#!/usr/bin/env ts-node
/**
 * Excel Datasheet Generator
 *
 * Generates per-product .xlsx datasheets using ONLY data from Payload CMS.
 * No external Excel files required.
 */

import * as fs from 'fs';
import * as path from 'path';

import * as XLSX from 'xlsx';
import { getPayload } from 'payload';
import configPromise from '@payload-config';
import { buildExcelModel, ProductData as ExcelProductData } from './lib/excel-data-parser';

const CONFIG = {
    outputDir: path.join(process.cwd(), 'public/datasheets'),
} as const;

// ─── Types ──────────────────────────────────────────────────────────────────────

interface ProductData {
    title: string;
    slug: string;
    sku: string;
    locale: string;
    categories: string[];
    description: string;
    technicalItems: Array<{ label: string; value: string; unit?: string }>;
    voltageTables: Array<{
        voltageLabel: string;
        metaItems: Array<{ label: string; value: string; unit?: string }>;
        columns: Array<{ key: string; label: string; get: (rowIndex: number) => string }>;
        crossSections: string[];
    }>;
}

// ─── Helpers ────────────────────────────────────────────────────────────────────

function stripHtml(html: string): string {
    if (!html) return '';
    return html.replace(/<[^>]*>/g, '').trim();
}

function ensureOutputDir(): void {
    if (!fs.existsSync(CONFIG.outputDir)) {
        fs.mkdirSync(CONFIG.outputDir, { recursive: true });
    }
}

// ─── CMS Product Loading ────────────────────────────────────────────────────────

async function fetchProductsFromCMS(locale: 'en' | 'de'): Promise<ProductData[]> {
    const products: ProductData[] = [];
    try {
        const payload = await getPayload({ config: configPromise });
        const isDev = process.env.NODE_ENV === 'development';

        const result = await payload.find({
            collection: 'products',
            where: {
                ...(!isDev ? { _status: { equals: 'published' } } : {}),
            },
            locale: locale as any,
            pagination: false,
        });

        for (const doc of result.docs) {
            if (!doc.title || !doc.slug) continue;

            const excelProductData: ExcelProductData = {
                name: String(doc.title),
                slug: String(doc.slug),
                sku: String(doc.sku || ''),
                locale,
            };

            const parsedModel = buildExcelModel({ product: excelProductData, locale });

            products.push({
                title: String(doc.title),
                slug: String(doc.slug),
                sku: String(doc.sku || ''),
                locale,
                categories: Array.isArray(doc.categories)
                    ? doc.categories.map((c: any) => String(c.category || c)).filter(Boolean)
                    : [],
                description: stripHtml(String(doc.description || '')),
                technicalItems: parsedModel.ok ? parsedModel.technicalItems : [],
                voltageTables: parsedModel.ok ? parsedModel.voltageTables : [],
            });
        }
    } catch (error) {
        console.error(`[Payload] Failed to fetch products (${locale}):`, error);
    }

    return products;
}

// ─── Excel Generation ───────────────────────────────────────────────────────────

function generateExcelForProduct(product: ProductData): Buffer {
    const workbook = XLSX.utils.book_new();
    const l = product.locale === 'de';

    // Single sheet: all cross-sections from all voltage tables combined
    const hasMultipleVoltages = product.voltageTables.length > 1;
    const allRows: string[][] = [];

    // Build unified header row
    // Use columns from the first voltage table (they're the same across tables)
    const refTable = product.voltageTables[0];
    if (!refTable) {
        // No voltage tables — create a minimal info sheet
        const ws = XLSX.utils.aoa_to_sheet([
            [product.title],
            [l ? 'Keine Querschnittsdaten verfügbar' : 'No cross-section data available'],
        ]);
        ws['!cols'] = [{ wch: 40 }];
        XLSX.utils.book_append_sheet(workbook, ws, product.title.substring(0, 31));
        return Buffer.from(XLSX.write(workbook, { type: 'buffer', bookType: 'xlsx' }));
    }

    const headers: string[] = [
        l ? 'Querschnitt' : 'Cross-section',
        ...(hasMultipleVoltages ? [l ? 'Spannung' : 'Voltage'] : []),
        ...refTable.columns.map(c => c.label),
    ];
    allRows.push(headers);

    // Merge rows from all voltage tables
    for (const table of product.voltageTables) {
        for (let rowIdx = 0; rowIdx < table.crossSections.length; rowIdx++) {
            const row: string[] = [
                table.crossSections[rowIdx],
                ...(hasMultipleVoltages ? [table.voltageLabel] : []),
                ...table.columns.map(c => c.get(rowIdx) || '-'),
            ];
            allRows.push(row);
        }
    }

    const ws = XLSX.utils.aoa_to_sheet(allRows);
    // Auto-width: first col wider for cross-section labels
    ws['!cols'] = headers.map((_, i) => ({ wch: i === 0 ? 30 : 18 }));

    const sheetName = product.title.substring(0, 31);
    XLSX.utils.book_append_sheet(workbook, ws, sheetName);

    const buffer = XLSX.write(workbook, { type: 'buffer', bookType: 'xlsx' });
    return Buffer.from(buffer);
}

// ─── Main ───────────────────────────────────────────────────────────────────────

async function main(): Promise<void> {
    const start = Date.now();
    console.log('Starting Excel datasheet generation (Legacy Excel Source)');
    ensureOutputDir();

    const locales: Array<'en' | 'de'> = ['en', 'de'];
    let generated = 0;

    for (const locale of locales) {
        console.log(`\n[${locale.toUpperCase()}] Fetching products...`);
        const products = await fetchProductsFromCMS(locale);
        console.log(`Found ${products.length} products.`);

        for (const product of products) {
            try {
                const buffer = generateExcelForProduct(product);
                const fileName = `${product.slug}-${locale}.xlsx`;

                const subfolder = path.join(CONFIG.outputDir, 'products');
                if (!fs.existsSync(subfolder)) fs.mkdirSync(subfolder, { recursive: true });

                fs.writeFileSync(path.join(subfolder, fileName), buffer);
                console.log(`✓ Generated: ${fileName}`);
                generated++;
            } catch (error) {
                console.error(`✗ Failed for ${product.title}:`, error);
            }
        }
    }

    console.log(`\n✅ Done! Generated ${generated} files.`);
    console.log(`Output: ${CONFIG.outputDir}`);
    console.log(`Time: ${((Date.now() - start) / 1000).toFixed(2)}s`);
}

main().catch(console.error);