"""Discord a další notifikace pro provoz EMS."""

from __future__ import annotations

import logging
from datetime import datetime

import asyncpg
import httpx

from app.config import get_settings

logger = logging.getLogger(__name__)


def _discord_level_for_mode_change(activated_by: str) -> str:
    if activated_by == "system:mismatch":
        return "critical"
    if activated_by.startswith("system:"):
        return "warning"
    return "info"


async def notify_operating_mode_changed(
    site_code: str,
    previous_mode: str,
    new_mode: str,
    activated_by: str,
    notes: str | None,
    *,
    level: str | None = None,
) -> None:
    lvl = level or _discord_level_for_mode_change(activated_by)
    note_line = f"\nPoznámka: {notes}" if notes else ""
    msg = (
        f"Přepnutí provozního režimu – lokalita `{site_code}`\n"
        f"**{previous_mode}** → **{new_mode}**\n"
        f"Aktivoval: `{activated_by}`{note_line}"
    )
    await send_discord(msg, level=lvl)


async def run_fn_set_mode_with_discord(
    conn: asyncpg.Connection,
    site_id: int,
    mode_code: str,
    activated_by: str,
    valid_until: datetime | None,
    notes: str | None,
    *,
    notify_level: str | None = None,
) -> str:
    """
    Zavolá ems.fn_set_mode. Při skutečné změně režimu pošle Discord (pokud je webhook).
    Vrátí aktuální mode_code z DB po volání.
    """
    prev = await conn.fetchval(
        "SELECT mode_code FROM ems.site_operating_mode WHERE site_id = $1",
        site_id,
    )
    await conn.execute(
        "SELECT ems.fn_set_mode($1, $2, $3, $4, $5)",
        site_id,
        mode_code,
        activated_by,
        valid_until,
        notes,
    )
    new = await conn.fetchval(
        "SELECT mode_code FROM ems.site_operating_mode WHERE site_id = $1",
        site_id,
    )
    if new is None:
        new = mode_code
    if prev is not None and prev != new:
        site_code = await conn.fetchval(
            "SELECT code FROM ems.site WHERE id = $1", site_id
        )
        await notify_operating_mode_changed(
            site_code or str(site_id),
            str(prev),
            str(new),
            activated_by,
            notes,
            level=notify_level,
        )
    return str(new)


async def send_discord(message: str, level: str = "info") -> bool:
    """
    Pošle notifikaci na Discord webhook.
    level: 'info', 'warning', 'error', 'critical'
    Vrátí True při úspěchu.
    """
    settings = get_settings()
    webhook_url = settings.discord_webhook_url
    if not webhook_url:
        logger.debug("Discord webhook not configured, skipping notification")
        return False

    emoji = {"info": "ℹ️", "warning": "⚠️", "error": "❌", "critical": "🚨"}.get(level, "ℹ️")

    try:
        async with httpx.AsyncClient(timeout=10) as client:
            resp = await client.post(
                webhook_url,
                json={
                    "content": f"{emoji} **EMS Alert** [{level.upper()}]\n{message}",
                },
            )
            resp.raise_for_status()
            return True
    except Exception as e:
        logger.warning("Discord notification failed: %s", e)
        return False


async def notify_modbus_mismatch(
    asset_code: str,
    register: int,
    register_name: str,
    value_written: int,
    value_verified: int,
    attempt: int,
) -> None:
    msg = (
        f"Modbus mismatch na **{asset_code}**\n"
        f"Registr: `0x{register:04X}` ({register_name})\n"
        f"Zapsáno: `{value_written}` | Přečteno: `{value_verified}`\n"
        f"Pokus č. {attempt}"
    )
    await send_discord(msg, level="error")


async def notify_self_sustain_activated(site_code: str, reason: str) -> None:
    msg = (
        f"Přepnutí na **SELF_SUSTAIN** – lokalita `{site_code}`\n"
        f"Důvod: {reason}"
    )
    await send_discord(msg, level="critical")


async def notify_modbus_clock_verify_exhausted(
    site_code: str,
    asset_code: str,
    written: tuple[int, int, int],
    actual: tuple[int, int, int],
) -> None:
    msg = (
        f"Modbus **systémový čas 62–64** – po 3 neúspěšných ověřeních **bez** přepnutí režimu.\n"
        f"Lokalita `{site_code}`, zařízení `{asset_code}`\n"
        f"Zapsáno: `{written}` | Přečteno: `{actual}`\n"
        f"Doporučení: zkontrolovat firmware/RS485; režim EMS se nemění automaticky."
    )
    await send_discord(msg, level="critical")


async def notify_daily_economics(
    site_code: str,
    day: str,
    import_kwh: float,
    import_cost: float,
    export_kwh: float,
    export_revenue: float,
    green_bonus: float,
    total_balance: float,
    planned_balance: float | None,
) -> None:
    lines = [
        f"Ekonomika **{site_code}** {day}:",
        f"  Import: {import_kwh:.1f} kWh = {import_cost:.2f} Kč",
        f"  Export: {export_kwh:.1f} kWh = {export_revenue:.2f} Kč",
    ]
    if green_bonus > 0:
        lines.append(f"  Zelený bonus: {green_bonus:.2f} Kč")
    sign = "+" if total_balance >= 0 else ""
    lines.append(f"  **BILANCE: {sign}{total_balance:.2f} Kč**")
    if planned_balance is not None:
        dev = total_balance - planned_balance
        dev_sign = "+" if dev >= 0 else ""
        lines.append(
            f"  Plán předpokládal: {planned_balance:+.2f} Kč "
            f"(odchylka {dev_sign}{dev:.2f} Kč)"
        )
    await send_discord("\n".join(lines), level="info")