package aggregator

import (
	"time"

	"github.com/opencost/opencost/core/pkg/source"
	"github.com/opencost/opencost/core/pkg/util"
)

// MetricValue is a resulting data point value with an optional timestamp.
type MetricValue struct {
	Value     float64
	Timestamp *time.Time
}

// ToVector converts the MetricValue into a util.Vector (adapter for source.QueryResults).
func (mv *MetricValue) ToVector() *util.Vector {
	timestamp := 0.0
	if mv.Timestamp != nil {
		timestamp = float64(mv.Timestamp.Unix())
	}
	return &util.Vector{
		Timestamp: timestamp,
		Value:     mv.Value,
	}
}

// MetricResult contains the metric result labels and label values, and a slice of
// MetricValues.
type MetricResult struct {
	MetricLabels map[string]string
	Values       []MetricValue
}

// ToQueryResult converts the MetricResult into a source.QueryResult, which is the format used by
// the data source to return query results.
func (mr *MetricResult) ToQueryResult() *source.QueryResult {
	metrics := make(map[string]any, len(mr.MetricLabels))
	for key, value := range mr.MetricLabels {
		metrics[key] = value
	}

	values := make([]*util.Vector, len(mr.Values))
	for i, value := range mr.Values {
		values[i] = value.ToVector()
	}

	return source.NewQueryResult(metrics, values, nil)
}

// MetricAggregator is an interface that defines the methods for a metric metric aggregation.
// For example, we have a metric `foo_metric`, and we wish to query and collect the average over time.
// In this case, the `AverageOverTime` component is the MetricAggregator. It is the component responsible
// for routing updates to metric values into their proper condensed form.
type MetricAggregator interface {
	AdditionInfo() map[string]string
	Update(value float64, timestamp time.Time, additionalInfo map[string]string)
	Value() []MetricValue
	LabelValues() []string
}

// MetricAggregatorFactory is a function that accepts a string name and returns a pointer to a MetricAggregator
// implementation.
type MetricAggregatorFactory func(labelValues []string) MetricAggregator