<?php

namespace App\Console\Commands;

use App\Models\User;
use Illuminate\Console\Command;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;

class MergeDuplicateUsersByMobile extends Command
{
    protected $signature = 'merge_duplicate_users_by_mobile
                            {--dry-run : 只打印将执行的操作，不实际更新或删除}';

    protected $description = '将手机号重复的用户合并：保留 id 最大的用户，把旧用户的关联数据转移到新用户后软删除旧用户（仅处理有报名审核通过的重复手机号）';

    /**
     * 需要把 user_id 从旧用户改成新用户的表
     */
    protected array $tablesWithUserId = [
        'course_signs',
        'course_keeps',
        'appointments',
        'supply_demands',
        'supply_demand_keeps',
        'course_content_evaluation_forms',
        'course_content_checks',
        'course_appointment_totals',
        'score_logs',
        'third_appointment_logs',
    ];

    /**
     * 表里既有 user_id 又有 to_user_id，都需要把旧用户 id 替换为新用户 id
     */
    protected array $tablesWithToUserId = [
        'dialogues',
        'messages',
    ];

    public function handle()
    {
        $dryRun = $this->option('dry-run');
        if ($dryRun) {
            $this->warn('【预检模式】不会修改数据库');
        }

        $duplicateGroups = $this->getDuplicateMobileUsers();
        if ($duplicateGroups->isEmpty()) {
            $this->info('没有需要合并的重复手机号。');
            return 0;
        }

        $this->info('共 ' . $duplicateGroups->count() . ' 组重复手机号待处理。');

        $merged = 0;
        $failed = 0;

        foreach ($duplicateGroups as $mobile => $users) {
            // 按 id 升序，id 最大为“新”，保留；其余为“旧”，合并后软删
            $sorted = $users->sortBy('id')->values();
            $newUser = $sorted->last();
            $oldUsers = $sorted->slice(0, -1);

            $newId = (int) $newUser->id;
            $oldIds = $oldUsers->pluck('id')->map(fn($v) => (int) $v)->toArray();

            $this->line('');
            $this->line("手机号: {$mobile} | 保留用户 id={$newId} ({$newUser->name}), 合并并删除: " . implode(', ', $oldIds));

            if ($dryRun) {
                $this->listTransfers($newId, $oldIds);
                $merged++;
                continue;
            }

            try {
                DB::transaction(function () use ($newId, $oldIds) {
                    foreach ($oldIds as $oldId) {
                        $this->transferRelations($oldId, $newId);
                    }
                    User::whereIn('id', $oldIds)->delete(); // 软删除
                });
                $this->info("  已合并并软删除旧用户: " . implode(', ', $oldIds));
                $merged++;
            } catch (\Throwable $e) {
                $this->error("  失败: " . $e->getMessage());
                $failed++;
            }
        }

        $this->line('');
        $this->info("完成: 成功 {$merged} 组" . ($failed > 0 ? ", 失败 {$failed} 组" : '') . ($dryRun ? '（未写入）' : ''));
        return $failed > 0 ? 1 : 0;
    }

    /**
     * 查询：有报名审核通过且手机号重复的用户，按手机号分组
     */
    protected function getDuplicateMobileUsers()
    {
        $sql = "
            SELECT u.id, u.name, u.mobile
            FROM users u
            WHERE u.deleted_at IS NULL
              AND u.mobile IS NOT NULL AND TRIM(u.mobile) != ''
              AND EXISTS (
                SELECT 1 FROM course_signs cs
                WHERE cs.user_id = u.id AND cs.status = 1 AND cs.deleted_at IS NULL
              )
              AND u.mobile IN (
                SELECT u2.mobile
                FROM users u2
                INNER JOIN course_signs cs2 ON cs2.user_id = u2.id AND cs2.status = 1 AND cs2.deleted_at IS NULL
                WHERE u2.deleted_at IS NULL
                  AND u2.mobile IS NOT NULL AND TRIM(u2.mobile) != ''
                GROUP BY u2.mobile
                HAVING COUNT(DISTINCT u2.id) > 1
              )
            ORDER BY u.mobile, u.id
        ";
        $rows = DB::select($sql);
        return collect($rows)->groupBy('mobile');
    }

    /**
     * 把 oldUserId 的关联全部改为 newUserId
     */
    protected function transferRelations(int $oldUserId, int $newUserId): void
    {
        foreach ($this->tablesWithUserId as $table) {
            if (!Schema::hasTable($table) || !Schema::hasColumn($table, 'user_id')) {
                continue;
            }
            $n = DB::table($table)->where('user_id', $oldUserId)->update(['user_id' => $newUserId]);
            if ($n > 0) {
                $this->line("    {$table}.user_id: {$oldUserId} -> {$newUserId}, 更新 {$n} 行");
            }
        }

        foreach ($this->tablesWithToUserId as $table) {
            if (!Schema::hasTable($table)) {
                continue;
            }
            if (Schema::hasColumn($table, 'user_id')) {
                $n = DB::table($table)->where('user_id', $oldUserId)->update(['user_id' => $newUserId]);
                if ($n > 0) {
                    $this->line("    {$table}.user_id: {$oldUserId} -> {$newUserId}, 更新 {$n} 行");
                }
            }
            if (Schema::hasColumn($table, 'to_user_id')) {
                $n = DB::table($table)->where('to_user_id', $oldUserId)->update(['to_user_id' => $newUserId]);
                if ($n > 0) {
                    $this->line("    {$table}.to_user_id: {$oldUserId} -> {$newUserId}, 更新 {$n} 行");
                }
            }
        }
    }

    /**
     * dry-run：只统计并打印每个表将更新的行数
     */
    protected function listTransfers(int $newUserId, array $oldIds): void
    {
        foreach ($oldIds as $oldId) {
            foreach ($this->tablesWithUserId as $table) {
                if (!Schema::hasTable($table) || !Schema::hasColumn($table, 'user_id')) {
                    continue;
                }
                $n = DB::table($table)->where('user_id', $oldId)->count();
                if ($n > 0) {
                    $this->line("    [拟] {$table}.user_id: {$oldId} -> {$newUserId}, 约 {$n} 行");
                }
            }
            foreach ($this->tablesWithToUserId as $table) {
                if (!Schema::hasTable($table)) {
                    continue;
                }
                if (Schema::hasColumn($table, 'user_id')) {
                    $n = DB::table($table)->where('user_id', $oldId)->count();
                    if ($n > 0) {
                        $this->line("    [拟] {$table}.user_id: {$oldId} -> {$newUserId}, 约 {$n} 行");
                    }
                }
                if (Schema::hasColumn($table, 'to_user_id')) {
                    $n = DB::table($table)->where('to_user_id', $oldId)->count();
                    if ($n > 0) {
                        $this->line("    [拟] {$table}.to_user_id: {$oldId} -> {$newUserId}, 约 {$n} 行");
                    }
                }
            }
        }
    }
}