package exporter

import (
	"net/http"

	"git.ar21.de/yolokube/country-geo-locations/internal/cache"
	"git.ar21.de/yolokube/country-geo-locations/internal/cmd"
	"git.ar21.de/yolokube/country-geo-locations/internal/database"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)

type Exporter struct {
	config   *cmd.AppSettings
	cache    *cache.Cache
	database *database.Database
	metrics  *Metrics
}

func NewExporter(config *cmd.AppSettings, c *cache.Cache, db *database.Database) *Exporter {
	exporter := &Exporter{
		config:   config,
		cache:    c,
		database: db,
	}

	exporter.metrics = NewMetrics(exporter)
	return exporter
}

func (e *Exporter) Collect() {
	e.metrics.collectCacheTTLMetric()
	e.metrics.collectCurrentlyCachedMetric()
	e.metrics.collectDatabaseReadyMetric()
	e.metrics.collectDatabaseTimestampMetric()
}

func (e *Exporter) Middleware() func(next http.Handler) http.Handler {
	return Middleware{
		metrics: e.metrics,
	}.handler
}

func (e *Exporter) Start() error {
	prometheus.MustRegister(
		e.metrics.metricCacheTTL,
		e.metrics.metricCurrentlyCached,
		e.metrics.metricDatabaseTimestamp,
		e.metrics.metricDatabaseReady,
		e.metrics.metricRequestsTotal,
		e.metrics.metricRequestLatency,
	)

	server := &http.Server{
		Addr:              e.config.ExporterAddress,
		Handler:           promhttp.Handler(),
		ReadHeaderTimeout: e.config.ReadHeaderTimeout,
	}

	return server.ListenAndServe()
}