"""
K8s Pod 健康监控 - 扫描异常 Pod 并上报到 Log Center
作为 K8s CronJob 每 5 分钟运行一次
"""
import os
import logging
import requests
from kubernetes import client, config

LOG_CENTER_URL = os.getenv("LOG_CENTER_URL", "https://qiyuan-log-center-api.airlabs.art")
NAMESPACE = os.getenv("MONITOR_NAMESPACE", "default")

# 需要监控的异常状态
ABNORMAL_STATES = {
    "CrashLoopBackOff",
    "ImagePullBackOff",
    "ErrImagePull",
    "OOMKilled",
    "Error",
    "CreateContainerConfigError",
    "InvalidImageName",
    "RunContainerError",
}

logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s")
logger = logging.getLogger(__name__)

# 动态映射表，启动时从 API 加载
APP_TO_PROJECT: dict[str, str] = {}


def load_project_mapping():
    """从 Log Center API 拉取项目列表，自动生成 app label -> project_id 映射。

    映射规则：project_id 中的下划线替换为短横线作为 app label，
    同时生成 -dev 后缀的变体用于开发环境。
    例如 project_id="rtc_backend" -> app labels: "rtc-backend", "rtc-backend-dev"
    """
    try:
        resp = requests.get(f"{LOG_CENTER_URL}/api/v1/projects", timeout=10)
        resp.raise_for_status()
        projects = resp.json().get("projects", [])

        mapping = {}
        for project in projects:
            pid = project["project_id"]
            # project_id 下划线转短横线作为 app label
            app_label = pid.replace("_", "-")
            mapping[app_label] = pid
            mapping[f"{app_label}-dev"] = pid

        APP_TO_PROJECT.update(mapping)
        logger.info(f"从 API 加载了 {len(projects)} 个项目，生成 {len(mapping)} 条映射")
    except Exception as e:
        logger.warning(f"从 API 加载项目映射失败: {e}，将使用 app label 原值作为 project_id")


def get_project_id(pod_labels: dict) -> str:
    app_name = pod_labels.get("app", "unknown")
    return APP_TO_PROJECT.get(app_name, app_name)


def check_pod_health(pod) -> list[dict]:
    """检查单个 Pod 的异常状态，返回错误列表"""
    errors = []
    pod_name = pod.metadata.name
    namespace = pod.metadata.namespace
    labels = pod.metadata.labels or {}

    if not pod.status or not pod.status.container_statuses:
        return errors

    for cs in pod.status.container_statuses:
        state = cs.state
        reason = None
        message = None

        if state.waiting:
            reason = state.waiting.reason
            message = state.waiting.message or ""
        elif state.terminated and state.terminated.reason in ABNORMAL_STATES:
            reason = state.terminated.reason
            message = state.terminated.message or ""

        if reason and reason in ABNORMAL_STATES:
            errors.append({
                "project_id": get_project_id(labels),
                "reason": reason,
                "message": message,
                "pod_name": pod_name,
                "container_name": cs.name,
                "namespace": namespace,
                "deployment_name": labels.get("app", pod_name),
                "restart_count": cs.restart_count,
                "node_name": pod.spec.node_name,
            })

    return errors


def get_container_logs(v1, pod_name: str, namespace: str, container: str, lines: int = 50) -> str:
    """获取容器日志，优先拿崩溃前的日志"""
    try:
        return v1.read_namespaced_pod_log(
            name=pod_name, namespace=namespace, container=container,
            tail_lines=lines, previous=True,
        )
    except Exception:
        try:
            return v1.read_namespaced_pod_log(
                name=pod_name, namespace=namespace, container=container,
                tail_lines=lines,
            )
        except Exception as e:
            return f"获取日志失败: {e}"


def report_error(error: dict, logs: str):
    """上报错误到 Log Center"""
    payload = {
        "project_id": error["project_id"],
        "environment": "production",
        "level": "CRITICAL",
        "source": "deployment",
        "error": {
            "type": error["reason"],
            "message": f"{error['reason']}: {error['message']} (pod: {error['pod_name']}, container: {error['container_name']})",
            "file_path": None,
            "line_number": None,
            "stack_trace": logs.split("\n")[-50:] if logs else [],
        },
        "context": {
            "namespace": error["namespace"],
            "pod_name": error["pod_name"],
            "container_name": error["container_name"],
            "deployment_name": error["deployment_name"],
            "restart_count": error["restart_count"],
            "node_name": error["node_name"],
        },
    }

    try:
        resp = requests.post(
            f"{LOG_CENTER_URL}/api/v1/logs/report",
            json=payload,
            timeout=10,
        )
        logger.info(f"上报 {error['reason']} ({error['pod_name']}): {resp.json()}")
    except Exception as e:
        logger.error(f"上报失败: {e}")


def main():
    # 从 Log Center API 动态加载项目映射
    load_project_mapping()

    try:
        config.load_incluster_config()
    except config.ConfigException:
        config.load_kube_config()

    v1 = client.CoreV1Api()
    pods = v1.list_namespaced_pod(namespace=NAMESPACE)

    total_errors = 0
    for pod in pods.items:
        errors = check_pod_health(pod)
        for error in errors:
            logs = get_container_logs(v1, error["pod_name"], error["namespace"], error["container_name"])
            report_error(error, logs)
            total_errors += 1

    logger.info(f"扫描完成，命名空间 '{NAMESPACE}' 发现 {total_errors} 个异常 Pod")


if __name__ == "__main__":
    main()