<?php
namespace App\Core;

class PK10Algorithm implements GameAlgorithmInterface {

    /**
     * 生成随机开奖结果 (1-10的排列)
     */
    public static function generateResult(): array {
        $cars = range(1, 10);
        shuffle($cars);
        return $cars; // index 0=冠军, 1=亚军, ..., 9=第十名
    }

    /**
     * 带放水机制的开奖结果生成
     *
     * 算法策略：
     * - targetProfitRate > 0 时：选择利润最接近「总投注额 × 目标盈利率」的结果
     * - targetProfitRate == 0 时：选择平台利润最高的结果（原逻辑）
     *
     * @param array $bets 当期所有投注 [{bet_type, bet_target, amount, odds}, ...]
     * @param array $waterConfig [{bet_type => win_rate_pct}, ...]
     *        当前版本中 waterConfig 的 win_rate_pct 未直接参与结果选择，
     *        因为开奖结果是全局排列，无法单独控制某个投注类型的胜率。
     *        保留此参数供未来扩展（如按类型加权评分、分类型概率偏移等）。
     * @param int $attempts 最大尝试次数
     * @param float $targetProfitRate 目标盈利率（百分比，如 5.0 表示 5%）
     */
    public static function generateControlledResult(array $bets, array $waterConfig, int $attempts = 100, float $targetProfitRate = 0): array {
        if (empty($bets)) {
            return self::generateResult();
        }

        // 计算目标利润（仅当 targetProfitRate > 0 时生效）
        $targetProfit = 0;
        if ($targetProfitRate > 0) {
            $totalBet = 0;
            foreach ($bets as $bet) {
                $totalBet += (float)$bet['amount'];
            }
            $targetProfit = $totalBet * ($targetProfitRate / 100);
        }

        $bestResult = null;
        $bestProfit = PHP_INT_MIN;
        $bestDistance = PHP_FLOAT_MAX;

        for ($i = 0; $i < $attempts; $i++) {
            $result = self::generateResult();
            $profit = self::calculatePlatformProfit($result, $bets);

            if ($targetProfitRate > 0) {
                // 目标盈利率模式：选择利润最接近目标值的结果
                $distance = abs($profit - $targetProfit);
                if ($distance < $bestDistance) {
                    $bestDistance = $distance;
                    $bestProfit = $profit;
                    $bestResult = $result;
                }
            } else {
                // 原逻辑：选择平台利润最高的结果
                if ($profit > $bestProfit) {
                    $bestProfit = $profit;
                    $bestResult = $result;
                }
            }
        }

        return $bestResult;
    }

    /**
     * 计算某个开奖结果下平台的利润
     */
    public static function calculatePlatformProfit(array $result, array $bets): float {
        $totalBet = 0;
        $totalPayout = 0;
        foreach ($bets as $bet) {
            $amount = (float)$bet['amount'];
            $totalBet += $amount;
            if (self::checkWin($result, $bet['bet_type'], $bet['bet_target'])) {
                $totalPayout += $amount + $amount * (float)$bet['odds'];
            }
        }
        return $totalBet - $totalPayout;
    }

    /**
     * 核心中奖判定
     * @param array $result 开奖排名 [冠军车号, 亚军车号, ..., 第十名车号]
     * @param string $betType 投注类型: rank/bs/oe/dt/sum/sum_bs
     * @param string $betTarget 投注目标: rank1_5/rank1_big/dt1_dragon/sum_11/sum_big...
     */
    public static function checkWin(array $result, string $betType, string $betTarget): bool {
        switch ($betType) {
            case 'rank': return self::checkRank($result, $betTarget);
            case 'bs':   return self::checkBigSmall($result, $betTarget);
            case 'oe':   return self::checkOddEven($result, $betTarget);
            case 'dt':   return self::checkDragonTiger($result, $betTarget);
            case 'sum':  return self::checkSum($result, $betTarget);
            case 'sum_bs': return self::checkSumBigSmall($result, $betTarget);
            default: return false;
        }
    }

    // 名次投注: rank{N}_{carNo} 如 rank1_5 = 冠军是5号车
    private static function checkRank(array $r, string $target): bool {
        if (!preg_match('/^rank(\d+)_(\d+)$/', $target, $m)) return false;
        $pos = (int)$m[1] - 1; // 0-indexed
        $car = (int)$m[2];
        return isset($r[$pos]) && $r[$pos] === $car;
    }

    // 大小: rank{N}_big/small, 车号>=6为大, <=5为小
    private static function checkBigSmall(array $r, string $target): bool {
        if (!preg_match('/^rank(\d+)_(big|small)$/', $target, $m)) return false;
        $pos = (int)$m[1] - 1;
        if (!isset($r[$pos])) return false;
        $car = $r[$pos];
        return $m[2] === 'big' ? $car >= 6 : $car <= 5;
    }

    // 单双: rank{N}_odd/even
    private static function checkOddEven(array $r, string $target): bool {
        if (!preg_match('/^rank(\d+)_(odd|even)$/', $target, $m)) return false;
        $pos = (int)$m[1] - 1;
        if (!isset($r[$pos])) return false;
        $car = $r[$pos];
        return $m[2] === 'odd' ? ($car % 2 === 1) : ($car % 2 === 0);
    }

    // 龙虎: dt{N}_dragon/tiger, N=1-5, 对应 1vs10, 2vs9, 3vs8, 4vs7, 5vs6
    private static function checkDragonTiger(array $r, string $target): bool {
        if (!preg_match('/^dt(\d)_(dragon|tiger)$/', $target, $m)) return false;
        $pair = (int)$m[1]; // 1-5
        $frontPos = $pair - 1;       // 0,1,2,3,4
        $backPos  = 10 - $pair;      // 9,8,7,6,5
        if (!isset($r[$frontPos], $r[$backPos])) return false;
        $front = $r[$frontPos];
        $back  = $r[$backPos];
        if ($front === $back) return false; // 和局（PK10不会出现）
        return $m[2] === 'dragon' ? $front > $back : $front < $back;
    }

    // 冠亚和值: sum_{3-19}
    private static function checkSum(array $r, string $target): bool {
        if (!preg_match('/^sum_(\d+)$/', $target, $m)) return false;
        $sumVal = $r[0] + $r[1]; // 冠军+亚军
        return $sumVal === (int)$m[1];
    }

    // 冠亚和大小单双: sum_big/small/odd/even, 和>=12为大, <=11为小
    private static function checkSumBigSmall(array $r, string $target): bool {
        $sumVal = $r[0] + $r[1];
        switch ($target) {
            case 'sum_big':   return $sumVal >= 12;
            case 'sum_small': return $sumVal <= 11;
            case 'sum_odd':   return $sumVal % 2 === 1;
            case 'sum_even':  return $sumVal % 2 === 0;
            default: return false;
        }
    }

    /**
     * 获取名次中文/英文名称
     */
    public static function getRankName(int $pos): string {
        $names = [1=>'champion',2=>'runner_up',3=>'rank_n',4=>'rank_n',5=>'rank_n',
                  6=>'rank_n',7=>'rank_n',8=>'rank_n',9=>'rank_n',10=>'rank_n'];
        return $names[$pos] ?? 'rank_n';
    }

    /**
     * 龙虎对应关系
     */
    public static function getDragonTigerPairs(): array {
        return [
            1 => [1, 10], // 第1名 vs 第10名
            2 => [2, 9],
            3 => [3, 8],
            4 => [4, 7],
            5 => [5, 6],
        ];
    }

    /**
     * 期号生成
     */
    public static function generatePeriodNumber(int $gameId): string {
        return 'PK' . $gameId . date('Ymd') . str_pad(mt_rand(1, 9999), 4, '0', STR_PAD_LEFT);
    }

    public static function getResultTable(): ?string { return 'pk10_results'; }

    public static function formatResultForStorage(array $result, int $periodId): array {
        return [
            'period_id' => $periodId,
            'rank_1' => $result[0], 'rank_2' => $result[1], 'rank_3' => $result[2],
            'rank_4' => $result[3], 'rank_5' => $result[4], 'rank_6' => $result[5],
            'rank_7' => $result[6], 'rank_8' => $result[7], 'rank_9' => $result[8],
            'rank_10' => $result[9], 'champion_sum' => $result[0] + $result[1],
        ];
    }

    public static function parseResultFromDb(array $row): array {
        $r = [];
        for ($i = 1; $i <= 10; $i++) $r[] = (int)($row['rank_' . $i] ?? 0);
        return $r;
    }
}