/**
 * Factory-Defaults: Export + Import von Stammdaten-Katalogen.
 * Enthält KEINE Kundendaten, Verträge, Dokumente oder Einstellungen –
 * nur reine Kataloge: Anbieter, Tarife, Kündigungsfristen, Laufzeiten,
 * Vertragskategorien und PDF-Auftragsvorlagen.
 */

import fs from 'fs';
import path from 'path';
import archiver from 'archiver';
import prisma from '../lib/prisma.js';

export interface FactoryDefaultsManifest {
  version: 1;
  exportedAt: string;
  counts: {
    providers: number;
    tariffs: number;
    cancellationPeriods: number;
    contractDurations: number;
    contractCategories: number;
    pdfTemplates: number;
  };
}

export interface ProviderExport {
  name: string;
  portalUrl: string | null;
  usernameFieldName: string | null;
  passwordFieldName: string | null;
  isActive: boolean;
  tariffs: { name: string; isActive: boolean }[];
}

export interface PdfTemplateExport {
  name: string;
  description: string | null;
  providerName: string | null;
  originalName: string;
  fieldMapping: any;
  phoneFieldPrefix: string | null;
  maxPhoneFields: number | null;
  isActive: boolean;
  // Datei wird separat im ZIP abgelegt unter pdf-templates/<name>.pdf
  pdfFilename: string;
}

/**
 * Sammelt alle Katalog-Daten aus der DB.
 */
export async function collectFactoryDefaults() {
  const [providers, cancellationPeriods, contractDurations, contractCategories, pdfTemplates] =
    await Promise.all([
      prisma.provider.findMany({
        include: { tariffs: { select: { name: true, isActive: true } } },
        orderBy: { name: 'asc' },
      }),
      prisma.cancellationPeriod.findMany({ orderBy: { code: 'asc' } }),
      prisma.contractDuration.findMany({ orderBy: { code: 'asc' } }),
      prisma.contractCategory.findMany({ orderBy: { sortOrder: 'asc' } }),
      prisma.pdfTemplate.findMany({ orderBy: { name: 'asc' } }),
    ]);

  return {
    providers: providers.map<ProviderExport>((p) => ({
      name: p.name,
      portalUrl: p.portalUrl,
      usernameFieldName: p.usernameFieldName,
      passwordFieldName: p.passwordFieldName,
      isActive: p.isActive,
      tariffs: p.tariffs.map((t) => ({ name: t.name, isActive: t.isActive })),
    })),
    cancellationPeriods: cancellationPeriods.map((c) => ({
      code: c.code,
      description: c.description,
      isActive: c.isActive,
    })),
    contractDurations: contractDurations.map((d) => ({
      code: d.code,
      description: d.description,
      isActive: d.isActive,
    })),
    contractCategories: contractCategories.map((c) => ({
      code: c.code,
      name: c.name,
      icon: c.icon,
      color: c.color,
      sortOrder: c.sortOrder,
      isActive: c.isActive,
    })),
    pdfTemplates: pdfTemplates.map<PdfTemplateExport>((t) => {
      // fieldMapping ist im DB als String abgelegt – zu Objekt parsen
      let fieldMapping: any = {};
      try {
        fieldMapping = JSON.parse(t.fieldMapping);
      } catch {
        fieldMapping = {};
      }
      return {
        name: t.name,
        description: t.description,
        providerName: t.providerName,
        originalName: t.originalName,
        fieldMapping,
        phoneFieldPrefix: t.phoneFieldPrefix,
        maxPhoneFields: t.maxPhoneFields,
        isActive: t.isActive,
        pdfFilename: sanitizeFilename(t.name) + path.extname(t.originalName || '.pdf'),
      };
    }),
  };
}

function sanitizeFilename(name: string): string {
  return name.replace(/[^a-zA-Z0-9äöüÄÖÜß_-]/g, '_').replace(/_+/g, '_');
}

/**
 * Erstellt ein ZIP-Archiv mit allen Factory-Defaults.
 * Die PDF-Dateien werden aus dem uploads-Verzeichnis gelesen.
 */
export async function exportFactoryDefaults(): Promise<Buffer> {
  const data = await collectFactoryDefaults();

  const manifest: FactoryDefaultsManifest = {
    version: 1,
    exportedAt: new Date().toISOString(),
    counts: {
      providers: data.providers.length,
      tariffs: data.providers.reduce((sum, p) => sum + p.tariffs.length, 0),
      cancellationPeriods: data.cancellationPeriods.length,
      contractDurations: data.contractDurations.length,
      contractCategories: data.contractCategories.length,
      pdfTemplates: data.pdfTemplates.length,
    },
  };

  return new Promise<Buffer>((resolve, reject) => {
    const archive = archiver('zip', { zlib: { level: 9 } });
    const chunks: Buffer[] = [];

    archive.on('data', (chunk: Buffer) => chunks.push(chunk));
    archive.on('end', () => resolve(Buffer.concat(chunks)));
    archive.on('error', reject);

    // JSON-Dateien vorbereiten
    archive.append(JSON.stringify(manifest, null, 2), { name: 'manifest.json' });
    archive.append(JSON.stringify(data.providers, null, 2), {
      name: 'providers/providers.json',
    });
    archive.append(JSON.stringify(data.cancellationPeriods, null, 2), {
      name: 'contract-meta/cancellation-periods.json',
    });
    archive.append(JSON.stringify(data.contractDurations, null, 2), {
      name: 'contract-meta/contract-durations.json',
    });
    archive.append(JSON.stringify(data.contractCategories, null, 2), {
      name: 'contract-meta/contract-categories.json',
    });
    archive.append(JSON.stringify(data.pdfTemplates, null, 2), {
      name: 'pdf-templates/pdf-templates.json',
    });

    // PDF-Dateien physisch hinzufügen (Pfade aus DB laden)
    const uploadsRoot = path.join(process.cwd(), 'uploads');
    (async () => {
      try {
        const templateRows = await prisma.pdfTemplate.findMany({
          select: { name: true, templatePath: true },
        });
        const pathByName = new Map(templateRows.map((r) => [r.name, r.templatePath]));

        for (const t of data.pdfTemplates) {
          const storedPath = pathByName.get(t.name);
          if (!storedPath) continue;

          const relPath = storedPath.startsWith('/uploads/')
            ? storedPath.substring('/uploads/'.length)
            : storedPath;
          const absPath = path.join(uploadsRoot, relPath);

          if (fs.existsSync(absPath)) {
            archive.file(absPath, { name: `pdf-templates/${t.pdfFilename}` });
          } else {
            console.warn(`[factoryDefaults] PDF-Datei nicht gefunden: ${absPath}`);
          }
        }
        archive.finalize();
      } catch (err) {
        reject(err);
      }
    })();
  });
}