from dataclasses import dataclass
import os
import re

from flask import Blueprint, current_app, escape, flash, render_template
from flask import jsonify

from .. import util


VIDEO_EXTENSIONS = ['.avi', '.m4v', '.mkv', '.mp4', '.mpg']
MAX_RECURSE_DEPTH = 5
bp = Blueprint('file_listing', __name__, url_prefix='/file_listing')


@dataclass
class path_entry:
    base_name = ''
    rel_path = '' # NOTE: fs path relative to config['MOVIE_DIR']
    file_extension = ''
    is_dir = False
    depth = 0
    contents = []


@bp.route('/folder_contents/')
def getBaseFolderContents():
    full_path = current_app.config['MOVIE_DIR']
    paths = []

    # validate input
    if not os.path.exists(full_path):
        flash('path in "MOVIE_DIR" is invalid')
    else:
        for entry in os.scandir(full_path):
            paths.append(getPathInfo(entry, MAX_RECURSE_DEPTH))

    return render_template(
            'file_listing/folder_contents.html',
            paths=paths,
            debug_str=util.dumpObject(paths)
        )


# NOTE: return a listing of files and directories in a sub_directory as JSON
#   @param subpath a path relative to config['MOVIE_DIR']
@bp.route('/folder_contents/<path:subpath>')
def getFolderJSON(subpath = ''):
    video_path = current_app.config['MOVIE_DIR']
    full_path = os.path.join(video_path, subpath)
    errors = []
    paths = []

    current_app.logger.debug('video_path: {}'.format(video_path))
    current_app.logger.debug('subpath: {}'.format(subpath))
    current_app.logger.debug('full_path: {}'.format(full_path))

    # validate input
    if re.search('\.\.', subpath) or not os.path.exists(full_path):
        errors.append('invalid path: {}'.format(full_path))
    elif not os.path.isdir(full_path):
        errors.append('path is not a directory: {}'.format(full_path))
    else:
        for entry in os.scandir(full_path):
            # TODO: remove 'getPathInfo()' when finished with async file listing
            #   make sure to continue to test for '.' and symlinks
            # TODO: add errors to json, 'flash()' won't trigger on this function since it's async
            pe = getPathInfo(entry, MAX_RECURSE_DEPTH)
            if pe:
                paths.append({
                        'base_name': pe.base_name,
                        'rel_path': pe.rel_path,
                        'file_extension': pe.file_extension,
                        'is_dir': pe.is_dir,
                    })

    return jsonify(errors=errors, paths=paths)


def getPathInfo(entry, depth=0):
    if not entry.name.startswith('.') and not entry.is_symlink():
        video_path = current_app.config['MOVIE_DIR']
        pe = path_entry()
        pe.base_name = entry.name
        pe.rel_path = re.sub(video_path, '', entry.path)
        pe.is_dir = entry.is_dir()
        pe.depth = depth

        if entry.is_file():
            ext = os.path.splitext(entry)[1]

            if ext in VIDEO_EXTENSIONS:
                pe.file_extension = ext
            else:
                return None
        elif entry.is_dir() and depth < MAX_RECURSE_DEPTH:
            for e in os.scandir(entry):
                p = getPathInfo(e, depth + 1)
                if p:
                    pe.contents.append(p)

        return pe

    return None