#!/usr/bin/env python3
"""
AWOOOI Docker 容器自動發現
===========================

ADR-037 Wave C.3: 掃描 Docker 主機，自動更新 service-registry.yaml

功能:
1. SSH 連線 Docker 主機 (188, 110)
2. 取得執行中容器清單
3. 比對 service-registry.yaml
4. 輸出差異報告 (新增/移除/未監控)

用法:
    python ops/monitoring/discover_docker.py
    python ops/monitoring/discover_docker.py --update  # 自動更新 registry
    python ops/monitoring/discover_docker.py --json    # JSON 輸出

版本: v1.0
建立: 2026-03-29 (台北時區)
建立者: Claude Code (Phase 21 ADR-037)
"""

import argparse
import json
import subprocess
import sys
from pathlib import Path

import yaml

# 配置
SCRIPT_DIR = Path(__file__).parent
REGISTRY_FILE = SCRIPT_DIR / "service-registry.yaml"

# Docker 主機清單
DOCKER_HOSTS = [
    {
        "host": "192.168.0.188",
        "name": "pg",
        "role": "ai-web",
        "ssh_user": "ogt",
    },
    {
        "host": "192.168.0.110",
        "name": "harbor",
        "role": "devops",
        "ssh_user": "wooo",
    },
]

# 忽略的容器 (系統容器)
IGNORE_CONTAINERS = {
    "k3s-agent",
    "k3s",
    "rancher-",
    "portainer",
}


def run_ssh_command(host: str, user: str, command: str) -> tuple[bool, str]:
    """執行 SSH 命令"""
    try:
        result = subprocess.run(
            [
                "ssh",
                "-o",
                "BatchMode=yes",
                "-o",
                "ConnectTimeout=5",
                "-o",
                "StrictHostKeyChecking=accept-new",
                f"{user}@{host}",
                command,
            ],
            capture_output=True,
            text=True,
            timeout=30
        )
        return result.returncode == 0, result.stdout
    except subprocess.TimeoutExpired:
        return False, "SSH timeout"
    except Exception as e:
        return False, str(e)


def discover_containers(host_info: dict) -> list[dict]:
    """發現 Docker 容器"""
    host = host_info["host"]
    user = host_info["ssh_user"]

    # 取得容器清單 (JSON 格式)
    cmd = 'docker ps --format "{{json .}}"'
    success, output = run_ssh_command(host, user, cmd)

    if not success:
        print(f"  ❌ 無法連線 {host}: {output}")
        return []

    containers = []
    for line in output.strip().split("\n"):
        if not line:
            continue
        try:
            data = json.loads(line)
            name = data.get("Names", "")

            # 過濾系統容器
            if any(name.startswith(ignore) for ignore in IGNORE_CONTAINERS):
                continue

            # 解析 Port
            ports = data.get("Ports", "")
            exposed_port = None
            if ports:
                # 格式: "0.0.0.0:8080->8080/tcp"
                for port_part in ports.split(","):
                    if "->" in port_part:
                        host_port = port_part.split("->")[0].split(":")[-1]
                        try:
                            exposed_port = int(host_port)
                        except ValueError:
                            pass
                        break

            containers.append({
                "name": name,
                "image": data.get("Image", ""),
                "status": data.get("Status", ""),
                "port": exposed_port,
                "host": host,
                "host_name": host_info["name"],
                "role": host_info["role"],
            })
        except json.JSONDecodeError:
            continue

    return containers


def load_registry() -> dict:
    """載入服務註冊表"""
    if not REGISTRY_FILE.exists():
        return {"services": []}

    with open(REGISTRY_FILE) as f:
        return yaml.safe_load(f) or {"services": []}


def compare_with_registry(containers: list[dict], registry: dict) -> dict:
    """比對容器與 registry"""
    # 建立 registry 服務索引 (按 host + name)
    registry_services = {}
    for svc in registry.get("services", []):
        if svc.get("type") == "docker":
            key = f"{svc.get('host', '')}:{svc.get('name', '')}"
            registry_services[key] = svc

    # 分類
    result = {
        "monitored": [],      # 已監控
        "new": [],            # 新發現 (未在 registry)
        "missing": [],        # registry 有但容器不存在
        "no_prometheus": [],  # 在 registry 但未啟用 Prometheus
    }

    discovered_keys = set()

    for container in containers:
        key = f"{container['host']}:{container['name']}"
        discovered_keys.add(key)

        if key in registry_services:
            svc = registry_services[key]
            if svc.get("monitoring", {}).get("prometheus"):
                result["monitored"].append({
                    **container,
                    "registry_name": svc["name"]
                })
            else:
                result["no_prometheus"].append({
                    **container,
                    "registry_name": svc["name"]
                })
        else:
            result["new"].append(container)

    # 找出 registry 有但容器不存在的
    for key, svc in registry_services.items():
        if key not in discovered_keys:
            result["missing"].append({
                "name": svc["name"],
                "host": svc.get("host", ""),
                "port": svc.get("port"),
            })

    return result


def generate_service_entry(container: dict) -> dict:
    """生成 service-registry.yaml entry"""
    return {
        "name": container["name"],
        "type": "docker",
        "host": container["host"],
        "port": container.get("port", 8080),
        "health_endpoint": "/health",
        "monitoring": {
            "prometheus": True,
            "sentry": False,
            "otel": False,
        },
        "alerts": ["service_down"],
        "auto_repair": {
            "enabled": False,
        },
        "owner": f"{container['role']}-team",
        "criticality": "P2",
    }


def print_report(comparison: dict):
    """輸出報告"""
    print("\n" + "=" * 60)
    print("  AWOOOI Docker Container Discovery Report")
    print("=" * 60)

    print(f"\n  ✅ 已監控容器 ({len(comparison['monitored'])})")
    for c in comparison["monitored"]:
        print(f"     - {c['name']} @ {c['host']}:{c.get('port', 'N/A')}")

    if comparison["new"]:
        print(f"\n  🆕 新發現容器 ({len(comparison['new'])})")
        for c in comparison["new"]:
            print(f"     - {c['name']} @ {c['host']}:{c.get('port', 'N/A')}")
            print(f"       Image: {c['image']}")

    if comparison["no_prometheus"]:
        print(f"\n  ⚠️  未啟用 Prometheus ({len(comparison['no_prometheus'])})")
        for c in comparison["no_prometheus"]:
            print(f"     - {c['name']} @ {c['host']}")

    if comparison["missing"]:
        print(f"\n  ❌ Registry 有但容器不存在 ({len(comparison['missing'])})")
        for c in comparison["missing"]:
            print(f"     - {c['name']} @ {c['host']}")

    print("\n" + "=" * 60)

    # 統計
    total = (
        len(comparison["monitored"]) +
        len(comparison["new"]) +
        len(comparison["no_prometheus"])
    )
    monitored = len(comparison["monitored"])
    coverage = round(100 * monitored / total, 1) if total > 0 else 0

    print(f"\n  總容器數: {total}")
    print(f"  已監控: {monitored}")
    print(f"  覆蓋率: {coverage}%")

    return len(comparison["new"]) == 0  # 沒有新發現 = 通過


def main():
    parser = argparse.ArgumentParser(description="AWOOOI Docker Container Discovery")
    parser.add_argument("--update", action="store_true", help="Auto-update service-registry.yaml")
    parser.add_argument("--json", action="store_true", help="Output as JSON")
    parser.add_argument("--host", type=str, help="Only scan specific host")
    args = parser.parse_args()

    print("Discovering Docker containers...")

    # 發現容器
    all_containers = []
    for host_info in DOCKER_HOSTS:
        if args.host and host_info["host"] != args.host:
            continue
        print(f"  Scanning {host_info['name']} ({host_info['host']})...")
        containers = discover_containers(host_info)
        print(f"    Found {len(containers)} containers")
        all_containers.extend(containers)

    # 載入 registry 並比對
    registry = load_registry()
    comparison = compare_with_registry(all_containers, registry)

    if args.json:
        print(json.dumps(comparison, indent=2, default=str))
        return

    # 輸出報告
    all_good = print_report(comparison)

    # 自動更新
    if args.update and comparison["new"]:
        print("\nUpdating service-registry.yaml...")
        for container in comparison["new"]:
            entry = generate_service_entry(container)
            registry["services"].append(entry)
            print(f"  Added: {entry['name']}")

        with open(REGISTRY_FILE, "w") as f:
            yaml.dump(registry, f, default_flow_style=False, allow_unicode=True)
        print(f"Updated: {REGISTRY_FILE}")

    if not all_good:
        print("\n⚠️  有新發現的容器未加入監控，請檢查上方報告")
        sys.exit(1)


if __name__ == "__main__":
    main()