<?php

namespace Modules\Licensing\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use Modules\Licensing\Models\License;
use Modules\Licensing\Models\LicenseActivation;
use Modules\Licensing\Services\LicenseKey;
use Modules\Licensing\Services\LicenseSigner;
use Modules\Licensing\Services\LicenseTokenVerifier;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;

final class LicenseActivationController extends Controller
{
    public function activate(Request $request, LicenseSigner $signer): JsonResponse
    {
        $data = $request->validate([
            'licenseKey' => ['required', 'string', 'max:128'],
            'installationID' => ['required', 'uuid'],
            'appVersion' => ['required', 'string', 'max:32'],
            'platform' => ['required', 'string', 'max:32'],
        ]);

        return DB::transaction(function () use ($data, $signer) {
            $license = License::where('license_key_hash', LicenseKey::hash($data['licenseKey']))
                ->lockForUpdate()
                ->first();

            if (! $license) {
                throw ValidationException::withMessages(['licenseKey' => 'The licence key is not valid.']);
            }

            if (! $license->is_usable) {
                return response()->json(['message' => 'This licence is expired or has been revoked.'], 403);
            }

            $installationID = strtolower($data['installationID']);
            $activation = LicenseActivation::where('license_id', $license->id)
                ->where('installation_id', $installationID)
                ->first();

            if ($activation && $activation->deactivated_at === null) {
                $activation->update([
                    'last_seen_at' => now(),
                    'platform' => $data['platform'],
                    'app_version' => $data['appVersion'],
                ]);
            } else {
                $activeCount = LicenseActivation::where('license_id', $license->id)
                    ->whereNull('deactivated_at')
                    ->count();

                if ($activeCount >= $license->activation_limit) {
                    return response()->json(['message' => 'This licence has reached its activation limit. Deactivate another Mac first.'], 409);
                }

                if ($activation) {
                    $activation->update([
                        'deactivated_at' => null,
                        'activated_at' => now(),
                        'last_seen_at' => now(),
                        'platform' => $data['platform'],
                        'app_version' => $data['appVersion'],
                    ]);
                } else {
                    LicenseActivation::create([
                        'license_id' => $license->id,
                        'installation_id' => $installationID,
                        'platform' => $data['platform'],
                        'app_version' => $data['appVersion'],
                        'activated_at' => now(),
                        'last_seen_at' => now(),
                    ]);
                }
            }

            return response()->json([
                'licenseToken' => $signer->sign($license, $data['installationID']),
            ]);
        });
    }

    public function validateInstallation(
        Request $request,
        LicenseTokenVerifier $verifier,
        LicenseSigner $signer,
    ): JsonResponse {
        $data = $request->validate([
            'licenseToken' => ['required', 'string', 'max:8192'],
            'installationID' => ['required', 'uuid'],
            'appVersion' => ['required', 'string', 'max:32'],
            'platform' => ['required', 'string', 'max:32'],
        ]);

        try {
            $payload = $verifier->verify($data['licenseToken']);
        } catch (\Throwable) {
            return response()->json(['message' => 'The licence token is invalid.'], 400);
        }

        if (strcasecmp((string) ($payload['installationID'] ?? ''), $data['installationID']) !== 0) {
            return response()->json(['message' => 'The installation does not match this licence token.'], 400);
        }

        return DB::transaction(function () use ($data, $payload, $signer) {
            $license = License::whereKey((string) ($payload['licenseID'] ?? ''))
                ->lockForUpdate()
                ->first();

            if (! $license || ! $license->is_usable) {
                return response()->json(['message' => 'This licence is expired or has been revoked.'], 403);
            }

            $activation = LicenseActivation::where('license_id', $license->id)
                ->where('installation_id', strtolower($data['installationID']))
                ->first();

            if (! $activation || $activation->deactivated_at !== null) {
                return response()->json(['message' => 'This Mac has been deactivated from the licence portal.'], 403);
            }

            $activation->update([
                'last_seen_at' => now(),
                'platform' => $data['platform'],
                'app_version' => $data['appVersion'],
            ]);

            return response()->json([
                'active' => true,
                // Refreshing the signed token also applies subscription edition/expiry changes
                // without requiring the user to reactivate manually.
                'licenseToken' => $signer->sign($license, $data['installationID']),
            ]);
        });
    }

    public function deactivate(Request $request, LicenseTokenVerifier $verifier): JsonResponse
    {
        $data = $request->validate([
            'licenseToken' => ['required', 'string', 'max:8192'],
            'installationID' => ['required', 'uuid'],
        ]);

        try {
            $payload = $verifier->verify($data['licenseToken']);
        } catch (\Throwable) {
            return response()->json(['message' => 'The licence token is invalid.'], 400);
        }

        if (strcasecmp((string) ($payload['installationID'] ?? ''), $data['installationID']) !== 0) {
            return response()->json(['message' => 'The installation does not match this licence token.'], 400);
        }

        LicenseActivation::where('license_id', (string) ($payload['licenseID'] ?? ''))
            ->where('installation_id', strtolower($data['installationID']))
            ->whereNull('deactivated_at')
            ->update(['deactivated_at' => now(), 'last_seen_at' => now()]);

        return response()->json((object) []);
    }
}