'use strict';

const PdfGenerationService = require('./pdfGenerationService');
const { assertCustomerDocumentLanguage } = require('./customerDocumentLanguage');
const { SCHEMA, GenericQuoteSnapshotService } = require('./genericQuoteSnapshotService');
const pick = (object, keys) => Object.fromEntries(keys.filter(key => object[key] !== undefined).map(key => [key, object[key]]));
const error = (code, message) => { throw Object.assign(new Error(message), { status: 422, code }); };

function customerDocument(snapshot) {
  if (snapshot?.artifact?.schema !== SCHEMA || !snapshot.approved || snapshot.approval?.signature !== snapshot.signature) {
    error('GENERIC_QUOTE_APPROVAL_REQUIRED', 'Approved generic snapshot required');
  }
  new GenericQuoteSnapshotService().assertExpectedSignature(snapshot, snapshot.signature);
  const artifact = snapshot.artifact;
  const lines = Object.fromEntries(Object.entries(artifact.lines).map(([kind, rows]) => [kind, rows.map(line =>
    pick(line, kind === 'tasks' ? ['name', 'totalHours', 'rate', 'lineTotal'] : ['name', 'quantity', 'unit', 'unitPrice', 'lineTotal']))]));
  const categoryTotal = kind => Math.round((lines[kind] || []).reduce((sum, line) => sum + Number(line.lineTotal || 0), 0) * 100) / 100;
  const subtotals = {
    materials: categoryTotal('materials'),
    labor: categoryTotal('tasks'),
    rentals: categoryTotal('rentals'),
    references: categoryTotal('references')
  };
  subtotals.lineTotal = Math.round(Object.values(subtotals).reduce((sum, value) => sum + value, 0) * 100) / 100;
  const totals = pick(artifact.economics, ['totalExclVat', 'vatPercentage', 'vatAmount', 'totalInclVat']);
  const customerPriceAdjustment = {
    label: 'Aftalt pristilpasning',
    explanation: 'Forskellen mellem de viste linjer og den aftalte samlede pris for projektets levering og udførelse.',
    amount: Math.round((totals.totalExclVat - subtotals.lineTotal) * 100) / 100
  };
  const document = {
    project: pick(artifact.customerProject, ['id', 'project_name', 'customer_number', 'customer_name', 'customer_address', 'customer_email']),
    quoteText: artifact.quoteText, reservations: artifact.reservations, lines, subtotals, customerPriceAdjustment, totals
  };
  // Do not silently rewrite signed customer text or expose internal labels through it.
  const customerText = [document.quoteText, ...Object.values(document.project), ...document.reservations,
    ...Object.values(lines).flat().map(line => line.name)];
  assertCustomerDocumentLanguage(customerText);
  return document;
}

function ordrestyringPayload(snapshot) {
  const document = customerDocument(snapshot);
  return {
    projectId: document.project.id, customerNumber: document.project.customer_number,
    description: document.quoteText, reservations: document.reservations,
    lines: Object.entries(document.lines).flatMap(([type, rows]) => rows.map(line => ({ type, ...line }))),
    ...document.totals, snapshotSignature: snapshot.signature,
    snapshotSchema: SCHEMA, approval: snapshot.approval
  };
}

const escapeHtml = value => String(value ?? '').replace(/[&<>"']/g, char => ({
  '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;'
}[char]));

const formatMoney = value => `${Number(value || 0).toLocaleString('da-DK', {
  minimumFractionDigits: 2,
  maximumFractionDigits: 2
})} kr.`;

class GenericQuotePdfService extends PdfGenerationService {
  async generatePdfHtml(document) {
    const { project, lines, totals, subtotals, customerPriceAdjustment, quoteText, reservations } = document;
    assertCustomerDocumentLanguage([
      quoteText,
      ...Object.values(project || {}),
      ...(Array.isArray(reservations) ? reservations : []),
      ...Object.values(lines || {}).flat().map(line => line?.name)
    ]);
    const sections = { materials: 'Materialer', tasks: 'Arbejde', rentals: 'Leje', references: 'Øvrige ydelser' };
    const rows = Object.entries(lines).map(([kind, items]) => {
      if (!items.length) return '';
      const labor = kind === 'tasks';
      const heading = labor
        ? '<th>Beskrivelse</th><th>Timer</th><th>Timepris ekskl. moms</th><th>Linjetotal ekskl. moms</th>'
        : '<th>Beskrivelse</th><th>Antal</th><th>Enhed</th><th>Enhedspris ekskl. moms</th><th>Linjetotal ekskl. moms</th>';
      const body = items.map(line => labor
        ? `<tr><td>${escapeHtml(line.name)}</td><td>${escapeHtml(line.totalHours)} timer</td><td>${formatMoney(line.rate)}</td><td>${formatMoney(line.lineTotal)}</td></tr>`
        : `<tr><td>${escapeHtml(line.name)}</td><td>${escapeHtml(line.quantity)}</td><td>${escapeHtml(line.unit)}</td><td>${formatMoney(line.unitPrice)}</td><td>${formatMoney(line.lineTotal)}</td></tr>`).join('');
      return `<h2>${sections[kind]}</h2><table><thead><tr>${heading}</tr></thead><tbody>${body}</tbody></table>`;
    }).join('');
    const subtotalRows = [
      ['Materialer', subtotals.materials], ['Arbejde', subtotals.labor], ['Leje', subtotals.rentals],
      ['Øvrige ydelser', subtotals.references], ['Linjer i alt', subtotals.lineTotal]
    ].map(([label, value]) => `<tr><th>${label}</th><td>${formatMoney(value)}</td></tr>`).join('');
    return `<!doctype html><html lang="da"><head><meta charset="utf-8"><title>Tilbud – ${escapeHtml(project.project_name)}</title>
      <style>body{font:14px Arial;color:#182b36;line-height:1.45}h1{font-size:28px}h2{font-size:17px;margin:22px 0 6px}
      table{width:100%;border-collapse:collapse}td,th{text-align:left;padding:7px;border-bottom:1px solid #ddd}thead th{font-size:11px}
      td:last-child,th:last-child{text-align:right}.summary{margin-top:8px}.explanation{font-size:12px;color:#455a64;margin:3px 0 10px}
      p{white-space:pre-wrap}.grand-total{font-size:16px;font-weight:bold}</style></head><body>
      <h1>Tilbud: ${escapeHtml(project.project_name)}</h1><p>${escapeHtml(project.customer_name)}\n${escapeHtml(project.customer_address)}</p>
      <p>${escapeHtml(quoteText)}</p>${rows}
      <h2>Prisoversigt</h2><table class="summary"><tbody>${subtotalRows}
      <tr><th>${escapeHtml(customerPriceAdjustment.label)}</th><td>${formatMoney(customerPriceAdjustment.amount)}</td></tr></tbody></table>
      <p class="explanation">${escapeHtml(customerPriceAdjustment.explanation)}</p>
      <table class="summary"><tbody><tr><th>Samlet pris ekskl. moms</th><td>${formatMoney(totals.totalExclVat)}</td></tr>
      <tr><th>Moms (${escapeHtml(totals.vatPercentage)}%)</th><td>${formatMoney(totals.vatAmount)}</td></tr>
      <tr class="grand-total"><th>I alt inkl. moms</th><td>${formatMoney(totals.totalInclVat)}</td></tr></tbody></table>
      ${reservations.length ? `<h2>Forbehold</h2><p>${reservations.map(escapeHtml).join('\n')}</p>` : ''}</body></html>`;
  }
}

module.exports = { customerDocument, ordrestyringPayload, GenericQuotePdfService };