package api

import (
	"fuj-management/go/internal/config"
	"sort"
	"strings"

	domreconcile "fuj-management/go/internal/domain/reconcile"
)

// buildPaymentsResponse constructs the PaymentsResponse wire type.
// Mirrors scripts/views.py:build_payments_view_model.
func buildPaymentsResponse(
	txns []domreconcile.Transaction,
	memberNames []string,
) PaymentsResponse {
	grouped := groupRawPaymentsByPerson(txns, memberNames)

	// Add unmatched/unknown bucket for transactions with no person set.
	const unknownKey = "Unmatched / Unknown"
	for _, tx := range txns {
		if strings.TrimSpace(tx.Person) == "" {
			grouped[unknownKey] = append(grouped[unknownKey], rawTxFromDomain(tx))
		}
	}
	// Sort the unknown bucket newest-first (others are sorted in groupRawPaymentsByPerson).
	if rows, ok := grouped[unknownKey]; ok {
		sort.Slice(rows, func(i, j int) bool { return rows[i].Date > rows[j].Date })
		grouped[unknownKey] = rows
	}

	sortedPeople := make([]string, 0, len(grouped))
	for p := range grouped {
		sortedPeople = append(sortedPeople, p)
	}
	sort.Strings(sortedPeople)

	return PaymentsResponse{
		GroupedPayments: grouped,
		SortedPeople:    sortedPeople,
		AttendanceURL:   "https://docs.google.com/spreadsheets/d/" + config.AttendanceSheetID + "/edit",
		PaymentsURL:     "https://docs.google.com/spreadsheets/d/" + config.PaymentsSheetID + "/edit",
	}
}