// Copyright 2016 The Go Authors.  All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package benchfmt

import (
	"bytes"
	"fmt"
	"reflect"
	"strings"
	"testing"

	"golang.org/x/perf/internal/diff"
)

func readAllResults(t *testing.T, r *Reader) []*Result {
	var out []*Result
	for r.Next() {
		out = append(out, r.Result())
	}
	if err := r.Err(); err != nil {
		t.Fatal(err)
	}
	return out
}

func TestBenchmarkReader(t *testing.T) {
	tests := []struct {
		name, input string
		want        []*Result
	}{
		{
			"basic",
			`key: value
BenchmarkOne 1 ns/sec
`,
			[]*Result{{
				Labels{"key": "value"},
				Labels{"name": "One"},
				2,
				"BenchmarkOne 1 ns/sec",
			}},
		},
		{
			"two results with indexed and named subnames",
			`key: value
BenchmarkOne/foo/bar=1-2 1 ns/sec
BenchmarkTwo 2 ns/sec
`,
			[]*Result{
				{
					Labels{"key": "value"},
					Labels{"name": "One", "sub1": "foo", "bar": "1", "gomaxprocs": "2"},
					2,
					"BenchmarkOne/foo/bar=1-2 1 ns/sec",
				},
				{
					Labels{"key": "value"},
					Labels{"name": "Two"},
					3,
					"BenchmarkTwo 2 ns/sec",
				},
			},
		},
		{
			"remove existing label",
			`key: value
key:
BenchmarkOne 1 ns/sec
`,
			[]*Result{
				{
					Labels{},
					Labels{"name": "One"},
					3,
					"BenchmarkOne 1 ns/sec",
				},
			},
		},
		{
			"parse file headers",
			`key: fixed

key: haha
BenchmarkOne 1 ns/sec
`,
			[]*Result{
				{
					Labels{"key": "fixed"},
					Labels{"name": "One"},
					4,
					"BenchmarkOne 1 ns/sec",
				},
			},
		},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			r := NewReader(strings.NewReader(test.input))
			have := readAllResults(t, r)
			want := test.want
			diff := ""
			mismatch := false
			for i := 0; i < len(have) || i < len(want); i++ {
				if i < len(have) && i < len(want) && reflect.DeepEqual(have[i], want[i]) {
					diff += fmt.Sprintf(" %+v\n", have[i])
					continue
				}
				mismatch = true
				if i < len(have) {
					diff += fmt.Sprintf("-%+v\n", have[i])
				}
				if i < len(want) {
					diff += fmt.Sprintf("+%+v\n", want[i])
				}
			}
			if mismatch {
				t.Errorf("wrong results: (- have/+ want)\n%s", diff)
			}
		})
	}
}

func TestBenchmarkPrinter(t *testing.T) {
	tests := []struct {
		name, input, want string
	}{
		{
			"basic",
			`key: value
BenchmarkOne 1 ns/sec
`,
			`key: value
BenchmarkOne 1 ns/sec
`,
		},
		{
			"missing newline",
			`key: value
BenchmarkOne 1 ns/sec`,
			`key: value
BenchmarkOne 1 ns/sec
`,
		},
		{
			"duplicate and removed fields",
			`one: 1
two: 2
BenchmarkOne 1 ns/sec
one: 1
two: 3
BenchmarkOne 1 ns/sec
two:
BenchmarkOne 1 ns/sec
`,
			`one: 1
two: 2
BenchmarkOne 1 ns/sec
two: 3
BenchmarkOne 1 ns/sec
two:
BenchmarkOne 1 ns/sec
`,
		},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			r := NewReader(strings.NewReader(test.input))
			results := readAllResults(t, r)
			var have bytes.Buffer
			bp := NewPrinter(&have)
			for _, result := range results {
				if err := bp.Print(result); err != nil {
					t.Errorf("Print returned %v", err)
				}
			}
			if diff := diff.Diff(have.String(), test.want); diff != "" {
				t.Errorf("wrong output: (- got/+ want)\n%s", diff)
			}
		})
	}
}