package nebula

// This file is a trimmed, inlined copy of the graphite exporter from
// github.com/cyberdelia/go-metrics-graphite, retaining only the Config type and
// the Once entrypoint that Nebula uses. The upstream package has been
// unmaintained for 10+ years, so it was vendored here to drop the dependency.
// See https://github.com/slackhq/nebula/issues/1831.
//
// Copyright 2015 Timothée Peignier. All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//  1. Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//
//  2. Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

import (
	"bufio"
	"fmt"
	"net"
	"strconv"
	"strings"
	"time"

	"github.com/rcrowley/go-metrics"
)

// graphiteConfigExport provides a container with configuration parameters for
// the Graphite exporter.
type graphiteConfigExport struct {
	Addr          *net.TCPAddr     // Network address to connect to
	Registry      metrics.Registry // Registry to be exported
	FlushInterval time.Duration    // Flush interval
	DurationUnit  time.Duration    // Time conversion unit for durations
	Prefix        string           // Prefix to be prepended to metric names
	Percentiles   []float64        // Percentiles to export from timers and histograms
}

// graphiteOnce performs a single submission to Graphite, returning a non-nil
// error on failed connections.
func graphiteOnce(c graphiteConfigExport) error {
	now := time.Now().Unix()
	du := float64(c.DurationUnit)
	flushSeconds := float64(c.FlushInterval) / float64(time.Second)
	conn, err := net.DialTCP("tcp", nil, c.Addr)
	if err != nil {
		return err
	}
	defer conn.Close()
	w := bufio.NewWriter(conn)
	c.Registry.Each(func(name string, i any) {
		switch metric := i.(type) {
		case metrics.Counter:
			count := metric.Count()
			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, count, now)
			fmt.Fprintf(w, "%s.%s.count_ps %.2f %d\n", c.Prefix, name, float64(count)/flushSeconds, now)
		case metrics.Gauge:
			fmt.Fprintf(w, "%s.%s.value %d %d\n", c.Prefix, name, metric.Value(), now)
		case metrics.GaugeFloat64:
			fmt.Fprintf(w, "%s.%s.value %f %d\n", c.Prefix, name, metric.Value(), now)
		case metrics.Histogram:
			h := metric.Snapshot()
			ps := h.Percentiles(c.Percentiles)
			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, h.Count(), now)
			fmt.Fprintf(w, "%s.%s.min %d %d\n", c.Prefix, name, h.Min(), now)
			fmt.Fprintf(w, "%s.%s.max %d %d\n", c.Prefix, name, h.Max(), now)
			fmt.Fprintf(w, "%s.%s.mean %.2f %d\n", c.Prefix, name, h.Mean(), now)
			fmt.Fprintf(w, "%s.%s.std-dev %.2f %d\n", c.Prefix, name, h.StdDev(), now)
			for psIdx, psKey := range c.Percentiles {
				key := strings.Replace(strconv.FormatFloat(psKey*100.0, 'f', -1, 64), ".", "", 1)
				fmt.Fprintf(w, "%s.%s.%s-percentile %.2f %d\n", c.Prefix, name, key, ps[psIdx], now)
			}
		case metrics.Meter:
			m := metric.Snapshot()
			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, m.Count(), now)
			fmt.Fprintf(w, "%s.%s.one-minute %.2f %d\n", c.Prefix, name, m.Rate1(), now)
			fmt.Fprintf(w, "%s.%s.five-minute %.2f %d\n", c.Prefix, name, m.Rate5(), now)
			fmt.Fprintf(w, "%s.%s.fifteen-minute %.2f %d\n", c.Prefix, name, m.Rate15(), now)
			fmt.Fprintf(w, "%s.%s.mean %.2f %d\n", c.Prefix, name, m.RateMean(), now)
		case metrics.Timer:
			t := metric.Snapshot()
			ps := t.Percentiles(c.Percentiles)
			count := t.Count()
			fmt.Fprintf(w, "%s.%s.count %d %d\n", c.Prefix, name, count, now)
			fmt.Fprintf(w, "%s.%s.count_ps %.2f %d\n", c.Prefix, name, float64(count)/flushSeconds, now)
			fmt.Fprintf(w, "%s.%s.min %d %d\n", c.Prefix, name, t.Min()/int64(du), now)
			fmt.Fprintf(w, "%s.%s.max %d %d\n", c.Prefix, name, t.Max()/int64(du), now)
			fmt.Fprintf(w, "%s.%s.mean %.2f %d\n", c.Prefix, name, t.Mean()/du, now)
			fmt.Fprintf(w, "%s.%s.std-dev %.2f %d\n", c.Prefix, name, t.StdDev()/du, now)
			for psIdx, psKey := range c.Percentiles {
				key := strings.Replace(strconv.FormatFloat(psKey*100.0, 'f', -1, 64), ".", "", 1)
				fmt.Fprintf(w, "%s.%s.%s-percentile %.2f %d\n", c.Prefix, name, key, ps[psIdx]/du, now)
			}
			fmt.Fprintf(w, "%s.%s.one-minute %.2f %d\n", c.Prefix, name, t.Rate1(), now)
			fmt.Fprintf(w, "%s.%s.five-minute %.2f %d\n", c.Prefix, name, t.Rate5(), now)
			fmt.Fprintf(w, "%s.%s.fifteen-minute %.2f %d\n", c.Prefix, name, t.Rate15(), now)
			fmt.Fprintf(w, "%s.%s.mean-rate %.2f %d\n", c.Prefix, name, t.RateMean(), now)
		}
		w.Flush()
	})
	return nil
}