// Code generated by gotmpl. DO NOT MODIFY.
// source: internal/shared/semconv/server.go.tmpl

// Copyright The OpenTelemetry Authors
// SPDX-License-Identifier: Apache-2.0

// Package semconv provides OpenTelemetry semantic convention types and
// functionality.
package semconv // import "go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux/internal/semconv"

import (
	"context"
	"fmt"
	"net/http"
	"slices"
	"strings"
	"sync"

	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/semconv/v1.39.0"
	"go.opentelemetry.io/otel/semconv/v1.39.0/httpconv"
)

type RequestTraceAttrsOpts struct {
	// If set, this is used as value for the "http.client_ip" attribute.
	HTTPClientIP string
}

type ResponseTelemetry struct {
	StatusCode int
	ReadBytes  int64
	ReadError  error
	WriteBytes int64
	WriteError error
}

type HTTPServer struct{
	requestBodySizeHistogram  httpconv.ServerRequestBodySize
	responseBodySizeHistogram httpconv.ServerResponseBodySize
	requestDurationHistogram  httpconv.ServerRequestDuration
}

func NewHTTPServer(meter metric.Meter) HTTPServer {
	server := HTTPServer{}

	var err error
	server.requestBodySizeHistogram, err = httpconv.NewServerRequestBodySize(meter)
	handleErr(err)

	server.responseBodySizeHistogram, err = httpconv.NewServerResponseBodySize(meter)
	handleErr(err)

	server.requestDurationHistogram, err = httpconv.NewServerRequestDuration(
		meter,
		metric.WithExplicitBucketBoundaries(
			0.005, 0.01, 0.025, 0.05, 0.075, 0.1,
			0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10,
		),
	)
	handleErr(err)
	return server
}

// Status returns a span status code and message for an HTTP status code
// value returned by a server. Status codes in the 400-499 range are not
// returned as errors.
func (n HTTPServer) Status(code int) (codes.Code, string) {
	if code < 100 || code >= 600 {
		return codes.Error, fmt.Sprintf("Invalid HTTP status code %d", code)
	}
	if code >= 500 {
		return codes.Error, ""
	}
	return codes.Unset, ""
}

// RequestTraceAttrs returns trace attributes for an HTTP request received by a
// server.
//
// The server must be the primary server name if it is known. For example this
// would be the ServerName directive
// (https://httpd.apache.org/docs/2.4/mod/core.html#servername) for an Apache
// server, and the server_name directive
// (http://nginx.org/en/docs/http/ngx_http_core_module.html#server_name) for an
// nginx server. More generically, the primary server name would be the host
// header value that matches the default virtual host of an HTTP server. It
// should include the host identifier and if a port is used to route to the
// server that port identifier should be included as an appropriate port
// suffix.
//
// If the primary server name is not known, server should be an empty string.
// The req Host will be used to determine the server instead.
func (n HTTPServer) RequestTraceAttrs(server string, req *http.Request, opts RequestTraceAttrsOpts) []attribute.KeyValue {
	count := 3 // ServerAddress, Method, Scheme

	var host string
	var p int
	if server == "" {
		host, p = SplitHostPort(req.Host)
	} else {
		// Prioritize the primary server name.
		host, p = SplitHostPort(server)
		if p < 0 {
			_, p = SplitHostPort(req.Host)
		}
	}

	hostPort := requiredHTTPPort(req.TLS != nil, p)
	if hostPort > 0 {
		count++
	}

	method, methodOriginal := n.method(req.Method)
	if methodOriginal != (attribute.KeyValue{}) {
		count++
	}

	scheme := n.scheme(req.TLS != nil)

	peer, peerPort := SplitHostPort(req.RemoteAddr)
	if peer != "" {
		// The Go HTTP server sets RemoteAddr to "IP:port", this will not be a
		// file-path that would be interpreted with a sock family.
		count++
		if peerPort > 0 {
			count++
		}
	}

	useragent := req.UserAgent()
	if useragent != "" {
		count++
	}

	// For client IP, use, in order:
	// 1. The value passed in the options
	// 2. The value in the X-Forwarded-For header
	// 3. The peer address
	clientIP := opts.HTTPClientIP
	if clientIP == "" {
		clientIP = serverClientIP(req.Header.Get("X-Forwarded-For"))
		if clientIP == "" {
			clientIP = peer
		}
	}
	if clientIP != "" {
		count++
	}

	if req.URL != nil && req.URL.Path != "" {
		count++
	}

	protoName, protoVersion := netProtocol(req.Proto)
	if protoName != "" && protoName != "http" {
		count++
	}
	if protoVersion != "" {
		count++
	}

	route := httpRoute(req.Pattern)
	if route != "" {
		count++
	}

	attrs := make([]attribute.KeyValue, 0, count)
	attrs = append(attrs,
		semconv.ServerAddress(host),
		method,
		scheme,
	)

	if hostPort > 0 {
		attrs = append(attrs, semconv.ServerPort(hostPort))
	}
	if methodOriginal != (attribute.KeyValue{}) {
		attrs = append(attrs, methodOriginal)
	}

	if peer, peerPort := SplitHostPort(req.RemoteAddr); peer != "" {
		// The Go HTTP server sets RemoteAddr to "IP:port", this will not be a
		// file-path that would be interpreted with a sock family.
		attrs = append(attrs, semconv.NetworkPeerAddress(peer))
		if peerPort > 0 {
			attrs = append(attrs, semconv.NetworkPeerPort(peerPort))
		}
	}

	if useragent != "" {
		attrs = append(attrs, semconv.UserAgentOriginal(useragent))
	}

	if clientIP != "" {
		attrs = append(attrs, semconv.ClientAddress(clientIP))
	}

	if req.URL != nil && req.URL.Path != "" {
		attrs = append(attrs, semconv.URLPath(req.URL.Path))
	}

	if protoName != "" && protoName != "http" {
		attrs = append(attrs, semconv.NetworkProtocolName(protoName))
	}
	if protoVersion != "" {
		attrs = append(attrs, semconv.NetworkProtocolVersion(protoVersion))
	}

	if route != "" {
		attrs = append(attrs, n.Route(route))
	}

	return attrs
}

func (s HTTPServer) NetworkTransportAttr(network string) []attribute.KeyValue {
	attr := semconv.NetworkTransportPipe
	switch network {
	case "tcp", "tcp4", "tcp6":
		attr = semconv.NetworkTransportTCP
	case "udp", "udp4", "udp6":
		attr = semconv.NetworkTransportUDP
	case "unix", "unixgram", "unixpacket":
		attr = semconv.NetworkTransportUnix
	}

	return []attribute.KeyValue{attr}
}

type ServerMetricData struct {
	ServerName   string
	ResponseSize int64

	MetricData
	MetricAttributes
}

type MetricAttributes struct {
	Req                  *http.Request
	StatusCode           int
	Route                string
	AdditionalAttributes []attribute.KeyValue
}

type MetricData struct {
	RequestSize int64

	// The request duration, in milliseconds
	ElapsedTime float64
}

var (
	metricAddOptionPool = &sync.Pool{
		New: func() any {
			return &[]metric.AddOption{}
		},
	}

	metricRecordOptionPool = &sync.Pool{
		New: func() any {
			return &[]metric.RecordOption{}
		},
	}
)

func (n HTTPServer) RecordMetrics(ctx context.Context, md ServerMetricData) {
	attributes := n.MetricAttributes(md.ServerName, md.Req, md.StatusCode, md.Route, md.AdditionalAttributes)
	o := metric.WithAttributeSet(attribute.NewSet(attributes...))
	recordOpts := metricRecordOptionPool.Get().(*[]metric.RecordOption)
	*recordOpts = append(*recordOpts, o)
	n.requestBodySizeHistogram.Inst().Record(ctx, md.RequestSize, *recordOpts...)
	n.responseBodySizeHistogram.Inst().Record(ctx, md.ResponseSize, *recordOpts...)
	n.requestDurationHistogram.Inst().Record(ctx, md.ElapsedTime/1000.0, o)
	*recordOpts = (*recordOpts)[:0]
	metricRecordOptionPool.Put(recordOpts)
}

func (n HTTPServer) method(method string) (attribute.KeyValue, attribute.KeyValue) {
	if method == "" {
		return semconv.HTTPRequestMethodGet, attribute.KeyValue{}
	}
	if attr, ok := methodLookup[method]; ok {
		return attr, attribute.KeyValue{}
	}

	orig := semconv.HTTPRequestMethodOriginal(method)
	if attr, ok := methodLookup[strings.ToUpper(method)]; ok {
		return attr, orig
	}
	return semconv.HTTPRequestMethodGet, orig
}

func (n HTTPServer) scheme(https bool) attribute.KeyValue { //nolint:revive // ignore linter
	if https {
		return semconv.URLScheme("https")
	}
	return semconv.URLScheme("http")
}

// ResponseTraceAttrs returns trace attributes for telemetry from an HTTP
// response.
//
// If any of the fields in the ResponseTelemetry are not set the attribute will
// be omitted.
func (n HTTPServer) ResponseTraceAttrs(resp ResponseTelemetry) []attribute.KeyValue {
	var count int

	if resp.ReadBytes > 0 {
		count++
	}
	if resp.WriteBytes > 0 {
		count++
	}
	if resp.StatusCode > 0 {
		count++
	}

	attributes := make([]attribute.KeyValue, 0, count)

	if resp.ReadBytes > 0 {
		attributes = append(attributes,
			semconv.HTTPRequestBodySize(int(resp.ReadBytes)),
		)
	}
	if resp.WriteBytes > 0 {
		attributes = append(attributes,
			semconv.HTTPResponseBodySize(int(resp.WriteBytes)),
		)
	}
	if resp.StatusCode > 0 {
		attributes = append(attributes,
			semconv.HTTPResponseStatusCode(resp.StatusCode),
		)
	}

	return attributes
}

// Route returns the attribute for the route.
func (n HTTPServer) Route(route string) attribute.KeyValue {
	return semconv.HTTPRoute(route)
}

func (n HTTPServer) MetricAttributes(server string, req *http.Request, statusCode int, route string, additionalAttributes []attribute.KeyValue) []attribute.KeyValue {
	num := len(additionalAttributes) + 3
	var host string
	var p int
	if server == "" {
		host, p = SplitHostPort(req.Host)
	} else {
		// Prioritize the primary server name.
		host, p = SplitHostPort(server)
		if p < 0 {
			_, p = SplitHostPort(req.Host)
		}
	}
	hostPort := requiredHTTPPort(req.TLS != nil, p)
	if hostPort > 0 {
		num++
	}
	protoName, protoVersion := netProtocol(req.Proto)
	if protoName != "" {
		num++
	}
	if protoVersion != "" {
		num++
	}

	if statusCode > 0 {
		num++
	}

	if route != "" {
        num++
    }

	attributes := slices.Grow(additionalAttributes, num)
	attributes = append(attributes,
		semconv.HTTPRequestMethodKey.String(standardizeHTTPMethod(req.Method)),
		n.scheme(req.TLS != nil),
		semconv.ServerAddress(host))

	if hostPort > 0 {
		attributes = append(attributes, semconv.ServerPort(hostPort))
	}
	if protoName != "" {
		attributes = append(attributes, semconv.NetworkProtocolName(protoName))
	}
	if protoVersion != "" {
		attributes = append(attributes, semconv.NetworkProtocolVersion(protoVersion))
	}

	if statusCode > 0 {
		attributes = append(attributes, semconv.HTTPResponseStatusCode(statusCode))
	}

	if route != "" {
        attributes = append(attributes, semconv.HTTPRoute(route))
    }
	return attributes
}
