<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Carbon\Carbon;

class Patient extends Model
{
    protected $fillable = [
        'user_id',
        'name',
        'gender',
        'age',
        'diagnosis',
        'discharge_date',
        'address',
        'phone',
        'remark',
        'follow_up_count',
        'last_follow_up_date',
    ];

    /**
     * 获取患者所属用户
     */
    public function user(): BelongsTo
    {
        return $this->belongsTo(User::class);
    }

    protected $casts = [
        'discharge_date' => 'date',
        'last_follow_up_date' => 'date',
    ];

    /**
     * 获取随访时间规则（月数）
     * 脑卒中/心肌梗塞: 1, 3, 6, 12 个月
     * 慢性肾脏病: 1, 2, 3, 6 个月
     */
    public function getFollowUpSchedule(): array
    {
        $diagnosis = $this->diagnosis;
        
        if (str_contains($diagnosis, '慢性肾') || str_contains($diagnosis, '肾脏病')) {
            return [1, 2, 3, 6]; // 慢性肾脏病
        }
        
        // 脑卒中、心肌梗塞及其他
        return [1, 3, 6, 12];
    }

    /**
     * 获取下次随访日期
     */
    public function getNextFollowUpDate(): ?Carbon
    {
        $schedule = $this->getFollowUpSchedule();
        $nextIndex = $this->follow_up_count;
        
        if ($nextIndex >= count($schedule)) {
            return null; // 已完成所有随访
        }
        
        $months = $schedule[$nextIndex];
        return $this->discharge_date->copy()->addMonths($months);
    }

    /**
     * 获取下次随访是第几次
     */
    public function getNextFollowUpNumber(): int
    {
        return $this->follow_up_count + 1;
    }

    /**
     * 检查是否需要随访（到期或已过期）
     */
    public function needsFollowUp(): bool
    {
        $nextDate = $this->getNextFollowUpDate();
        
        if (!$nextDate) {
            return false;
        }
        
        return $nextDate->lte(Carbon::today());
    }

    /**
     * 获取随访状态
     */
    public function getFollowUpStatus(): string
    {
        $nextDate = $this->getNextFollowUpDate();
        
        if (!$nextDate) {
            return '已完成';
        }
        
        $today = Carbon::today();
        $diff = $today->diffInDays($nextDate, false);
        
        if ($diff < 0) {
            return '已过期 ' . abs($diff) . ' 天';
        } elseif ($diff == 0) {
            return '今日到期';
        } elseif ($diff <= 7) {
            return '即将到期（' . $diff . '天后）';
        } else {
            return '未到期';
        }
    }

    /**
     * 检查是否已完成所有随访
     */
    public function isCompleted(): bool
    {
        return $this->follow_up_count >= count($this->getFollowUpSchedule());
    }

    /**
     * 获取诊断类型名称
     */
    public function getDiagnosisType(): string
    {
        if (str_contains($this->diagnosis, '脑卒中')) {
            return '脑卒中';
        } elseif (str_contains($this->diagnosis, '心肌梗') || str_contains($this->diagnosis, '心梗')) {
            return '心肌梗塞';
        } elseif (str_contains($this->diagnosis, '慢性肾') || str_contains($this->diagnosis, '肾脏病')) {
            return '慢性肾脏病';
        }
        return $this->diagnosis;
    }
}