<?php

namespace App\Services\Students;

use App\Models\Students\Student;
use App\Models\Students\StudentClass;
use App\Models\Schools\SchoolClass;
use App\Services\BaseService;
use App\Exceptions\BusinessException;
use App\Helpers\ResponseEnum;
use Illuminate\Support\Facades\Hash;
use Illuminate\Support\Facades\Log;

/**
 * 学生服务类
 */
class StudentService extends BaseService
{
    /**
     * 构造函数
     */
    public function __construct()
    {
        parent::__construct();
    }

    /**
     * 获取学生列表
     * @param array $params
     * @return array
     */
    public function getStudentList(array $params = []): array
    {
        $query = Student::query();

        // 基础筛选
        if (!empty($params['username'])) {
            $query->where('username', 'like', '%' . $params['username'] . '%');
        }

        if (!empty($params['real_name'])) {
            $query->where('real_name', 'like', '%' . $params['real_name'] . '%');
        }

        if (!empty($params['email'])) {
            $query->where('email', 'like', '%' . $params['email'] . '%');
        }

        if (!empty($params['phone_number'])) {
            $query->where('phone_number', 'like', '%' . $params['phone_number'] . '%');
        }

        if (isset($params['role'])) {
            $query->where('role', $params['role']);
        }

        if (isset($params['status'])) {
            $query->where('status', $params['status']);
        }

        if (isset($params['sex'])) {
            $query->where('sex', $params['sex']);
        }

        if (!empty($params['grade_id'])) {
            $query->where('grade_id', $params['grade_id']);
        }

        if (!empty($params['parent_id'])) {
            $query->where('parent_id', $params['parent_id']);
        }

        if (!empty($params['class_id'])) {
            $query->whereHas('studentClasses', function ($q) use ($params) {
                $q->where('class_id', $params['class_id']);
                $q->where('status', StudentClass::STATUS_NORMAL);
            });
        }

        // 排序
        $query->orderBy('id', 'desc');

        return $this->paginate($query, $params);
    }

    /**
     * 获取学生详情
     * @param int $id
     * @return array
     */
    public function getStudentDetail(int $id): array
    {
        $student = Student::find($id);
        if (!$student) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        return $student->getFullInfo();
    }

    /**
     * 创建学生
     * @param array $data
     * @return array
     */
    public function createStudent(array $data): array
    {
        // 检查用户名是否已存在
        if (Student::where('username', $data['username'])->exists()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '用户名已存在');
        }

        // 检查邮箱是否已存在
        if (!empty($data['email']) && Student::where('email', $data['email'])->exists()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '邮箱已存在');
        }

        // 检查手机号是否已存在
        if (!empty($data['phone_number']) && Student::where('phone_number', $data['phone_number'])->exists()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '手机号已存在');
        }

        // 生成密码盐值
        $salt = Student::generateSalt();
        $data['salt'] = $salt;
        $data['password'] = Student::encryptPassword($data['password'], $salt);
        $data['reg_time'] = now();
        $data['reg_ip'] = request()->ip();

        $student = Student::create($data);

        Log::info('创建学生', [
            'student_id' => $student->id,
            'username' => $student->username,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return $student->getFullInfo();
    }

    /**
     * 更新学生
     * @param int $id
     * @param array $data
     * @return array
     */
    public function updateStudent(int $id, array $data): array
    {
        $student = Student::find($id);
        if (!$student) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        // 检查用户名是否已存在（排除自己）
        if (!empty($data['username']) && Student::where('username', $data['username'])->where('id', '!=', $id)->exists()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '用户名已存在');
        }

        // 检查邮箱是否已存在（排除自己）
        if (!empty($data['email']) && Student::where('email', $data['email'])->where('id', '!=', $id)->exists()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '邮箱已存在');
        }

        // 检查手机号是否已存在（排除自己）
        if (!empty($data['phone_number']) && Student::where('phone_number', $data['phone_number'])->where('id', '!=', $id)->exists()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '手机号已存在');
        }

        // 如果修改密码，需要重新加密
        if (!empty($data['password'])) {
            $salt = Student::generateSalt();
            $data['salt'] = $salt;
            $data['password'] = Student::encryptPassword($data['password'], $salt);
        }

        $student->update($data);

        Log::info('更新学生', [
            'student_id' => $student->id,
            'username' => $student->username,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return $student->refresh()->getFullInfo();
    }

    /**
     * 删除学生
     * @param int $id
     * @return bool
     */
    public function deleteStudent(int $id): bool
    {
        $student = Student::find($id);
        if (!$student) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        // 检查是否有关联的班级记录
        if ($student->studentClasses()->exists()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '学生有关联的班级记录，无法删除');
        }

        // 检查是否有子女关联
        if ($student->children()->exists()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '该家长有关联的子女，无法删除');
        }

        $student->delete();

        Log::info('删除学生', [
            'student_id' => $id,
            'username' => $student->username,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return true;
    }

    /**
     * 重置学生密码
     * @param int $id
     * @param string $newPassword
     * @return bool
     */
    public function resetPassword(int $id, string $newPassword): bool
    {
        $student = Student::find($id);
        if (!$student) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        $salt = Student::generateSalt();
        $student->update([
            'password' => Student::encryptPassword($newPassword, $salt),
            'salt' => $salt
        ]);

        Log::info('重置学生密码', [
            'student_id' => $id,
            'username' => $student->username,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return true;
    }

    /**
     * 更新学生状态
     * @param int $id
     * @param int $status
     * @return array
     */
    public function updateStatus(int $id, int $status): array
    {
        $student = Student::find($id);
        if (!$student) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        $student->update(['status' => $status]);

        Log::info('更新学生状态', [
            'student_id' => $id,
            'username' => $student->username,
            'old_status' => $student->status,
            'new_status' => $status,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return $student->refresh()->getFullInfo();
    }

    /**
     * 获取学生的班级历史
     * @param int $id
     * @return array
     */
    public function getStudentClassHistory(int $id): array
    {
        $student = Student::find($id);
        if (!$student) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        $classes = $student->studentClasses()
            ->with(['schoolClass.school', 'schoolClass.campus'])
            ->orderBy('join_time', 'desc')
            ->get();

        return $classes->map(function ($studentClass) {
            return [
                'id' => $studentClass->id,
                'school_name' => $studentClass->schoolClass->school->name ?? '',
                'campus_name' => $studentClass->schoolClass->campus->name ?? '',
                'class_name' => $studentClass->schoolClass->name ?? '',
                'join_time' => $studentClass->join_time,
                'leave_time' => $studentClass->leave_time,
                'status' => $studentClass->status,
                'status_name' => $studentClass->status_name,
                'study_days' => $studentClass->getStudyDays(),
                'remark' => $studentClass->remark
            ];
        })->toArray();
    }

    /**
     * 将学生分配到班级
     * @param int $studentId
     * @param int $classId
     * @param array $data
     * @return array
     */
    public function assignToClass(int $studentId, int $classId, array $data = []): array
    {
        $student = Student::find($studentId);
        if (!$student) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        $class = SchoolClass::find($classId);
        if (!$class) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '班级不存在');
        }

        // 检查是否已经在该班级中
        $existingRecord = StudentClass::where('student_id', $studentId)
            ->where('class_id', $classId)
            ->where('status', StudentClass::STATUS_NORMAL)
            ->first();

        if ($existingRecord) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '学生已在该班级中');
        }

        // 将学生在其他班级的记录设为转班状态
        StudentClass::where('student_id', $studentId)
            ->where('status', StudentClass::STATUS_NORMAL)
            ->update([
                'status' => StudentClass::STATUS_TRANSFERRED,
                'leave_time' => now(),
                'remark' => '转班'
            ]);

        // 创建新的班级记录
        $studentClass = StudentClass::create([
            'student_id' => $studentId,
            'school_id' => $class->school_id,
            'class_id' => $classId,
            'join_time' => $data['join_time'] ?? now(),
            'status' => StudentClass::STATUS_NORMAL,
            'remark' => $data['remark'] ?? ''
        ]);

        Log::info('学生分配到班级', [
            'student_id' => $studentId,
            'class_id' => $classId,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return $studentClass->load(['student', 'schoolClass'])->toArray();
    }

    /**
     * 从班级中移除学生
     * @param int $studentId
     * @param int $classId
     * @param array $data
     * @return bool
     */
    public function removeFromClass(int $studentId, int $classId, array $data = []): bool
    {
        $studentClass = StudentClass::where('student_id', $studentId)
            ->where('class_id', $classId)
            ->where('status', StudentClass::STATUS_NORMAL)
            ->first();

        if (!$studentClass) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不在该班级中');
        }

        $studentClass->update([
            'status' => $data['status'] ?? StudentClass::STATUS_TRANSFERRED,
            'leave_time' => $data['leave_time'] ?? now(),
            'remark' => $data['remark'] ?? '移除'
        ]);

        Log::info('从班级移除学生', [
            'student_id' => $studentId,
            'class_id' => $classId,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return true;
    }

    /**
     * 获取家长的子女列表
     * @param int $parentId
     * @return array
     */
    public function getParentChildren(int $parentId): array
    {
        $parent = Student::find($parentId);
        if (!$parent) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '家长不存在');
        }

        if (!$parent->isParent()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '用户不是家长');
        }

        return $parent->children()->with(['studentClasses.schoolClass'])->get()->map(function ($child) {
            return $child->getFullInfo();
        })->toArray();
    }

    /**
     * 绑定家长和子女关系
     * @param int $parentId
     * @param int $childId
     * @return bool
     */
    public function bindParentChild(int $parentId, int $childId): bool
    {
        $parent = Student::find($parentId);
        if (!$parent) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '家长不存在');
        }

        if (!$parent->isParent()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '用户不是家长');
        }

        $child = Student::find($childId);
        if (!$child) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        if (!$child->isStudent()) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '用户不是学生');
        }

        if ($child->parent_id) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '学生已有家长');
        }

        $child->update(['parent_id' => $parentId]);

        Log::info('绑定家长和子女关系', [
            'parent_id' => $parentId,
            'child_id' => $childId,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return true;
    }

    /**
     * 解除家长和子女关系
     * @param int $childId
     * @return bool
     */
    public function unbindParentChild(int $childId): bool
    {
        $child = Student::find($childId);
        if (!$child) {
            throw new BusinessException(ResponseEnum::CLIENT_NOT_FOUND, '学生不存在');
        }

        if (!$child->parent_id) {
            throw new BusinessException(ResponseEnum::CLIENT_PARAMETER_ERROR, '学生没有家长');
        }

        $parentId = $child->parent_id;
        $child->update(['parent_id' => null]);

        Log::info('解除家长和子女关系', [
            'parent_id' => $parentId,
            'child_id' => $childId,
            'operator' => $this->getCurrentUser()['id'] ?? 0
        ]);

        return true;
    }

    /**
     * 获取学生统计信息
     * @return array
     */
    public function getStudentStatistics(): array
    {
        $totalStudents = Student::students()->count();
        $totalParents = Student::parents()->count();
        $normalStudents = Student::students()->where('status', Student::STATUS_NORMAL)->count();
        $maleStudents = Student::students()->where('sex', Student::SEX_MALE)->count();
        $femaleStudents = Student::students()->where('sex', Student::SEX_FEMALE)->count();

        return [
            'total_students' => $totalStudents,
            'total_parents' => $totalParents,
            'normal_students' => $normalStudents,
            'male_students' => $maleStudents,
            'female_students' => $femaleStudents,
            'status_distribution' => [
                'normal' => Student::where('status', Student::STATUS_NORMAL)->count(),
                'disabled' => Student::where('status', Student::STATUS_DISABLED)->count(),
                'arrears' => Student::where('status', Student::STATUS_ARREARS)->count(),
                'inactive' => Student::where('status', Student::STATUS_INACTIVE)->count(),
            ]
        ];
    }
}