<?php

namespace App\Http\Controllers\Api;

use App\Events\SentinelSynchronized;
use App\Http\Controllers\Controller;
use App\Jobs\CheckAndStartSentinelJob;
use App\Jobs\PushServerUpdateJob;
use App\Models\Server;
use Exception;
use Illuminate\Contracts\Cache\LockTimeoutException;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Validator;

class SentinelController extends Controller
{
    /**
     * Handle a Sentinel agent metrics push.
     *
     * Sentinel pushes its full container list on a fixed interval (default 60s),
     * even when nothing changed. To avoid dispatching one PushServerUpdateJob per
     * server per minute, the job is only dispatched when the container state hash
     * changes, or when the force window has elapsed.
     */
    public function push(Request $request)
    {
        $token = $request->header('Authorization');
        if (! $token) {
            auditLogWebhookFailure('sentinel', 'token_missing');

            return response()->json(['message' => 'Unauthorized'], 401);
        }
        $naked_token = str_replace('Bearer ', '', $token);
        try {
            $decrypted = decrypt($naked_token);
            $decrypted_token = json_decode($decrypted, true);
        } catch (Exception $e) {
            auditLogWebhookFailure('sentinel', 'decrypt_failed');

            return response()->json(['message' => 'Invalid token'], 401);
        }
        $server_uuid = data_get($decrypted_token, 'server_uuid');
        if (! $server_uuid) {
            auditLogWebhookFailure('sentinel', 'invalid_token_payload');

            return response()->json(['message' => 'Invalid token'], 401);
        }
        $server = Server::where('uuid', $server_uuid)->first();
        if (! $server) {
            auditLogWebhookFailure('sentinel', 'server_not_found', [
                'server_uuid' => $server_uuid,
            ]);

            return response()->json(['message' => 'Server not found'], 404);
        }

        if (isCloud() && data_get($server->team->subscription, 'stripe_invoice_paid', false) === false && $server->team->id !== 0) {
            auditLogWebhookFailure('sentinel', 'subscription_unpaid', [
                'server_uuid' => $server->uuid,
                'team_id' => $server->team_id,
            ]);
            $server->rememberSentinelPushProblem('Coolify rejected the push: the subscription of this team is not active.');

            return response()->json(['message' => 'Unauthorized'], 401);
        }

        if ($server->isFunctional() === false) {
            auditLogWebhookFailure('sentinel', 'server_not_functional', [
                'server_uuid' => $server->uuid,
                'team_id' => $server->team_id,
            ]);
            $server->rememberSentinelPushProblem('Coolify rejected the push: the server is marked unreachable, not usable, or disabled. Validate the server connection.');

            return response()->json(['message' => 'Server is not functional'], 401);
        }

        if ($server->settings->sentinel_token !== $naked_token) {
            auditLogWebhookFailure('sentinel', 'token_mismatch', [
                'server_uuid' => $server->uuid,
                'team_id' => $server->team_id,
            ]);
            $server->rememberSentinelPushProblem('Coolify rejected the push: the Sentinel token does not match. Sync Sentinel to apply the current token.');

            return response()->json(['message' => 'Unauthorized'], 401);
        }
        $validator = Validator::make($request->all(), [
            'containers' => ['present', 'array'],
        ]);

        if ($validator->fails()) {
            $server->rememberSentinelPushProblem('Coolify rejected the push: the payload is not valid.');

            return response()->json(serializeApiResponse([
                'message' => 'Validation failed.',
                'errors' => $validator->errors(),
            ]), 422);
        }

        $data = $request->all();

        $wasSentinelLive = $server->sentinel_updated_at !== null && $server->isSentinelLive();

        // Heartbeat MUST update on every push — drives isSentinelLive() and SSH-check skipping.
        $server->sentinel_waiting_since = null;
        $server->sentinelHeartbeat();

        if (! $wasSentinelLive) {
            $server->rememberSentinelPushProblem(null);
            SentinelSynchronized::dispatch($server);
        }

        $this->updateSentinelIfOutdated($server, $request->header('X-Sentinel-Version'));

        if ($this->shouldDispatchUpdate($server, $data)) {
            PushServerUpdateJob::dispatch($server, $data);
        }

        return response()->json(['message' => 'ok'], 200);
    }

    /**
     * Sentinel sends its version on every push, so an outdated Sentinel is found without SSH.
     * The reported version also tells ServerManagerJob to skip its hourly SSH version check.
     * Old Sentinel versions do not send the header and keep the hourly SSH check.
     */
    private function updateSentinelIfOutdated(Server $server, ?string $runningVersion): void
    {
        if (! is_string($runningVersion) || preg_match('/^\d+\.\d+\.\d+$/', $runningVersion) !== 1) {
            return;
        }

        Cache::put(Server::sentinelReportedVersionCacheKey($server->id), $runningVersion, now()->addHours(2));

        $latestVersion = data_get(get_versions_data(), 'coolify.sentinel.version');
        if (blank($latestVersion) || version_compare($runningVersion, $latestVersion, '>=')) {
            return;
        }

        // Retry at most hourly if an update fails.
        if (Cache::add("sentinel:update-dispatched:{$server->id}", true, 3600)) {
            CheckAndStartSentinelJob::dispatch($server);
        }
    }

    /**
     * Decide whether PushServerUpdateJob should be dispatched for this push.
     *
     * Dispatches when: first push (no cached hash), the container state changed,
     * or the force window elapsed.
     */
    private function shouldDispatchUpdate(Server $server, array $data): bool
    {
        $hash = $this->containerStateHash($data);
        $hashKey = "sentinel:push-hash:{$server->id}";
        $forceKey = "sentinel:push-force:{$server->id}";
        $lockKey = "sentinel:push-lock:{$server->id}";

        try {
            return Cache::lock($lockKey, 10)->block(5, function () use ($hashKey, $forceKey, $hash): bool {
                $cachedHash = Cache::get($hashKey);
                $forceActive = Cache::has($forceKey);

                $shouldDispatch = $cachedHash === null || $cachedHash !== $hash || ! $forceActive;

                if ($shouldDispatch) {
                    // Day-long TTL bounds memory if a server stops pushing entirely.
                    Cache::put($hashKey, $hash, now()->addDay());
                    Cache::put($forceKey, true, config('constants.sentinel.push_force_interval_seconds', 300));
                }

                return $shouldDispatch;
            });
        } catch (LockTimeoutException) {
            return false;
        }
    }

    /**
     * Build a stable hash of container state.
     *
     * Covers [name, state, health_status, restart_count] only — metrics and
     * filesystem_usage_root are excluded on purpose because disk % churns
     * constantly and would dispatch PushServerUpdateJob on every push. Health is
     * included so a healthy/unhealthy change reaches the UI on the next push
     * instead of after the force window. The snapshot completeness flag is
     * included so a complete snapshot always dispatches after a partial
     * snapshot. Sorted by name so container ordering from Sentinel does not
     * affect the hash.
     */
    private function containerStateHash(array $data): string
    {
        $containers = collect(data_get($data, 'containers', []))
            ->map(fn ($c) => [
                'name' => data_get($c, 'name'),
                'state' => data_get($c, 'state'),
                'health_status' => data_get($c, 'health_status'),
                'restart_count' => data_get($c, 'restart_count'),
            ])
            ->sortBy('name')
            ->values()
            ->all();

        return hash('xxh128', json_encode([
            'snapshot_complete' => $this->isCompleteSnapshot($data),
            'containers' => $containers,
        ]));
    }

    private function isCompleteSnapshot(array $data): bool
    {
        return data_get($data, 'snapshot.complete', true) !== false;
    }
}