package metrics

import (
	"database/sql"
	"testing"
	"time"
)

type fixedDBStats struct {
	stats sql.DBStats
}

func (s fixedDBStats) Stats() sql.DBStats { return s.stats }

func TestDBPoolCollector(t *testing.T) {
	RegisterDBPool("test", fixedDBStats{stats: sql.DBStats{
		MaxOpenConnections: 32,
		OpenConnections:    12,
		InUse:              7,
		Idle:               5,
		WaitCount:          9,
		WaitDuration:       1500 * time.Millisecond,
	}})

	families, err := Registry.Gather()
	if err != nil {
		t.Fatal(err)
	}
	want := map[string]bool{
		"im_db_pool_max_open_connections":        false,
		"im_db_pool_open_connections":            false,
		"im_db_pool_in_use_connections":          false,
		"im_db_pool_idle_connections":            false,
		"im_db_pool_wait_total":                  false,
		"im_db_pool_wait_duration_seconds_total": false,
	}
	for _, family := range families {
		if _, ok := want[family.GetName()]; ok {
			want[family.GetName()] = true
		}
	}
	for name, found := range want {
		if !found {
			t.Errorf("metric %s was not gathered", name)
		}
	}
}