package core

import (
	"testing"
	"time"

	"github.com/benbjohnson/clock"
	"github.com/evcc-io/evcc/api"
	"github.com/evcc-io/evcc/core/metrics"
	"github.com/evcc-io/evcc/server/db"
	"github.com/evcc-io/evcc/util"
	"github.com/evcc-io/evcc/util/config"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestGreenShare(t *testing.T) {
	tc := []struct {
		title                                                 string
		grid, pv, battery, home, lp                           float64
		greenShareTotal, greenShareHome, greenShareLoadpoints float64
	}{
		{
			"half grid, half pv, green home",
			1000, 1000, 0, 1000, 1000,
			0.5, 1, 0,
		},
		{
			"half grid, half pv, no home",
			1000, 1000, 0, 0, 2000,
			0.5, 1, 0.5,
		},
		{
			"half grid, half pv, no lp",
			2500, 2500, 0, 5000, 0,
			0.5, 0.5, 0,
		},
		{
			"full pv",
			0, 5000, 0, 1000, 4000,
			1, 1, 1,
		},
		{
			"full grid",
			5000, 0, 0, 1000, 4000,
			0, 0, 0,
		},
		{
			"half grid, half battery, green home",
			1000, 0, 1000, 1000, 1000,
			0.5, 1, 0,
		},
		{
			"half grid, half battery, no home",
			1000, 0, 1000, 0, 2000,
			0.5, 1, 0.5,
		},
		{
			"half grid, half battery, no lp",
			1000, 0, 1000, 2000, 0,
			0.5, 0.5, 0,
		},
		{
			"full pv, pv export",
			-5000, 10000, 0, 1000, 4000,
			1, 1, 1,
		},
		{
			"full pv, pv export, no lp",
			-5000, 10000, 0, 5000, 0,
			1, 1, 1,
		},
		{
			"full pv, pv export, battery charge",
			-2500, 10000, -2500, 1000, 4000,
			1, 1, 1,
		},
		{
			"full grid, battery charge",
			3000, 0, -1000, 1000, 1000,
			0, 0, 0,
		},
		{
			"full grid, battery charge, no lp",
			2000, 0, -1000, 1000, 0,
			0, 0, 0,
		},
		{
			"half grid, half pv, battery charge, no lp",
			1000, 1000, -1000, 1000, 0,
			0.5, 1, 0,
		},
		{
			"half grid, half pv, battery charge, home, lp",
			1000, 1000, -1000, 500, 500,
			0.5, 1, 0,
		},
		{
			"pv ac limited, battery charge & grid import",
			1000, 3000, -1000, 1000, 2000,
			0.75, 1, 0.5,
		},
	}

	for _, tc := range tc {
		t.Log(tc.title)

		s := &Site{
			gridPower:    tc.grid,
			pvPower:      tc.pv,
			batteryPower: tc.battery,
		}

		totalPower := tc.grid + tc.pv + max(0, tc.battery)
		greenShareTotal := s.greenShare(0, totalPower)
		if greenShareTotal != tc.greenShareTotal {
			t.Errorf("greenShareTotal wanted %.3f, got %.3f", tc.greenShareTotal, greenShareTotal)
		}
		greenShareHome := s.greenShare(0, tc.home)
		if greenShareHome != tc.greenShareHome {
			t.Errorf("greenShareHome wanted %.3f, got %.3f", tc.greenShareHome, greenShareHome)
		}
		greenShareLoadpoints := s.greenShare(tc.home+max(0, -tc.battery), totalPower)
		if greenShareLoadpoints != tc.greenShareLoadpoints {
			t.Errorf("greenShareLoadpoints wanted %.3f, got %.3f", tc.greenShareLoadpoints, greenShareLoadpoints)
		}
	}
}

func TestRequiredBatteryMode(t *testing.T) {
	tc := []struct {
		gridChargeActive bool
		mode, res        api.BatteryMode
	}{
		{false, api.BatteryUnknown, api.BatteryUnknown}, // ignore
		{false, api.BatteryNormal, api.BatteryUnknown},  // ignore
		{false, api.BatteryHold, api.BatteryNormal},
		{false, api.BatteryCharge, api.BatteryNormal},

		{true, api.BatteryUnknown, api.BatteryCharge},
		{true, api.BatteryNormal, api.BatteryCharge},
		{true, api.BatteryHold, api.BatteryCharge},
		{true, api.BatteryCharge, api.BatteryUnknown}, // ignore
	}

	{
		// no battery
		res := new(Site).requiredBatteryMode(true, api.Rate{})
		assert.Equal(t, api.BatteryUnknown, res, "expected %s, got %s", api.BatteryUnknown, res)
	}

	for _, tc := range tc {
		t.Logf("%+v", tc)

		s := &Site{
			batteryMeters: []config.Device[api.Meter]{nil},
			batteryMode:   tc.mode,
		}

		res := s.requiredBatteryMode(tc.gridChargeActive, api.Rate{})
		assert.Equal(t, tc.res, res, "expected %s, got %s", tc.res, res)
	}
}

func TestUpdateHomeConsumption(t *testing.T) {
	clock := clock.NewMock()

	require.NoError(t, db.NewInstance("sqlite", ":memory:"))
	metrics.Init()

	s := &Site{
		log:             util.NewLogger("foo"),
		gridPower:       4e3,
		householdEnergy: &meterEnergy{clock: clock},
	}

	require.True(t, s.householdEnergy.updated.IsZero())

	clock.Add(5 * time.Minute)
	s.updateHomeConsumption(1e3)
	require.False(t, s.householdEnergy.updated.IsZero())

	clock.Add(5 * time.Minute)
	s.updateHomeConsumption(1e3)
	require.Equal(t, 1e3*5/60/1e3, s.householdEnergy.AccumulatedEnergy()) // kWh

	clock.Add(5 * time.Minute)
	s.updateHomeConsumption(1e3)
	require.Equal(t, 0.0, s.householdEnergy.AccumulatedEnergy()) // accumulator reset after 15 minutes

	clock.Add(15 * time.Minute)
	s.updateHomeConsumption(1e3)
	require.Equal(t, 0.0, s.householdEnergy.AccumulatedEnergy()) // accumulator reset after 15 minutes
}