<?php

declare(strict_types=1);

namespace app\miniapi\service;

use app\miniapi\model\MiniCheckout;
use app\miniapi\model\MiniBalanceLedger;
use app\miniapi\http\Fields;
use app\miniapi\http\Input;
use app\miniapi\exception\ApiException;
use plugin\saiadmin\app\model\water\WaterEnterprise;
use plugin\saiadmin\app\service\WaterPurchaseReceipt;
use plugin\saiadmin\app\model\water\WaterSku;

/** Checkout intents become water receipts and rights only after a successful balance payment. */
final class CheckoutService
{
    public function __construct(private readonly Access $access)
    {
    }

    public function quote(int $enterprise, array $input): array
    {
        return $this->buildQuote($enterprise, $input, false);
    }

    private function buildQuote(int $enterprise, array $input, bool $lock): array
    {
        $this->access->enterprise($enterprise, true);
        Fields::only($input, ['items']);
        $items = $input['items'] ?? null;
        if (!is_array($items) || !array_is_list($items) || count($items) < 1 || count($items) > 20) {
            throw new ApiException(42201, '请选择1至20种套餐', 422);
        }
        $result = [];
        $seen = [];
        $total = 0;
        $parsed = [];
        foreach ($items as $item) {
            if (!is_array($item)) {
                throw new ApiException(42201, '套餐明细格式不正确', 422);
            }
            Fields::only($item, ['package_id', 'quantity']);
            $id = Fields::id($item, 'package_id');
            $quantity = Input::integer($item['quantity'] ?? null, 'quantity', 1, 100);
            if (isset($seen[$id])) {
                throw new ApiException(42201, '同一套餐请合并数量', 422);
            }
            $seen[$id] = true;
            $parsed[] = ['package_id' => $id, 'quantity' => $quantity];
        }
        $catalog = new Catalog();
        $locked = $lock ? $catalog->lockedDetails(array_keys($seen)) : [];
        foreach ($parsed as $item) {
            $id = $item['package_id'];
            $quantity = $item['quantity'];
            $package = $lock ? $locked[$id] : $catalog->detail($id);
            $amount = $package['price_cents'] * $quantity;
            $total += $amount;
            $result[] = [
                'package_id' => $id,
                'name' => $package['name'],
                'sku_id' => $package['sku_id'],
                'quantity' => $quantity,
                'buckets' => $package['buckets'] * $quantity,
                'unit_price_cents' => $package['price_cents'],
                'amount_cents' => $amount,
            ];
        }
        usort($result, fn ($a, $b) => $a['package_id'] <=> $b['package_id']);

        return [
            'items' => $result,
            'quote_revision' => hash('sha256', json_encode($result, JSON_THROW_ON_ERROR)),
            'subtotal_cents' => $total,
            'discount_cents' => 0,
            'amount_cents' => $total,
            'payment_methods' => ['balance', 'wechat'],
            'capabilities' => [
                'payment' => false,
                'balance' => true,
                'first_purchase_discount' => false,
                'invoice_issuance' => false,
            ],
            'balance_cents' => BalanceService::cents($enterprise),
            'agreement_url' => config('mini_api.purchase_agreement_url', '') ?: null,
        ];
    }

    public function create(int $enterprise, array $input): array
    {
        $this->access->enterprise($enterprise, true);
        Fields::only($input, [
            'items',
            'expected_amount_cents',
            'quote_revision',
            'agreement_accepted',
            'invoice',
            'request_key',
        ]);
        if (($input['agreement_accepted'] ?? false) !== true) {
            throw new ApiException(42201, '请确认购买与配送服务协议', 422);
        }
        $expected = Input::integer($input['expected_amount_cents'] ?? null, 'expected_amount_cents', 0, PHP_INT_MAX);
        $invoice = $input['invoice'] ?? null;
        if ($invoice !== null) {
            if (!is_array($invoice)) {
                throw new ApiException(42201, '发票资料格式不正确', 422);
            }
            Fields::only($invoice, ['title', 'tax_number', 'email']);
            $invoice = [
                'title' => Fields::text($invoice, 'title', 120),
                'tax_number' => Fields::text($invoice, 'tax_number', 30),
                'email' => Fields::text($invoice, 'email', 120),
            ];
            if (!filter_var($invoice['email'], FILTER_VALIDATE_EMAIL)) {
                throw new ApiException(42201, '发票邮箱格式不正确', 422);
            }
        }
        $key = Fields::text($input, 'request_key', 80);
        $revision = isset($input['quote_revision']) ? Fields::text($input, 'quote_revision', 64) : null;

        return Commands::run($this->access->actor, $key, 'checkout:' . $enterprise, $input, function () use ($enterprise, $input, $expected, $invoice, $revision) {
            $enterpriseRow = $this->access->enterprise($enterprise, true);
            $quote = $this->buildQuote($enterprise, ['items' => $input['items'] ?? null], true);
            if ($quote['amount_cents'] !== $expected || ($revision !== null && !hash_equals($quote['quote_revision'], $revision))) {
                throw new ApiException(40904, '套餐内容或价格已变化，请重新确认', 409);
            }
            $checkout = MiniCheckout::query()->create([
                'user_id' => $this->access->actor->userId,
                'enterprise_id' => $enterprise,
                'code' => 'MP' . date('YmdHis') . bin2hex(random_bytes(6)),
                'status' => 'pending',
                'items' => $quote['items'],
                'address_snapshot' => [
                    'name' => $enterpriseRow->name,
                    'address' => $enterpriseRow->address,
                    'region' => $enterpriseRow->region,
                    'contact' => $enterpriseRow->contact,
                    'phone' => $enterpriseRow->phone,
                ],
                'invoice' => $invoice,
                'amount_cents' => $quote['amount_cents'],
                'created_at' => date('Y-m-d H:i:s'),
                'expires_at' => date('Y-m-d H:i:s', time() + 1800),
            ]);

            return self::present($checkout);
        }, fn () => $this->access->enterprise($enterprise, true));
    }

    public static function present($checkout): array
    {
        return [
            'id' => (int) $checkout->id,
            'code' => $checkout->code,
            'enterprise_id' => (int) $checkout->enterprise_id,
            'status' => $checkout->status === 'pending' && $checkout->expires_at <= date('Y-m-d H:i:s') ? 'expired' : $checkout->status,
            'items' => $checkout->items,
            'amount_cents' => (int) $checkout->amount_cents,
            'created_at' => $checkout->created_at,
            'expires_at' => $checkout->expires_at,
            'payment_enabled' => true,
            'payment_method' => $checkout->payment_method,
            'paid_at' => $checkout->paid_at,
            'balance_cents' => BalanceService::cents((int) $checkout->enterprise_id),
        ];
    }

    public function detail(int $enterprise, int $id): array
    {
        $this->access->enterprise($enterprise);
        $checkout = MiniCheckout::query()->where('enterprise_id', $enterprise)->find($id);
        if (!$checkout) {
            throw new ApiException(40401, '订单不存在', 404);
        }
        $address = $checkout->address_snapshot;
        $address['phone'] = WaterPresenter::phone($address['phone']);

        return self::present($checkout) + ['address' => $address];
    }

    public function cancel(int $enterprise, int $id, array $input): array
    {
        $this->access->enterprise($enterprise, true);
        Fields::only($input, ['request_key']);

        return Commands::run($this->access->actor, Fields::text($input, 'request_key', 80), 'checkout.cancel:' . $enterprise . ':' . $id, $input, function () use ($enterprise, $id) {
            $this->access->enterprise($enterprise, true);
            $checkout = MiniCheckout::query()->where('enterprise_id', $enterprise)->where('id', $id)->lockForUpdate()->first();
            if (!$checkout) {
                throw new ApiException(40401, '订单不存在', 404);
            }
            if (!in_array($checkout->status, ['pending', 'cancelled'], true)) {
                throw new ApiException(40902, '当前订单不能取消', 409);
            }
            $checkout->status = 'cancelled';
            $checkout->save();

            return self::present($checkout);
        }, fn () => $this->access->enterprise($enterprise, true));
    }

    public function pay(int $enterprise, int $id, array $input): array
    {
        $this->access->enterprise($enterprise, true);
        Fields::only($input, ['request_key', 'payment_method']);
        $key = Fields::text($input, 'request_key', 80);
        $method = Fields::choice($input, 'payment_method', ['balance', 'wechat']);
        if ($method === 'wechat') {
            throw new ApiException(50303, '微信支付接口已预留，请先使用企业余额', 503);
        }

        return Commands::run($this->access->actor, $key, 'checkout.pay:' . $enterprise . ':' . $id, $input, function () use ($enterprise, $id, $method, $key) {
            $checkout = MiniCheckout::query()->where('enterprise_id', $enterprise)->where('id', $id)->lockForUpdate()->first();
            if (!$checkout) {
                throw new ApiException(40401, '订单不存在', 404);
            }
            if ($checkout->status !== 'pending') {
                throw new ApiException(40902, '当前订单不能支付', 409);
            }
            if ($checkout->expires_at <= date('Y-m-d H:i:s')) {
                throw new ApiException(40906, '订单已超期，请重新创建订单', 409);
            }

            $items = $this->snapshotItems($checkout);
            // Receipt writers consistently lock SKU(s), then enterprise, then accounts/balance.
            $skuIds = array_unique(array_column($items, 'sku_id'));
            sort($skuIds, SORT_NUMERIC);
            foreach ($skuIds as $skuId) {
                $sku = WaterSku::query()->where('id', $skuId)->lockForUpdate()->first();
                if (!$sku || (int) $sku->status !== 1) {
                    throw new ApiException(40902, '订单中的商品规格已停用或不存在，请联系平台', 409);
                }
            }
            $enterpriseRow = WaterEnterprise::query()->where('id', $enterprise)->lockForUpdate()->first();
            if (!$enterpriseRow || (int) $enterpriseRow->status !== 1) {
                throw new ApiException(40301, '企业已停用或不存在', 403);
            }
            $balance = BalanceService::locked($enterprise);
            $amount = (int) $checkout->amount_cents;
            $before = (int) $balance->balance_cents;
            if ($before < $amount) {
                throw new ApiException(40905, '企业余额不足', 409, [
                    'balance_cents' => $before,
                    'required_cents' => $amount,
                ]);
            }

            $receipts = new WaterPurchaseReceipt();
            foreach ($items as $item) {
                for ($index = 1; $index <= $item['quantity']; $index++) {
                    $receipts->issue(
                        $enterprise,
                        [
                            'id' => $item['package_id'],
                            'name' => $item['name'],
                            'sku_id' => $item['sku_id'],
                            'buckets' => intdiv($item['buckets'], $item['quantity']),
                            'price_cents' => $item['unit_price_cents'],
                        ],
                        $checkout->code . '-' . $item['package_id'] . '-' . $index,
                        0,
                        true,
                        $id
                    );
                }
            }

            $after = $before - $amount;
            $now = date('Y-m-d H:i:s');
            $balance->balance_cents = $after;
            $balance->updated_at = $now;
            $balance->save();
            MiniBalanceLedger::query()->insert([
                'enterprise_id' => $enterprise,
                'checkout_id' => $id,
                'user_id' => $this->access->actor->userId,
                'request_key' => $key,
                'direction' => -1,
                'amount_cents' => $amount,
                'before_balance' => $before,
                'after_balance' => $after,
                'source' => 'checkout_balance',
                'created_at' => $now,
            ]);
            $checkout->status = 'paid';
            $checkout->payment_method = $method;
            $checkout->paid_at = $now;
            $checkout->save();

            return self::present($checkout) + ['balance_cents' => $after];
        }, fn () => $this->access->enterprise($enterprise, true));
    }

    /** Check persisted server snapshots before any financial write. */
    private function snapshotItems(MiniCheckout $checkout): array
    {
        $items = $checkout->items;
        if (!is_array($items) || !array_is_list($items) || count($items) < 1 || count($items) > 20) {
            throw new ApiException(40902, '订单快照不完整，请联系平台', 409);
        }
        $total = 0;
        $seen = [];
        foreach ($items as $item) {
            if (!is_array($item)) {
                throw new ApiException(40902, '订单快照不完整，请联系平台', 409);
            }
            foreach (['package_id', 'sku_id', 'quantity', 'buckets', 'unit_price_cents', 'amount_cents'] as $field) {
                if (!isset($item[$field]) || !is_int($item[$field]) || $item[$field] <= 0) {
                    throw new ApiException(40902, '订单快照数据无效，请联系平台', 409);
                }
            }
            if ($item['quantity'] > 100 || $item['buckets'] % $item['quantity'] !== 0
                || $item['amount_cents'] !== $item['quantity'] * $item['unit_price_cents']
                || !is_string($item['name'] ?? null) || trim($item['name']) === ''
                || isset($seen[$item['package_id']])) {
                throw new ApiException(40902, '订单快照数据无效，请联系平台', 409);
            }
            $seen[$item['package_id']] = true;
            $total += $item['amount_cents'];
        }
        if ($total !== (int) $checkout->amount_cents) {
            throw new ApiException(40902, '订单快照与应付金额不一致，请联系平台', 409);
        }

        return $items;
    }
}