package circuit

import (
	"testing"

	"github.com/evcc-io/evcc/api"
	"github.com/evcc-io/evcc/util"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"go.uber.org/mock/gomock"
)

type circuitTest struct {
	// current values for parent, circuit 1, circuit 2
	p, c1, c2 float64
	// old/new demand values and allowed result
	old, new, res float64
}

func circuitTests() []circuitTest {
	return []circuitTest{
		// no load
		{0, 0, 0, 0, 0, 0}, // =
		{0, 0, 0, 0, 1, 1}, // +
		{0, 0, 0, 0, 2, 1}, // +
		{0, 0, 0, 1, 1, 1}, // =

		// circuit 1 loaded
		{0, 1, 0, 0, 0, 0}, // =
		{0, 1, 0, 0, 1, 0}, // +
		{0, 1, 0, 0, 2, 0}, // +
		{0, 1, 0, 1, 1, 1}, // =
		{0, 1, 0, 2, 1, 1}, // -

		// circuit 1 overloaded
		{0, 2, 0, 0, 0, 0}, // =
		{0, 2, 0, 0, 1, 0}, // +
		{0, 2, 0, 1, 1, 0}, // =
		{0, 2, 0, 2, 2, 1}, // =
		{0, 2, 0, 2, 3, 1}, // +
		{0, 2, 0, 2, 1, 1}, // -

		{0, 1.1, 0, 2, 1, 1}, // -
		{0, 1.1, 0, 1, 0, 0}, // -

		// parent loaded
		{1, 0, 0, 0, 0, 0}, // =
		{1, 0, 0, 0, 1, 0}, // +
		{1, 0, 0, 0, 2, 0}, // +
		{1, 0, 0, 1, 1, 1}, // =
		{1, 0, 0, 2, 1, 1}, // -

		// parent overloaded
		{2, 0, 0, 0, 0, 0}, // =
		{2, 0, 0, 0, 1, 0}, // +
		{2, 0, 0, 1, 1, 0}, // =
		{2, 0, 0, 2, 2, 1}, // =
		{2, 0, 0, 2, 3, 1}, // +
		{2, 0, 0, 2, 1, 1}, // -

		{1.1, 0, 0, 2, 1, 1}, // -
		{1.1, 0, 0, 1, 0, 0}, // -

		// negative load
		{-1, -1, 0, 0, 2, 2}, // +
	}
}

func TestCircuitPower(t *testing.T) {
	log := util.NewLogger("foo")

	circ := func(t *testing.T, ctrl *gomock.Controller, maxP float64) (*Circuit, *api.MockMeter) {
		m := api.NewMockMeter(ctrl)
		c, err := New(log, "foo", 0, maxP, m, 0)
		require.NoError(t, err)
		return c, m
	}

	for _, tc := range circuitTests() {
		ctrl := gomock.NewController(t)

		pc, pm := circ(t, ctrl, 1)
		c1, cm1 := circ(t, ctrl, 1)
		c2, cm2 := circ(t, ctrl, 1)

		c1.setParent(pc)
		c2.setParent(pc)

		// update meters
		pm.EXPECT().CurrentPower().Return(tc.p, nil)
		cm1.EXPECT().CurrentPower().Return(tc.c1, nil)
		cm2.EXPECT().CurrentPower().Return(tc.c2, nil)
		require.NoError(t, pc.Update(nil))

		assert.Equal(t, tc.res, c1.ValidatePower(tc.old, tc.new), tc)

		ctrl.Finish()
	}
}

func TestCircuitCurrents(t *testing.T) {
	log := util.NewLogger("foo")

	type combined struct {
		*api.MockMeter
		*api.MockPhaseCurrents
	}
	circ := func(t *testing.T, ctrl *gomock.Controller, maxC float64) (*Circuit, combined) {
		m := combined{
			api.NewMockMeter(ctrl),
			api.NewMockPhaseCurrents(ctrl),
		}
		c, err := New(log, "foo", maxC, 0, m, 0)
		require.NoError(t, err)
		return c, m
	}

	for _, tc := range circuitTests() {
		ctrl := gomock.NewController(t)

		pc, pm := circ(t, ctrl, 1)
		c1, cm1 := circ(t, ctrl, 1)
		c2, cm2 := circ(t, ctrl, 1)

		c1.setParent(pc)
		c2.setParent(pc)

		// update meters
		pm.MockMeter.EXPECT().CurrentPower().AnyTimes().Return(0.0, nil)
		cm1.MockMeter.EXPECT().CurrentPower().AnyTimes().Return(0.0, nil)
		cm2.MockMeter.EXPECT().CurrentPower().AnyTimes().Return(0.0, nil)
		pm.MockPhaseCurrents.EXPECT().Currents().Return(tc.p, tc.p, tc.p, nil)
		cm1.MockPhaseCurrents.EXPECT().Currents().Return(tc.c1, tc.c1, tc.c1, nil)
		cm2.MockPhaseCurrents.EXPECT().Currents().Return(tc.c2, tc.c2, tc.c2, nil)
		require.NoError(t, pc.Update(nil))

		assert.Equal(t, tc.res, c1.ValidateCurrent(tc.old, tc.new), tc)

		ctrl.Finish()
	}
}

// TestHEMSConsumptionClamp verifies that ValidatePower clamps against the
// HEMS consumption limit when one is registered on the root circuit.
func TestHEMSConsumptionClamp(t *testing.T) {
	log := util.NewLogger("foo")

	for _, tc := range []struct {
		name      string
		maxPower  float64
		hemsLimit float64
		request   float64
		want      float64
	}{
		{"no hems, no max", 0, 0, 9000, 9000},
		{"no hems, max set", 5000, 0, 9000, 5000},
		{"hems below max", 5000, 4200, 9000, 4200},
		{"hems above max", 5000, 9000, 9000, 5000},
		{"hems but no user max", 0, 4200, 9000, 4200},
	} {
		t.Run(tc.name, func(t *testing.T) {
			c, err := New(log, "root", 0, tc.maxPower, nil, 0)
			require.NoError(t, err)

			if tc.hemsLimit > 0 {
				ctrl := gomock.NewController(t)
				hems := api.NewMockHEMS(ctrl)
				hems.EXPECT().MaxConsumptionPower().Return(&tc.hemsLimit).AnyTimes()
				c.hems = hems
			}

			assert.Equal(t, tc.want, c.ValidatePower(0, tc.request))
		})
	}
}