package diagram

import (
	"testing"

	"github.com/redis/go-redis/v9"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestLatestMeasurementValueUsesMemberTimestamp(t *testing.T) {
	value, err := latestMeasurementValue([]redis.Z{
		{Member: "100", Score: 999},
		{Member: "300", Score: 12},
		{Member: "200", Score: 500},
	}, "measurement-key")

	require.NoError(t, err)
	assert.Equal(t, float64(12), value)
}

func TestLatestMeasurementValueRejectsMissingOrInvalidTimestamps(t *testing.T) {
	_, err := latestMeasurementValue(nil, "measurement-key")
	require.Error(t, err)

	_, err = latestMeasurementValue([]redis.Z{{Member: "invalid", Score: 1}}, "measurement-key")
	require.Error(t, err)
}

func TestLatestMeasurementValuesReturnsNewestWindow(t *testing.T) {
	values, err := latestMeasurementValues([]redis.Z{
		{Member: "100", Score: 10},
		{Member: "400", Score: 40},
		{Member: "invalid", Score: 999},
		{Member: "200", Score: 20},
		{Member: "300", Score: 30},
	}, "measurement-key", 3)

	require.NoError(t, err)
	assert.Equal(t, []float64{40, 30, 20}, values)
}

func TestLatestMeasurementValuesReturnsAvailableWindow(t *testing.T) {
	values, err := latestMeasurementValues([]redis.Z{
		{Member: "100", Score: 10},
		{Member: "200", Score: 20},
	}, "measurement-key", 5)

	require.NoError(t, err)
	assert.Equal(t, []float64{20, 10}, values)
}

func TestLatestMeasurementValuesRejectsInvalidSize(t *testing.T) {
	_, err := latestMeasurementValues([]redis.Z{{Member: "100", Score: 10}}, "measurement-key", 0)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "window size must be greater than 0")
}