// SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
// SPDX-License-Identifier: Apache-2.0

#![cfg(feature = "e2e")]

//! E2E coverage for reconciling Docker sandboxes after a standalone gateway restart.
//!
//! This intentionally targets the Docker-driver gateway started by
//! `e2e/with-docker-gateway.sh`. Existing-endpoint E2E runs do not own the
//! gateway process, so they skip this restart-only coverage.

use std::process::{Command, Stdio};
use std::time::Duration;

use openshell_e2e::harness::cli::{
    run_cli, sandbox_names, wait_for_healthy, wait_for_sandbox_exec_contains,
    wait_for_sandbox_phase,
};
use openshell_e2e::harness::gateway::ManagedGateway;
use openshell_e2e::harness::sandbox::SandboxGuard;
use tokio::time::sleep;

const MANAGED_BY_LABEL_FILTER: &str = "label=openshell.ai/managed-by=openshell";
const READY_MARKER: &str = "gateway-start-ready";
const STOPPED_READY_MARKER: &str = "gateway-start-stopped-ready";
const START_FILE: &str = "/sandbox/gateway-start-state";
const SANDBOX_NAMESPACE_LABEL: &str = "openshell.ai/sandbox-namespace";
const SANDBOX_NAME_LABEL: &str = "openshell.ai/sandbox-name";
const SANDBOX_ROLE_LABEL_FILTER: &str = "label=openshell.ai/isolation-role=sandbox";

fn sandbox_container_id(namespace: &str, sandbox_name: &str) -> Result<String, String> {
    let namespace_filter = format!("label={SANDBOX_NAMESPACE_LABEL}={namespace}");
    let sandbox_name_filter = format!("label={SANDBOX_NAME_LABEL}={sandbox_name}");
    let output = Command::new("docker")
        .args([
            "ps",
            "-aq",
            "--filter",
            MANAGED_BY_LABEL_FILTER,
            "--filter",
            SANDBOX_ROLE_LABEL_FILTER,
            "--filter",
        ])
        .arg(namespace_filter)
        .args(["--filter"])
        .arg(sandbox_name_filter)
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .output()
        .map_err(|err| format!("failed to run docker ps: {err}"))?;
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);
    let combined = format!("{stdout}{stderr}");
    if !output.status.success() {
        return Err(format!(
            "docker ps failed (exit {:?}):\n{combined}",
            output.status.code()
        ));
    }

    let ids = stdout
        .lines()
        .map(str::trim)
        .filter(|line| !line.is_empty())
        .collect::<Vec<_>>();
    match ids.as_slice() {
        [id] => Ok((*id).to_string()),
        [] => Err(format!(
            "no Docker container found for sandbox '{sandbox_name}' in namespace '{namespace}'"
        )),
        _ => Err(format!(
            "multiple Docker containers found for sandbox '{sandbox_name}' in namespace '{namespace}': {ids:?}"
        )),
    }
}

fn sandbox_container_running(namespace: &str, sandbox_name: &str) -> Result<bool, String> {
    let container_id = sandbox_container_id(namespace, sandbox_name)?;
    let output = Command::new("docker")
        .args(["inspect", "-f", "{{.State.Running}}", &container_id])
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .output()
        .map_err(|err| format!("failed to run docker inspect: {err}"))?;
    let stdout = String::from_utf8_lossy(&output.stdout);
    let stderr = String::from_utf8_lossy(&output.stderr);
    let combined = format!("{stdout}{stderr}");
    if !output.status.success() {
        return Err(format!(
            "docker inspect failed (exit {:?}):\n{combined}",
            output.status.code()
        ));
    }

    match stdout.trim() {
        "true" => Ok(true),
        "false" => Ok(false),
        other => Err(format!(
            "unexpected Docker running state for container {container_id}: {other}"
        )),
    }
}

async fn wait_for_container_running(
    namespace: &str,
    sandbox_name: &str,
    expected: bool,
    timeout: Duration,
) -> Result<(), String> {
    let start = std::time::Instant::now();
    let mut last_state: String;

    loop {
        match sandbox_container_running(namespace, sandbox_name) {
            Ok(running) if running == expected => return Ok(()),
            Ok(running) => last_state = format!("running={running}"),
            Err(err) => last_state = err,
        }

        if start.elapsed() > timeout {
            return Err(format!(
                "sandbox container '{sandbox_name}' did not reach running={expected} within {}s. Last state: {last_state}",
                timeout.as_secs()
            ));
        }
        sleep(Duration::from_secs(1)).await;
    }
}

#[tokio::test]
async fn docker_gateway_restart_preserves_running_and_stopped_intent() {
    let Some(gateway) = ManagedGateway::from_env().expect("load managed e2e gateway metadata")
    else {
        eprintln!("Skipping gateway start test: e2e gateway is not managed by this test run");
        return;
    };
    let Some(namespace) = std::env::var("OPENSHELL_E2E_DOCKER_NETWORK_NAME")
        .ok()
        .filter(|value| !value.trim().is_empty())
    else {
        eprintln!("Skipping gateway start test: Docker e2e namespace is unavailable");
        return;
    };

    wait_for_healthy(Duration::from_secs(30))
        .await
        .expect("gateway should start healthy");

    let script = format!(
        "echo before-restart > {START_FILE}; echo {READY_MARKER}; while true; do sleep 1; done"
    );
    let mut sandbox = SandboxGuard::create_keep(&["sh", "-lc", &script], READY_MARKER)
        .await
        .expect("create long-running sandbox");

    let before_restart = sandbox
        .exec(&["cat", START_FILE])
        .await
        .expect("read sandbox state before restart");
    assert!(
        before_restart.contains("before-restart"),
        "sandbox state was not written before restart:\n{before_restart}"
    );

    wait_for_container_running(&namespace, &sandbox.name, true, Duration::from_mins(1))
        .await
        .expect("sandbox container should be running before gateway restart");

    let stopped_script = format!("echo {STOPPED_READY_MARKER}; while true; do sleep 1; done");
    let mut stopped_sandbox =
        SandboxGuard::create_keep(&["sh", "-lc", &stopped_script], STOPPED_READY_MARKER)
            .await
            .expect("create Docker sandbox that will remain stopped");
    let (stop_output, stop_code) = run_cli(&["sandbox", "stop", &stopped_sandbox.name]).await;
    assert_eq!(stop_code, 0, "sandbox stop should succeed:\n{stop_output}");
    wait_for_sandbox_phase(&stopped_sandbox.name, "Stopped", Duration::from_secs(30))
        .await
        .expect("sandbox should be stopped before gateway restart");
    wait_for_container_running(
        &namespace,
        &stopped_sandbox.name,
        false,
        Duration::from_secs(30),
    )
    .await
    .expect("stopped Docker sandbox container should not be running");

    gateway.stop().expect("stop e2e gateway");
    wait_for_container_running(&namespace, &sandbox.name, false, Duration::from_secs(30))
        .await
        .expect("gateway shutdown should stop a running-intent Docker sandbox");

    gateway.start().expect("restart e2e gateway");
    wait_for_healthy(Duration::from_mins(2))
        .await
        .expect("gateway should become healthy after restart");
    wait_for_container_running(&namespace, &sandbox.name, true, Duration::from_mins(2))
        .await
        .expect("gateway startup should restart the running-intent Docker sandbox container");
    wait_for_sandbox_phase(&stopped_sandbox.name, "Stopped", Duration::from_mins(2))
        .await
        .expect("explicitly stopped Docker sandbox should remain stopped after restart");
    wait_for_container_running(
        &namespace,
        &stopped_sandbox.name,
        false,
        Duration::from_secs(30),
    )
    .await
    .expect("gateway startup should not start an explicitly stopped Docker sandbox");

    let names = sandbox_names().await.expect("list sandboxes after restart");
    assert!(
        names.contains(&sandbox.name),
        "sandbox '{}' should still be listed after gateway restart. Names: {names:?}",
        sandbox.name
    );

    wait_for_sandbox_exec_contains(
        &sandbox.name,
        &["cat", START_FILE],
        "before-restart",
        Duration::from_mins(4),
    )
    .await
    .expect("sandbox should become ready again with its state preserved");

    sandbox.cleanup().await;
    stopped_sandbox.cleanup().await;
}