_path', 'data')
    default_jinja2_filters = """markdown = flatfilecms.filters:markdown2html
        fileglob = flatfilecms.filters:fileglob
        merge_dict = flatfilecms.filters.merge_dict
        join_url = flatfilecms.filters.join_url"""
    settings['jinja2.filters'] = default_jinja2_filters + settings.get(
        'jinja2.filters', '')

    config = Configurator(settings=settings, root_factory=root_factory)
    config.include('pyramid_jinja2')
    config.include('.routes')
    config.scan()
    if watchdog:
        observer = Observer()
        event_handler = PagesEventHandler(settings['pages_path'])
        observer.schedule(event_handler, event_handler.abspath, recursive=True)
        observer.start()
    return config.make_wsgi_app()