import json
import os
import subprocess
import time

import redis


NODE_NAME = os.getenv("NODE_NAME", "node")
REDIS_HOST = os.getenv("REDIS_HOST", "redis")


def redis_client():
    return redis.Redis(host=REDIS_HOST, port=6379, decode_responses=True)


def build_result(task_id, status, result="", error=None, run_id=None):
    return {
        "task_id": task_id,
        "run_id": run_id,
        "node": NODE_NAME,
        "status": status,
        "result": result,
        "error": error,
    }


def run_command(cmd):
    completed = subprocess.run(
        cmd,
        shell=True,
        text=True,
        capture_output=True,
        timeout=30,
    )
    output = completed.stdout.strip()
    error = completed.stderr.strip()

    if completed.returncode != 0:
        return "error", output, error or f"exit code {completed.returncode}"

    return "ok", output, None


def docker_ps(params):
    container = params.get("container")
    cmd = "docker ps --format '{{.Names}}|{{.Status}}'"
    status, output, error = run_command(cmd)
    if status != "ok":
        return status, output, error

    containers = []
    for line in output.splitlines():
        name, _, state = line.partition("|")
        if container and container not in name:
            continue
        containers.append({"name": name, "status": state})

    return "ok", containers, None


def docker_logs(params):
    container = params.get("container")
    if not container:
        return "error", "", "container parameter is required"

    return run_command(f"docker logs --tail 120 {container}")


def handle_task(task):
    action = task.get("action")
    params = task.get("params") or {}

    if action == "exec":
        return run_command(params.get("cmd", ""))
    if action == "docker_ps":
        return docker_ps(params)
    if action == "docker_logs":
        return docker_logs(params)

    return "error", "", f"unknown action: {action}"


def main():
    client = redis_client()
    print(f"[node-agent] ready node={NODE_NAME} redis={REDIS_HOST}")

    while True:
        try:
            _, raw_task = client.brpop("tasks")
            task = json.loads(raw_task)
            if task.get("target") != NODE_NAME:
                client.lpush("tasks", raw_task)
                time.sleep(1)
                continue

            status, result, error = handle_task(task)
            client.lpush(
                "results",
                json.dumps(
                    build_result(
                        task.get("task_id"),
                        status,
                        result,
                        error,
                        task.get("run_id"),
                    )
                ),
            )
        except Exception as exc:
            print(f"[node-agent] error: {exc}")
            time.sleep(2)


if __name__ == "__main__":
    main()