"""
AirDep 部署运行时 — V2 新增组件。
SSH 远程构建 + 二进制传输 + systemd 生命周期管理 + 部署验证。
"""

from __future__ import annotations

import hashlib
import subprocess
from dataclasses import dataclass
from pathlib import Path

from air_runtime.contracts import DeploymentRecord, now_iso
from air_runtime.io import atomic_json_write, safe_json_load
from air_runtime.paths import dep_state_path


@dataclass
class DeployTarget:
    host: str
    user: str = "root"
    port: int = 22
    build_dir: str = "/tmp/airdep-build"
    deploy_dir: str = "/opt/app"


@dataclass
class DeployResult:
    task_id: str
    success: bool
    binary_md5: str = ""
    service_status: str = ""
    error: str = ""
    journal_excerpt: str = ""


def _ssh(target: DeployTarget, cmd: str, timeout: int = 120) -> subprocess.CompletedProcess[str]:
    return subprocess.run(
        ["ssh", "-o", "StrictHostKeyChecking=accept-new", "-p", str(target.port),
         f"{target.user}@{target.host}", cmd],
        capture_output=True, text=True, timeout=timeout,
    )


def _scp(target: DeployTarget, local: Path, remote: str, timeout: int = 300) -> subprocess.CompletedProcess[str]:
    return subprocess.run(
        ["scp", "-o", "StrictHostKeyChecking=accept-new", "-P", str(target.port),
         str(local), f"{target.user}@{target.host}:{remote}"],
        capture_output=True, text=True, timeout=timeout,
    )


def _md5_file(path: Path) -> str:
    h = hashlib.md5()
    with open(path, "rb") as f:
        while chunk := f.read(8192):
            h.update(chunk)
    return h.hexdigest()


def deploy(task_id: str, project_root: Path, target: DeployTarget,
           local_binary: Path, service_name: str,
           build_cmd: str | None = None,
           smoke_test_cmd: str | None = None) -> DeployResult:
    """执行完整部署流程：构建 → 传输 → systemd → 验证。"""
    state_file = dep_state_path(project_root)

    try:
        # Step 1: 远程构建（可选）
        if build_cmd:
            result = _ssh(target, f"cd {target.build_dir} && {build_cmd}", timeout=600)
            if result.returncode != 0:
                return DeployResult(task_id=task_id, success=False,
                                   error=f"build failed: {result.stderr[-500:]}")

        # Step 2: 二进制传输 + MD5 校验
        remote_tmp = f"/tmp/{local_binary.name}"
        scp_result = _scp(target, local_binary, remote_tmp)
        if scp_result.returncode != 0:
            return DeployResult(task_id=task_id, success=False,
                               error=f"scp failed: {scp_result.stderr[-500:]}")

        local_md5 = _md5_file(local_binary)
        md5_result = _ssh(target, f"md5sum {remote_tmp} | cut -d' ' -f1")
        remote_md5 = md5_result.stdout.strip()
        if local_md5 != remote_md5:
            return DeployResult(task_id=task_id, success=False,
                               binary_md5=f"local={local_md5} remote={remote_md5}",
                               error="md5 mismatch after transfer")

        # Step 3: 部署二进制
        _ssh(target, f"mv {remote_tmp} {target.deploy_dir}/{local_binary.name}")

        # Step 4: systemd 生命周期
        _ssh(target, f"systemctl daemon-reload")
        _ssh(target, f"systemctl restart {service_name}")
        status_result = _ssh(target, f"systemctl is-active {service_name}")
        service_status = status_result.stdout.strip()

        # Step 5: 冒烟验证（可选）
        smoke_passed: bool | None = None
        if smoke_test_cmd:
            smoke_result = _ssh(target, smoke_test_cmd, timeout=60)
            smoke_passed = (smoke_result.returncode == 0)

        # Step 6: 记录部署产物
        record = DeploymentRecord(
            task_id=task_id,
            host=target.host,
            binary_path=str(target.deploy_dir / local_binary.name),
            md5=local_md5,
            service_name=service_name,
            service_status=service_status,
            smoke_test_passed=smoke_passed,
        )

        # 持久化
        sessions = safe_json_load(state_file) or {"sessions": []}
        if isinstance(sessions, dict):
            sessions.setdefault("sessions", []).append(record.__dict__)
        atomic_json_write(state_file, sessions)

        return DeployResult(
            task_id=task_id,
            success=service_status == "active",
            binary_md5=local_md5,
            service_status=service_status,
        )

    except subprocess.TimeoutExpired as exc:
        return DeployResult(task_id=task_id, success=False, error=f"timeout: {exc}")
    except Exception as exc:
        return DeployResult(task_id=task_id, success=False, error=str(exc))