package regex

import (
	"testing"
	"time"

	"github.com/influxdata/telegraf"
	"github.com/influxdata/telegraf/metric"
	"github.com/stretchr/testify/assert"
)

func newM1() telegraf.Metric {
	m1, _ := metric.New("access_log",
		map[string]string{
			"verb":      "GET",
			"resp_code": "200",
		},
		map[string]interface{}{
			"request": "/users/42/",
		},
		time.Now(),
	)
	return m1
}

func newM2() telegraf.Metric {
	m2, _ := metric.New("access_log",
		map[string]string{
			"verb":      "GET",
			"resp_code": "200",
		},
		map[string]interface{}{
			"request":       "/api/search/?category=plugins&q=regex&sort=asc",
			"ignore_number": int64(200),
			"ignore_bool":   true,
		},
		time.Now(),
	)
	return m2
}

func TestFieldConversions(t *testing.T) {
	tests := []struct {
		message        string
		converter      converter
		expectedFields map[string]interface{}
	}{
		{
			message: "Should change existing field",
			converter: converter{
				Key:         "request",
				Pattern:     "^/users/\\d+/$",
				Replacement: "/users/{id}/",
			},
			expectedFields: map[string]interface{}{
				"request": "/users/{id}/",
			},
		},
		{
			message: "Should add new field",
			converter: converter{
				Key:         "request",
				Pattern:     "^/users/\\d+/$",
				Replacement: "/users/{id}/",
				ResultKey:   "normalized_request",
			},
			expectedFields: map[string]interface{}{
				"request":            "/users/42/",
				"normalized_request": "/users/{id}/",
			},
		},
	}

	for _, test := range tests {
		regex := NewRegex()
		regex.Fields = []converter{
			test.converter,
		}

		processed := regex.Apply(newM1())

		expectedTags := map[string]string{
			"verb":      "GET",
			"resp_code": "200",
		}

		assert.Equal(t, test.expectedFields, processed[0].Fields(), test.message)
		assert.Equal(t, expectedTags, processed[0].Tags(), "Should not change tags")
		assert.Equal(t, "access_log", processed[0].Name(), "Should not change name")
	}
}

func TestTagConversions(t *testing.T) {
	tests := []struct {
		message      string
		converter    converter
		expectedTags map[string]string
	}{
		{
			message: "Should change existing tag",
			converter: converter{
				Key:         "resp_code",
				Pattern:     "^(\\d)\\d\\d$",
				Replacement: "${1}xx",
			},
			expectedTags: map[string]string{
				"verb":      "GET",
				"resp_code": "2xx",
			},
		},
		{
			message: "Should append to existing tag",
			converter: converter{
				Key:         "verb",
				Pattern:     "^(.*)$",
				Replacement: " (${1})",
				ResultKey:   "resp_code",
				Append:      true,
			},
			expectedTags: map[string]string{
				"verb":      "GET",
				"resp_code": "200 (GET)",
			},
		},
		{
			message: "Should add new tag",
			converter: converter{
				Key:         "resp_code",
				Pattern:     "^(\\d)\\d\\d$",
				Replacement: "${1}xx",
				ResultKey:   "resp_code_group",
			},
			expectedTags: map[string]string{
				"verb":            "GET",
				"resp_code":       "200",
				"resp_code_group": "2xx",
			},
		},
	}

	for _, test := range tests {
		regex := NewRegex()
		regex.Tags = []converter{
			test.converter,
		}

		processed := regex.Apply(newM1())

		expectedFields := map[string]interface{}{
			"request": "/users/42/",
		}

		assert.Equal(t, expectedFields, processed[0].Fields(), test.message, "Should not change fields")
		assert.Equal(t, test.expectedTags, processed[0].Tags(), test.message)
		assert.Equal(t, "access_log", processed[0].Name(), "Should not change name")
	}
}

func TestMultipleConversions(t *testing.T) {
	regex := NewRegex()
	regex.Tags = []converter{
		{
			Key:         "resp_code",
			Pattern:     "^(\\d)\\d\\d$",
			Replacement: "${1}xx",
			ResultKey:   "resp_code_group",
		},
		{
			Key:         "resp_code_group",
			Pattern:     "2xx",
			Replacement: "OK",
			ResultKey:   "resp_code_text",
		},
	}
	regex.Fields = []converter{
		{
			Key:         "request",
			Pattern:     "^/api(?P<method>/[\\w/]+)\\S*",
			Replacement: "${method}",
			ResultKey:   "method",
		},
		{
			Key:         "request",
			Pattern:     ".*category=(\\w+).*",
			Replacement: "${1}",
			ResultKey:   "search_category",
		},
	}

	processed := regex.Apply(newM2())

	expectedFields := map[string]interface{}{
		"request":         "/api/search/?category=plugins&q=regex&sort=asc",
		"method":          "/search/",
		"search_category": "plugins",
		"ignore_number":   int64(200),
		"ignore_bool":     true,
	}
	expectedTags := map[string]string{
		"verb":            "GET",
		"resp_code":       "200",
		"resp_code_group": "2xx",
		"resp_code_text":  "OK",
	}

	assert.Equal(t, expectedFields, processed[0].Fields())
	assert.Equal(t, expectedTags, processed[0].Tags())
}

func TestNoMatches(t *testing.T) {
	tests := []struct {
		message        string
		converter      converter
		expectedFields map[string]interface{}
	}{
		{
			message: "Should not change anything if there is no field with given key",
			converter: converter{
				Key:         "not_exists",
				Pattern:     "\\.*",
				Replacement: "x",
			},
			expectedFields: map[string]interface{}{
				"request": "/users/42/",
			},
		},
		{
			message: "Should not change anything if regex doesn't match",
			converter: converter{
				Key:         "request",
				Pattern:     "not_match",
				Replacement: "x",
			},
			expectedFields: map[string]interface{}{
				"request": "/users/42/",
			},
		},
		{
			message: "Should not emit new tag/field when result_key given but regex doesn't match",
			converter: converter{
				Key:         "request",
				Pattern:     "not_match",
				Replacement: "x",
				ResultKey:   "new_field",
			},
			expectedFields: map[string]interface{}{
				"request": "/users/42/",
			},
		},
	}

	for _, test := range tests {
		regex := NewRegex()
		regex.Fields = []converter{
			test.converter,
		}

		processed := regex.Apply(newM1())

		assert.Equal(t, test.expectedFields, processed[0].Fields(), test.message)
	}
}

func BenchmarkConversions(b *testing.B) {
	regex := NewRegex()
	regex.Tags = []converter{
		{
			Key:         "resp_code",
			Pattern:     "^(\\d)\\d\\d$",
			Replacement: "${1}xx",
			ResultKey:   "resp_code_group",
		},
	}
	regex.Fields = []converter{
		{
			Key:         "request",
			Pattern:     "^/users/\\d+/$",
			Replacement: "/users/{id}/",
		},
	}

	for n := 0; n < b.N; n++ {
		processed := regex.Apply(newM1())
		_ = processed
	}
}
