<?php

namespace App\Services\Hosting;

use App\Models\CustomerHostingOrder;
use App\Models\ServerAgent;
use Illuminate\Support\Str;
use Illuminate\Validation\ValidationException;

class ServerAgentBootstrapService
{
    /**
     * @return array{agent: ServerAgent, bootstrap_token: string, registration_url: string, heartbeat_url: string}
     */
    public function ensureBootstrap(CustomerHostingOrder $order): array
    {
        $order->loadMissing('serverAgent');

        $meta = (array) ($order->meta ?? []);
        $agentMeta = (array) ($meta['server_agent'] ?? []);
        $bootstrapToken = $this->decryptBootstrapToken((string) ($agentMeta['bootstrap_token_encrypted'] ?? ''));

        if ($bootstrapToken === null) {
            $bootstrapToken = Str::random(64);
        }

        $agent = $order->serverAgent ?: new ServerAgent([
            'customer_hosting_order_id' => $order->id,
            'uuid' => (string) Str::uuid(),
            'status' => ServerAgent::STATUS_PENDING_REGISTRATION,
        ]);

        $agent->fill([
            'bootstrap_token_hash' => hash('sha256', $bootstrapToken),
        ]);
        $agent->save();

        $agentMeta = array_merge($agentMeta, [
            'agent_id' => $agent->id,
            'agent_uuid' => $agent->uuid,
            'bootstrap_token_encrypted' => encrypt($bootstrapToken),
            'registration_url' => route('api.server-agents.register'),
            'heartbeat_url' => route('api.server-agents.heartbeat'),
            'task_progress_url_template' => url('/api/server-agents/tasks/{task}/progress'),
            'task_complete_url_template' => url('/api/server-agents/tasks/{task}/complete'),
            'task_fail_url_template' => url('/api/server-agents/tasks/{task}/fail'),
        ]);

        $meta['server_agent'] = $agentMeta;
        $meta['server_panel_runtime'] = $this->withRuntimeAgentState(
            (array) ($meta['server_panel_runtime'] ?? []),
            $agent
        );

        $order->update(['meta' => $meta]);

        return [
            'agent' => $agent->fresh(),
            'bootstrap_token' => $bootstrapToken,
            'registration_url' => $agentMeta['registration_url'],
            'heartbeat_url' => $agentMeta['heartbeat_url'],
        ];
    }

    /**
     * @param  array<string, mixed>  $attributes
     * @return array{agent: ServerAgent, access_token: string}
     */
    public function register(CustomerHostingOrder $order, string $bootstrapToken, array $attributes): array
    {
        $bootstrap = $this->ensureBootstrap($order);
        $agent = $bootstrap['agent'];

        if (! hash_equals((string) $agent->bootstrap_token_hash, hash('sha256', $bootstrapToken))) {
            throw ValidationException::withMessages([
                'bootstrap_token' => 'The bootstrap token is invalid.',
            ]);
        }

        $accessToken = Str::random(80);

        $agent->fill([
            'status' => ServerAgent::STATUS_ONLINE,
            'hostname' => (string) ($attributes['hostname'] ?? $agent->hostname),
            'agent_version' => (string) ($attributes['agent_version'] ?? $agent->agent_version),
            'platform' => (string) ($attributes['platform'] ?? $agent->platform),
            'capabilities' => array_values(array_unique((array) ($attributes['capabilities'] ?? []))),
            'metadata' => (array) ($attributes['metadata'] ?? $agent->metadata ?? []),
            'access_token_hash' => hash('sha256', $accessToken),
            'access_token_issued_at' => now(),
            'registered_at' => $agent->registered_at ?? now(),
            'last_heartbeat_at' => now(),
            'last_seen_ip' => (string) ($attributes['last_seen_ip'] ?? $agent->last_seen_ip),
        ]);
        $agent->save();

        $this->syncOrderRuntime($order->fresh(), $agent->fresh());

        return [
            'agent' => $agent->fresh(),
            'access_token' => $accessToken,
        ];
    }

    /**
     * @param  array<string, mixed>  $attributes
     */
    public function recordHeartbeat(ServerAgent $agent, array $attributes = []): ServerAgent
    {
        $agent->fill([
            'status' => ServerAgent::STATUS_ONLINE,
            'hostname' => (string) ($attributes['hostname'] ?? $agent->hostname),
            'agent_version' => (string) ($attributes['agent_version'] ?? $agent->agent_version),
            'platform' => (string) ($attributes['platform'] ?? $agent->platform),
            'capabilities' => array_values(array_unique((array) ($attributes['capabilities'] ?? $agent->capabilities ?? []))),
            'metadata' => array_replace((array) ($agent->metadata ?? []), (array) ($attributes['metadata'] ?? [])),
            'last_heartbeat_at' => now(),
            'last_seen_ip' => (string) ($attributes['last_seen_ip'] ?? $agent->last_seen_ip),
        ]);
        $agent->save();

        if ($agent->relationLoaded('order')) {
            $this->syncOrderRuntime($agent->order, $agent);
        } else {
            $this->syncOrderRuntime($agent->order()->firstOrFail(), $agent);
        }

        return $agent->fresh();
    }

    public function syncOrderRuntime(CustomerHostingOrder $order, ServerAgent $agent): void
    {
        $meta = (array) ($order->meta ?? []);
        $meta['server_agent'] = array_merge((array) ($meta['server_agent'] ?? []), [
            'agent_id' => $agent->id,
            'agent_uuid' => $agent->uuid,
            'status' => $agent->status,
            'hostname' => $agent->hostname,
            'agent_version' => $agent->agent_version,
            'platform' => $agent->platform,
            'capabilities' => (array) ($agent->capabilities ?? []),
            'registered_at' => optional($agent->registered_at)->toIso8601String(),
            'last_heartbeat_at' => optional($agent->last_heartbeat_at)->toIso8601String(),
        ]);
        $meta['server_panel_runtime'] = $this->withRuntimeAgentState(
            (array) ($meta['server_panel_runtime'] ?? []),
            $agent
        );

        $order->update(['meta' => $meta]);
    }

    /**
     * @param  array<string, mixed>  $runtime
     * @return array<string, mixed>
     */
    private function withRuntimeAgentState(array $runtime, ServerAgent $agent): array
    {
        $current = array_values(array_unique(array_merge(
            (array) ($runtime['current_capabilities'] ?? []),
            ['Agent registration', 'Async task dispatch']
        )));

        if ($agent->status === ServerAgent::STATUS_ONLINE) {
            $current = array_values(array_unique(array_merge($current, [
                'Files',
                'Databases',
                'Domains',
                'SSL',
                'PHP',
                'Cron',
                'Logs',
                'Site management',
            ])));
        }

        $runtime['hosting_panel_ready'] = $agent->registered_at !== null;
        $runtime['future_hosting_panel_status'] = $agent->registered_at !== null ? 'agent_registered' : ($runtime['future_hosting_panel_status'] ?? 'planned');
        $runtime['agent_status'] = $agent->status;
        $runtime['current_capabilities'] = $current;
        $runtime['secondary_message'] = $agent->registered_at !== null
            ? 'The server agent is registered. Managed tasks for files, databases, domains, SSL, PHP, cron, logs, and site actions are now queued through Ladill.'
            : ($runtime['secondary_message'] ?? null);

        return $runtime;
    }

    private function decryptBootstrapToken(string $encryptedToken): ?string
    {
        if ($encryptedToken === '') {
            return null;
        }

        try {
            $token = decrypt($encryptedToken);
        } catch (\Throwable) {
            return null;
        }

        return is_string($token) && $token !== '' ? $token : null;
    }
}