<?php

namespace App\Services\HR;

use App\Models\HR\Employee;
use App\Models\HR\Position;
use App\Models\Tenants\Department;
use App\Models\User;
use Illuminate\Contracts\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;

class EmployeeService
{
    /**
     * 사원 목록 조회 (페이지네이션)
     */
    public function getEmployees(array $filters = [], int $perPage = 20): LengthAwarePaginator
    {
        $tenantId = session('selected_tenant_id');

        $query = Employee::query()
            ->with(['user', 'department'])
            ->forTenant($tenantId);

        // 검색 필터 (이름, 사번, 이메일)
        if (! empty($filters['q'])) {
            $search = $filters['q'];
            $query->where(function ($q) use ($search) {
                $q->where('display_name', 'like', "%{$search}%")
                    ->orWhereHas('user', function ($uq) use ($search) {
                        $uq->where('name', 'like', "%{$search}%")
                            ->orWhere('email', 'like', "%{$search}%")
                            ->orWhere('phone', 'like', "%{$search}%");
                    })
                    ->orWhereRaw("JSON_UNQUOTE(JSON_EXTRACT(json_extra, '$.employee_code')) LIKE ?", ["%{$search}%"]);
            });
        }

        // 상태 필터
        if (! empty($filters['status'])) {
            $query->where('employee_status', $filters['status']);
        }

        // 부서 필터
        if (! empty($filters['department_id'])) {
            $query->where('department_id', $filters['department_id']);
        }

        // 정렬
        $query->orderByRaw("FIELD(employee_status, 'active', 'leave', 'resigned')")
            ->orderBy('created_at', 'desc');

        return $query->paginate($perPage);
    }

    /**
     * 사원 상세 조회
     */
    public function getEmployeeById(int $id): ?Employee
    {
        $tenantId = session('selected_tenant_id');

        return Employee::query()
            ->with(['user', 'department', 'manager'])
            ->forTenant($tenantId)
            ->find($id);
    }

    /**
     * 사원 통계
     */
    public function getStats(): array
    {
        $tenantId = session('selected_tenant_id');

        $baseQuery = Employee::query()->forTenant($tenantId);

        return [
            'total' => (clone $baseQuery)->count(),
            'active' => (clone $baseQuery)->where('employee_status', 'active')->count(),
            'leave' => (clone $baseQuery)->where('employee_status', 'leave')->count(),
            'resigned' => (clone $baseQuery)->where('employee_status', 'resigned')->count(),
        ];
    }

    /**
     * 사원 등록 (User + TenantUserProfile 동시 생성)
     */
    public function createEmployee(array $data): Employee
    {
        $tenantId = session('selected_tenant_id');

        return DB::transaction(function () use ($data, $tenantId) {
            // User 생성
            $user = User::create([
                'name' => $data['name'],
                'email' => $data['email'] ?? null,
                'phone' => $data['phone'] ?? null,
                'password' => bcrypt($data['password'] ?? 'sam1234!'),
                'is_active' => true,
            ]);

            // json_extra 구성
            $jsonExtra = [];
            if (! empty($data['employee_code'])) {
                $jsonExtra['employee_code'] = $data['employee_code'];
            }
            if (! empty($data['hire_date'])) {
                $jsonExtra['hire_date'] = $data['hire_date'];
            }
            if (! empty($data['address'])) {
                $jsonExtra['address'] = $data['address'];
            }
            if (! empty($data['emergency_contact'])) {
                $jsonExtra['emergency_contact'] = $data['emergency_contact'];
            }

            // Employee(TenantUserProfile) 생성
            $employee = Employee::create([
                'tenant_id' => $tenantId,
                'user_id' => $user->id,
                'department_id' => $data['department_id'] ?? null,
                'position_key' => $data['position_key'] ?? null,
                'job_title_key' => $data['job_title_key'] ?? null,
                'work_location_key' => $data['work_location_key'] ?? null,
                'employment_type_key' => $data['employment_type_key'] ?? null,
                'employee_status' => $data['employee_status'] ?? 'active',
                'manager_user_id' => $data['manager_user_id'] ?? null,
                'display_name' => $data['display_name'] ?? $data['name'],
                'json_extra' => ! empty($jsonExtra) ? $jsonExtra : null,
            ]);

            return $employee->load(['user', 'department']);
        });
    }

    /**
     * 사원 정보 수정
     */
    public function updateEmployee(int $id, array $data): ?Employee
    {
        $employee = $this->getEmployeeById($id);
        if (! $employee) {
            return null;
        }

        // 기본 필드 업데이트
        $updateData = array_filter([
            'department_id' => $data['department_id'] ?? null,
            'position_key' => $data['position_key'] ?? null,
            'job_title_key' => $data['job_title_key'] ?? null,
            'work_location_key' => $data['work_location_key'] ?? null,
            'employment_type_key' => $data['employment_type_key'] ?? null,
            'employee_status' => $data['employee_status'] ?? null,
            'manager_user_id' => $data['manager_user_id'] ?? null,
            'display_name' => $data['display_name'] ?? null,
        ], fn ($v) => $v !== null);

        // json_extra 업데이트
        $jsonExtraKeys = ['employee_code', 'hire_date', 'address', 'emergency_contact', 'salary', 'bank_account'];
        $extra = $employee->json_extra ?? [];
        foreach ($jsonExtraKeys as $key) {
            if (array_key_exists($key, $data)) {
                if ($data[$key] === null || $data[$key] === '') {
                    unset($extra[$key]);
                } else {
                    $extra[$key] = $data[$key];
                }
            }
        }
        $updateData['json_extra'] = ! empty($extra) ? $extra : null;

        $employee->update($updateData);

        // User 기본정보 동기화
        if ($employee->user) {
            $userUpdate = [];
            if (! empty($data['name'])) {
                $userUpdate['name'] = $data['name'];
            }
            if (! empty($data['email'])) {
                $userUpdate['email'] = $data['email'];
            }
            if (! empty($data['phone'])) {
                $userUpdate['phone'] = $data['phone'];
            }
            if (! empty($userUpdate)) {
                $employee->user->update($userUpdate);
            }
        }

        return $employee->fresh(['user', 'department']);
    }

    /**
     * 사원 삭제 (퇴직 처리)
     */
    public function deleteEmployee(int $id): bool
    {
        $employee = $this->getEmployeeById($id);
        if (! $employee) {
            return false;
        }

        $employee->update(['employee_status' => 'resigned']);

        return true;
    }

    /**
     * 부서 목록 (드롭다운용)
     */
    public function getDepartments(): \Illuminate\Database\Eloquent\Collection
    {
        $tenantId = session('selected_tenant_id');

        return Department::query()
            ->where('is_active', true)
            ->when($tenantId, fn ($q) => $q->where('tenant_id', $tenantId))
            ->orderBy('sort_order')
            ->orderBy('name')
            ->get(['id', 'name', 'code']);
    }

    /**
     * 직급 목록 (드롭다운용)
     */
    public function getPositions(string $type = 'rank'): \Illuminate\Database\Eloquent\Collection
    {
        return Position::query()
            ->forTenant()
            ->where('type', $type)
            ->where('is_active', true)
            ->ordered()
            ->get(['id', 'key', 'name']);
    }
}