package weather

import (
	"context"
	"errors"

	"github.com/rs/zerolog"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/metric"

	"gitea.libretechconsulting.com/rmcguire/ambient-weather-local-exporter/pkg/ambient/config"
)

type MetricRecorder struct {
	ctx context.Context
	l   *zerolog.Logger
}

type RecordOpts struct {
	Float64Gauge metric.Float64Gauge
	Int64Gauge   metric.Int64Gauge
	IntVal       *int
	FloatVal     *float64
	Attributes   []attribute.KeyValue
	Field        string
	Station      *config.WeatherStation
}

func (r *MetricRecorder) Record(opts *RecordOpts) {
	if opts.Station != nil && !opts.keep() {
		r.l.Trace().
			Str("field", string(opts.Field)).
			Str("station", opts.Station.Name).
			Msg("Metric dropped by station config")
		return
	} else if opts.Int64Gauge == nil && opts.Float64Gauge == nil {
		r.l.Err(errors.New("neither int nor float gauge provided")).Send()
		return
	}

	if opts.Int64Gauge != nil {
		if opts.IntVal == nil {
			log := r.l.Trace().Str("field", string(opts.Field))
			if opts.Station != nil {
				log = log.Str("station", opts.Station.Name)
			}
			log.Msg("Dropping nil int metric")
			return
		}
		r.recordInt(opts.Int64Gauge, *opts.IntVal, opts.Attributes...)
	} else if opts.Float64Gauge != nil {
		if opts.FloatVal == nil {
			log := r.l.Trace().Str("field", string(opts.Field))
			if opts.Station != nil {
				log = log.Str("station", opts.Station.Name)
			}
			log.Msg("Dropping nil float metric")
			return
		}
		r.recordFloat(opts.Float64Gauge, *opts.FloatVal, opts.Attributes...)
	}
}

func (o *RecordOpts) keep() bool {
	// If keep fields are given, only check keep fields
	if len(o.Station.KeepMetrics) > 0 {
		for _, f := range o.Station.KeepMetrics {
			if f == o.Field {
				return true
			}
		}
		return false
	}

	for _, f := range o.Station.DropMetrics {
		if f == o.Field {
			return false
		}
	}
	return true
}

func (r *MetricRecorder) recordInt(
	m metric.Int64Gauge, value int, attributes ...attribute.KeyValue,
) {
	// Prepare metric attributes
	options := make([]metric.RecordOption, 0, len(attributes))
	if len(attributes) > 0 {
		options = append(options, metric.WithAttributes(attributes...))
	}

	val := int64(value)
	m.Record(r.ctx, val, options...)
}

func (r *MetricRecorder) recordFloat(
	m metric.Float64Gauge, value float64, attributes ...attribute.KeyValue,
) {
	// Prepare metric attributes
	options := make([]metric.RecordOption, 0, len(attributes))
	if len(attributes) > 0 {
		options = append(options, metric.WithAttributes(attributes...))
	}

	m.Record(r.ctx, value, options...)
}