from __future__ import annotations

# 容器日志命令里需要安全拼接容器名。
import shlex
from typing import Any

from .compose_templates import container_name
from core.config import SERVICE_LOG_EXPORT_MAX_LINES, SERVICE_LOG_PREVIEW_LINES, flatten_services, load_hosts, utc_now
from .ssh_remote import run_host_script


def loggable_service_records() -> list[dict[str, Any]]:
    # 当前日志查看只开放业务服务实例，不扩展到 nacos / mongo 这类非业务容器。
    return [service for service in flatten_services(load_hosts()) if service.get("kind") in {"java", "golang"}]


def find_service_record(service_name: str, host_name: str) -> dict[str, Any]:
    # 日志查看必须定位到单实例，避免多机部署时把不同节点的日志混到一起。
    normalized_service = str(service_name or "").strip()
    normalized_host = str(host_name or "").strip()
    for service in loggable_service_records():
        if service.get("service") == normalized_service and service.get("host") == normalized_host:
            return service
    raise KeyError(f"service instance not found: {normalized_service}@{normalized_host}")


def normalize_export_lines(raw_value: str | int | None) -> int:
    # 导出条数允许用户自定义，但要限制上限，避免一次把过多日志塞进页面进程。
    if raw_value in {None, ""}:
        return SERVICE_LOG_PREVIEW_LINES
    value = int(raw_value)
    if value <= 0:
        raise ValueError("lines must be greater than 0")
    return min(value, SERVICE_LOG_EXPORT_MAX_LINES)


def fetch_service_log_text(service_name: str, host_name: str, lines: int) -> tuple[dict[str, Any], str]:
    # 统一执行 docker logs，并返回实例元数据给接口层复用。
    service = find_service_record(service_name, host_name)
    container = container_name(service["host"], service["service"])
    script = f"""set -eu
docker logs --timestamps --tail {int(lines)} {shlex.quote(container)} 2>&1
"""
    result = run_host_script(
        service,
        script,
        command_name=f"service-log-{service['host']}-{service['service']}",
        timeout_seconds=120,
    )
    if result.get("status") != "SUCCESS":
        raise RuntimeError(str(result.get("output") or result.get("status") or "docker logs failed").strip())

    return (
        {
            "service": service["service"],
            "host": service["host"],
            "ip": service["ip"],
            "kind": service["kind"],
            "container": container,
            "updatedAt": utc_now(),
            "lines": int(lines),
        },
        str(result.get("output") or ""),
    )


def get_service_log_preview_payload(service_name: str, host_name: str) -> dict[str, Any]:
    # 页面预览固定最近 1000 条，避免日志面板过重。
    meta, content = fetch_service_log_text(service_name, host_name, SERVICE_LOG_PREVIEW_LINES)
    return {
        "ok": True,
        **meta,
        "content": content,
        "previewLines": SERVICE_LOG_PREVIEW_LINES,
        "exportMaxLines": SERVICE_LOG_EXPORT_MAX_LINES,
    }


def get_service_log_export_payload(service_name: str, host_name: str, raw_lines: str | int | None) -> tuple[dict[str, Any], str]:
    # 导出接口允许指定条数，但会按统一上限裁剪。
    lines = normalize_export_lines(raw_lines)
    meta, content = fetch_service_log_text(service_name, host_name, lines)
    return meta, content