<?php

namespace App\Http\Controllers;

use App\Models\Patient;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;
use Carbon\Carbon;
use Illuminate\Support\Facades\Response;

class PatientController extends Controller
{
    /**
     * 获取当前用户的患者查询构建器
     */
    private function userPatients()
    {
        return Patient::where('user_id', Auth::id());
    }

    /**
     * 显示患者列表页面
     */
    public function index(Request $request)
    {
        $query = $this->userPatients();

        // 搜索功能
        if ($request->filled('search')) {
            $search = $request->input('search');
            $query->where(function ($q) use ($search) {
                $q->where('name', 'like', "%{$search}%")
                    ->orWhere('phone', 'like', "%{$search}%")
                    ->orWhere('address', 'like', "%{$search}%");
            });
        }

        // 诊断筛选
        if ($request->filled('diagnosis')) {
            $query->where('diagnosis', 'like', "%{$request->input('diagnosis')}%");
        }

        $patients = $query->orderBy('discharge_date', 'desc')->paginate(20);

        return view('patients.index', compact('patients'));
    }

    /**
     * 显示需要随访提醒的患者
     */
    public function reminders(Request $request)
    {
        $patients = $this->userPatients()->get();
        
        // 筛选需要随访的患者
        $reminders = $patients->filter(function ($patient) {
            return !$patient->isCompleted();
        })->map(function ($patient) {
            $nextDate = $patient->getNextFollowUpDate();
            return [
                'patient' => $patient,
                'next_follow_up_date' => $nextDate,
                'next_follow_up_number' => $patient->getNextFollowUpNumber(),
                'status' => $patient->getFollowUpStatus(),
                'needs_attention' => $patient->needsFollowUp(),
                'days_until' => $nextDate ? Carbon::today()->diffInDays($nextDate, false) : null,
            ];
        })->sortBy('days_until');

        // 筛选类型
        $filter = $request->input('filter', 'all');
        
        if ($filter === 'overdue') {
            $reminders = $reminders->filter(fn($r) => $r['days_until'] !== null && $r['days_until'] < 0);
        } elseif ($filter === 'today') {
            $reminders = $reminders->filter(fn($r) => $r['days_until'] === 0);
        } elseif ($filter === 'upcoming') {
            $reminders = $reminders->filter(fn($r) => $r['days_until'] !== null && $r['days_until'] > 0 && $r['days_until'] <= 7);
        }

        // 统计数据
        $stats = [
            'total' => $this->userPatients()->count(),
            'overdue' => $patients->filter(fn($p) => !$p->isCompleted() && $p->getNextFollowUpDate()?->lt(Carbon::today()))->count(),
            'today' => $patients->filter(fn($p) => !$p->isCompleted() && $p->getNextFollowUpDate()?->isToday())->count(),
            'upcoming' => $patients->filter(function ($p) {
                if ($p->isCompleted()) return false;
                $next = $p->getNextFollowUpDate();
                if (!$next) return false;
                $diff = Carbon::today()->diffInDays($next, false);
                return $diff > 0 && $diff <= 7;
            })->count(),
            'completed' => $patients->filter(fn($p) => $p->isCompleted())->count(),
        ];

        return view('patients.reminders', compact('reminders', 'stats', 'filter'));
    }

    /**
     * 显示导入页面
     */
    public function showImport()
    {
        return view('patients.import');
    }

    /**
     * 处理Excel导入
     */
    public function import(Request $request)
    {
        $request->validate([
            'file' => 'required|file|mimes:xlsx,xls,csv|max:10240',
        ]);

        $file = $request->file('file');
        $path = $file->getRealPath();
        
        try {
            $data = $this->parseExcel($path, $file->getClientOriginalExtension());
            
            $imported = 0;
            $errors = [];
            $headerSkipped = false;
            
            foreach ($data as $index => $row) {
                try {
                    // 跳过空行
                    if (empty($row) || !is_array($row)) {
                        continue;
                    }
                    
                    $firstCell = trim((string)($row[0] ?? ''));
                    
                    // 跳过表头行（第一行或包含"姓名"的行）
                    if (!$headerSkipped && ($index === 0 || mb_strpos($firstCell, '姓名') !== false)) {
                        $headerSkipped = true;
                        continue;
                    }
                    
                    // 跳过空行
                    if (empty($firstCell)) {
                        continue;
                    }
                    
                    // 解析数据
                    $patientData = $this->parseRow($row);
                    
                    if ($patientData) {
                        // 关联到当前用户
                        $patientData['user_id'] = Auth::id();
                        Patient::create($patientData);
                        $imported++;
                    }
                } catch (\Exception $e) {
                    $errors[] = "第 " . ($index + 1) . " 行导入失败: " . $e->getMessage();
                }
            }
            
            $message = "成功导入 {$imported} 条记录。";
            if (count($errors) > 0) {
                $message .= " " . count($errors) . " 条记录导入失败。";
            }
            
            return redirect()->route('patients.index')
                ->with('success', $message)
                ->with('errors', $errors);
                
        } catch (\Exception $e) {
            return back()->withErrors(['file' => '文件解析失败: ' . $e->getMessage()]);
        }
    }

    /**
     * 解析Excel/CSV文件 (使用 xlswriter 扩展)
     */
    private function parseExcel(string $path, string $extension): array
    {
        $data = [];
        
        if ($extension === 'csv') {
            // 检测文件编码并转换
            $content = file_get_contents($path);
            $encoding = mb_detect_encoding($content, ['UTF-8', 'GBK', 'GB2312', 'BIG5'], true);
            
            if ($encoding && $encoding !== 'UTF-8') {
                $content = mb_convert_encoding($content, 'UTF-8', $encoding);
                $tempPath = sys_get_temp_dir() . '/converted_' . time() . '.csv';
                file_put_contents($tempPath, $content);
                $path = $tempPath;
            }
            
            $handle = fopen($path, 'r');
            // 跳过 BOM
            $bom = fread($handle, 3);
            if ($bom !== "\xEF\xBB\xBF") {
                rewind($handle);
            }
            
            while (($row = fgetcsv($handle)) !== false) {
                $data[] = $row;
            }
            fclose($handle);
            
            // 清理临时文件
            if (isset($tempPath) && file_exists($tempPath)) {
                @unlink($tempPath);
            }
        } elseif ($extension === 'xls') {
            // .xls 是旧版 Excel 格式，xlswriter 不支持读取
            // 尝试使用 PhpSpreadsheet 或提示用户转换格式
            if (class_exists(\PhpOffice\PhpSpreadsheet\IOFactory::class)) {
                $spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($path);
                $worksheet = $spreadsheet->getActiveSheet();
                foreach ($worksheet->getRowIterator() as $row) {
                    $rowData = [];
                    $cellIterator = $row->getCellIterator();
                    $cellIterator->setIterateOnlyExistingCells(false);
                    foreach ($cellIterator as $cell) {
                        $rowData[] = $cell->getValue();
                    }
                    $data[] = $rowData;
                }
            } else {
                throw new \Exception('不支持 .xls 格式（Excel 97-2003）。请将文件另存为 .xlsx 格式（Excel 2007+）或 .csv 格式后重新上传。操作方法：在 Excel 中打开文件 → 文件 → 另存为 → 选择"Excel 工作簿 (*.xlsx)"或"CSV UTF-8"');
            }
        } else {
            // 使用 xlswriter 扩展解析 xlsx
            if (!class_exists(\Vtiful\Kernel\Excel::class)) {
                throw new \Exception('xlswriter 扩展未安装，请安装后重试');
            }
            
            $config = ['path' => sys_get_temp_dir()];
            $excel = new \Vtiful\Kernel\Excel($config);
            
            // 复制文件到临时目录
            $tempFile = sys_get_temp_dir() . '/' . uniqid('import_') . '.' . $extension;
            copy($path, $tempFile);
            
            // 读取Excel数据
            $data = $excel->openFile(basename($tempFile))
                ->openSheet()
                ->getSheetData();
            
            // 如果没有读取到数据，可能是格式问题
            if (empty($data)) {
                throw new \Exception('无法读取 Excel 文件内容。请确保文件是有效的 .xlsx 格式，或尝试另存为 .csv 格式后重新上传。');
            }
            
            // 释放 Excel 对象
            unset($excel);
            
            // 清理临时文件 (使用 @ 抑制 Windows 上的文件锁定警告)
            if (file_exists($tempFile)) {
                @unlink($tempFile);
            }
        }
        
        return $data;
    }

    /**
     * 解析单行数据
     */
    private function parseRow(array $row): ?array
    {
        // 期望的列顺序: 姓名, 性别, 年龄, 出院诊断, 转诊时间, 户籍地址, 联系方式, 备注
        if (count($row) < 5) {
            return null;
        }

        $name = trim((string)($row[0] ?? ''));
        if (empty($name) || mb_strpos($name, '姓名') !== false) {
            return null;
        }

        // 解析日期
        $dateValue = $row[4] ?? '';
        $dischargeDate = $this->parseDate($dateValue);
        
        if (!$dischargeDate) {
            throw new \Exception("日期格式无效: {$dateValue}");
        }

        // 处理年龄（可能是数字或字符串）
        $age = $row[2] ?? 0;
        if (is_string($age)) {
            $age = (int)preg_replace('/[^0-9]/', '', $age);
        }

        // 处理电话号码（可能是科学计数法或数字）
        $phone = $row[6] ?? '';
        if (is_numeric($phone)) {
            $phone = number_format($phone, 0, '', '');
        }

        return [
            'name' => $name,
            'gender' => trim((string)($row[1] ?? '未知')),
            'age' => (int)$age,
            'diagnosis' => trim((string)($row[3] ?? '')),
            'discharge_date' => $dischargeDate,
            'address' => trim((string)($row[5] ?? '')),
            'phone' => trim((string)$phone),
            'remark' => trim((string)($row[7] ?? '')),
            'follow_up_count' => 0,
        ];
    }

    /**
     * 解析日期
     */
    private function parseDate($value): ?string
    {
        if (empty($value)) {
            return null;
        }

        $value = trim((string)$value);

        // Excel 日期序列号（纯数字且大于25569）
        if (is_numeric($value) && (float)$value > 25569 && (float)$value < 50000) {
            // Excel日期是从1900年1月1日开始的天数
            // 25569 是 1970-01-01 的Excel序列号
            $unixTimestamp = ((float)$value - 25569) * 86400;
            return date('Y-m-d', (int)$unixTimestamp);
        }

        // 字符串格式日期 - 各种格式
        $formats = [
            'Y.m.d',      // 2025.12.01
            'Y-m-d',      // 2025-12-01
            'Y/m/d',      // 2025/12/01
            'Y.n.j',      // 2025.1.1 (无前导零)
            'Y-n-j',      // 2025-1-1
            'Y/n/j',      // 2025/1/1
            'd/m/Y',      // 01/12/2025
            'm/d/Y',      // 12/01/2025
        ];
        
        foreach ($formats as $format) {
            $date = \DateTime::createFromFormat($format, $value);
            if ($date) {
                // 验证日期是否有效
                $errors = \DateTime::getLastErrors();
                if (empty($errors['warning_count']) && empty($errors['error_count'])) {
                    return $date->format('Y-m-d');
                }
            }
        }

        // 尝试通过 strtotime（处理更多格式）
        $timestamp = strtotime(str_replace('.', '-', $value));
        if ($timestamp && $timestamp > 0) {
            return date('Y-m-d', $timestamp);
        }

        return null;
    }

    /**
     * 导出提醒列表 (使用 xlswriter 生成 Excel)
     */
    public function export(Request $request)
    {
        $filter = $request->input('filter', 'all');
        
        $patients = $this->userPatients()->get();
        
        // 筛选需要随访的患者
        $reminders = $patients->filter(function ($patient) {
            return !$patient->isCompleted();
        })->map(function ($patient) {
            $nextDate = $patient->getNextFollowUpDate();
            return [
                'patient' => $patient,
                'next_follow_up_date' => $nextDate,
                'next_follow_up_number' => $patient->getNextFollowUpNumber(),
                'status' => $patient->getFollowUpStatus(),
                'days_until' => $nextDate ? Carbon::today()->diffInDays($nextDate, false) : null,
            ];
        })->sortBy('days_until');

        // 根据筛选条件过滤
        if ($filter === 'overdue') {
            $reminders = $reminders->filter(fn($r) => $r['days_until'] !== null && $r['days_until'] < 0);
        } elseif ($filter === 'today') {
            $reminders = $reminders->filter(fn($r) => $r['days_until'] === 0);
        } elseif ($filter === 'upcoming') {
            $reminders = $reminders->filter(fn($r) => $r['days_until'] !== null && $r['days_until'] > 0 && $r['days_until'] <= 7);
        }

        // 使用 xlswriter 生成 Excel 文件
        $config = ['path' => sys_get_temp_dir()];
        $filename = '随访提醒_' . date('Y-m-d_His') . '.xlsx';
        
        $excel = new \Vtiful\Kernel\Excel($config);
        
        // 创建文件并设置表头
        $fileHandle = $excel->fileName($filename)
            ->header(['姓名', '性别', '年龄', '出院诊断', '转诊时间', '下次随访日期', '第几次随访', '状态', '户籍地址', '联系方式', '备注']);
        
        // 设置表头样式
        $headerStyle = $fileHandle->getHandle();
        $format = new \Vtiful\Kernel\Format($headerStyle);
        $boldFormat = $format->bold()->toResource();
        
        // 添加数据行
        $rows = [];
        foreach ($reminders as $reminder) {
            $p = $reminder['patient'];
            $rows[] = [
                $p->name,
                $p->gender,
                $p->age,
                $p->diagnosis,
                $p->discharge_date->format('Y-m-d'),
                $reminder['next_follow_up_date']?->format('Y-m-d') ?? '',
                '第' . $reminder['next_follow_up_number'] . '次',
                $reminder['status'],
                $p->address ?? '',
                $p->phone ?? '',
                $p->remark ?? '',
            ];
        }
        
        $fileHandle->data($rows)->output();
        
        $filePath = $config['path'] . '/' . $filename;
        
        return Response::download($filePath, $filename, [
            'Content-Type' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
        ])->deleteFileAfterSend(true);
    }

    /**
     * 标记已随访
     */
    public function markFollowedUp(Patient $patient)
    {
        // 验证患者属于当前用户
        if ($patient->user_id !== Auth::id()) {
            abort(403, '无权操作此患者');
        }

        if (!$patient->isCompleted()) {
            $patient->follow_up_count += 1;
            $patient->last_follow_up_date = Carbon::today();
            $patient->save();
        }

        return back()->with('success', "{$patient->name} 已标记为完成第 {$patient->follow_up_count} 次随访");
    }

    /**
     * 删除患者
     */
    public function destroy(Patient $patient)
    {
        // 验证患者属于当前用户
        if ($patient->user_id !== Auth::id()) {
            abort(403, '无权操作此患者');
        }

        $name = $patient->name;
        $patient->delete();
        
        return back()->with('success', "已删除患者: {$name}");
    }

    /**
     * 下载导入模板 (使用 xlswriter 生成 Excel)
     */
    public function downloadTemplate()
    {
        $config = ['path' => sys_get_temp_dir()];
        $filename = '导入模板.xlsx';
        
        $excel = new \Vtiful\Kernel\Excel($config);
        
        // 创建文件
        $fileHandle = $excel->fileName($filename)
            ->header(['姓名', '性别', '年龄', '出院诊断', '转诊时间', '户籍地址', '联系方式', '备注']);
        
        // 添加示例数据
        $data = [
            ['张三', '男', 65, '脑卒中', '2025.12.01', '北京市朝阳区', '13800138000', '常住'],
            ['李四', '女', 70, '慢性肾脏病', '2025.11.15', '上海市浦东新区', '13900139000', ''],
            ['王五', '男', 58, '心肌梗塞', '2025.10.20', '广州市天河区', '13700137000', ''],
        ];
        
        $fileHandle->data($data)->output();
        
        $filePath = $config['path'] . '/' . $filename;
        
        return Response::download($filePath, $filename, [
            'Content-Type' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
        ])->deleteFileAfterSend(true);
    }
}