"""
Service handler for get_price service.

This service fetches raw price interval data for any time range using the
interval pool's intelligent caching. Only intervals not already cached are
fetched from the Tibber API.

Functions:
    handle_get_price: Service handler for fetching price data

"""

from __future__ import annotations

from datetime import datetime
import logging
from typing import TYPE_CHECKING
from zoneinfo import ZoneInfo

import voluptuous as vol

from custom_components.tibber_prices.const import DOMAIN
from homeassistant.exceptions import ServiceValidationError
from homeassistant.helpers import config_validation as cv
from homeassistant.util import dt as dt_util

from .entity_resolver import or_entity_ref, resolve_entity_references
from .helpers import async_fetch_service_intervals, get_entry_and_data

if TYPE_CHECKING:
    from homeassistant.core import HomeAssistant, ServiceCall, ServiceResponse

_LOGGER = logging.getLogger(__name__)

GET_PRICE_SERVICE_NAME = "get_price"

_PRICE_ENTITY_PARAMS: dict[str, type] = {
    "start_time": datetime,
    "end_time": datetime,
}

GET_PRICE_SERVICE_SCHEMA = vol.Schema(
    {
        vol.Optional("entry_id", default=""): cv.string,
        vol.Required("start_time"): or_entity_ref(cv.datetime),
        vol.Required("end_time"): or_entity_ref(cv.datetime),
    }
)


def _raise_user_data_error() -> None:
    """Raise user data not available error."""
    msg = "User data not available"
    raise ServiceValidationError(
        translation_domain=DOMAIN,
        translation_key="user_data_not_available",
    ) from ValueError(msg)


async def handle_get_price(call: ServiceCall) -> ServiceResponse:
    """
    Handle get_price service call.

    Fetches price data for a specified time range using the interval pool.
    The pool intelligently caches intervals and only fetches missing data from the API.

    Args:
        call: Service call with entry_id, start_time, and end_time

    Returns:
        Dict with price data and metadata

    Raises:
        ServiceValidationError: If arguments invalid or request fails

    """
    hass: HomeAssistant = call.hass

    # Resolve entity references
    data, resolved_refs = resolve_entity_references(hass, call.data, _PRICE_ENTITY_PARAMS)

    entry_id: str = data.get("entry_id", "")
    start_time: datetime = data["start_time"]
    end_time: datetime = data["end_time"]

    # Validate and get entry data
    entry, coordinator, _data = get_entry_and_data(hass, entry_id)

    # Get home_id from entry
    home_id = entry.data.get("home_id")
    if not home_id:
        raise ServiceValidationError(
            translation_domain=DOMAIN,
            translation_key="missing_home_id",
        )

    # Get API client from coordinator
    api_client = coordinator.api

    # Get user data (needed for timezone) - coordinator doesn't expose this publicly yet
    user_data = coordinator._cached_user_data  # noqa: SLF001

    if not user_data:
        _raise_user_data_error()

    # Extract home timezone from user_data
    home_timezone = None
    if user_data and "viewer" in user_data:
        for home in user_data["viewer"].get("homes", []):
            if home.get("id") == home_id:
                home_timezone = home.get("timeZone")
                break

    if not home_timezone:
        raise ServiceValidationError(
            translation_domain=DOMAIN,
            translation_key="timezone_not_found",
        )

    # Ensure times are timezone-aware using HOME timezone (not HA server timezone!)
    # CRITICAL TWO-STEP PROCESS:
    # 1. GUI gives us naive datetime in HA SERVER timezone → localize to HA timezone
    # 2. Convert from HA timezone to HOME timezone (Tibber home location)
    home_tz = ZoneInfo(home_timezone)

    if start_time.tzinfo is None:
        # Step 1: Localize to HA server timezone
        start_time = dt_util.as_local(start_time)
    # Step 2: Convert to home timezone
    start_time = start_time.astimezone(home_tz)

    if end_time.tzinfo is None:
        # Step 1: Localize to HA server timezone
        end_time = dt_util.as_local(end_time)
    # Step 2: Convert to home timezone
    end_time = end_time.astimezone(home_tz)

    # Validate: end must be after start
    if end_time <= start_time:
        raise ServiceValidationError(
            translation_domain=DOMAIN,
            translation_key="end_before_start",
        )

    _LOGGER.info(
        "get_price service called: entry_id=%s, home_id=%s, range=%s to %s",
        entry_id,
        home_id,
        start_time,
        end_time,
    )

    # Get interval pool from entry runtime_data (one pool per config entry)
    pool = entry.runtime_data.interval_pool

    # Resilient fetch: never impairs sensors, returns empty result on API failure
    # instead of raising. Single-home architecture: pool knows its home_id.
    price_info, fetch_ok = await async_fetch_service_intervals(
        pool,
        api_client=api_client,
        user_data=user_data,
        start_time=start_time,
        end_time=end_time,
        service_label="get_price",
    )

    if not fetch_ok:
        # Price data could not be fetched (API outage on an uncached range). Return a
        # well-formed empty response with success=False so automations can detect this
        # without inspecting the data fields.
        response = {
            "success": False,
            "reason": "price_data_unavailable",
            "home_id": home_id,
            "start_time": start_time.isoformat(),
            "end_time": end_time.isoformat(),
            "interval_count": 0,
            "price_info": [],
        }
        if resolved_refs:
            response["_resolved"] = resolved_refs
        _LOGGER.info("get_price service completed: price data unavailable")
        return response

    # Add metadata to response
    response = {
        "success": True,
        "home_id": home_id,
        "start_time": start_time.isoformat(),
        "end_time": end_time.isoformat(),
        "interval_count": len(price_info),
        "price_info": price_info,
    }

    _LOGGER.info(
        "get_price service completed: fetched %d intervals",
        len(price_info),
    )

    if resolved_refs:
        response["_resolved"] = resolved_refs

    return response