package grok

import (
	"testing"
	"time"

	"github.com/influxdata/telegraf"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

var benchM telegraf.Metric

func Benchmark_ParseLine_CommonLogFormat(b *testing.B) {
	p := &Parser{
		Patterns: []string{"%{COMMON_LOG_FORMAT}"},
	}
	p.Compile()

	var m telegraf.Metric
	for n := 0; n < b.N; n++ {
		m, _ = p.ParseLine(`127.0.0.1 user-identifier frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326`)
	}
	benchM = m
}

func Benchmark_ParseLine_CombinedLogFormat(b *testing.B) {
	p := &Parser{
		Patterns: []string{"%{COMBINED_LOG_FORMAT}"},
	}
	p.Compile()

	var m telegraf.Metric
	for n := 0; n < b.N; n++ {
		m, _ = p.ParseLine(`127.0.0.1 user-identifier frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326 "-" "Mozilla"`)
	}
	benchM = m
}

func Benchmark_ParseLine_InfluxLog(b *testing.B) {
	p := &Parser{
		Patterns: []string{"%{INFLUXDB_HTTPD_LOG}"},
	}
	p.Compile()

	var m telegraf.Metric
	for n := 0; n < b.N; n++ {
		m, _ = p.ParseLine(`[httpd] 192.168.1.1 - - [14/Jun/2016:11:33:29 +0100] "POST /write?consistency=any&db=telegraf&precision=ns&rp= HTTP/1.1" 204 0 "-" "InfluxDBClient" 6f61bc44-321b-11e6-8050-000000000000 2513`)
	}
	benchM = m
}

func Benchmark_ParseLine_InfluxLog_NoMatch(b *testing.B) {
	p := &Parser{
		Patterns: []string{"%{INFLUXDB_HTTPD_LOG}"},
	}
	p.Compile()

	var m telegraf.Metric
	for n := 0; n < b.N; n++ {
		m, _ = p.ParseLine(`[retention] 2016/06/14 14:38:24 retention policy shard deletion check commencing`)
	}
	benchM = m
}

func Benchmark_ParseLine_CustomPattern(b *testing.B) {
	p := &Parser{
		Patterns: []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
		CustomPatterns: `
			DURATION %{NUMBER}[nuµm]?s
			RESPONSE_CODE %{NUMBER:response_code:tag}
			RESPONSE_TIME %{DURATION:response_time:duration}
			TEST_LOG_A %{NUMBER:myfloat:float} %{RESPONSE_CODE} %{IPORHOST:clientip} %{RESPONSE_TIME}
		`,
	}
	p.Compile()

	var m telegraf.Metric
	for n := 0; n < b.N; n++ {
		m, _ = p.ParseLine(`[04/Jun/2016:12:41:45 +0100] 1.25 200 192.168.1.1 5.432µs 101`)
	}
	benchM = m
}

func TestMeasurementName(t *testing.T) {
	p := &Parser{
		Measurement: "my_web_log",
		Patterns:    []string{"%{COMMON_LOG_FORMAT}"},
	}
	assert.NoError(t, p.Compile())

	// Parse an influxdb POST request
	m, err := p.ParseLine(`127.0.0.1 user-identifier frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326`)
	require.NotNil(t, m)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"resp_bytes":   int64(2326),
			"auth":         "frank",
			"client_ip":    "127.0.0.1",
			"http_version": float64(1.0),
			"ident":        "user-identifier",
			"request":      "/apache_pb.gif",
		},
		m.Fields())
	assert.Equal(t, map[string]string{"verb": "GET", "resp_code": "200"}, m.Tags())
	assert.Equal(t, "my_web_log", m.Name())
}

func TestBuiltinInfluxdbHttpd(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{INFLUXDB_HTTPD_LOG}"},
	}
	assert.NoError(t, p.Compile())

	// Parse an influxdb POST request
	m, err := p.ParseLine(`[httpd] ::1 - - [14/Jun/2016:11:33:29 +0100] "POST /write?consistency=any&db=telegraf&precision=ns&rp= HTTP/1.1" 204 0 "-" "InfluxDBClient" 6f61bc44-321b-11e6-8050-000000000000 2513`)
	require.NotNil(t, m)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"resp_bytes":       int64(0),
			"auth":             "-",
			"client_ip":        "::1",
			"http_version":     float64(1.1),
			"ident":            "-",
			"referrer":         "-",
			"request":          "/write?consistency=any&db=telegraf&precision=ns&rp=",
			"response_time_us": int64(2513),
			"agent":            "InfluxDBClient",
		},
		m.Fields())
	assert.Equal(t, map[string]string{"verb": "POST", "resp_code": "204"}, m.Tags())

	// Parse an influxdb GET request
	m, err = p.ParseLine(`[httpd] ::1 - - [14/Jun/2016:12:10:02 +0100] "GET /query?db=telegraf&q=SELECT+bytes%2Cresponse_time_us+FROM+logparser_grok+WHERE+http_method+%3D+%27GET%27+AND+response_time_us+%3E+0+AND+time+%3E+now%28%29+-+1h HTTP/1.1" 200 578 "http://localhost:8083/" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.84 Safari/537.36" 8a3806f1-3220-11e6-8006-000000000000 988`)
	require.NotNil(t, m)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"resp_bytes":       int64(578),
			"auth":             "-",
			"client_ip":        "::1",
			"http_version":     float64(1.1),
			"ident":            "-",
			"referrer":         "http://localhost:8083/",
			"request":          "/query?db=telegraf&q=SELECT+bytes%2Cresponse_time_us+FROM+logparser_grok+WHERE+http_method+%3D+%27GET%27+AND+response_time_us+%3E+0+AND+time+%3E+now%28%29+-+1h",
			"response_time_us": int64(988),
			"agent":            "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.84 Safari/537.36",
		},
		m.Fields())
	assert.Equal(t, map[string]string{"verb": "GET", "resp_code": "200"}, m.Tags())
}

// common log format
// 127.0.0.1 user-identifier frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326
func TestBuiltinCommonLogFormat(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{COMMON_LOG_FORMAT}"},
	}
	assert.NoError(t, p.Compile())

	// Parse an influxdb POST request
	m, err := p.ParseLine(`127.0.0.1 user-identifier frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326`)
	require.NotNil(t, m)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"resp_bytes":   int64(2326),
			"auth":         "frank",
			"client_ip":    "127.0.0.1",
			"http_version": float64(1.0),
			"ident":        "user-identifier",
			"request":      "/apache_pb.gif",
		},
		m.Fields())
	assert.Equal(t, map[string]string{"verb": "GET", "resp_code": "200"}, m.Tags())
}

// combined log format
// 127.0.0.1 user-identifier frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326 "-" "Mozilla"
func TestBuiltinCombinedLogFormat(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{COMBINED_LOG_FORMAT}"},
	}
	assert.NoError(t, p.Compile())

	// Parse an influxdb POST request
	m, err := p.ParseLine(`127.0.0.1 user-identifier frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326 "-" "Mozilla"`)
	require.NotNil(t, m)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"resp_bytes":   int64(2326),
			"auth":         "frank",
			"client_ip":    "127.0.0.1",
			"http_version": float64(1.0),
			"ident":        "user-identifier",
			"request":      "/apache_pb.gif",
			"referrer":     "-",
			"agent":        "Mozilla",
		},
		m.Fields())
	assert.Equal(t, map[string]string{"verb": "GET", "resp_code": "200"}, m.Tags())
}

func TestCompileStringAndParse(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{TEST_LOG_A}"},
		CustomPatterns: `
			DURATION %{NUMBER}[nuµm]?s
			RESPONSE_CODE %{NUMBER:response_code:tag}
			RESPONSE_TIME %{DURATION:response_time:duration}
			TEST_LOG_A %{NUMBER:myfloat:float} %{RESPONSE_CODE} %{IPORHOST:clientip} %{RESPONSE_TIME}
		`,
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`1.25 200 192.168.1.1 5.432µs`)
	require.NotNil(t, metricA)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"clientip":      "192.168.1.1",
			"myfloat":       float64(1.25),
			"response_time": int64(5432),
		},
		metricA.Fields())
	assert.Equal(t, map[string]string{"response_code": "200"}, metricA.Tags())
}

func TestCompileErrorsOnInvalidPattern(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
		CustomPatterns: `
			DURATION %{NUMBER}[nuµm]?s
			RESPONSE_CODE %{NUMBER:response_code:tag}
			RESPONSE_TIME %{DURATION:response_time:duration}
			TEST_LOG_A %{NUMBER:myfloat:float} %{RESPONSE_CODE} %{IPORHOST:clientip} %{RESPONSE_TIME}
		`,
	}
	assert.Error(t, p.Compile())

	metricA, _ := p.ParseLine(`1.25 200 192.168.1.1 5.432µs`)
	require.Nil(t, metricA)
}

func TestParsePatternsWithoutCustom(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{POSINT:ts:ts-epochnano} response_time=%{POSINT:response_time:int} mymetric=%{NUMBER:metric:float}"},
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`1466004605359052000 response_time=20821 mymetric=10890.645`)
	require.NotNil(t, metricA)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"response_time": int64(20821),
			"metric":        float64(10890.645),
		},
		metricA.Fields())
	assert.Equal(t, map[string]string{}, metricA.Tags())
	assert.Equal(t, time.Unix(0, 1466004605359052000), metricA.Time())
}

func TestParseEpochNano(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{MYAPP}"},
		CustomPatterns: `
			MYAPP %{POSINT:ts:ts-epochnano} response_time=%{POSINT:response_time:int} mymetric=%{NUMBER:metric:float}
		`,
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`1466004605359052000 response_time=20821 mymetric=10890.645`)
	require.NotNil(t, metricA)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"response_time": int64(20821),
			"metric":        float64(10890.645),
		},
		metricA.Fields())
	assert.Equal(t, map[string]string{}, metricA.Tags())
	assert.Equal(t, time.Unix(0, 1466004605359052000), metricA.Time())
}

func TestParseEpoch(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{MYAPP}"},
		CustomPatterns: `
			MYAPP %{POSINT:ts:ts-epoch} response_time=%{POSINT:response_time:int} mymetric=%{NUMBER:metric:float}
		`,
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`1466004605 response_time=20821 mymetric=10890.645`)
	require.NotNil(t, metricA)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"response_time": int64(20821),
			"metric":        float64(10890.645),
		},
		metricA.Fields())
	assert.Equal(t, map[string]string{}, metricA.Tags())
	assert.Equal(t, time.Unix(1466004605, 0), metricA.Time())
}

func TestParseEpochErrors(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{MYAPP}"},
		CustomPatterns: `
			MYAPP %{WORD:ts:ts-epoch} response_time=%{POSINT:response_time:int} mymetric=%{NUMBER:metric:float}
		`,
	}
	assert.NoError(t, p.Compile())

	_, err := p.ParseLine(`foobar response_time=20821 mymetric=10890.645`)
	assert.NoError(t, err)

	p = &Parser{
		Patterns: []string{"%{MYAPP}"},
		CustomPatterns: `
			MYAPP %{WORD:ts:ts-epochnano} response_time=%{POSINT:response_time:int} mymetric=%{NUMBER:metric:float}
		`,
	}
	assert.NoError(t, p.Compile())

	_, err = p.ParseLine(`foobar response_time=20821 mymetric=10890.645`)
	assert.NoError(t, err)
}

func TestParseGenericTimestamp(t *testing.T) {
	p := &Parser{
		Patterns: []string{`\[%{HTTPDATE:ts:ts}\] response_time=%{POSINT:response_time:int} mymetric=%{NUMBER:metric:float}`},
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`[09/Jun/2016:03:37:03 +0000] response_time=20821 mymetric=10890.645`)
	require.NotNil(t, metricA)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"response_time": int64(20821),
			"metric":        float64(10890.645),
		},
		metricA.Fields())
	assert.Equal(t, map[string]string{}, metricA.Tags())
	assert.Equal(t, time.Unix(1465443423, 0).UTC(), metricA.Time().UTC())

	metricB, err := p.ParseLine(`[09/Jun/2016:03:37:04 +0000] response_time=20821 mymetric=10890.645`)
	require.NotNil(t, metricB)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"response_time": int64(20821),
			"metric":        float64(10890.645),
		},
		metricB.Fields())
	assert.Equal(t, map[string]string{}, metricB.Tags())
	assert.Equal(t, time.Unix(1465443424, 0).UTC(), metricB.Time().UTC())
}

func TestParseGenericTimestampNotFound(t *testing.T) {
	p := &Parser{
		Patterns: []string{`\[%{NOTSPACE:ts:ts}\] response_time=%{POSINT:response_time:int} mymetric=%{NUMBER:metric:float}`},
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`[foobar] response_time=20821 mymetric=10890.645`)
	require.NotNil(t, metricA)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"response_time": int64(20821),
			"metric":        float64(10890.645),
		},
		metricA.Fields())
	assert.Equal(t, map[string]string{}, metricA.Tags())
}

func TestCompileFileAndParse(t *testing.T) {
	p := &Parser{
		Patterns:           []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
		CustomPatternFiles: []string{"./testdata/test-patterns"},
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`[04/Jun/2016:12:41:45 +0100] 1.25 200 192.168.1.1 5.432µs 101`)
	require.NotNil(t, metricA)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"clientip":      "192.168.1.1",
			"myfloat":       float64(1.25),
			"response_time": int64(5432),
			"myint":         int64(101),
		},
		metricA.Fields())
	assert.Equal(t, map[string]string{"response_code": "200"}, metricA.Tags())
	assert.Equal(t,
		time.Date(2016, time.June, 4, 12, 41, 45, 0, time.FixedZone("foo", 60*60)).Nanosecond(),
		metricA.Time().Nanosecond())

	metricB, err := p.ParseLine(`[04/06/2016--12:41:45] 1.25 mystring dropme nomodifier`)
	require.NotNil(t, metricB)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"myfloat":    1.25,
			"mystring":   "mystring",
			"nomodifier": "nomodifier",
		},
		metricB.Fields())
	assert.Equal(t, map[string]string{}, metricB.Tags())
	assert.Equal(t,
		time.Date(2016, time.June, 4, 12, 41, 45, 0, time.FixedZone("foo", 60*60)).Nanosecond(),
		metricB.Time().Nanosecond())
}

func TestCompileNoModifiersAndParse(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{TEST_LOG_C}"},
		CustomPatterns: `
			DURATION %{NUMBER}[nuµm]?s
			TEST_LOG_C %{NUMBER:myfloat} %{NUMBER} %{IPORHOST:clientip} %{DURATION:rt}
		`,
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`1.25 200 192.168.1.1 5.432µs`)
	require.NotNil(t, metricA)
	assert.NoError(t, err)
	assert.Equal(t,
		map[string]interface{}{
			"clientip": "192.168.1.1",
			"myfloat":  "1.25",
			"rt":       "5.432µs",
		},
		metricA.Fields())
	assert.Equal(t, map[string]string{}, metricA.Tags())
}

func TestCompileNoNamesAndParse(t *testing.T) {
	p := &Parser{
		Patterns: []string{"%{TEST_LOG_C}"},
		CustomPatterns: `
			DURATION %{NUMBER}[nuµm]?s
			TEST_LOG_C %{NUMBER} %{NUMBER} %{IPORHOST} %{DURATION}
		`,
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`1.25 200 192.168.1.1 5.432µs`)
	require.Nil(t, metricA)
	assert.NoError(t, err)
}

func TestParseNoMatch(t *testing.T) {
	p := &Parser{
		Patterns:           []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
		CustomPatternFiles: []string{"./testdata/test-patterns"},
	}
	assert.NoError(t, p.Compile())

	metricA, err := p.ParseLine(`[04/Jun/2016:12:41:45 +0100] notnumber 200 192.168.1.1 5.432µs 101`)
	assert.NoError(t, err)
	assert.Nil(t, metricA)
}

func TestCompileErrors(t *testing.T) {
	// Compile fails because there are multiple timestamps:
	p := &Parser{
		Patterns: []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
		CustomPatterns: `
			TEST_LOG_A %{HTTPDATE:ts1:ts-httpd} %{HTTPDATE:ts2:ts-httpd} %{NUMBER:mynum:int}
		`,
	}
	assert.Error(t, p.Compile())

	// Compile fails because file doesn't exist:
	p = &Parser{
		Patterns:           []string{"%{TEST_LOG_A}", "%{TEST_LOG_B}"},
		CustomPatternFiles: []string{"/tmp/foo/bar/baz"},
	}
	assert.Error(t, p.Compile())
}

func TestParseErrors(t *testing.T) {
	// Parse fails because the pattern doesn't exist
	p := &Parser{
		Patterns: []string{"%{TEST_LOG_B}"},
		CustomPatterns: `
			TEST_LOG_A %{HTTPDATE:ts:ts-httpd} %{WORD:myword:int} %{}
		`,
	}
	assert.Error(t, p.Compile())
	_, err := p.ParseLine(`[04/Jun/2016:12:41:45 +0100] notnumber 200 192.168.1.1 5.432µs 101`)
	assert.Error(t, err)

	// Parse fails because myword is not an int
	p = &Parser{
		Patterns: []string{"%{TEST_LOG_A}"},
		CustomPatterns: `
			TEST_LOG_A %{HTTPDATE:ts:ts-httpd} %{WORD:myword:int}
		`,
	}
	assert.NoError(t, p.Compile())
	_, err = p.ParseLine(`04/Jun/2016:12:41:45 +0100 notnumber`)
	assert.Error(t, err)

	// Parse fails because myword is not a float
	p = &Parser{
		Patterns: []string{"%{TEST_LOG_A}"},
		CustomPatterns: `
			TEST_LOG_A %{HTTPDATE:ts:ts-httpd} %{WORD:myword:float}
		`,
	}
	assert.NoError(t, p.Compile())
	_, err = p.ParseLine(`04/Jun/2016:12:41:45 +0100 notnumber`)
	assert.Error(t, err)

	// Parse fails because myword is not a duration
	p = &Parser{
		Patterns: []string{"%{TEST_LOG_A}"},
		CustomPatterns: `
			TEST_LOG_A %{HTTPDATE:ts:ts-httpd} %{WORD:myword:duration}
		`,
	}
	assert.NoError(t, p.Compile())
	_, err = p.ParseLine(`04/Jun/2016:12:41:45 +0100 notnumber`)
	assert.Error(t, err)

	// Parse fails because the time layout is wrong.
	p = &Parser{
		Patterns: []string{"%{TEST_LOG_A}"},
		CustomPatterns: `
			TEST_LOG_A %{HTTPDATE:ts:ts-unix} %{WORD:myword:duration}
		`,
	}
	assert.NoError(t, p.Compile())
	_, err = p.ParseLine(`04/Jun/2016:12:41:45 +0100 notnumber`)
	assert.Error(t, err)
}

func TestTsModder(t *testing.T) {
	tsm := &tsModder{}

	reftime := time.Date(2006, time.December, 1, 1, 1, 1, int(time.Millisecond), time.UTC)
	modt := tsm.tsMod(reftime)
	assert.Equal(t, reftime, modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Microsecond*1), modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Microsecond*2), modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Microsecond*3), modt)

	reftime = time.Date(2006, time.December, 1, 1, 1, 1, int(time.Microsecond), time.UTC)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime, modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Nanosecond*1), modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Nanosecond*2), modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Nanosecond*3), modt)

	reftime = time.Date(2006, time.December, 1, 1, 1, 1, int(time.Microsecond)*999, time.UTC)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime, modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Nanosecond*1), modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Nanosecond*2), modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Nanosecond*3), modt)

	reftime = time.Date(2006, time.December, 1, 1, 1, 1, 0, time.UTC)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime, modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Millisecond*1), modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Millisecond*2), modt)
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime.Add(time.Millisecond*3), modt)

	reftime = time.Time{}
	modt = tsm.tsMod(reftime)
	assert.Equal(t, reftime, modt)
}

func TestTsModder_Rollover(t *testing.T) {
	tsm := &tsModder{}

	reftime := time.Date(2006, time.December, 1, 1, 1, 1, int(time.Millisecond), time.UTC)
	modt := tsm.tsMod(reftime)
	for i := 1; i < 1000; i++ {
		modt = tsm.tsMod(reftime)
	}
	assert.Equal(t, reftime.Add(time.Microsecond*999+time.Nanosecond), modt)

	reftime = time.Date(2006, time.December, 1, 1, 1, 1, int(time.Microsecond), time.UTC)
	modt = tsm.tsMod(reftime)
	for i := 1; i < 1001; i++ {
		modt = tsm.tsMod(reftime)
	}
	assert.Equal(t, reftime.Add(time.Nanosecond*1000), modt)
}