import argparse
from dataclasses import asdict
import dataclasses
from datetime import datetime as dt
import json
import os
from pathlib import Path
import sys
from typing import Any, Dict, List

import pytumblr
import polars as pl
import fetcher
from model import StatsModel


def get_args() -> Dict[str, Any]:
    """Pull arguments from command line, turn them into a dictionary of <arg, value>"""
    parser: argparse.ArgumentParser = argparse.ArgumentParser(
        prog='tumblr_stats.py',
        description='Use pytumblr and Polars to calculate stats after setting these enviroment variables: '
        + '$TUMBLR_CONSUMER_KEY, $TUMBLR_CONSUMER_SECRET, $TUMBLR_OAUTH_TOKEN, and $TUMBLR_OAUTH_SECRET',
        epilog='— Be gay and do crime')
    parser.add_argument('-b', '--blog', type=str, required=True,
                        help='blog name for which to calculate stats')
    parser.add_argument('-t', '--tags', type=str, nargs='+',
                        help='tag(s) on which to filter (only affects posts)')
    parser.add_argument('-s', '--suppress', type=str, nargs='+',
                        choices=['none', 'posts', 'queued', 'drafts', 'activity'],
                        default='activity',
                        help='objects to skip when aggregating data; will render some stats empty')
    parser.add_argument('--until', type=lambda s: dt.strptime(s, '%Y-%m-%d'),
                        help='only gather posts and activity until YYYY-MM-DD')
    parser.add_argument('--since', type=lambda s: dt.strptime(s, '%Y-%m-%d'),
                        help='only fetch posts and activity since YYYY-MM-DD')
    parser.add_argument('--queued-file', type=str,
                        help='read queued posts from this path instead of fetching them from APIs')
    parser.add_argument('--drafts-file', type=str,
                        help='read drafts from this path instead of fetching them from APIs')
    parser.add_argument('--posts-file', type=str,
                        help='read posts from this path instead of fetching them from APIs')
    parser.add_argument('--activity-file', type=str,
                        help='read activity from this path instead of fetching it from APIs')
    return vars(parser.parse_args())


def init_client() -> pytumblr.TumblrRestClient:
    consumer_key = os.getenv('TUMBLR_CONSUMER_KEY')
    consumer_secret = os.getenv('TUMBLR_CONSUMER_SECRET')
    oauth_token = os.getenv('TUMBLR_OAUTH_TOKEN')
    oauth_secret = os.getenv('TUMBLR_OAUTH_SECRET')

    missing_vars: List[str] = [name for name,
                               val in [('$TUMBLR_CONSUMER_KEY', consumer_key),
                                       ('$TUMBLR_CONSUMER_SECRET', consumer_secret),
                                       ('$TUMBLR_OAUTH_TOKEN', oauth_token),
                                       ('$TUMBLR_OAUTH_SECRET', oauth_secret)] if val is None]

    if missing_vars:
        print("Missing important environment variables:", missing_vars)
        sys.exit(1)

    return pytumblr.TumblrRestClient(
        consumer_key=consumer_key,  # type: ignore
        consumer_secret=consumer_secret,  # type: ignore
        oauth_token=oauth_token,  # type: ignore
        oauth_secret=oauth_secret,  # type: ignore
    )


def json_encoder(obj):
    if dataclasses.is_dataclass(obj):
        return dataclasses.asdict(obj) # type: ignore
    elif isinstance(obj, pl.DataFrame):
        return json.loads(obj.write_json())
    raise TypeError(f"Type {type(obj)} is not serializable!")           


def file_is_used(obj_arg: str, args: Dict[str, Any]) -> bool:
    return obj_arg in args and args[obj_arg]


def load_from_file(path: str) -> pl.DataFrame:
    return pl.read_json(source=Path(path), infer_schema_length=None)


def main() -> None:
    args: Dict[str, Any] = get_args()
    suppress = args['suppress']
    client: pytumblr.TumblrRestClient = init_client()

    # Read queued posts from a file, or fetch them via API and write queued post JSON.
    queued_posts: pl.DataFrame = pl.DataFrame()
    if not suppress or 'queued' not in suppress:
        if file_is_used('queued_file', args):
            queued_posts = load_from_file(args['queued_file'])
        else:
            queued_posts = fetcher.fetch_queued_posts(client, args)
            queued_posts.write_json("queued_posts.json")

    # Read drafts from a file, or fetch them via API and write draft JSON.
    drafts: pl.DataFrame = pl.DataFrame()
    if not suppress or 'drafts' not in suppress:
        if file_is_used('drafts_file', args):
            drafts = load_from_file(args['drafts_file'])
        else:
            drafts = fetcher.fetch_drafts(client, args)
            drafts.write_json("drafts.json")

    # Read posts from a file, or fetch them via API and write post JSON.
    posts: pl.DataFrame = pl.DataFrame()
    if not suppress or 'posts' not in suppress:
        if file_is_used('posts_file', args):
            posts = load_from_file(args['posts_file'])
        else:
            posts = fetcher.fetch_posts(client, args)
            posts.write_json("posts.json")

    # Read activity from a file, or fetch them via API and write activity JSON.
    activity: pl.DataFrame = pl.DataFrame(infer_schema_length=None)
    if not suppress or 'activity' not in suppress:
        if file_is_used('activity_file', args):
            activity = load_from_file(args['activity_file'])
        else:
            activity = fetcher.fetch_activity(client, args, posts)
            activity.write_json('activity.json')

    # The model.
    model: StatsModel = StatsModel(blog_name=args['blog'],
                                   posts = posts,
                                   queued_posts = queued_posts,
                                   drafts = drafts,
                                   activity = activity,
                                   tags = args['tags'])

    # Write the model as JSON output.
    # https://stackoverflow.com/q/26244323
    with open('./tumblr_stats.json', 'w') as f:
        json.dump(asdict(model), f, indent=1, default=json_encoder)

    return


# DO NOT DELETE. The main if statement.
if __name__ == '__main__':
    main()
    print('All done.')
    sys.exit(0)