<?php

namespace app\model;

use app\DbCoroutineContext;
use think\Collection;
use think\db\Connection;
use think\facade\Cache;
use think\facade\Db;
use think\facade\Log;

class DatabaseRoute
{

    /**
     * 跨所有分库分页（自动 count，自动追加 LIMIT 和 ORDER BY）
     *
     * @param \Closure $sqlBuilder 生成基础 SQL 的闭包函数（不包含 LIMIT）
     * @param int $page 当前页码
     * @param int $pageSize 每页条数
     * @param string|null $orderCol 排序字段（全局排序使用）
     * @return array
     */
    public static function paginateAllDbBySqlAutoCount(
        \Closure $sqlBuilder,
        int      $page = 1,
        int      $pageSize = 20,
        string   $orderCol = null,
        int      $count = null,
    ): array
    {
        $dbMap = config('database.db_map');
        $counts = [];
        $total = 0;


        if ($count === null) {
            // 1. 自动 count 分库总数
            $dbList = DatabaseRoute::getAllSelectDb();
            foreach ($dbMap as $connName) {
                if (in_array($connName, $dbList) ) {
                    $baseSql = call_user_func($sqlBuilder, $connName);
                    $countSql = self::buildCountSql($baseSql);
                    $count = Db::connect($connName)->query($countSql)[0]['count'] ?? 0;
                    $counts[$connName] = $count;
                    $total += $count;
                }
            }
        }


        if ($total === 0) {
            return [
                'list' => [],
                'totalCount' => 0,
                'totalPage' => 0,
                'currPage' => $page,
                'pageSize' => $pageSize,
            ];
        }

        $offset = ($page - 1) * $pageSize;
        if ($offset >= $total) {
            return [
                'list' => [],
                'totalCount' => $total,
                'totalPage' => (int)ceil($total / $pageSize),
                'currPage' => $page,
                'pageSize' => $pageSize,
            ];
        }

        $limit = $pageSize;
        $allRows = [];
        $skip = $offset;

        // 2. 分库分页查询
        foreach ($counts as $connName => $count) {
            if ($count <= 0) continue;
            if ($skip >= $count) {
                $skip -= $count;
                continue;
            }

            $localOffset = $skip;
            $localLimit = min($count - $localOffset, $limit);

            $baseSql = call_user_func($sqlBuilder, $connName);
            $sql = rtrim($baseSql, ';');

            if ($orderCol) {
                $sql .= " ORDER BY {$orderCol} DESC";
            }
            $sql .= " LIMIT {$localOffset}, {$localLimit}";

            $rows = Db::connect($connName)->query($sql);
            $allRows = array_merge($allRows, $rows);

            $limit -= $localLimit;
            $skip = 0;
            if ($limit <= 0) break;
        }

        // 3. 全局排序（若指定排序字段）
        if ($orderCol) {
            usort($allRows, function ($a, $b) use ($orderCol) {
                return strtotime($b[$orderCol]) <=> strtotime($a[$orderCol]);
            });
        }

        // 4. 返回结构
        return [
            'list' => $allRows,
            'totalCount' => $total,
            'totalPage' => (int)ceil($total / $pageSize),
            'currPage' => $page,
            'pageSize' => $pageSize,
        ];
    }

    /**
     * 从 SELECT SQL 自动构建对应的 COUNT SQL
     *
     * @param string $sql
     * @return string
     */
    private static function buildCountSql(string $sql): string
    {
        $sql = preg_replace('/\s+ORDER\s+BY\s+.+?$/i', '', $sql);
        $sql = preg_replace('/\s+LIMIT\s+\d+(\s*,\s*\d+)?$/i', '', $sql);
        if (preg_match('/FROM\s+(.*)/i', $sql, $matches)) {
            return 'SELECT COUNT(*) AS count FROM ' . $matches[1];
        }
        throw new \RuntimeException("无法从 SQL 自动构建 COUNT 查询，请检查 SQL 是否规范");
    }

    public static function paginateDb(
        string   $table,
        \Closure $builder,
        int      $page = 1,
        int      $pageSize = 20,
        string|array $keyInfo = null,
        $isRecords = false
    ) {
        // 构建基础查询
        if ($keyInfo) {
            $query = self::getDb($table, $keyInfo);
        }else{
            $query = Db::table($table);
        }
        $builder($query); // 应用外部闭包设置查询条件，如 where/order 等

        // 获取总数
        $totalCount = (clone $query)->count();

        // 计算总页数
        $totalPage = (int) ceil($totalCount / $pageSize);
        $currPage = max(1, min($page, $totalPage));

        // 获取分页数据
        $list = $query
            ->page($currPage, $pageSize)
            ->select()
            ->toArray();
        $query->getConnection()->close();

        return [
            'totalCount' => $totalCount,
            'pageSize'   => $pageSize,
            'totalPage'  => $totalPage,
            'currPage'   => $currPage,
            $isRecords ? 'records' : 'list'       => convertToCamelCase($list),
        ];
    }

    /**
     * 跨所有从库分页（支持游标分页和传统页码分页）
     * @param string $table 表名
     * @param \Closure $builder 查询构造器
     * @param int|null $page 当前页（null 表示使用游标分页）
     * @param int $pageSize 每页条数
     * @param string|null $lastCreateTime 游标分页的游标值（create_time）
     * @return array [list, total|nextCursor, hasMore]
     */
    public static function paginateAllDb(
        string   $table,
        \Closure $builder,
        int      $page = 1,
        int      $pageSize = 20,
        string   $orderCol = 'create_time',
        string   $modelOrderCol = null,
        bool $isRecords = false
    ): array
    {
        $dbMap = config('database.db_map');
        $counts = [];
        $total = 0;

        // 1. 统计每个分库总数
        $dbList = DatabaseRoute::getAllSelectDb();
        foreach ($dbMap as $connName) {
            if (in_array($connName, $dbList) ) {
                $query = Db::connect($connName)->name($table);
                $query = call_user_func($builder, $query);
                // 不要order，避免报错
                $query->removeOption('order');
                $count = $query->count();
                $query->getConnection()->close();
                $counts[$connName] = $count;
                $total += $count;
            }
        }

        if ($total === 0) {
            return [
                $isRecords ? 'records' : 'list' => [],
                'totalCount' => 0,
                'totalPage' => 0,
                'currPage' => $page,
                'pageSize' => $pageSize,
            ];
        }

        $offset = ($page - 1) * $pageSize;
        if ($offset >= $total) {
            // 超出总数，返回空数据
            return [
                $isRecords ? 'records' : 'list' => [],
                'totalCount' => $total,
                'totalPage' => (int)ceil($total / $pageSize),
                'currPage' => $page,
                'pageSize' => $pageSize,
            ];
        }

        $limit = $pageSize;
        $allRows = [];

        // 2. 计算每个库需要查询的偏移和条数
        $skip = $offset; // 还需要跳过多少条
        foreach ($counts as $connName => $count) {
            if ($count <= 0) continue;

            if ($skip >= $count) {
                // 跳过整个分库
                $skip -= $count;
                continue;
            }

            // 本库要查询的起始 offset
            $localOffset = $skip;
            // 本库剩余条数
            $localLimit = min($count - $localOffset, $limit);

            // 查询数据
            $query = Db::connect($connName)->name($table);
            $query = call_user_func($builder, $query);
            $rows = $query->order($orderCol, 'desc')
                ->limit($localOffset, $localLimit)
                ->select()
                ->toArray();
            $query->getConnection()->close();

            $allRows = array_merge($allRows, $rows);

            $limit -= $localLimit; // 剩余要查询的条数
            $skip = 0; // 之后库不再跳过

            if ($limit <= 0) break; // 已查够
        }

        // 3. 全局排序（降序）
        if ($modelOrderCol) {
            usort($allRows, function ($a, $b) use ($modelOrderCol) {
                return strtotime($b[$modelOrderCol]) <=> strtotime($a[$modelOrderCol]);
            });
        }

        // 4. 返回分页数据
        return [
            $isRecords ? 'records' : 'list' => $allRows,
            'totalCount' => $total,
            'totalPage' => (int)ceil($total / $pageSize),
            'currPage' => $page,
            'pageSize' => $pageSize,
        ];
    }


    /**
     * 对所有从库执行事务（XA 分布式模拟，非真实两阶段提交）
     * @param \Closure $callback
     * @return mixed
     * @throws \Throwable
     */
    public static function transactionXa(\Closure $callback)
    {
        DbCoroutineContext::set('startTrans', true);

        try {

            // 执行用户操作（传入事务闭包）
            $result = call_user_func($callback);
            // 提交所有连接
            DbCoroutineContext::commit();
            return $result;
        } catch (\Throwable $e) {
            // 回滚所有连接
            DbCoroutineContext::rollback();

            Log::error("transactionXa 全部回滚：" . $e->getMessage());
            Log::info('错误信息'.$e->getMessage().'具体信息'.$e->getTraceAsString());
            throw $e;
        }finally {
            DbCoroutineContext::clearList();
            DbCoroutineContext::set('startTrans', false);
        }
    }

    public static function getMasterDb($table, $isWrite = false)
    {
        $conn = Db::connect();
        if ($isWrite) {
            DbCoroutineContext::put($conn);
        }
        return $conn->name($table);
    }


    /**
     * 根据表和分库值获取db
     * @param $table string 表名
     * @param $keyInfo string | array
     */
    public static function getDb($table, $keyInfo, $isWrite = false, $isUpdate = false, $addWhere = true)
    {
        if (is_array($keyInfo)) {
            $con = Db::connect(DatabaseRoute::getConnection($table, $keyInfo, $isWrite));
            if ($isWrite) {
                DbCoroutineContext::put($con);
            }
            $model = $con->name($table);
            if ($addWhere && (!$isWrite || $isUpdate)) {
                $model->where($keyInfo);
            }
        } else {
            $con = Db::connect(DatabaseRoute::getConnection($table, ['user_id' => $keyInfo], $isWrite));
            if ($isWrite) {
                DbCoroutineContext::put($con);
            }
            $model = $con->name($table);
            if ($addWhere && (!$isWrite || $isUpdate)) {
                $model->where([
                    'user_id' => $keyInfo
                ]);
            }
        }

        return $model;
    }

    /**
     * 跨所有分库直接删除（危险操作，务必确认条件准确）
     * @param string $table 表名
     * @param \Closure $builder 条件构造器，如 function($query) { return $query->where('xxx', xxx); }
     * @return int 删除的总记录数
     */
    public static function deleteAllDbDirect(string $table, \Closure $builder): int
    {
        $dbMap = config('database.db_master_map');
        $totalDeleted = 0;

        foreach ($dbMap as $connName) {
            if ($connName === 'duanju_master') continue;

            $query = Db::connect($connName)->name($table);
            $query = call_user_func($builder, $query);
            $deleted = $query->delete();
            $query->getConnection()->close();
            $totalDeleted += $deleted;
        }

        return $totalDeleted;
    }

    public static function getAllDbData($table, \Closure $builder)
    {

        return new class($table, $builder) {
            protected $table;
            protected $builder;
            protected $dbMap;
            protected $masterDbMap;

            public function __construct($table, $builder)
            {
                $this->table = $table;
                $this->builder = $builder;
                $this->dbMap = config('database.db_map');
                $this->masterDbMap = config('database.db_master_map');
            }

            public function __call($method, $args)
            {
                $finalResult = null;
                try {
                    if ($method == 'insert') {
                        throw new \RuntimeException("不支持insert");
                    }
                    // insert 和 update 使用主库
                    if ($method == 'update' || $method == 'delete') {
                        foreach ($this->masterDbMap as $dbname) {
                            if ($dbname !== 'duanju_master') {
                                $query = Db::connect($dbname)->name($this->table);
                                $query = call_user_func($this->builder, $query);
                                if (method_exists($query, $method)) {
                                    $result = call_user_func_array([$query, $method], $args);
                                    $finalResult = $result;
                                    $query->getConnection()->close();
                                    // find 返回 null，select 返回空数组，count 返回数字
                                    if ($result || $result === 0) {
                                        return $result;
                                    }
                                }else {
                                    $query->getConnection()->close();
                                }
                            }
                        }
                        return $finalResult;
                    }else{
                        $dbList = DatabaseRoute::getAllSelectDb();
                        foreach ($this->dbMap as $dbname) {
                            if (in_array($dbname, $dbList) ) {
                                $query = Db::connect($dbname)->name($this->table);
                                $query = call_user_func($this->builder, $query);
                                if (method_exists($query, $method)) {
                                    $result = call_user_func_array([$query, $method], $args);
                                    // find 返回 null，select 返回空数组，count 返回数字
                                    $finalResult = $result;
                                    $query->getConnection()->close();
                                    if ($result instanceof Collection) {
                                        if (!$result->isEmpty()) {
                                            return $result;
                                        }
                                    }elseif (is_int($result) && $result != 0) {
                                        return $result;
                                    } else if ($result) {
                                        return $result;
                                    }
                                }else {
                                    $query->getConnection()->close();
                                }
                            }
                        }
                    }
                }catch (\Throwable $e) {
                    Log::error("错误信息".$e->getMessage());
                    throw $e;
                }


                return $finalResult;
            }
        };
    }

    public static function getAllSelectDb()
    {
        $index = self::getIndex();
        return ["duanju$index-0_slave", "duanju$index-1_slave", "duanju$index-2_slave", "duanju$index-3_slave", "duanju$index-4_slave"];
    }


    private static function getIndex()
    {
        $INDEX = \cache('db_index');
        if ($INDEX == null) {
            $INDEX = 0;
        }
        $INDEX = ++$INDEX % 4;
        \cache('db_index', $INDEX);
        return $INDEX;
    }


    /**
     * 获取数据库连接
     * @param string $tableName 表名
     * @param array $data 数据
     * @param bool $isWrite 是否为写操作
     * @return Connection
     */
    public static function getConnection($table, $data = [], $isWrite = false)
    {
        $routeConfig = config('think-orm.route');
        $keyField = strpos($table, 'user') !== false || in_array($table, [
            'orders', 'course_collect', 'pay_details', 'disc_spinning_record',
            'cash_out', 'course_user', 'tb_user', 'task_center_record',
            'user_money', 'user_sign_record', 'invite_achievement',
            'invite_money', 'user_info', 'sys_user', 'user_money_details', 'sys_user_money_details'
        ]) ? 'user_id' : 'course_id';

        if (!isset($data[$keyField])) {
            Log::warning("分库警告: 表={$table}, 数据中缺少 {$keyField} 字段");
            return $isWrite ? 'duanju_master' : 'duanju_slave';
        }

        $index = abs($data[$keyField] % 5);
        $connectionTemplate = $isWrite
            ? $routeConfig[$table]['master']
            : $routeConfig[$table]['slave'];

        $connectionName = str_replace("{\${$keyField}%5}", $index, $connectionTemplate);
        return $connectionName;
    }
}