#!/usr/bin/env python3

import os
import stat
import errno
import fuse
from time import time
import json
from collections import defaultdict

fuse.fuse_python_api = (0, 2)

class MyStat(fuse.Stat):
    def __init__(self):
        self.st_mode = stat.S_IFDIR | 0o755
        self.st_ino = 0
        self.st_dev = 0
        self.st_nlink = 2
        self.st_uid = 0
        self.st_gid = 0
        self.st_size = 4096
        self.st_atime = 0
        self.st_mtime = 0
        self.st_ctime = 0

class CommentFS(fuse.Fuse):
    def __init__(self, *args, **kw):
        fuse.Fuse.__init__(self, *args, **kw)

        with open('comments.jsonl', 'r', encoding='utf-8') as f:
            self.comments = [json.loads(line) for line in f]

        self.tree = self.build_comment_tree(self.comments)
        self.files = {}
        self.build_file_structure()

    def build_comment_tree(self, comments):
        tree = defaultdict(list)
        for comment in comments:
            parent = comment['parent'] if comment['parent'] != 'root' else ''
            tree[parent].append(comment)
        return tree

    def build_file_structure(self):
        def add_comment(comment, path):
            comment_path = os.path.join(path, comment['id'])
            self.files[comment_path] = comment
            for reply in self.tree.get(comment['id'], []):
                add_comment(reply, comment_path)

        for comment in self.tree['']:
            add_comment(comment, '/')

    def getattr(self, path):
        st = MyStat()
        st.st_atime = int(time())
        st.st_mtime = st.st_atime
        st.st_ctime = st.st_atime

        if path == '/':
            return st
        elif path in self.files:
            st.st_mode = stat.S_IFREG | 0o444
            st.st_nlink = 1
            content = f"ID: {self.files[path]['id']}\nText: {self.files[path]['text']}\nParent: {self.files[path]['parent']}\n"
            st.st_size = len(content.encode('utf-8'))
            return st
        else:
            return -errno.ENOENT

    def readdir(self, path, offset):
        dirents = ['.', '..']
        if path == '/':
            dirents.extend(comment['id'] for comment in self.tree[''])
        elif path[1:] in [comment['id'] for comment in self.comments]:
            dirents.extend(reply['id'] for reply in self.tree.get(path[1:], []))

        for r in dirents:
            yield fuse.Direntry(r)

    def open(self, path, flags):
        if path not in self.files:
            return -errno.ENOENT
        accmode = os.O_RDONLY | os.O_WRONLY | os.O_RDWR
        if (flags & accmode) != os.O_RDONLY:
            return -errno.EACCES
        return 0

    def read(self, path, size, offset):
        if path not in self.files:
            return -errno.ENOENT
        comment = self.files[path]
        content = f"ID: {comment['id']}\nText: {comment['text']}\nParent: {comment['parent']}\n"
        return content.encode('utf-8')[offset:offset+size]

def main():
    usage = "YouTubeCommentFS: A filesystem to browse YouTube comments"
    server = CommentFS(version="%prog " + fuse.__version__, usage=usage, dash_s_do='setsingle')
    server.parse(errex=1)
    server.main()

if __name__ == '__main__':
    main()