import {
  captureAfterLabel,
  parseDayMonthYear,
  parseIdrAmount,
} from "../lib/parse-helpers.js";

const QTY_LINE = /^(\d+)\s*x\s*(Rp[\d.,]+)\s*$/i;
const RP_ONLY = /^(Rp[\d.,]+)\s*$/i;
const URL_LINE = /^(?:https?:\/\/|<https?:\/\/)/i;

function isUrlLine(line) {
  return URL_LINE.test(line.trim());
}

/**
 * Extract product line items from the Toko…Subtotal block.
 * Handles single- and multi-item orders from the same shop.
 */
export function extractTokopediaItems(itemBlock) {
  if (!itemBlock) return [];

  const lines = itemBlock
    .split(/\r?\n/)
    .map((l) => l.trim())
    .filter((l) => l && !isUrlLine(l));

  const items = [];
  let nameParts = [];

  for (let i = 0; i < lines.length; i++) {
    const line = lines[i];
    const qtyMatch = line.match(QTY_LINE);
    if (qtyMatch) {
      const qty = Number(qtyMatch[1]);
      const unitPrice = parseIdrAmount(qtyMatch[2]);
      let lineTotal = unitPrice;
      const next = lines[i + 1];
      if (next && RP_ONLY.test(next)) {
        lineTotal = parseIdrAmount(next);
        i += 1;
      }
      const name = nameParts.join(" ").replace(/\s+/g, " ").trim();
      nameParts = [];
      if (name && unitPrice != null) {
        items.push({
          name,
          qty,
          unitPrice,
          lineTotal: lineTotal ?? unitPrice,
        });
      }
      continue;
    }
    nameParts.push(line);
  }

  return items;
}

function extractItemBlock(body) {
  const tokoIdx = body.search(/Toko\s*:/i);
  if (tokoIdx < 0) return null;

  const afterToko = body.slice(tokoIdx);
  const shopLineEnd = afterToko.search(/\r?\n/);
  const rest =
    shopLineEnd >= 0 ? afterToko.slice(shopLineEnd + 1) : afterToko;

  const endMatch = rest.search(/Subtotal harga produk|Total belanja/i);
  return endMatch >= 0 ? rest.slice(0, endMatch) : rest;
}

function parseTotalBelanja(body) {
  const m = body.match(/Total\s+belanja\s*\r?\n\s*(Rp[\d.,]+)/i);
  if (m) return parseIdrAmount(m[1]);
  // Fallback: value on same line
  return parseIdrAmount(captureAfterLabel(body, "Total belanja"));
}

/**
 * Parse Tokopedia “Pesanan Selesai” body (plain text).
 * Required: No.Invoice + Total belanja. One row per invoice.
 */
export function parseTokopediaOrder(body) {
  if (!body) return null;

  const invoiceMatch = body.match(/No\.?\s*Invoice\s*:?\s*(\d+)/i);
  const reference = invoiceMatch?.[1] || null;

  const amount = parseTotalBelanja(body);
  if (amount == null || !reference) return null;

  const cleanRef = reference.trim();
  if (!cleanRef) return null;

  const shopMatch = body.match(/Toko\s*:\s*([^\n<]+)/i);
  const shop = shopMatch
    ? shopMatch[1].replace(/[<\s]*https?:\/\/.*$/i, "").trim() || null
    : null;

  const items = extractTokopediaItems(extractItemBlock(body));

  const tanggalRaw = captureAfterLabel(body, "Tanggal Terima");
  const occurredAt = parseDayMonthYear(tanggalRaw);

  const trackingNumber = captureAfterLabel(body, "Nomor Resi");
  const shippingService = captureAfterLabel(body, "Layanan Pengiriman");

  const details = {};
  if (shop) details.shop = shop;
  if (items.length) details.items = items;
  if (trackingNumber && !isUrlLine(trackingNumber)) {
    details.trackingNumber = trackingNumber.trim();
  }
  if (shippingService && !isUrlLine(shippingService)) {
    details.shippingService = shippingService.trim();
  }

  return {
    amount,
    currency: "IDR",
    reference: cleanRef,
    occurredAt,
    details,
  };
}