"""Provider construction and history-source selection."""

from __future__ import annotations

import logging

from .base import (  # noqa: F401
    Account,
    AuthError,
    Coverage,
    HistoryProvider,
    Item,
    Library,
    MediaProvider,
    Part,
    ProviderError,
    ServerInfo,
    WatchEvent,
)
from .plex import PlexClient, PlexHistoryProvider, PlexProvider
from .tautulli import TautulliClient, TautulliHistoryProvider

log = logging.getLogger(__name__)


def build_media_provider(cfg) -> PlexProvider:
    client = PlexClient(
        cfg.plex_base_url, cfg.plex_token,
        timeout=cfg.plex_timeout_s,
        verify_ssl=cfg.plex_verify_ssl,
        page_size=cfg.plex_page_size,
        request_delay_ms=cfg.plex_request_delay_ms,
    )
    return PlexProvider(client)


def build_history_provider(cfg, media: PlexProvider):
    """Pick a history source per HISTORY_SOURCE (§4.11).

    'auto' prefers Tautulli and falls back to Plex, reporting the reason rather
    than degrading silently — a silently degraded score is one that gets trusted
    when it shouldn't be. Returns (provider, degraded_reason_or_None).
    """
    mode = (cfg.history_source or "auto").lower()

    if mode == "plex":
        return PlexHistoryProvider(media.client), None

    if mode in ("auto", "tautulli"):
        if not cfg.tautulli_configured:
            if mode == "tautulli":
                raise ProviderError("HISTORY_SOURCE=tautulli but Tautulli is not configured")
            return PlexHistoryProvider(media.client), "Tautulli is not configured"
        client = TautulliClient(
            cfg.tautulli_base_url, cfg.tautulli_api_key,
            timeout=cfg.tautulli_timeout_s, page_size=cfg.tautulli_page_size,
        )
        provider = TautulliHistoryProvider(client)
        try:
            provider.server_info()
            return provider, None
        except ProviderError as e:
            if mode == "tautulli":
                raise
            log.warning("Tautulli unreachable, falling back to Plex history: %s", e)
            return PlexHistoryProvider(media.client), "Tautulli unreachable: %s" % e

    raise ProviderError("unknown HISTORY_SOURCE %r" % cfg.history_source)