package testutil

import (
	"fmt"
	"reflect"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"github.com/stretchr/testify/require"

	"github.com/influxdata/telegraf"
	"github.com/influxdata/telegraf/metric"
)

// Metric defines a single point measurement
type Metric struct {
	Measurement string
	Tags        map[string]string
	Fields      map[string]interface{}
	Time        time.Time
	Type        telegraf.ValueType
}

func (p *Metric) String() string {
	return fmt.Sprintf("%s %v %v", p.Measurement, p.Tags, p.Fields)
}

// Accumulator defines a mocked out accumulator
type Accumulator struct {
	nMetrics    uint64 // Needs to be first to avoid unaligned atomic operations on 32-bit archs
	Metrics     []*Metric
	accumulated []telegraf.Metric
	Discard     bool
	Errors      []error
	debug       bool
	deliverChan chan telegraf.DeliveryInfo
	delivered   []telegraf.DeliveryInfo

	TimeFunc func() time.Time

	trackingMutex sync.Mutex
	sync.Mutex
	*sync.Cond
}

func (a *Accumulator) NMetrics() uint64 {
	return atomic.LoadUint64(&a.nMetrics)
}

func (a *Accumulator) NDelivered() int {
	a.Lock()
	defer a.Unlock()
	return len(a.delivered)
}

// GetTelegrafMetrics returns all the metrics collected by the accumulator
// If you are getting race conditions here then you are not waiting for all of your metrics to arrive: see Wait()
func (a *Accumulator) GetTelegrafMetrics() []telegraf.Metric {
	a.Lock()
	defer a.Unlock()
	metrics := make([]telegraf.Metric, 0, len(a.accumulated))
	metrics = append(metrics, a.accumulated...)
	return metrics
}

func (a *Accumulator) GetDeliveries() []telegraf.DeliveryInfo {
	a.Lock()
	defer a.Unlock()
	info := make([]telegraf.DeliveryInfo, 0, len(a.delivered))
	info = append(info, a.delivered...)
	return info
}

func (a *Accumulator) FirstError() error {
	if len(a.Errors) == 0 {
		return nil
	}
	return a.Errors[0]
}

func (a *Accumulator) ClearMetrics() {
	a.Lock()
	defer a.Unlock()
	atomic.StoreUint64(&a.nMetrics, 0)
	a.Metrics = make([]*Metric, 0)
	a.accumulated = make([]telegraf.Metric, 0)
}

func (a *Accumulator) addMeasurement(
	measurement string,
	tags map[string]string,
	fields map[string]interface{},
	tp telegraf.ValueType,
	timestamp ...time.Time,
) {
	a.Lock()
	defer a.Unlock()
	atomic.AddUint64(&a.nMetrics, 1)
	if a.Cond != nil {
		a.Cond.Broadcast()
	}
	if a.Discard {
		return
	}

	if len(fields) == 0 {
		return
	}

	tagsCopy := make(map[string]string, len(tags))
	for k, v := range tags {
		tagsCopy[k] = v
	}

	fieldsCopy := make(map[string]interface{}, len(fields))
	for k, v := range fields {
		fieldsCopy[k] = v
	}

	var t time.Time
	if len(timestamp) > 0 {
		t = timestamp[0]
	} else {
		if a.TimeFunc == nil {
			t = time.Now()
		} else {
			t = a.TimeFunc()
		}
	}

	m := &Metric{
		Measurement: measurement,
		Fields:      fieldsCopy,
		Tags:        tagsCopy,
		Time:        t,
		Type:        tp,
	}

	a.Metrics = append(a.Metrics, m)
	a.accumulated = append(a.accumulated, FromTestMetric(m))
}

// AddFields adds a measurement point with a specified timestamp.
func (a *Accumulator) AddFields(
	measurement string,
	fields map[string]interface{},
	tags map[string]string,
	timestamp ...time.Time,
) {
	a.addMeasurement(measurement, tags, fields, telegraf.Untyped, timestamp...)
}

func (a *Accumulator) AddCounter(
	measurement string,
	fields map[string]interface{},
	tags map[string]string,
	timestamp ...time.Time,
) {
	a.addMeasurement(measurement, tags, fields, telegraf.Counter, timestamp...)
}

func (a *Accumulator) AddGauge(
	measurement string,
	fields map[string]interface{},
	tags map[string]string,
	timestamp ...time.Time,
) {
	a.addMeasurement(measurement, tags, fields, telegraf.Gauge, timestamp...)
}

func (a *Accumulator) AddMetrics(metrics []telegraf.Metric) {
	for _, m := range metrics {
		a.AddMetric(m)
	}
}

func (a *Accumulator) AddSummary(
	measurement string,
	fields map[string]interface{},
	tags map[string]string,
	timestamp ...time.Time,
) {
	a.addMeasurement(measurement, tags, fields, telegraf.Summary, timestamp...)
}

func (a *Accumulator) AddHistogram(
	measurement string,
	fields map[string]interface{},
	tags map[string]string,
	timestamp ...time.Time,
) {
	a.addMeasurement(measurement, tags, fields, telegraf.Histogram, timestamp...)
}

func (a *Accumulator) AddMetric(m telegraf.Metric) {
	a.Lock()
	defer a.Unlock()
	atomic.AddUint64(&a.nMetrics, 1)
	if a.Cond != nil {
		a.Cond.Broadcast()
	}
	if a.Discard {
		return
	}

	// Drop metrics without fields
	if len(m.FieldList()) == 0 {
		return
	}

	a.Metrics = append(a.Metrics, ToTestMetric(m))
	a.accumulated = append(a.accumulated, m)
}

func (a *Accumulator) WithTracking(maxTracked int) telegraf.TrackingAccumulator {
	a.trackingMutex.Lock()
	defer a.trackingMutex.Unlock()
	a.deliverChan = make(chan telegraf.DeliveryInfo, maxTracked)
	a.delivered = make([]telegraf.DeliveryInfo, 0, maxTracked)
	return a
}

func (a *Accumulator) AddTrackingMetric(m telegraf.Metric) telegraf.TrackingID {
	dm, id := metric.WithTracking(m, a.onDelivery)
	a.AddMetric(dm)
	return id
}

func (a *Accumulator) AddTrackingMetricGroup(group []telegraf.Metric) telegraf.TrackingID {
	db, id := metric.WithGroupTracking(group, a.onDelivery)
	for _, m := range db {
		a.AddMetric(m)
	}
	return id
}

func (a *Accumulator) onDelivery(info telegraf.DeliveryInfo) {
	select {
	case a.deliverChan <- info:
	default:
		// This is a programming error in the input.  More items were sent for
		// tracking than space requested.
		panic("channel is full")
	}
}

func (a *Accumulator) Delivered() <-chan telegraf.DeliveryInfo {
	a.trackingMutex.Lock()
	defer a.trackingMutex.Unlock()
	return a.deliverChan
}

// AddError appends the given error to Accumulator.Errors.
func (a *Accumulator) AddError(err error) {
	if err == nil {
		return
	}
	a.Lock()
	a.Errors = append(a.Errors, err)
	if a.Cond != nil {
		a.Cond.Broadcast()
	}
	a.Unlock()
}

func (a *Accumulator) SetPrecision(_ time.Duration) {
}

func (a *Accumulator) DisablePrecision() {
}

func (a *Accumulator) Debug() bool {
	// stub for implementing Accumulator interface.
	return a.debug
}

func (a *Accumulator) SetDebug(debug bool) {
	// stub for implementing Accumulator interface.
	a.debug = debug
}

// Get gets the specified measurement point from the accumulator
func (a *Accumulator) Get(measurement string) (*Metric, bool) {
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			return p, true
		}
	}

	return nil, false
}

func (a *Accumulator) HasTag(measurement, key string) bool {
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			_, ok := p.Tags[key]
			return ok
		}
	}
	return false
}

func (a *Accumulator) TagSetValue(measurement, key string) string {
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			v, ok := p.Tags[key]
			if ok {
				return v
			}
		}
	}
	return ""
}

func (a *Accumulator) TagValue(measurement, key string) string {
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			v, ok := p.Tags[key]
			if !ok {
				return ""
			}
			return v
		}
	}
	return ""
}

// GatherError calls the given Gather function and returns the first error found.
func (a *Accumulator) GatherError(gf func(telegraf.Accumulator) error) error {
	if err := gf(a); err != nil {
		return err
	}
	if len(a.Errors) > 0 {
		return a.Errors[0]
	}
	return nil
}

// NFields returns the total number of fields in the accumulator, across all
// measurements
func (a *Accumulator) NFields() int {
	a.Lock()
	defer a.Unlock()
	counter := 0
	for _, pt := range a.Metrics {
		for range pt.Fields {
			counter++
		}
	}
	return counter
}

// Wait waits for the given number of metrics to be added to the accumulator.
func (a *Accumulator) Wait(n int) {
	a.Lock()
	defer a.Unlock()
	if a.Cond == nil {
		a.Cond = sync.NewCond(&a.Mutex)
	}
	for int(a.NMetrics()) < n {
		a.Cond.Wait()
	}
}

// WaitError waits for the given number of errors to be added to the accumulator.
func (a *Accumulator) WaitError(n int) {
	a.Lock()
	if a.Cond == nil {
		a.Cond = sync.NewCond(&a.Mutex)
	}
	for len(a.Errors) < n {
		a.Cond.Wait()
	}
	a.Unlock()
}

func (a *Accumulator) AssertContainsTaggedFields(
	t *testing.T,
	measurement string,
	fields map[string]interface{},
	tags map[string]string,
) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if !reflect.DeepEqual(tags, p.Tags) {
			continue
		}

		if p.Measurement == measurement && reflect.DeepEqual(fields, p.Fields) {
			return
		}
	}
	// We've failed. spit out some debug logging
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			t.Log("measurement", p.Measurement, "tags", p.Tags, "fields", p.Fields)
		}
	}
	msg := fmt.Sprintf("unknown measurement %q with tags %v", measurement, tags)
	require.Fail(t, msg)
}

func (a *Accumulator) AssertDoesNotContainsTaggedFields(
	t *testing.T,
	measurement string,
	fields map[string]interface{},
	tags map[string]string,
) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if !reflect.DeepEqual(tags, p.Tags) {
			continue
		}

		if p.Measurement == measurement && reflect.DeepEqual(fields, p.Fields) {
			msg := fmt.Sprintf(
				"found measurement %s with tagged fields (tags %v) which should not be there",
				measurement, tags)
			require.Fail(t, msg)
		}
	}
}
func (a *Accumulator) AssertContainsFields(
	t *testing.T,
	measurement string,
	fields map[string]interface{},
) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			require.Equal(t, fields, p.Fields)
			return
		}
	}
	msg := fmt.Sprintf("unknown measurement %q", measurement)
	require.Fail(t, msg)
}

func (a *Accumulator) HasPoint(
	measurement string,
	tags map[string]string,
	fieldKey string,
	fieldValue interface{},
) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement != measurement {
			continue
		}

		if !reflect.DeepEqual(tags, p.Tags) {
			continue
		}

		v, ok := p.Fields[fieldKey]
		if ok && reflect.DeepEqual(v, fieldValue) {
			return true
		}
	}
	return false
}

func (a *Accumulator) AssertDoesNotContainMeasurement(t *testing.T, measurement string) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			msg := "found unexpected measurement " + measurement
			require.Fail(t, msg)
		}
	}
}

// HasTimestamp returns true if the measurement has a matching Time value
func (a *Accumulator) HasTimestamp(measurement string, timestamp time.Time) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			return timestamp.Equal(p.Time)
		}
	}

	return false
}

// HasField returns true if the given measurement has a field with the given
// name
func (a *Accumulator) HasField(measurement, field string) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			if _, ok := p.Fields[field]; ok {
				return true
			}
		}
	}

	return false
}

// HasIntField returns true if the measurement has an Int value
func (a *Accumulator) HasIntField(measurement, field string) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					_, ok := value.(int)
					return ok
				}
			}
		}
	}

	return false
}

// HasInt64Field returns true if the measurement has an Int64 value
func (a *Accumulator) HasInt64Field(measurement, field string) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					_, ok := value.(int64)
					return ok
				}
			}
		}
	}

	return false
}

// HasInt32Field returns true if the measurement has an Int value
func (a *Accumulator) HasInt32Field(measurement, field string) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					_, ok := value.(int32)
					return ok
				}
			}
		}
	}

	return false
}

// HasStringField returns true if the measurement has a String value
func (a *Accumulator) HasStringField(measurement, field string) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					_, ok := value.(string)
					return ok
				}
			}
		}
	}

	return false
}

// HasUIntField returns true if the measurement has a UInt value
func (a *Accumulator) HasUIntField(measurement, field string) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					_, ok := value.(uint64)
					return ok
				}
			}
		}
	}

	return false
}

// HasFloatField returns true if the given measurement has a float value
func (a *Accumulator) HasFloatField(measurement, field string) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					_, ok := value.(float64)
					return ok
				}
			}
		}
	}

	return false
}

// HasMeasurement returns true if the accumulator has a measurement with the
// given name
func (a *Accumulator) HasMeasurement(measurement string) bool {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			return true
		}
	}
	return false
}

// IntField returns the int value of the given measurement and field or false.
func (a *Accumulator) IntField(measurement, field string) (int, bool) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					v, ok := value.(int)
					return v, ok
				}
			}
		}
	}

	return 0, false
}

// Int64Field returns the int64 value of the given measurement and field or false.
func (a *Accumulator) Int64Field(measurement, field string) (int64, bool) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					v, ok := value.(int64)
					return v, ok
				}
			}
		}
	}

	return 0, false
}

// Uint64Field returns the int64 value of the given measurement and field or false.
func (a *Accumulator) Uint64Field(measurement, field string) (uint64, bool) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					v, ok := value.(uint64)
					return v, ok
				}
			}
		}
	}

	return 0, false
}

// Int32Field returns the int32 value of the given measurement and field or false.
func (a *Accumulator) Int32Field(measurement, field string) (int32, bool) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					v, ok := value.(int32)
					return v, ok
				}
			}
		}
	}

	return 0, false
}

// FloatField returns the float64 value of the given measurement and field or false.
func (a *Accumulator) FloatField(measurement, field string) (float64, bool) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					v, ok := value.(float64)
					return v, ok
				}
			}
		}
	}

	return 0.0, false
}

// StringField returns the string value of the given measurement and field or false.
func (a *Accumulator) StringField(measurement, field string) (string, bool) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					v, ok := value.(string)
					return v, ok
				}
			}
		}
	}
	return "", false
}

// BoolField returns the bool value of the given measurement and field or false.
func (a *Accumulator) BoolField(measurement, field string) (v, ok bool) {
	a.Lock()
	defer a.Unlock()
	for _, p := range a.Metrics {
		if p.Measurement == measurement {
			for fieldname, value := range p.Fields {
				if fieldname == field {
					v, ok = value.(bool)
					return v, ok
				}
			}
		}
	}

	return false, false
}

// NopAccumulator is used for benchmarking to isolate the plugin from the internal
// telegraf accumulator machinery.
type NopAccumulator struct{}

func (n *NopAccumulator) AddFields(_ string, _ map[string]interface{}, _ map[string]string, _ ...time.Time) {
}
func (n *NopAccumulator) AddGauge(_ string, _ map[string]interface{}, _ map[string]string, _ ...time.Time) {
}
func (n *NopAccumulator) AddCounter(_ string, _ map[string]interface{}, _ map[string]string, _ ...time.Time) {
}
func (n *NopAccumulator) AddSummary(_ string, _ map[string]interface{}, _ map[string]string, _ ...time.Time) {
}
func (n *NopAccumulator) AddHistogram(_ string, _ map[string]interface{}, _ map[string]string, _ ...time.Time) {
}
func (n *NopAccumulator) AddMetric(telegraf.Metric)                       {}
func (n *NopAccumulator) SetPrecision(_ time.Duration)                    {}
func (n *NopAccumulator) AddError(_ error)                                {}
func (n *NopAccumulator) WithTracking(_ int) telegraf.TrackingAccumulator { return nil }
