import logging
from typing import Any
from typing import Dict
from typing import Iterable
from typing import NamedTuple
from typing import Set

import requests
from requests.adapters import HTTPAdapter
from requests.adapters import Retry

logging.basicConfig(level=logging.DEBUG)

URL = "https://rosettacode.org/w/api.php"

CM_QUERY = {
    "action": "query",
    "generator": "categorymembers",
    "format": "json",
    "formatversion": "2",
    "prop": "info",
    "inprop": "url|touched",
    "gcmlimit": 500,
}


class PageInfo(NamedTuple):
    pageid: int
    ns: int
    title: str
    contentmodel: str
    pagelanguage: str
    pagelanguagehtmlcode: str
    pagelanguagedir: str
    touched: str
    lastrevid: int
    length: int
    fullurl: str
    editurl: str
    canonicalurl: str


def get_session() -> requests.Session:
    """Setup a requests.Session with retries."""
    retry_strategy = Retry(
        total=5,
        status_forcelist=[429, 500, 502, 503, 504],
        allowed_methods=["HEAD", "GET", "OPTIONS"],
    )
    adapter = HTTPAdapter(max_retries=retry_strategy)
    session = requests.Session()
    session.mount("https://", adapter)
    session.mount("http://", adapter)
    session.headers["User-Agent"] = "Rosetta Code Task bot"
    return session


def category_members(category: str, url: str = URL) -> Iterable[PageInfo]:
    params: Dict[str, Any] = {**CM_QUERY, "gcmtitle": category}
    session = get_session()

    response = session.get(url, params=params)
    response.raise_for_status()
    data = response.json()

    if not data.get("query"):
        # Empty category
        return

    for page in data["query"]["pages"]:
        yield PageInfo(**{k: v for k, v in page.items() if k in PageInfo._fields})

    _continue = data.get("continue", {}).get("gcmcontinue")

    while _continue:
        params["continue"] = data["continue"]["continue"]
        params["gcmcontinue"] = _continue

        response = session.get(url, params=params)
        response.raise_for_status()
        data = response.json()

        for page in data["query"]["pages"]:
            yield PageInfo(**{k: v for k, v in page.items() if k in PageInfo._fields})

        _continue = data.get("continue", {}).get("gcmcontinue")


def lang_tasks(language: str) -> Set[PageInfo]:
    return set(category_members(f"Category:{language}"))


def omitted_tasks(language: str) -> Set[PageInfo]:
    return set(category_members(f"Category:{language}/Omit"))


def unimplemented_tasks(
    lang_tasks: Set[PageInfo], omitted: Set[PageInfo]
) -> Set[PageInfo]:
    tasks = set(category_members("Category:Programming Tasks"))
    return tasks.difference(lang_tasks).difference(omitted)


def unimplemented_draft_tasks(
    lang_tasks: Set[PageInfo], omitted: Set[PageInfo]
) -> Set[PageInfo]:
    tasks = set(category_members("Category:Draft Programming Tasks"))
    return tasks.difference(lang_tasks).difference(omitted)


def display(title: str, pages: Iterable[PageInfo]) -> None:
    print(title)
    for page in sorted(pages, key=lambda p: p.title):
        print("  ", page.title, page.canonicalurl)
    print("")


if __name__ == "__main__":
    import sys

    if len(sys.argv) > 1:
        language = sys.argv[1]
    else:
        language = "Python"

    tasks = lang_tasks(language)
    omitted = omitted_tasks(language)
    display("Programming Tasks", unimplemented_tasks(tasks, omitted))
    display("Draft Programming Tasks", unimplemented_draft_tasks(tasks, omitted))
    display("Omitted Tasks", omitted)