<?php

namespace App\Temporal\UserMigration;

use App\Models\User;
use App\Temporal\Shared\FaultSimulator;
use Illuminate\Support\Facades\Hash;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;
use Temporal\Activity;

class UserMigrationActivity implements UserMigrationActivityInterface
{
    public function fetchExternalUsers(int $count, array $simulationConfig = []): array
    {
        $users = [];
        $pageSize = 25;
        $totalPages = (int) ceil($count / $pageSize);

        for ($page = 0; $page < $totalPages; $page++) {
            Activity::heartbeat(['page' => $page + 1, 'totalPages' => $totalPages]);

            FaultSimulator::maybeApply($simulationConfig, 'fetchExternalUsers');

            $start = $page * $pageSize + 1;
            $end = min(($page + 1) * $pageSize, $count);

            for ($i = $start; $i <= $end; $i++) {
                $users[] = [
                    'name' => 'User ' . $i,
                    'email' => 'user_' . $i . '_' . Str::random(4) . '@example.com',
                    'legacy_id' => 'LEG-' . $i,
                ];
            }
        }

        return $users;
    }

    public function validateUsers(array $users, array $simulationConfig = []): array
    {
        FaultSimulator::maybeApply($simulationConfig, 'validateUsers');

        $validUsers = array_filter($users, function (array $user) {
            if (empty($user['name'])) {
                return false;
            }

            if (!filter_var($user['email'] ?? '', FILTER_VALIDATE_EMAIL)) {
                return false;
            }

            return true;
        });

        $validUsers = array_values($validUsers);

        Log::info(sprintf(
            'Validated users: %d valid out of %d total',
            count($validUsers),
            count($users)
        ));

        return $validUsers;
    }

    public function createAccounts(array $users, array $simulationConfig = []): array
    {
        FaultSimulator::maybeApply($simulationConfig, 'createAccounts');

        $created = 0;
        $failed = 0;
        $createdIds = [];
        $errors = [];

        foreach ($users as $index => $userData) {
            Activity::heartbeat(sprintf('Creating account %d of %d', $index + 1, count($users)));

            try {
                $user = User::create([
                    'name' => $userData['name'],
                    'email' => $userData['email'],
                    'password' => Hash::make(Str::random(16)),
                ]);

                $createdIds[] = $user->id;
                $created++;
            } catch (\Throwable $e) {
                $failed++;
                $errors[] = [
                    'email' => $userData['email'],
                    'error' => $e->getMessage(),
                ];

                Log::warning(sprintf(
                    'Failed to create account for %s: %s',
                    $userData['email'],
                    $e->getMessage()
                ));
            }
        }

        return [
            'created' => $created,
            'failed' => $failed,
            'created_ids' => $createdIds,
            'errors' => $errors,
            'attempt' => Activity::getInfo()->attempt,
        ];
    }

    public function sendWelcomeEmails(array $userIds, array $simulationConfig = []): bool
    {
        FaultSimulator::maybeApply($simulationConfig, 'sendWelcomeEmails');

        foreach ($userIds as $id) {
            Log::info(sprintf('Sending welcome email to user ID: %s', $id));
            usleep(50000);
        }

        return true;
    }

    public function generateMigrationReport(int $totalUsers, int $processedUsers, int $failedUsers, array $simulationConfig = []): array
    {
        FaultSimulator::maybeApply($simulationConfig, 'generateMigrationReport');

        $successRate = $totalUsers > 0
            ? round(($processedUsers / $totalUsers) * 100, 2)
            : 0.0;

        return [
            'total_users' => $totalUsers,
            'processed_users' => $processedUsers,
            'failed_users' => $failedUsers,
            'success_rate' => $successRate,
            'timestamp' => now()->toIso8601String(),
        ];
    }
}