<?php

declare(strict_types=1);

namespace Mod\Proxy\Controllers;

use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Routing\Controller;
use Mod\Gateway\Services\GatewayRegistry;
use Mod\Proxy\Services\NodeSelector;
use Mod\Proxy\Services\UsageMeter;

/**
 * api.lthn.io proxy gateway API.
 *
 *   POST /v1/proxy/connect     — get a gateway connection for your service type
 *   GET  /v1/proxy/usage       — check your usage (bytes, requests, GB)
 *   GET  /v1/proxy/nodes       — list available nodes by capability
 *   GET  /v1/proxy/status      — network availability summary
 */
class ProxyController extends Controller
{
    // Pricing per GB in USD (for display — actual billing via Blesta)
    private const PRICING = [
        'mobile' => 5.00,
        'residential' => 2.50,
        'seo' => 0.00, // per-request, not per-GB
    ];

    public function __construct(
        private readonly NodeSelector $selector,
        private readonly UsageMeter $meter,
        private readonly GatewayRegistry $registry,
    ) {}

    /**
     *   POST /v1/proxy/connect  {"type": "residential"}
     *
     * Returns a gateway node to connect to for the requested service type.
     * Requires API key (Bearer token from Blesta service).
     */
    public function connect(Request $request): JsonResponse
    {
        $type = strtolower(trim((string) $request->input('type', 'proxy')));
        $region = strtolower(trim((string) $request->input('region', '')));

        // Map service types to node capabilities
        $capMap = [
            'mobile' => 'proxy',
            'residential' => 'proxy',
            'seo' => 'exit',
            'vpn' => 'vpn',
            'proxy' => 'proxy',
            'dns' => 'dns',
        ];

        $capability = $capMap[$type] ?? 'proxy';
        $source = 'chain';

        // Prefer live paired gateways (real-time stats, verified endpoints)
        $liveGateway = $this->registry->selectBest($capability);

        if ($liveGateway) {
            $source = 'paired';
            $apiKey = $request->bearerToken() ?? 'anonymous';
            $this->meter->recordRequest($apiKey);

            return response()->json([
                'node' => $liveGateway['name'] . '.lthn',
                'type' => $type,
                'capabilities' => $liveGateway['capabilities'] ?? [],
                'region' => $liveGateway['region'] ?? 'unknown',
                'wireguard_endpoint' => $liveGateway['wireguard_endpoint'] ?? '',
                'proxy_endpoint' => $liveGateway['proxy_endpoint'] ?? '',
                'load' => $liveGateway['current_load'] ?? 0,
                'source' => $source,
                'pricing' => [
                    'model' => $type === 'seo' ? 'per-request' : 'per-gb',
                    'rate_usd' => self::PRICING[$type] ?? 0,
                    'currency' => 'LTHN',
                ],
                'session' => bin2hex(random_bytes(8)),
            ]);
        }

        // Fall back to chain-discovered nodes
        $node = $this->selector->selectNode($capability);

        if (! $node) {
            return response()->json([
                'error' => 'No nodes available for this service type.',
                'type' => $type,
            ], 503);
        }

        $apiKey = $request->bearerToken() ?? 'anonymous';
        $this->meter->recordRequest($apiKey);

        $comment = $node['comment'] ?? '';
        $caps = [];
        if (preg_match('/cap=([^;]+)/', $comment, $m)) {
            $caps = explode(',', $m[1]);
        }

        return response()->json([
            'node' => $node['alias'] . '.lthn',
            'address' => $node['address'] ?? '',
            'type' => $type,
            'capabilities' => $caps,
            'source' => $source,
            'pricing' => [
                'model' => $type === 'seo' ? 'per-request' : 'per-gb',
                'rate_usd' => self::PRICING[$type] ?? 0,
                'currency' => 'LTHN',
            ],
            'session' => bin2hex(random_bytes(8)),
        ]);
    }

    /**
     *   GET /v1/proxy/usage
     *
     * Returns usage for the authenticated API key.
     */
    public function usage(Request $request): JsonResponse
    {
        $apiKey = $request->bearerToken() ?? 'anonymous';
        $usage = $this->meter->getUsage($apiKey);

        return response()->json([
            'api_key' => substr($apiKey, 0, 8) . '...',
            'usage' => $usage,
            'billing' => [
                'mobile_cost' => round($usage['gb'] * self::PRICING['mobile'], 2),
                'residential_cost' => round($usage['gb'] * self::PRICING['residential'], 2),
                'seo_requests' => $usage['requests'],
            ],
        ]);
    }

    /**
     *   GET /v1/proxy/billing/{apiKey}
     *
     * Billing data for a customer's API key — Blesta queries this via cron.
     * Returns usage, cost per tier, and whether to invoice.
     */
    public function billing(string $apiKey): JsonResponse
    {
        $usage = $this->meter->getUsage($apiKey);
        $gb = $usage['gb'];
        $requests = $usage['requests'];

        return response()->json([
            'api_key' => $apiKey,
            'period' => [
                'start' => now()->startOfMonth()->toIso8601String(),
                'end' => now()->toIso8601String(),
            ],
            'usage' => $usage,
            'charges' => [
                'mobile_proxy' => [
                    'gb' => $gb,
                    'rate' => self::PRICING['mobile'],
                    'total' => round($gb * self::PRICING['mobile'], 2),
                ],
                'residential_proxy' => [
                    'gb' => $gb,
                    'rate' => self::PRICING['residential'],
                    'total' => round($gb * self::PRICING['residential'], 2),
                ],
                'seo_traffic' => [
                    'requests' => $requests,
                    'rate_per_1k' => 1.00,
                    'total' => round($requests / 1000 * 1.00, 2),
                ],
            ],
            'currency' => 'USD',
        ]);
    }

    /**
     *   GET /v1/proxy/nodes?cap=proxy&region=eu
     *
     * List available nodes by capability.
     */
    public function nodes(Request $request): JsonResponse
    {
        $capability = strtolower(trim((string) $request->get('cap', '')));
        $nodes = $this->selector->availableNodes($capability);

        $result = [];
        foreach ($nodes as $node) {
            $caps = [];
            if (preg_match('/cap=([^;]+)/', $node['comment'] ?? '', $m)) {
                $caps = explode(',', $m[1]);
            }

            $result[] = [
                'name' => $node['alias'] . '.lthn',
                'capabilities' => $caps,
                'status' => 'online',
            ];
        }

        return response()->json([
            'nodes' => $result,
            'count' => count($result),
            'filter' => $capability ?: 'all',
        ]);
    }

    /**
     *   GET /v1/proxy/status
     *
     * Network availability summary.
     */
    public function status(): JsonResponse
    {
        $vpn = $this->selector->availableNodes('vpn');
        $proxy = $this->selector->availableNodes('proxy');
        $exit = $this->selector->availableNodes('exit');
        $dns = $this->selector->availableNodes('dns');

        return response()->json([
            'status' => 'operational',
            'availability' => [
                'vpn' => ['nodes' => count($vpn), 'status' => count($vpn) > 0 ? 'available' : 'unavailable'],
                'proxy' => ['nodes' => count($proxy), 'status' => count($proxy) > 0 ? 'available' : 'unavailable'],
                'exit' => ['nodes' => count($exit), 'status' => count($exit) > 0 ? 'available' : 'unavailable'],
                'dns' => ['nodes' => count($dns), 'status' => count($dns) > 0 ? 'available' : 'unavailable'],
            ],
            'services' => [
                'mobile_proxy' => ['available' => count($proxy) > 0, 'rate' => '$5.00/GB'],
                'residential_proxy' => ['available' => count($proxy) > 0, 'rate' => '$2.50/GB'],
                'seo_traffic' => ['available' => count($exit) > 0, 'rate' => 'per-request'],
            ],
        ]);
    }
}