<?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];
    }

    /**
     * 自动计算已完成的随访次数（过期的月份自动算已完成）
     */
    public function getAutoFollowUpCount(): int
    {
        $schedule = $this->getFollowUpSchedule();
        $currentMonth = Carbon::now()->startOfMonth();
        $completed = 0;
        
        foreach ($schedule as $months) {
            $followUpDate = $this->discharge_date->copy()->addMonths($months);
            // 如果随访日期的月份早于当前月份，则算作已完成
            if ($followUpDate->startOfMonth()->lt($currentMonth)) {
                $completed++;
            } else {
                break;
            }
        }
        
        return $completed;
    }

    /**
     * 获取当月需要随访的日期（如果有的话）
     */
    public function getCurrentMonthFollowUpDate(): ?Carbon
    {
        $schedule = $this->getFollowUpSchedule();
        $currentMonth = Carbon::now();
        $monthStart = $currentMonth->copy()->startOfMonth();
        $monthEnd = $currentMonth->copy()->endOfMonth();
        
        foreach ($schedule as $index => $months) {
            $followUpDate = $this->discharge_date->copy()->addMonths($months);
            // 如果随访日期在当月内
            if ($followUpDate->gte($monthStart) && $followUpDate->lte($monthEnd)) {
                return $followUpDate;
            }
        }
        
        return null;
    }

    /**
     * 获取当月随访是第几次
     */
    public function getCurrentMonthFollowUpNumber(): ?int
    {
        $schedule = $this->getFollowUpSchedule();
        $currentMonth = Carbon::now();
        $monthStart = $currentMonth->copy()->startOfMonth();
        $monthEnd = $currentMonth->copy()->endOfMonth();
        
        foreach ($schedule as $index => $months) {
            $followUpDate = $this->discharge_date->copy()->addMonths($months);
            if ($followUpDate->gte($monthStart) && $followUpDate->lte($monthEnd)) {
                return $index + 1;
            }
        }
        
        return null;
    }

    /**
     * 检查当月是否需要随访
     */
    public function needsFollowUpThisMonth(): bool
    {
        return $this->getCurrentMonthFollowUpDate() !== null;
    }

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