package membership

import (
	"bytes"
	"context"
	"fuj-management/go/internal/domain/reconcile"
	"strings"
	"testing"
)

type fakeSources struct {
	members    []reconcile.Member
	months     []string
	txns       []reconcile.Transaction
	exceptions map[reconcile.ExceptionKey]reconcile.Exception
}

func (f fakeSources) LoadAdults(_ context.Context) ([]reconcile.Member, []string, error) {
	return f.members, f.months, nil
}

func (f fakeSources) LoadJuniors(_ context.Context) ([]reconcile.Member, []string, error) {
	return nil, nil, nil
}

func (f fakeSources) LoadTransactions(_ context.Context) ([]reconcile.Transaction, error) {
	return f.txns, nil
}

func (f fakeSources) LoadExceptions(_ context.Context) (map[reconcile.ExceptionKey]reconcile.Exception, error) {
	return f.exceptions, nil
}

func (fakeSources) FlushCache() (int, error) { return 0, nil }

func TestReconcileReport(t *testing.T) {
	t.Parallel()
	s := fakeSources{
		members: []reconcile.Member{
			{Name: "Alice", Tier: "A", Fees: map[string]reconcile.FeeData{
				"2026-04": {Expected: 700, Attendance: 3},
			}},
		},
		months: []string{"2026-04"},
		txns: []reconcile.Transaction{
			{
				Date: "2026-04-10", Amount: 700, Person: "Alice", Purpose: "2026-04",
				Sender: "Alice Bank", Message: "fee",
			},
		},
		exceptions: map[reconcile.ExceptionKey]reconcile.Exception{},
	}

	var buf bytes.Buffer
	if err := ReconcileReport(context.Background(), s, 2026, &buf); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	got := buf.String()
	if !strings.Contains(got, "PAYMENT RECONCILIATION REPORT") {
		t.Error("missing report header")
	}
	if !strings.Contains(got, "OK") {
		t.Errorf("expected 'OK' for fully-paid Alice, got:\n%s", got)
	}
}

func TestReconcileReportStubErrors(t *testing.T) {
	t.Parallel()
	var buf bytes.Buffer
	err := ReconcileReport(context.Background(), NewStubSources(), 2026, &buf)
	if err == nil {
		t.Fatal("expected error from stub, got nil")
	}
}