export default defineComponent({
  async run({ steps }) {
    const dashboard = steps.get_current_dashboard.$return_value;
    const slackEvent = steps.handle_slack_event.$return_value || {};

    const userId =
      slackEvent.user_id ||
      slackEvent.raw_body?.event?.user ||
      slackEvent.raw_body?.user ||
      slackEvent.raw_body?.authorizations?.[0]?.user_id;

    if (!dashboard || Object.keys(dashboard).length === 0) {
      throw new Error("No dashboard data found in Data Store.");
    }

    if (!userId) {
      throw new Error("No Slack user ID found in the event payload.");
    }

    const payments = Array.isArray(dashboard.payments) ? dashboard.payments : [];

    const formatCurrency = (value) =>
      new Intl.NumberFormat("en-US", {
        style: "currency",
        currency: "USD",
      }).format(Number(value || 0));

    const parseMDYLocal = (value) => {
      if (!value) return null;
      const parts = String(value).split("/");
      if (parts.length !== 3) return null;

      const [mm, dd, yyyy] = parts.map((p) => parseInt(p, 10));
      if (!mm || !dd || !yyyy) return null;

      return new Date(yyyy, mm - 1, dd);
    };

    const formatDateKey = (date) => {
      const y = date.getFullYear();
      const m = String(date.getMonth() + 1).padStart(2, "0");
      const d = String(date.getDate()).padStart(2, "0");
      return `${y}-${m}-${d}`;
    };

    const formatDisplayDate = (dateKey) => {
      const [y, m, d] = dateKey.split("-").map(Number);
      const dt = new Date(y, m - 1, d);
      return dt.toLocaleDateString("en-US", {
        weekday: "short",
        month: "short",
        day: "numeric",
      });
    };

    const today = new Date();
    today.setHours(0, 0, 0, 0);

    const futurePayments = payments.filter((p) => {
      const dt = parseMDYLocal(p.send_payment_on);
      return dt && dt >= today && (p.method === "ACH" || p.method === "Check");
    });

    const groupByMethodAndDay = (methodName) => {
      const grouped = {};

      for (const payment of futurePayments) {
        if (payment.method !== methodName) continue;

        const dt = parseMDYLocal(payment.send_payment_on);
        if (!dt) continue;

        const key = formatDateKey(dt);

        if (!grouped[key]) {
          grouped[key] = {
            count: 0,
            total: 0,
          };
        }

        grouped[key].count += 1;
        grouped[key].total += payment.amount_usd;
      }

      return Object.keys(grouped)
        .sort()
        .map((dateKey) => ({
          date_key: dateKey,
          display_date: formatDisplayDate(dateKey),
          count: grouped[dateKey].count,
          total: Number(grouped[dateKey].total.toFixed(2)),
        }));
    };

    const achDays = groupByMethodAndDay("ACH");
    const checkDays = groupByMethodAndDay("Check");

    const buildDayBlocks = (title, days) => {
      const total = days.reduce((sum, d) => sum + d.total, 0);
      const count = days.reduce((sum, d) => sum + d.count, 0);

      const blocks = [
        {
          type: "section",
          text: {
            type: "mrkdwn",
            text: `*${title}*\n${count} payments • ${formatCurrency(total)}`,
          },
        },
        {
          type: "divider",
        },
      ];

      if (!days.length) {
        blocks.push({
          type: "section",
          text: {
            type: "mrkdwn",
            text: "_No upcoming payments found._",
          },
        });
        blocks.push({ type: "divider" });
        return blocks;
      }

      for (const day of days) {
        blocks.push({
          type: "section",
          fields: [
            {
              type: "mrkdwn",
              text: `*${day.display_date}*`,
            },
            {
              type: "mrkdwn",
              text: `${day.count} payments • ${formatCurrency(day.total)}`,
            },
          ],
        });
      }

      blocks.push({ type: "divider" });
      return blocks;
    };

    return {
      user_id: userId,
      view: {
        type: "home",
        blocks: [
          {
            type: "header",
            text: {
              type: "plain_text",
              text: "Payments Dashboard",
            },
          },
          {
            type: "context",
            elements: [
              {
                type: "mrkdwn",
                text: `*Last updated:* ${dashboard.last_updated || "N/A"}`,
              },
              {
                type: "mrkdwn",
                text: `*Source:* ${dashboard.file_name || "N/A"}`,
              },
            ],
          },
          {
            type: "divider",
          },
          ...buildDayBlocks("ACH", achDays),
          ...buildDayBlocks("Check", checkDays),
        ],
      },
    };
  },
});