// 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 (
	"io"
	"net/http"
	"reflect"
	"sort"
	"strings"
	"testing"

	"github.com/prometheus/common/model"
)

func TestTextDecoder(t *testing.T) {
	var (
		ts = model.Now()
		in = `
# Only a quite simple scenario with two metric families.
# More complicated tests of the parser itself can be found in the text package.
# TYPE mf2 counter
mf2 3
mf1{label="value1"} -3.14 123456
mf1{label="value2"} 42
mf2 4
`
		out = model.Vector{
			&model.Sample{
				Metric: model.Metric{
					model.MetricNameLabel: "mf1",
					"label":               "value1",
				},
				Value:     -3.14,
				Timestamp: 123456,
			},
			&model.Sample{
				Metric: model.Metric{
					model.MetricNameLabel: "mf1",
					"label":               "value2",
				},
				Value:     42,
				Timestamp: ts,
			},
			&model.Sample{
				Metric: model.Metric{
					model.MetricNameLabel: "mf2",
				},
				Value:     3,
				Timestamp: ts,
			},
			&model.Sample{
				Metric: model.Metric{
					model.MetricNameLabel: "mf2",
				},
				Value:     4,
				Timestamp: ts,
			},
		}
	)

	dec := &SampleDecoder{
		Dec: &textDecoder{r: strings.NewReader(in)},
		Opts: &DecodeOptions{
			Timestamp: ts,
		},
	}
	var all model.Vector
	for {
		var smpls model.Vector
		err := dec.Decode(&smpls)
		if err == io.EOF {
			break
		}
		if err != nil {
			t.Fatal(err)
		}
		all = append(all, smpls...)
	}
	sort.Sort(all)
	sort.Sort(out)
	if !reflect.DeepEqual(all, out) {
		t.Fatalf("output does not match")
	}
}

func TestProtoDecoder(t *testing.T) {

	var testTime = model.Now()

	scenarios := []struct {
		in       string
		expected model.Vector
		fail     bool
	}{
		{
			in: "",
		},
		{
			in:   "\x8f\x01\n\rrequest_count\x12\x12Number of requests\x18\x00\"0\n#\n\x0fsome_!abel_name\x12\x10some_label_value\x1a\t\t\x00\x00\x00\x00\x00\x00E\xc0\"6\n)\n\x12another_label_name\x12\x13another_label_value\x1a\t\t\x00\x00\x00\x00\x00\x00U@",
			fail: true,
		},
		{
			in: "\x8f\x01\n\rrequest_count\x12\x12Number of requests\x18\x00\"0\n#\n\x0fsome_label_name\x12\x10some_label_value\x1a\t\t\x00\x00\x00\x00\x00\x00E\xc0\"6\n)\n\x12another_label_name\x12\x13another_label_value\x1a\t\t\x00\x00\x00\x00\x00\x00U@",
			expected: model.Vector{
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count",
						"some_label_name":     "some_label_value",
					},
					Value:     -42,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count",
						"another_label_name":  "another_label_value",
					},
					Value:     84,
					Timestamp: testTime,
				},
			},
		},
		{
			in: "\xb9\x01\n\rrequest_count\x12\x12Number of requests\x18\x02\"O\n#\n\x0fsome_label_name\x12\x10some_label_value\"(\x1a\x12\t\xaeG\xe1z\x14\xae\xef?\x11\x00\x00\x00\x00\x00\x00E\xc0\x1a\x12\t+\x87\x16\xd9\xce\xf7\xef?\x11\x00\x00\x00\x00\x00\x00U\xc0\"A\n)\n\x12another_label_name\x12\x13another_label_value\"\x14\x1a\x12\t\x00\x00\x00\x00\x00\x00\xe0?\x11\x00\x00\x00\x00\x00\x00$@",
			expected: model.Vector{
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count_count",
						"some_label_name":     "some_label_value",
					},
					Value:     0,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count_sum",
						"some_label_name":     "some_label_value",
					},
					Value:     0,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count",
						"some_label_name":     "some_label_value",
						"quantile":            "0.99",
					},
					Value:     -42,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count",
						"some_label_name":     "some_label_value",
						"quantile":            "0.999",
					},
					Value:     -84,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count_count",
						"another_label_name":  "another_label_value",
					},
					Value:     0,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count_sum",
						"another_label_name":  "another_label_value",
					},
					Value:     0,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count",
						"another_label_name":  "another_label_value",
						"quantile":            "0.5",
					},
					Value:     10,
					Timestamp: testTime,
				},
			},
		},
		{
			in: "\x8d\x01\n\x1drequest_duration_microseconds\x12\x15The response latency.\x18\x04\"S:Q\b\x85\x15\x11\xcd\xcc\xccL\x8f\xcb:A\x1a\v\b{\x11\x00\x00\x00\x00\x00\x00Y@\x1a\f\b\x9c\x03\x11\x00\x00\x00\x00\x00\x00^@\x1a\f\b\xd0\x04\x11\x00\x00\x00\x00\x00\x00b@\x1a\f\b\xf4\v\x11\x9a\x99\x99\x99\x99\x99e@\x1a\f\b\x85\x15\x11\x00\x00\x00\x00\x00\x00\xf0\u007f",
			expected: model.Vector{
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_duration_microseconds_bucket",
						"le": "100",
					},
					Value:     123,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_duration_microseconds_bucket",
						"le": "120",
					},
					Value:     412,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_duration_microseconds_bucket",
						"le": "144",
					},
					Value:     592,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_duration_microseconds_bucket",
						"le": "172.8",
					},
					Value:     1524,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_duration_microseconds_bucket",
						"le": "+Inf",
					},
					Value:     2693,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_duration_microseconds_sum",
					},
					Value:     1756047.3,
					Timestamp: testTime,
				},
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_duration_microseconds_count",
					},
					Value:     2693,
					Timestamp: testTime,
				},
			},
		},
		{
			// The metric type is unset in this protobuf, which needs to be handled
			// correctly by the decoder.
			in: "\x1c\n\rrequest_count\"\v\x1a\t\t\x00\x00\x00\x00\x00\x00\xf0?",
			expected: model.Vector{
				&model.Sample{
					Metric: model.Metric{
						model.MetricNameLabel: "request_count",
					},
					Value:     1,
					Timestamp: testTime,
				},
			},
		},
	}

	for i, scenario := range scenarios {
		dec := &SampleDecoder{
			Dec: &protoDecoder{r: strings.NewReader(scenario.in)},
			Opts: &DecodeOptions{
				Timestamp: testTime,
			},
		}

		var all model.Vector
		for {
			var smpls model.Vector
			err := dec.Decode(&smpls)
			if err == io.EOF {
				break
			}
			if scenario.fail {
				if err == nil {
					t.Fatal("Expected error but got none")
				}
				break
			}
			if err != nil {
				t.Fatal(err)
			}
			all = append(all, smpls...)
		}
		sort.Sort(all)
		sort.Sort(scenario.expected)
		if !reflect.DeepEqual(all, scenario.expected) {
			t.Fatalf("%d. output does not match, want: %#v, got %#v", i, scenario.expected, all)
		}
	}
}

func testDiscriminatorHTTPHeader(t testing.TB) {
	var scenarios = []struct {
		input  map[string]string
		output Format
		err    error
	}{
		{
			input:  map[string]string{"Content-Type": `application/vnd.google.protobuf; proto="io.prometheus.client.MetricFamily"; encoding="delimited"`},
			output: FmtProtoDelim,
		},
		{
			input:  map[string]string{"Content-Type": `application/vnd.google.protobuf; proto="illegal"; encoding="delimited"`},
			output: FmtUnknown,
		},
		{
			input:  map[string]string{"Content-Type": `application/vnd.google.protobuf; proto="io.prometheus.client.MetricFamily"; encoding="illegal"`},
			output: FmtUnknown,
		},
		{
			input:  map[string]string{"Content-Type": `text/plain; version=0.0.4`},
			output: FmtText,
		},
		{
			input:  map[string]string{"Content-Type": `text/plain`},
			output: FmtText,
		},
		{
			input:  map[string]string{"Content-Type": `text/plain; version=0.0.3`},
			output: FmtUnknown,
		},
	}

	for i, scenario := range scenarios {
		var header http.Header

		if len(scenario.input) > 0 {
			header = http.Header{}
		}

		for key, value := range scenario.input {
			header.Add(key, value)
		}

		actual := ResponseFormat(header)

		if scenario.output != actual {
			t.Errorf("%d. expected %s, got %s", i, scenario.output, actual)
		}
	}
}

func TestDiscriminatorHTTPHeader(t *testing.T) {
	testDiscriminatorHTTPHeader(t)
}

func BenchmarkDiscriminatorHTTPHeader(b *testing.B) {
	for i := 0; i < b.N; i++ {
		testDiscriminatorHTTPHeader(b)
	}
}