import type { Context } from "hono";
import { prisma } from "../../../lib/prisma";
import { logger } from "../../../lib/logger";

function parseArgentineAmount(raw: string): number {
  const cleaned = raw.replace("$", "").replace(/,/g, "").trim();
  return Number(cleaned);
}

function parsePeriods(raw: string): number[] {
  const inner = raw.replace(/^\{|\}$/g, "").trim();
  if (!inner) return [];
  return inner.split(",").map(Number);
}

export async function importPeriodicExpensesHandler(c: Context) {
  const body = await c.req.parseBody();
  const file = body["file"];

  if (!file || !(file instanceof File)) {
    return c.json({ error: "No se envió ningún archivo" }, 400);
  }

  const text = await file.text();
  const lines = text.trim().split("\n");

  if (lines.length < 2) {
    return c.json({ error: "El archivo está vacío o solo tiene encabezados" }, 400);
  }

  let imported = 0;
  let skippedNoPeriods = 0;
  let skippedDuplicate = 0;
  const errors: string[] = [];

  for (let i = 1; i < lines.length; i++) {
    const line = lines[i].trim();
    if (!line) continue;

    const parts = line.split("|");
    if (parts.length < 5) {
      errors.push(`Línea ${i + 1}: formato inválido`);
      continue;
    }

    const description = parts[1].trim();
    const defaultDueDay = Number(parts[2].trim());
    const rawAmount = parts[3].trim();
    const rawPeriods = parts[4].trim();

    const periods = parsePeriods(rawPeriods);

    if (periods.length === 0) {
      skippedNoPeriods++;
      continue;
    }

    try {
      const existing = await prisma.periodicExpense.findFirst({
        where: { description: { equals: description, mode: "insensitive" } },
      });

      if (existing) {
        skippedDuplicate++;
        continue;
      }

      const defaultAmount = parseArgentineAmount(rawAmount);

      await prisma.periodicExpense.create({
        data: {
          description,
          defaultDueDay: isNaN(defaultDueDay) ? 1 : defaultDueDay,
          defaultAmount: isNaN(defaultAmount) ? 0 : defaultAmount,
          periods,
        },
      });

      imported++;
    } catch (err) {
      const message = err instanceof Error ? err.message : String(err);
      errors.push(`Línea ${i + 1} ("${description}"): ${message}`);
      logger.error({ err, description }, "Error importing periodic expense");
    }
  }

  return c.json({
    imported,
    skipped: skippedNoPeriods + skippedDuplicate,
    skippedNoPeriods,
    skippedDuplicate,
    errors: errors.length > 0 ? errors : undefined,
  });
}