// ── procedures.controller.ts (reports) ────────────────────────────────────────
import { Controller, Get, Post, Body, Query, Res, UseGuards } from '@nestjs/common';
import { AuthGuard } from '@nestjs/passport';
import { ApiTags, ApiBearerAuth, ApiOperation, ApiQuery } from '@nestjs/swagger';
import { Response } from 'express';
import { ProceduresService } from './procedures.service';

@ApiTags('Reports')
@ApiBearerAuth()
@UseGuards(AuthGuard('jwt'))
@Controller('reports')
export class ProceduresController {
  constructor(private svc: ProceduresService) {}

  @Get('top-diagnoses')
  @ApiOperation({ summary: 'Most used ICD-10 diagnostic codes' })
  @ApiQuery({ name: 'limit', required: false })
  getTopDiagnoses(@Query('limit') limit = 10) {
    return this.svc.getTopDiagnoses(+limit);
  }

  @Get('top-procedures')
  @ApiOperation({ summary: 'Most used CPT procedure codes' })
  @ApiQuery({ name: 'limit', required: false })
  getTopProcedures(@Query('limit') limit = 10) {
    return this.svc.getTopProcedures(+limit);
  }

  @Get('encounters-by-month')
  @ApiOperation({ summary: 'Encounter volume by month' })
  getEncountersByMonth() {
    return this.svc.getEncountersByMonth();
  }

  @Get('status-breakdown')
  @ApiOperation({ summary: 'Encounter status breakdown' })
  getStatusBreakdown() {
    return this.svc.getStatusBreakdown();
  }

  @Post('export/pdf')
  @ApiOperation({ summary: 'Export encounters report as PDF' })
  async exportPDF(@Body() filters: any, @Res() res: Response) {
    const encounters = await this.svc.exportEncountersPDF();
    const PDFDocument = require('pdfkit');
    const doc = new PDFDocument({ margin: 50 });

    res.setHeader('Content-Type', 'application/pdf');
    res.setHeader('Content-Disposition', `attachment; filename="medicode-report-${new Date().toISOString().substring(0,10)}.pdf"`);
    doc.pipe(res);

    // Header
    doc.fontSize(20).fillColor('#0EA5E9').text('MediCode', 50, 50);
    doc.fontSize(12).fillColor('#64748b').text('Medical Coding Report', 50, 75);
    doc.fontSize(10).fillColor('#94a3b8').text(`Generated: ${new Date().toLocaleDateString()}`, 50, 92);
    doc.moveTo(50, 110).lineTo(545, 110).strokeColor('#e2e8f0').stroke();

    // Stats
    doc.fontSize(14).fillColor('#0f172a').text('Encounters Summary', 50, 125);
    doc.fontSize(10).fillColor('#374151');

    let y = 150;
    encounters.slice(0, 50).forEach((enc: any, i: number) => {
      if (y > 700) { doc.addPage(); y = 50; }
      const patient = enc.patient as any;
      const patientName = patient ? `${patient.firstName} ${patient.lastName}` : 'Unknown';
      const date = enc.encounterDate ? new Date(enc.encounterDate).toLocaleDateString() : '—';
      const status = enc.status?.toUpperCase() || 'DRAFT';

      doc.fillColor(i % 2 === 0 ? '#f8fafc' : 'white')
        .rect(50, y - 3, 495, 18).fill();

      doc.fillColor('#0f172a').text(`${i + 1}.`, 55, y, { width: 20 });
      doc.fillColor('#0f172a').text(patientName, 75, y, { width: 140 });
      doc.fillColor('#64748b').text(date, 220, y, { width: 80 });
      doc.fillColor('#64748b').text(enc.provider || '—', 305, y, { width: 140 });

      const statusColors: Record<string, string> = { DRAFT: '#b45309', CODED: '#1d4ed8', BILLED: '#7c3aed', PAID: '#065f46' };
      doc.fillColor(statusColors[status] || '#374151').text(status, 450, y, { width: 60 });

      const dx = (enc.diagnosticCodes || []).slice(0, 2).map((c: any) => c.code).join(', ');
      if (dx) { doc.fillColor('#94a3b8').fontSize(8).text(`ICD-10: ${dx}`, 75, y + 8, { width: 300 }); }
      doc.fontSize(10);

      y += dx ? 24 : 18;
    });

    doc.end();
  }

  @Post('export/excel')
  @ApiOperation({ summary: 'Export encounters report as Excel' })
  async exportExcel(@Body() filters: any, @Res() res: Response) {
    const encounters = await this.svc.exportEncountersExcel();
    const ExcelJS = require('exceljs');
    const workbook = new ExcelJS.Workbook();
    workbook.creator = 'MediCode';
    workbook.created = new Date();

    const sheet = workbook.addWorksheet('Encounters', {
      pageSetup: { paperSize: 9, orientation: 'landscape' },
    });

    // Columns
    sheet.columns = [
      { header: '#', key: 'num', width: 5 },
      { header: 'Patient', key: 'patient', width: 25 },
      { header: 'MRN', key: 'mrn', width: 14 },
      { header: 'Date', key: 'date', width: 14 },
      { header: 'Provider', key: 'provider', width: 22 },
      { header: 'Status', key: 'status', width: 12 },
      { header: 'ICD-10 Codes', key: 'icd10', width: 30 },
      { header: 'CPT Codes', key: 'cpt', width: 30 },
      { header: 'Insurance', key: 'insurance', width: 22 },
      { header: 'Coded By', key: 'codedBy', width: 18 },
      { header: 'Notes', key: 'notes', width: 40 },
    ];

    // Header style
    sheet.getRow(1).eachCell((cell: any) => {
      cell.font = { bold: true, color: { argb: 'FFFFFFFF' }, size: 11 };
      cell.fill = { type: 'pattern', pattern: 'solid', fgColor: { argb: 'FF0EA5E9' } };
      cell.alignment = { vertical: 'middle', horizontal: 'center' };
      cell.border = { bottom: { style: 'medium', color: { argb: 'FF0284C7' } } };
    });
    sheet.getRow(1).height = 28;

    // Data rows
    const statusColors: Record<string, string> = {
      draft: 'FFFEF3C7', coded: 'FFEFF6FF', billed: 'FFF3E8FF', paid: 'FFECFDF5',
    };

    encounters.forEach((enc: any, i: number) => {
      const patient = enc.patient as any;
      const row = sheet.addRow({
        num: i + 1,
        patient: patient ? `${patient.firstName} ${patient.lastName}` : '—',
        mrn: patient?.mrn || '—',
        date: enc.encounterDate ? new Date(enc.encounterDate).toLocaleDateString() : '—',
        provider: enc.provider || '—',
        status: enc.status?.toUpperCase() || 'DRAFT',
        icd10: (enc.diagnosticCodes || []).map((c: any) => `${c.code}: ${c.description}`).join('\n'),
        cpt: (enc.procedureCodes || []).map((c: any) => `${c.code}: ${c.description}`).join('\n'),
        insurance: patient?.insurance || '—',
        codedBy: (enc.codedBy as any)?.name || '—',
        notes: enc.notes || '',
      });

      row.height = Math.max(20, (enc.diagnosticCodes?.length || 1) * 15);
      row.eachCell((cell: any) => {
        cell.alignment = { vertical: 'top', wrapText: true };
        if (i % 2 === 1) {
          cell.fill = { type: 'pattern', pattern: 'solid', fgColor: { argb: 'FFF8FAFC' } };
        }
      });

      // Status color
      const statusCell = row.getCell('status');
      const bgColor = statusColors[enc.status] || 'FFFFFFFF';
      statusCell.fill = { type: 'pattern', pattern: 'solid', fgColor: { argb: bgColor } };
      statusCell.font = { bold: true };
      statusCell.alignment = { horizontal: 'center', vertical: 'middle' };
    });

    // Add summary sheet
    const summarySheet = workbook.addWorksheet('Summary');
    summarySheet.addRow(['MediCode Report Summary']);
    summarySheet.addRow(['Generated', new Date().toLocaleString()]);
    summarySheet.addRow(['Total Encounters', encounters.length]);
    const statusCounts: Record<string, number> = {};
    encounters.forEach((e: any) => { statusCounts[e.status] = (statusCounts[e.status] || 0) + 1; });
    Object.entries(statusCounts).forEach(([status, count]) => {
      summarySheet.addRow([status.toUpperCase(), count]);
    });

    res.setHeader('Content-Type', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
    res.setHeader('Content-Disposition', `attachment; filename="medicode-report-${new Date().toISOString().substring(0,10)}.xlsx"`);
    await workbook.xlsx.write(res);
    res.end();
  }
}