<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\StoreClient;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Str;

class ClientController extends Controller
{
    public function register(Request $request): JsonResponse
    {
        $validated = $request->validate([
            'site_url' => ['required', 'url', 'max:512'],
            'site_name' => ['nullable', 'string', 'max:255'],
            'typecho_version' => ['nullable', 'string', 'max:32'],
            'php_version' => ['nullable', 'string', 'max:32'],
            'plugin_version' => ['nullable', 'string', 'max:32'],
            'user_count' => ['nullable', 'integer', 'min:0'],
        ]);

        $siteUrl = $this->normalizeSiteUrl((string) $validated['site_url']);
        $now = now();

        $client = StoreClient::query()->firstOrNew([
            'site_url' => $siteUrl,
        ]);

        if (!$client->exists) {
            $client->registered_at = $now;
        }

        $client->site_name = $this->truncate((string) ($validated['site_name'] ?? ''), 255);
        $client->access_token = $this->issueAccessToken();
        $client->status = 'online';
        $client->user_count = max((int) ($validated['user_count'] ?? 0), 0);
        $client->typecho_version = $this->truncate((string) ($validated['typecho_version'] ?? ''), 32);
        $client->php_version = $this->truncate((string) ($validated['php_version'] ?? ''), 32);
        $client->plugin_version = $this->truncate((string) ($validated['plugin_version'] ?? ''), 32);
        $client->last_ip = $this->truncate((string) ($request->ip() ?? ''), 45);
        $client->last_user_agent = $this->truncate((string) ($request->userAgent() ?? ''), 512);
        $client->last_seen_at = $now;
        $client->save();

        return response()->json([
            'code' => 0,
            'message' => 'ok',
            'data' => $this->clientPayload($client, true),
        ]);
    }

    public function heartbeat(Request $request): JsonResponse
    {
        $client = $this->resolveClient($request);
        if (!$client) {
            return $this->unauthorizedResponse();
        }

        $validated = $request->validate([
            'site_name' => ['nullable', 'string', 'max:255'],
            'typecho_version' => ['nullable', 'string', 'max:32'],
            'php_version' => ['nullable', 'string', 'max:32'],
            'plugin_version' => ['nullable', 'string', 'max:32'],
            'user_count' => ['nullable', 'integer', 'min:0'],
        ]);

        if (array_key_exists('site_name', $validated)) {
            $client->site_name = $this->truncate((string) $validated['site_name'], 255);
        }
        if (array_key_exists('typecho_version', $validated)) {
            $client->typecho_version = $this->truncate((string) $validated['typecho_version'], 32);
        }
        if (array_key_exists('php_version', $validated)) {
            $client->php_version = $this->truncate((string) $validated['php_version'], 32);
        }
        if (array_key_exists('plugin_version', $validated)) {
            $client->plugin_version = $this->truncate((string) $validated['plugin_version'], 32);
        }
        if (array_key_exists('user_count', $validated)) {
            $client->user_count = max((int) $validated['user_count'], 0);
        }

        $client->status = 'online';
        $client->last_ip = $this->truncate((string) ($request->ip() ?? ''), 45);
        $client->last_user_agent = $this->truncate((string) ($request->userAgent() ?? ''), 512);
        $client->last_seen_at = now();
        $client->save();

        return response()->json([
            'code' => 0,
            'message' => 'ok',
            'data' => $this->clientPayload($client, false),
        ]);
    }

    public function status(Request $request): JsonResponse
    {
        $client = $this->resolveClient($request);
        if (!$client) {
            return $this->unauthorizedResponse();
        }

        $client->status = 'online';
        $client->last_ip = $this->truncate((string) ($request->ip() ?? ''), 45);
        $client->last_user_agent = $this->truncate((string) ($request->userAgent() ?? ''), 512);
        $client->last_seen_at = now();
        $client->save();

        return response()->json([
            'code' => 0,
            'message' => 'ok',
            'data' => $this->clientPayload($client, false),
        ]);
    }

    private function resolveClient(Request $request): ?StoreClient
    {
        $token = $this->extractToken($request);
        if ($token === '') {
            return null;
        }

        return StoreClient::query()->where('access_token', $token)->first();
    }

    private function extractToken(Request $request): string
    {
        return trim((string) (
            $request->bearerToken()
            ?: $request->header('X-Store-Plugin-Token')
            ?: $request->query('access_token', '')
        ));
    }

    private function unauthorizedResponse(): JsonResponse
    {
        return response()->json([
            'code' => 401,
            'message' => 'client unauthorized',
            'data' => null,
        ], 401);
    }

    private function issueAccessToken(): string
    {
        do {
            $token = Str::random(96);
        } while (StoreClient::query()->where('access_token', $token)->exists());

        return $token;
    }

    private function normalizeSiteUrl(string $url): string
    {
        $url = trim($url);
        if ($url === '') {
            return '';
        }

        return rtrim($url, '/');
    }

    private function truncate(string $value, int $length): string
    {
        return mb_substr(trim($value), 0, $length);
    }

    private function clientPayload(StoreClient $client, bool $includeToken): array
    {
        $payload = [
            'client_id' => $client->id,
            'site_url' => $client->site_url,
            'site_name' => $client->site_name,
            'status' => $client->status,
            'user_count' => (int) $client->user_count,
            'typecho_version' => $client->typecho_version,
            'php_version' => $client->php_version,
            'plugin_version' => $client->plugin_version,
            'registered_at' => optional($client->registered_at)->toAtomString(),
            'last_seen_at' => optional($client->last_seen_at)->toAtomString(),
            'server_time' => now()->toAtomString(),
            'stats' => [
                'registered_sites' => StoreClient::query()->count(),
                'online_sites' => StoreClient::query()->online()->count(),
                'tracked_users' => (int) StoreClient::query()->sum('user_count'),
            ],
        ];

        if ($includeToken) {
            $payload['access_token'] = $client->access_token;
        }

        return $payload;
    }
}