<?php
// application/common/library/GiftDataMigrator.php

namespace app\common\library;

use think\Db;
use think\Exception;
use think\Log;

class GiftDataMigrator
{
    /**
     * 迁移单个月份的数据
     * @param string $yearMonth 年月 202401
     * @param int $batchSize 每批数量
     * @param int $startId 起始ID
     * @return array 迁移结果
     */
    public static function migrateMonthData($yearMonth, $batchSize = 1000, $startId = 0)
    {
        // 确保目标表存在
        GiftTableManager::createMonthTable($yearMonth);

        $targetTable = 'fa_vs_give_gift_' . $yearMonth;
        $startTime = strtotime($yearMonth . '01 00:00:00');
        $endTime = strtotime(date('Y-m-01', strtotime('+1 month', $startTime)));

        $totalMigrated = 0;
        $lastId = $startId;
        $hasMore = true;

        Log::info("开始迁移 {$yearMonth} 数据，起始ID: {$startId}");

        while ($hasMore) {
            try {
                // 查询原始表数据
                $records = Db::name('vs_give_gift')
                    ->where('id', '>', $lastId)
                    ->where('createtime', '>=', $startTime)
                    ->where('createtime', '<', $endTime)
                    ->order('id', 'asc')
                    ->limit($batchSize)
                    ->select();

                if (empty($records)) {
                    $hasMore = false;
                    break;
                }

                // 转换数据格式，生成雪花ID
                $dataToInsert = [];
                foreach ($records as $record) {
                    $newRecord = [
                        'id' => Snowflake::generate(),
                        'user_id' => $record['user_id'] ?? 0,
                        'gift_id' => $record['gift_id'] ?? 0,
                        'gift_type' => $record['gift_type'] ?? 1,
                        'number' => $record['number'] ?? 0,
                        'gift_user' => $record['gift_user'] ?? 0,
                        'from_id' => $record['from_id'] ?? 0,
                        'pit_number' => $record['pit_number'] ?? 0,
                        'total_price' => $record['total_price'] ?? 0,
                        'type' => $record['type'] ?? 1,
                        'from' => $record['from'] ?? 1,
                        'createtime' => $record['createtime'] ?? time(),
                        'updatetime' => $record['updatetime'] ?? time(),
                    ];
                    $dataToInsert[] = $newRecord;
                    $lastId = $record['id']; // 使用原始表的ID
                }

                // 批量插入到分表
                if (!empty($dataToInsert)) {
                    Db::table($targetTable)->insertAll($dataToInsert);
                    $totalMigrated += count($dataToInsert);

                    Log::info("迁移批次成功: {$yearMonth}, 本批: " . count($dataToInsert) . " 条，总计: {$totalMigrated} 条");
                }

                // 防止内存占用过高
                unset($records, $dataToInsert);

                // 小睡一下，防止CPU占用过高
                usleep(10000);

            } catch (\Exception $e) {
                Log::error("迁移 {$yearMonth} 数据失败: " . $e->getMessage());
                return [
                    'success' => false,
                    'message' => $e->getMessage(),
                    'total' => $totalMigrated,
                    'last_id' => $lastId
                ];
            }
        }

        Log::info("完成迁移 {$yearMonth} 数据，总计: {$totalMigrated} 条");

        return [
            'success' => true,
            'message' => '迁移完成',
            'total' => $totalMigrated,
            'last_id' => $lastId
        ];
    }

    /**
     * 迁移所有历史数据
     * @param int $batchSize 每批数量
     * @return array
     */
    public static function migrateAllData($batchSize = 1000)
    {
        // 获取所有需要迁移的月份
        $firstRecord = Db::name('vs_give_gift')
            ->where('createtime', '>', 0)
            ->order('createtime', 'asc')
            ->find();
        $lastRecord = Db::name('vs_give_gift')
            ->where('createtime', '>', 0)
            ->order('createtime', 'desc')
            ->find();

        if (!$firstRecord || !$lastRecord) {
            return ['success' => true, 'message' => '没有数据需要迁移'];
        }

        $startMonth = date('Ym', $firstRecord['createtime']);
        $endMonth = date('Ym', $lastRecord['createtime']);

        // 生成月份列表
        $months = self::generateMonthRange($startMonth, $endMonth);

        Log::info("开始迁移数据，月份范围: {$startMonth} 到 {$endMonth}，共 " . count($months) . " 个月");

        $results = [];
        foreach ($months as $month) {
            Log::info("开始迁移 {$month} 数据");

            $result = self::migrateMonthData($month, $batchSize);
            $results[$month] = $result;

            if (!$result['success']) {
                Log::error("迁移 {$month} 数据失败，停止迁移");
                break;
            }

            Log::info("完成迁移 {$month} 数据，共 {$result['total']} 条");
        }

        return [
            'success' => true,
            'message' => '所有数据迁移完成',
            'results' => $results
        ];
    }

    /**
     * 生成月份范围
     * @param string $startMonth 202401
     * @param string $endMonth 202412
     * @return array
     */
    private static function generateMonthRange($startMonth, $endMonth)
    {
        $start = new \DateTime($startMonth . '01');
        $end = new \DateTime($endMonth . '01');

        $months = [];
        while ($start <= $end) {
            $months[] = $start->format('Ym');
            $start->modify('+1 month');
        }

        return $months;
    }

    /**
     * 获取迁移进度
     * @return array
     */
    public static function getMigrationProgress()
    {
        // 查询原始表数据量
        $totalCount = Db::name('vs_give_gift')->count();

        // 查询已迁移的数据量
        $migratedCount = 0;
        $tables = GiftTableManager::getAllTables();

        foreach ($tables as $tableInfo) {
            try {
                $count = Db::table($tableInfo['table_name'])->count();
                $migratedCount += $count;
            } catch (\Exception $e) {
                // 表可能不存在，跳过
            }
        }

        $progress = $totalCount > 0 ? round($migratedCount / $totalCount * 100, 2) : 0;

        return [
            'total' => $totalCount,
            'migrated' => $migratedCount,
            'progress' => $progress,
            'remaining' => $totalCount - $migratedCount
        ];
    }

    /**
     * 验证迁移数据一致性
     * @param string $yearMonth 年月
     * @return array
     */
    public static function verifyMigration($yearMonth)
    {
        $startTime = strtotime($yearMonth . '01 00:00:00');
        $endTime = strtotime(date('Y-m-01', strtotime('+1 month', $startTime)));

        // 原始表数据量
        $sourceCount = Db::name('vs_give_gift')
            ->where('createtime', '>=', $startTime)
            ->where('createtime', '<', $endTime)
            ->count();

        // 目标表数据量
        $targetTable = 'fa_vs_give_gift_' . $yearMonth;
        $targetCount = 0;
        try {
            $targetCount = Db::table($targetTable)->count();
        } catch (\Exception $e) {
            Log::error("验证迁移数据失败，目标表不存在: " . $targetTable);
        }

        // 比较总价值
        $sourceTotalPrice = Db::name('vs_give_gift')
            ->where('createtime', '>=', $startTime)
            ->where('createtime', '<', $endTime)
            ->sum('total_price');

        $targetTotalPrice = 0;
        try {
            $targetTotalPrice = Db::table($targetTable)->sum('total_price');
        } catch (\Exception $e) {
            // 表可能不存在
        }

        return [
            'source_count' => $sourceCount,
            'target_count' => $targetCount,
            'count_match' => $sourceCount == $targetCount,
            'source_total_price' => $sourceTotalPrice,
            'target_total_price' => $targetTotalPrice,
            'price_match' => abs(floatval($sourceTotalPrice) - floatval($targetTotalPrice)) < 0.01
        ];
    }
}