from __future__ import annotations

from typing import Any

from core.config import THRESHOLDS, load_hosts, settings_payload, utc_now
from .host_metrics import get_host_metrics
from .http_probe import get_service_payload
from .mongo_metrics import get_mongo_payload
from .mysql_metrics import get_mysql_overview_payload
from .nacos import get_nacos_payload


def classify_threshold(value: float | int | None, thresholds: dict[str, float | int]) -> str:
    # 没值时返回 neutral。
    if value is None:
        return "neutral"

    # 读取 warn 阈值。
    warn = float(thresholds["warn"])
    # 读取 bad 阈值。
    bad = float(thresholds["bad"])
    # 统一转成浮点数比较。
    numeric = float(value)

    # 超过 bad 阈值记为 bad。
    if numeric >= bad:
        return "bad"

    # 超过 warn 阈值记为 warn。
    if numeric >= warn:
        return "warn"

    # 其余情况记为 ok。
    return "ok"


def annotate_metric_levels(metrics: dict[str, Any]) -> dict[str, Any]:
    # 复制一份，避免直接修改缓存原对象。
    payload = dict(metrics)

    # 指标采集失败时统一按 bad 标记。
    if not payload.get("ok"):
        payload["cpuLevel"] = "bad"
        payload["memoryLevel"] = "bad"
        payload["diskLevel"] = "bad"
        payload["processLevel"] = "bad"
        return payload

    # 给 CPU 指标增加级别。
    payload["cpuLevel"] = classify_threshold(payload.get("cpuPercent"), THRESHOLDS["cpuPercent"])
    # 给内存指标增加级别。
    payload["memoryLevel"] = classify_threshold(payload.get("memoryPercent"), THRESHOLDS["memoryPercent"])
    # 给磁盘指标增加级别。
    payload["diskLevel"] = classify_threshold(payload.get("diskPercent"), THRESHOLDS["diskPercent"])
    # 给进程数增加级别。
    payload["processLevel"] = classify_threshold(payload.get("processCount"), THRESHOLDS["processCount"])

    # 返回加完等级的结构。
    return payload


def build_host_payload(
    hosts: list[dict[str, Any]],
    service_payload: dict[str, Any],
    metrics_by_host: dict[str, dict[str, Any]],
) -> list[dict[str, Any]]:
    # 先把服务结果按 host 分组。
    services_by_host: dict[str, list[dict[str, Any]]] = {}

    # 遍历所有服务结果。
    for item in service_payload.get("items") or []:
        services_by_host.setdefault(item["host"], []).append(item)

    # 最终的主机维度结果。
    grouped_hosts: list[dict[str, Any]] = []

    # 按配置顺序输出主机。
    for host in hosts:
        # 当前主机的服务结果列表。
        items = services_by_host.get(host["host"], [])
        # 当前主机健康服务数量。
        ok_count = sum(1 for item in items if item["ok"])
        # 当前主机原始指标。
        raw_metrics = metrics_by_host.get(host["host"], {"ok": False, "error": "metrics unavailable"})
        # 加上指标阈值等级。
        metrics = annotate_metric_levels(raw_metrics)

        # 追加主机结构。
        grouped_hosts.append(
            {
                "host": host["host"],
                "ip": host["ip"],
                "group": host["group"],
                "instanceId": host["instanceId"],
                "metrics": metrics,
                "serviceSummary": {
                    "total": len(items),
                    "ok": ok_count,
                    "down": len(items) - ok_count,
                },
                "items": items,
            }
        )

    # 返回主机分组结果。
    return grouped_hosts


def build_monitor_payload() -> dict[str, Any]:
    # 读取当前监控目标。
    hosts = load_hosts()
    # 获取服务探测结果。
    service_payload = get_service_payload(hosts, THRESHOLDS["latencyMs"])
    # 获取主机资源指标。
    metrics_by_host = get_host_metrics(hosts)
    # 获取 Nacos 注册信息。
    nacos_payload = get_nacos_payload()
    # 获取 Mongo 指标。
    mongo_payload = get_mongo_payload()
    # 获取 MySQL 指标。
    mysql_payload = get_mysql_overview_payload()
    # 组装主机维度视图。
    grouped_hosts = build_host_payload(hosts, service_payload, metrics_by_host)
    # 统计主机指标成功数。
    host_metric_ok = sum(1 for host in grouped_hosts if host["metrics"].get("ok"))

    # 返回完整的页面 API 载荷。
    return {
        "updatedAt": utc_now(),
        "settings": settings_payload(),
        "summary": {
            **service_payload["summary"],
            "hostMetricOk": host_metric_ok,
            "hostMetricDown": len(grouped_hosts) - host_metric_ok,
            "nacosServiceTotal": int(nacos_payload.get("summary", {}).get("serviceTotal", 0)),
            "nacosInstanceTotal": int(nacos_payload.get("summary", {}).get("instanceTotal", 0)),
            "nacosUnhealthyInstanceTotal": int(
                nacos_payload.get("summary", {}).get("unhealthyInstanceTotal", 0)
            ),
            "mongoDatabaseTotal": int(mongo_payload.get("summary", {}).get("databaseTotal", 0)),
            "mongoCollectionTotal": int(mongo_payload.get("summary", {}).get("collectionTotal", 0)),
            "mongoOk": 1 if mongo_payload.get("ok") else 0,
            "mysqlDatabaseTotal": int(mysql_payload.get("summary", {}).get("databaseTotal", 0)),
            "mysqlTableTotal": int(mysql_payload.get("summary", {}).get("tableTotal", 0)),
            "mysqlOk": 1 if mysql_payload.get("ok") else 0,
        },
        "hosts": grouped_hosts,
        "items": service_payload["items"],
        "nacos": nacos_payload,
        "mongo": mongo_payload,
        "mysql": mysql_payload,
    }