<?php

namespace App\Services\Simulation;

use App\Constants\HttpStatus;
use App\Support\MemberAudience;
use Exception;
use Illuminate\Support\Facades\DB;

/** 模拟管理的设置（config 表 simulation_* 键）以及每个写操作都要过的两道检查。 */
final class SimulationSettings
{
    /** 键 => [默认值, 最小, 最大]；最小为 null 的是字符串。 */
    public const KEYS = [
        'simulation_enabled' => ['0', 0, 1],
        'simulation_max_concurrency' => ['2', 1, 10],
        'simulation_rate_per_minute' => ['30', 1, 120],
        'simulation_max_members_per_task' => ['20', 1, 200],
        'simulation_max_members_total' => ['500', 1, 5000],
        'simulation_max_amount' => ['10000', 1, 1000000],
        'simulation_initial_balance' => ['0', 0, 1000000],
        'simulation_wager_bypass' => ['1', 0, 1],
        'simulation_default_domain' => ['sim.local', null, null],
    ];

    public static function all(): array
    {
        $stored = DB::table('config')->whereIn('field', array_keys(self::KEYS))->pluck('val', 'field');
        $out = [];
        foreach (self::KEYS as $key => [$default]) $out[$key] = (string) ($stored[$key] ?? $default);
        return $out;
    }

    public static function get(string $key): string
    {
        return self::all()[$key];
    }

    public static function save(array $input): array
    {
        $before = self::all();
        foreach (self::KEYS as $key => [, $min, $max]) {
            if (!array_key_exists($key, $input)) continue;
            $value = trim((string) $input[$key]);
            if ($min === null) {
                if ($value === '' || strlen($value) > 100) throw new Exception('域名格式不正确', HttpStatus::CUSTOM_ERROR);
            } elseif (!is_numeric($value) || $value < $min || $value > $max) {
                throw new Exception("{$key} 应在 {$min} 到 {$max} 之间", HttpStatus::CUSTOM_ERROR);
            }
            $exists = DB::table('config')->where('field', $key)->exists();
            if ($exists) DB::table('config')->where('field', $key)->update(['val' => $value]);
            else DB::table('config')->insert(['field' => $key, 'val' => $value]);
        }
        return ['before' => $before, 'after' => self::all()];
    }

    public static function enabled(): bool
    {
        return self::get('simulation_enabled') === '1';
    }

    public static function assertEnabled(): void
    {
        if (!MemberAudience::enabled()) throw new Exception('用户类型字段尚未迁移，无法使用模拟管理', HttpStatus::CUSTOM_ERROR);
        if (!self::enabled()) throw new Exception('模拟功能未开启，请先在“模拟设置”中开启', HttpStatus::CUSTOM_ERROR);
    }

    /** 写操作的目标必须是后台模拟会员，返回该会员。 */
    public static function member($memberId): object
    {
        $user = DB::table('users')->where('member_id', (string) $memberId)->where('user_type', MemberAudience::TYPE_SIMULATED)->first();
        if (!$user) throw new Exception('只能操作模拟会员', HttpStatus::CUSTOM_ERROR);
        return $user;
    }

    public static function assertAmount($amount): string
    {
        if (!is_numeric($amount) || $amount <= 0) throw new Exception('金额格式不正确', HttpStatus::CUSTOM_ERROR);
        if ($amount > (float) self::get('simulation_max_amount')) throw new Exception('金额超过模拟设置的单次上限', HttpStatus::CUSTOM_ERROR);
        return number_format((float) $amount, 2, '.', '');
    }
}