<?php

declare(strict_types=1);

namespace app\common\service\pharmacy;

use app\common\model\pharmacy\EjMedicineCatalog;
use RuntimeException;
use think\facade\Db;
use think\facade\Config;
use Throwable;

final class EjMedicineCatalogSyncService
{
    private const STATE_ID = 1;
    private const LOCK_TTL = 600;

    /** @return array{pages:int,pulled:int,received:int,created:int,updated:int,unchanged:int,deactivated:int,cursor:int} */
    public static function sync(int $limit = 200): array
    {
        if (!(bool) Config::get('ej_pharmacy.catalog_sync_enabled', false)) {
            throw new RuntimeException('恩济药房增量目录同步已关闭，请使用一次性 bootstrap 命令初始化药材目录');
        }
        if (!EjPharmacyClient::isConfigured()) {
            throw new RuntimeException('洛阳药房接口未启用或配置不完整');
        }

        self::ensureStateRow();
        $token = bin2hex(random_bytes(16));
        $client = new EjPharmacyClient();
        $workflow = new EjMedicineCatalogSyncWorkflow(
            static fn (): bool => self::acquireLock($token),
            static fn () => self::releaseLock($token),
            static fn (): int => (int) (Db::name('ej_pharmacy_sync_state')->where('id', self::STATE_ID)->value('cursor') ?? 0),
            static fn (int $cursor, int $pageLimit): array => $client->medicines($cursor, $pageLimit),
            static fn (array $items, int $nextCursor): array => self::mergePage($items, $nextCursor, $token),
            static function (int $cursor) use ($token): void {
                Db::name('ej_pharmacy_sync_state')->where('id', self::STATE_ID)
                    ->where('lock_token', $token)->update([
                    'cursor' => $cursor,
                    'last_success_time' => time(),
                    'last_error_summary' => '',
                    'update_time' => time(),
                ]);
            },
            static function (int $cursor, string $error) use ($token): void {
                Db::name('ej_pharmacy_sync_state')->where('id', self::STATE_ID)
                    ->where('lock_token', $token)->update([
                    'cursor' => $cursor,
                    'last_failure_time' => time(),
                    'last_error_summary' => $error,
                    'update_time' => time(),
                ]);
            }
        );

        return $workflow->sync($limit);
    }

    private static function ensureStateRow(): void
    {
        if (Db::name('ej_pharmacy_sync_state')->where('id', self::STATE_ID)->find()) {
            return;
        }
        try {
            Db::name('ej_pharmacy_sync_state')->insert([
                'id' => self::STATE_ID,
                'cursor' => 0,
                'lock_token' => '',
                'lock_expires_at' => 0,
                'create_time' => time(),
                'update_time' => time(),
            ]);
        } catch (Throwable $exception) {
            if (!self::isDuplicateKey($exception)) {
                throw $exception;
            }
        }
    }

    private static function acquireLock(string $token): bool
    {
        $now = time();
        $updated = Db::name('ej_pharmacy_sync_state')
            ->where('id', self::STATE_ID)
            ->where(function ($query) use ($now): void {
                $query->where('lock_token', '')->whereOr('lock_expires_at', '<', $now);
            })
            ->update([
                'lock_token' => $token,
                'lock_expires_at' => $now + self::LOCK_TTL,
                'update_time' => $now,
            ]);
        return $updated === 1;
    }

    private static function releaseLock(string $token): void
    {
        Db::name('ej_pharmacy_sync_state')
            ->where('id', self::STATE_ID)
            ->where('lock_token', $token)
            ->update(['lock_token' => '', 'lock_expires_at' => 0, 'update_time' => time()]);
    }

    /** @return array{created:int,updated:int,unchanged:int,deactivated:int} */
    private static function mergePage(array $items, int $nextCursor, string $token): array
    {
        return Db::transaction(function () use ($items, $nextCursor, $token): array {
            $stats = ['created' => 0, 'updated' => 0, 'unchanged' => 0, 'deactivated' => 0];
            foreach ($items as $item) {
                $code = trim((string) ($item['medicine_code'] ?? ''));
                $model = $code === '' ? null : EjMedicineCatalog::where('medicine_code', $code)->lock(true)->find();
                $result = EjMedicineCatalogSyncPolicy::merge($model ? $model->toArray() : null, $item);
                $values = $result['values'];
                if ($result['action'] === 'created') {
                    EjMedicineCatalog::create($values);
                } elseif ($result['action'] === 'updated' && $model) {
                    unset($values['medicine_code']);
                    $model->save($values);
                }
                ++$stats[$result['action']];
                $stats['deactivated'] += $result['deactivated'];

                if ($result['deactivated'] === 1) {
                    $now = time();
                    Db::name('ej_medicine_mapping')
                        ->where('medicine_code', $code)
                        ->where('status', 1)
                        ->update(['status' => 0, 'delete_time' => $now, 'update_time' => $now]);
                }
            }

            $state = Db::name('ej_pharmacy_sync_state')
                ->where('id', self::STATE_ID)
                ->lock(true)
                ->find();
            if (!$state || !hash_equals((string) $state['lock_token'], $token)) {
                throw new RuntimeException('洛阳药房目录同步锁已失效，请重试');
            }
            Db::name('ej_pharmacy_sync_state')
                ->where('id', self::STATE_ID)
                ->update([
                    'cursor' => $nextCursor,
                    'lock_expires_at' => time() + self::LOCK_TTL,
                    'update_time' => time(),
                ]);
            return $stats;
        });
    }

    private static function isDuplicateKey(Throwable $exception): bool
    {
        return (string) $exception->getCode() === '23000'
            || str_contains(strtolower($exception->getMessage()), 'duplicate');
    }
}