import { ReportData, Transaction, GroupKey } from "../../features/report";
import {
  mergeBucketPeriods,
  periodIdToKey,
  formatCurrency,
  filterBuckets,
} from "../report.helpers";
import { LatestItem } from "./LatestItems.models";

// ─── Transaction extraction ─────────────────────────────────

function extractTransactions(
  reportData: ReportData,
  selectedPeriodId: string | null,
  selectedGroupKey: GroupKey | null,
): Transaction[] {
  // 1. Get raw transactions
  let rawTxns: Transaction[] = [];

  if (selectedPeriodId) {
    const key = periodIdToKey(selectedPeriodId);
    const periods = mergeBucketPeriods(reportData.buckets, key);
    const selected = periods.find((p) => p.id === selectedPeriodId);
    rawTxns = selected?.metric.transactions || [];
  } else {
    const periods = mergeBucketPeriods(reportData.buckets, "all");
    if (periods.length > 0) {
      rawTxns = periods[0].metric.transactions || [];
    }
  }

  // 2. Filter by group key
  if (selectedGroupKey?.tags && selectedGroupKey.tags.length > 0) {
    return rawTxns.filter(txn => {
      if (!txn.tags) return false;
      const txnTags = txn.tags.map(t => typeof t === "string" ? t : t.name);
      return selectedGroupKey.tags!.every(selectedTag => txnTags.includes(selectedTag));
    });
  }

  return rawTxns;
}

// ─── Main adapter ────────────────────────────────────────────

export function buildLatestItems(
  reportData: ReportData,
  selectedPeriodId: string | null,
  selectedGroupKey: GroupKey | null,
  mode: "expense" | "income"
): LatestItem[] {
  const txns = extractTransactions(reportData, selectedPeriodId, selectedGroupKey);

  return txns
    .sort(
      (a, b) =>
        new Date(b.occurred_at).getTime() -
        new Date(a.occurred_at).getTime()
    )
    .map((t, index) => ({
      id: index + 1,
      title: t.payee.name,
      subtitle: t.tags.map((tag) => tag.name).join(", "),
      amount: formatCurrency(t.amount),
      timeAgo: new Date(t.occurred_at).toLocaleDateString("en-IN"),
    }));
}