from __future__ import annotations

import platform
import re
from dataclasses import dataclass

from src.core.config import load_settings
from src.core.constants import APP_NAME, APP_VERSION
from src.integrations.exchange.service import ExchangeService
from src.storage.session import check_database_health


@dataclass(slots=True)
class ComponentStatus:
    name: str
    state: str
    details: str = ""


@dataclass(slots=True)
class SystemSnapshot:
    app_name: str
    app_version: str
    db_label: str
    timezone_name: str
    mode_label: str
    default_symbol: str
    components: list[ComponentStatus]


def _extract_postgres_version(raw: str) -> str:
    if not raw:
        return "PostgreSQL"

    match = re.search(r"PostgreSQL\s+(\d+(?:\.\d+)?)", raw)
    if match:
        return f"PostgreSQL {match.group(1)}"

    return "PostgreSQL"


def _build_exchange_status(exchange_service: ExchangeService, default_symbol: str) -> ComponentStatus:
    try:
        symbol_validation = exchange_service.validate_symbol(default_symbol)
    except Exception as exc:
        return ComponentStatus(
            name="Биржа",
            state="🔴",
            details=f"Не удалось проверить инструмент: {exc}",
        )

    exchange_health = exchange_service.get_health()
    if exchange_health.ok and symbol_validation.is_valid:
        return ComponentStatus(name="Биржа", state="🟢")

    if not exchange_health.ok:
        return ComponentStatus(
            name="Биржа",
            state="🔴",
            details=exchange_health.message or "Ошибка подключения к API биржи.",
        )

    return ComponentStatus(
        name="Биржа",
        state="🔴",
        details=symbol_validation.message or "Инструмент не прошел проверку.",
    )


def _build_account_status(exchange_service: ExchangeService) -> ComponentStatus:
    private_auth_health = exchange_service.get_private_auth_health()
    if private_auth_health.ok:
        return ComponentStatus(name="Аккаунт", state="🟢")

    return ComponentStatus(
        name="Аккаунт",
        state="🔴",
        details=private_auth_health.message or "Ошибка private API.",
    )


def _build_database_status() -> tuple[ComponentStatus, str]:
    db_ok, db_message = check_database_health()
    db_label = _extract_postgres_version(db_message)

    if db_ok:
        return ComponentStatus(name="База данных", state="🟢"), db_label

    return (
        ComponentStatus(
            name="База данных",
            state="🔴",
            details=db_message or "Ошибка подключения к БД.",
        ),
        db_label,
    )


def _resolve_mode_label(exchange_testnet: bool) -> str:
    return "ДЕМО аккаунт" if exchange_testnet else "РЕАЛЬНЫЙ аккаунт"


def get_system_snapshot() -> SystemSnapshot:
    settings = load_settings()
    exchange_service = ExchangeService()

    database_status, db_label = _build_database_status()
    exchange_status = _build_exchange_status(exchange_service, settings.default_symbol)
    account_status = _build_account_status(exchange_service)

    components = [
        ComponentStatus(name="Приложение", state="🟢"),
        database_status,
        ComponentStatus(name="Telegram", state="🟢"),
        exchange_status,
        account_status,
    ]

    return SystemSnapshot(
        app_name=APP_NAME,
        app_version=APP_VERSION,
        db_label=db_label,
        timezone_name=settings.tz,
        mode_label=_resolve_mode_label(settings.exchange_testnet),
        default_symbol=settings.default_symbol,
        components=components,
    )


def _render_component(component: ComponentStatus) -> str:
    if component.state == "🟢":
        return f"{component.state} <b>{component.name}</b>"

    return f"{component.state} <b>{component.name}</b>\n— {component.details}"


def build_system_text() -> str:
    snapshot = get_system_snapshot()
    components_block = "\n".join(_render_component(component) for component in snapshot.components)

    return (
        "<b>⚙️ Система</b>\n\n"
        f"{components_block}\n\n"
        "<b>🌐 Окружение</b>\n"
        f"• приложение: {snapshot.app_name} {snapshot.app_version}\n"
        f"• база данных: {snapshot.db_label}\n"
        f"• часовой пояс: {snapshot.timezone_name}\n"
        f"• режим: {snapshot.mode_label}\n"
        f"• инструмент: {snapshot.default_symbol}"
    )