from __future__ import annotations

from collections.abc import Iterable
from dataclasses import dataclass

import requests
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry

COLLECTION_DETAILS_URL = (
    "https://api.steampowered.com/ISteamRemoteStorage/GetCollectionDetails/v1/"
)
PUBLISHED_FILE_DETAILS_URL = (
    "https://api.steampowered.com/ISteamRemoteStorage/GetPublishedFileDetails/v1/"
)


@dataclass(frozen=True)
class WorkshopDetails:
    workshop_id: str
    title: str
    time_updated: int
    file_size: int
    consumer_app_id: int
    result: int


def _chunks(values: list[str], size: int) -> Iterable[list[str]]:
    for index in range(0, len(values), size):
        yield values[index : index + size]


class SteamWorkshopClient:
    def __init__(self, timeout: int = 30):
        self.timeout = timeout
        self.session = requests.Session()
        retries = Retry(
            total=4,
            backoff_factor=0.75,
            status_forcelist=(429, 500, 502, 503, 504),
            allowed_methods=frozenset({"POST"}),
        )
        self.session.mount("https://", HTTPAdapter(max_retries=retries))
        self.session.headers.update({"User-Agent": "ProgressionMods/1.0"})

    def get_collections(
        self, collection_ids: list[str]
    ) -> tuple[dict[str, list[str]], set[str]]:
        payload: dict[str, str | int] = {"collectioncount": len(collection_ids)}
        for index, collection_id in enumerate(collection_ids):
            payload[f"publishedfileids[{index}]"] = collection_id

        response = self.session.post(
            COLLECTION_DETAILS_URL, data=payload, timeout=self.timeout
        )
        response.raise_for_status()
        details = response.json().get("response", {}).get("collectiondetails", [])

        result: dict[str, list[str]] = {}
        collection_references: set[str] = set()
        for detail in details:
            collection_id = str(detail.get("publishedfileid", ""))
            if int(detail.get("result", 0)) != 1:
                raise RuntimeError(f"Steam rejected collection {collection_id}")
            children = sorted(
                detail.get("children", []),
                key=lambda child: int(child.get("sortorder", 0)),
            )
            child_ids = [str(child["publishedfileid"]) for child in children]
            result[collection_id] = child_ids
            collection_references.update(
                str(child["publishedfileid"])
                for child in children
                if int(child.get("filetype", 0) or 0) == 2
            )

        # Steam currently reports filetype=2 for nested collections. Also
        # recognize configured collections by id in case that field is absent.
        all_children = {
            workshop_id for workshop_ids in result.values() for workshop_id in workshop_ids
        }
        collection_references.update(set(collection_ids) & all_children)
        return result, collection_references

    def get_item_details(self, workshop_ids: list[str]) -> dict[str, WorkshopDetails]:
        result: dict[str, WorkshopDetails] = {}
        for batch in _chunks(workshop_ids, 100):
            payload: dict[str, str | int] = {"itemcount": len(batch)}
            for index, workshop_id in enumerate(batch):
                payload[f"publishedfileids[{index}]"] = workshop_id
            response = self.session.post(
                PUBLISHED_FILE_DETAILS_URL, data=payload, timeout=self.timeout
            )
            response.raise_for_status()
            details = (
                response.json().get("response", {}).get("publishedfiledetails", [])
            )
            for detail in details:
                workshop_id = str(detail.get("publishedfileid", ""))
                result[workshop_id] = WorkshopDetails(
                    workshop_id=workshop_id,
                    title=str(detail.get("title", "")),
                    time_updated=int(detail.get("time_updated", 0) or 0),
                    file_size=int(detail.get("file_size", 0) or 0),
                    consumer_app_id=int(detail.get("consumer_app_id", 0) or 0),
                    result=int(detail.get("result", 0) or 0),
                )
        return result