// Copyright 2015 The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package expfmt

import (
	
	
	

	
	

	

	

	dto 
)

// Encoder types encode metric families into an underlying wire protocol.
type Encoder interface {
	Encode(*dto.MetricFamily) error
}

// Closer is implemented by Encoders that need to be closed to finalize
// encoding. (For example, OpenMetrics needs a final `# EOF` line.)
//
// Note that all Encoder implementations returned from this package implement
// Closer, too, even if the Close call is a no-op. This happens in preparation
// for adding a Close method to the Encoder interface directly in a (mildly
// breaking) release in the future.
type Closer interface {
	Close() error
}

type encoderCloser struct {
	encode func(*dto.MetricFamily) error
	close  func() error
}

func ( encoderCloser) ( *dto.MetricFamily) error {
	return .encode()
}

func ( encoderCloser) () error {
	return .close()
}

// Negotiate returns the Content-Type based on the given Accept header. If no
// appropriate accepted type is found, FmtText is returned (which is the
// Prometheus text format). This function will never negotiate FmtOpenMetrics,
// as the support is still experimental. To include the option to negotiate
// FmtOpenMetrics, use NegotiateOpenMetrics.
func ( http.Header) Format {
	 := Format(fmt.Sprintf("; escaping=%s", Format(model.NameEscapingScheme.String())))
	for ,  := range goautoneg.ParseAccept(.Get(hdrAccept)) {
		if  := .Params[model.EscapingKey];  != "" {
			switch Format() {
			case model.AllowUTF8, model.EscapeUnderscores, model.EscapeDots, model.EscapeValues:
				 = Format("; escaping=" + )
			default:
				// If the escaping parameter is unknown, ignore it.
			}
		}
		 := .Params["version"]
		if .Type+"/"+.SubType == ProtoType && .Params["proto"] == ProtoProtocol {
			switch .Params["encoding"] {
			case "delimited":
				return FmtProtoDelim + 
			case "text":
				return FmtProtoText + 
			case "compact-text":
				return FmtProtoCompact + 
			}
		}
		if .Type == "text" && .SubType == "plain" && ( == TextVersion ||  == "") {
			return FmtText + 
		}
	}
	return FmtText + 
}

// NegotiateIncludingOpenMetrics works like Negotiate but includes
// FmtOpenMetrics as an option for the result. Note that this function is
// temporary and will disappear once FmtOpenMetrics is fully supported and as
// such may be negotiated by the normal Negotiate function.
func ( http.Header) Format {
	 := Format(fmt.Sprintf("; escaping=%s", Format(model.NameEscapingScheme.String())))
	for ,  := range goautoneg.ParseAccept(.Get(hdrAccept)) {
		if  := .Params[model.EscapingKey];  != "" {
			switch Format() {
			case model.AllowUTF8, model.EscapeUnderscores, model.EscapeDots, model.EscapeValues:
				 = Format("; escaping=" + )
			default:
				// If the escaping parameter is unknown, ignore it.
			}
		}
		 := .Params["version"]
		if .Type+"/"+.SubType == ProtoType && .Params["proto"] == ProtoProtocol {
			switch .Params["encoding"] {
			case "delimited":
				return FmtProtoDelim + 
			case "text":
				return FmtProtoText + 
			case "compact-text":
				return FmtProtoCompact + 
			}
		}
		if .Type == "text" && .SubType == "plain" && ( == TextVersion ||  == "") {
			return FmtText + 
		}
		if .Type+"/"+.SubType == OpenMetricsType && ( == OpenMetricsVersion_0_0_1 ||  == OpenMetricsVersion_1_0_0 ||  == "") {
			switch  {
			case OpenMetricsVersion_1_0_0:
				return FmtOpenMetrics_1_0_0 + 
			default:
				return FmtOpenMetrics_0_0_1 + 
			}
		}
	}
	return FmtText + 
}

// NewEncoder returns a new encoder based on content type negotiation. All
// Encoder implementations returned by NewEncoder also implement Closer, and
// callers should always call the Close method. It is currently only required
// for FmtOpenMetrics, but a future (breaking) release will add the Close method
// to the Encoder interface directly. The current version of the Encoder
// interface is kept for backwards compatibility.
// In cases where the Format does not allow for UTF-8 names, the global
// NameEscapingScheme will be applied.
//
// NewEncoder can be called with additional options to customize the OpenMetrics text output.
// For example:
// NewEncoder(w, FmtOpenMetrics_1_0_0, WithCreatedLines())
//
// Extra options are ignored for all other formats.
func ( io.Writer,  Format,  ...EncoderOption) Encoder {
	 := .ToEscapingScheme()

	switch .FormatType() {
	case TypeProtoDelim:
		return encoderCloser{
			encode: func( *dto.MetricFamily) error {
				,  := protodelim.MarshalTo(, )
				return 
			},
			close: func() error { return nil },
		}
	case TypeProtoCompact:
		return encoderCloser{
			encode: func( *dto.MetricFamily) error {
				,  := fmt.Fprintln(, model.EscapeMetricFamily(, ).String())
				return 
			},
			close: func() error { return nil },
		}
	case TypeProtoText:
		return encoderCloser{
			encode: func( *dto.MetricFamily) error {
				,  := fmt.Fprintln(, prototext.Format(model.EscapeMetricFamily(, )))
				return 
			},
			close: func() error { return nil },
		}
	case TypeTextPlain:
		return encoderCloser{
			encode: func( *dto.MetricFamily) error {
				,  := MetricFamilyToText(, model.EscapeMetricFamily(, ))
				return 
			},
			close: func() error { return nil },
		}
	case TypeOpenMetrics:
		return encoderCloser{
			encode: func( *dto.MetricFamily) error {
				,  := MetricFamilyToOpenMetrics(, model.EscapeMetricFamily(, ), ...)
				return 
			},
			close: func() error {
				,  := FinalizeOpenMetrics()
				return 
			},
		}
	}
	panic(fmt.Errorf("expfmt.NewEncoder: unknown format %q", ))
}