// 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 parser

import (
	"testing"

	"github.com/stretchr/testify/require"

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

func TestExprString(t *testing.T) {
	ExperimentalDurationExpr = true
	t.Cleanup(func() {
		ExperimentalDurationExpr = false
	})
	// A list of valid expressions that are expected to be
	// returned as out when calling String(). If out is empty the output
	// is expected to equal the input.
	inputs := []struct {
		in, out string
	}{
		{
			in:  `sum by() (task:errors:rate10s{job="s"})`,
			out: `sum(task:errors:rate10s{job="s"})`,
		},
		{
			in:  `sum by(code) (task:errors:rate10s{job="s"})`,
			out: `sum by (code) (task:errors:rate10s{job="s"})`,
		},
		{
			in:  `sum without() (task:errors:rate10s{job="s"})`,
			out: `sum without () (task:errors:rate10s{job="s"})`,
		},
		{
			in:  `sum without(instance) (task:errors:rate10s{job="s"})`,
			out: `sum without (instance) (task:errors:rate10s{job="s"})`,
		},
		{
			in:  `sum by("foo.bar") (task:errors:rate10s{job="s"})`,
			out: `sum by ("foo.bar") (task:errors:rate10s{job="s"})`,
		},
		{
			in:  `sum without("foo.bar") (task:errors:rate10s{job="s"})`,
			out: `sum without ("foo.bar") (task:errors:rate10s{job="s"})`,
		},
		{
			in: `topk(5, task:errors:rate10s{job="s"})`,
		},
		{
			in: `count_values("value", task:errors:rate10s{job="s"})`,
		},
		{
			in:  `a - on() c`,
			out: `a - on () c`,
		},
		{
			in:  `a - on(b) c`,
			out: `a - on (b) c`,
		},
		{
			in:  `a - on(b) group_left(x) c`,
			out: `a - on (b) group_left (x) c`,
		},
		{
			in:  `a - on(b) group_left(x, y) c`,
			out: `a - on (b) group_left (x, y) c`,
		},
		{
			in:  `a - on(b) group_left c`,
			out: `a - on (b) group_left () c`,
		},
		{
			in:  `a - on(b) group_left() (c)`,
			out: `a - on (b) group_left () (c)`,
		},
		{
			in:  `a - ignoring(b) c`,
			out: `a - ignoring (b) c`,
		},
		{
			in:  `a - ignoring() c`,
			out: `a - c`,
		},
		{
			in: `up > bool 0`,
		},
		{
			in: `a offset 1m`,
		},
		{
			in: `a offset -7m`,
		},
		{
			in: `a{c="d"}[5m] offset 1m`,
		},
		{
			in: `a[5m] offset 1m`,
		},
		{
			in: `a[12m] offset -3m`,
		},
		{
			in: `a[1h:5m] offset 1m`,
		},
		{
			in: `{__name__="a"}`,
		},
		{
			in: `a{b!="c"}[1m]`,
		},
		{
			in: `a{b=~"c"}[1m]`,
		},
		{
			in: `a{b!~"c"}[1m]`,
		},
		{
			in:  `a @ 10`,
			out: `a @ 10.000`,
		},
		{
			in:  `a[1m] @ 10`,
			out: `a[1m] @ 10.000`,
		},
		{
			in: `a @ start()`,
		},
		{
			in: `a @ end()`,
		},
		{
			in: `a[1m] @ start()`,
		},
		{
			in: `a[1m] @ end()`,
		},
		{
			in: `{__name__="",a="x"}`,
		},
		{
			in: `{"a.b"="c"}`,
		},
		{
			in: `{"0"="1"}`,
		},
		{
			in:  `{"_0"="1"}`,
			out: `{_0="1"}`,
		},
		{
			in: `{""="0"}`,
		},
		{
			in:  "{``=\"0\"}",
			out: `{""="0"}`,
		},
		{
			in:  "1048576",
			out: "1048576",
		},
		{
			in: "foo[step()]",
		},
		{
			in: "foo[-step()]",
		},
		{
			in: "foo[(step())]",
		},
		{
			in: "foo[-(step())]",
		},
		{
			in: "foo offset step()",
		},
		{
			in: "foo offset -step()",
		},
		{
			in: "foo offset (step())",
		},
		{
			in: "foo offset -(step())",
		},
		{
			in:  "foo offset +(5*2)",
			out: "foo offset (5 * 2)",
		},
		{
			in:  "foo offset +min(10s, 20s)",
			out: "foo offset min(10s, 20s)",
		},
		{
			in: "foo offset -min(10s, 20s)",
		},
		{
			in:  "foo offset -min(10s, +max(step() ^ 2, 2))",
			out: "foo offset -min(10s, max(step() ^ 2, 2))",
		},
		{
			in:  "foo[200-min(-step()^+step(),1)]",
			out: "foo[200 - min(-step() ^ step(), 1)]",
		},
		{
			in: "foo[200 - min(step() + 10s, -max(step() ^ 2, 3))]",
		},
	}

	for _, test := range inputs {
		t.Run(test.in, func(t *testing.T) {
			expr, err := ParseExpr(test.in)
			require.NoError(t, err)

			exp := test.in
			if test.out != "" {
				exp = test.out
			}

			require.Equal(t, exp, expr.String())
		})
	}
}

func TestVectorSelector_String(t *testing.T) {
	for _, tc := range []struct {
		name     string
		vs       VectorSelector
		expected string
	}{
		{
			name:     "empty value",
			vs:       VectorSelector{},
			expected: ``,
		},
		{
			name:     "no matchers with name",
			vs:       VectorSelector{Name: "foobar"},
			expected: `foobar`,
		},
		{
			name: "one matcher with name",
			vs: VectorSelector{
				Name: "foobar",
				LabelMatchers: []*labels.Matcher{
					labels.MustNewMatcher(labels.MatchEqual, "a", "x"),
				},
			},
			expected: `foobar{a="x"}`,
		},
		{
			name: "two matchers with name",
			vs: VectorSelector{
				Name: "foobar",
				LabelMatchers: []*labels.Matcher{
					labels.MustNewMatcher(labels.MatchEqual, "a", "x"),
					labels.MustNewMatcher(labels.MatchEqual, "b", "y"),
				},
			},
			expected: `foobar{a="x",b="y"}`,
		},
		{
			name: "two matchers without name",
			vs: VectorSelector{
				LabelMatchers: []*labels.Matcher{
					labels.MustNewMatcher(labels.MatchEqual, "a", "x"),
					labels.MustNewMatcher(labels.MatchEqual, "b", "y"),
				},
			},
			expected: `{a="x",b="y"}`,
		},
		{
			name: "name matcher and name",
			vs: VectorSelector{
				Name: "foobar",
				LabelMatchers: []*labels.Matcher{
					labels.MustNewMatcher(labels.MatchEqual, labels.MetricName, "foobar"),
				},
			},
			expected: `foobar`,
		},
		{
			name: "name matcher only",
			vs: VectorSelector{
				LabelMatchers: []*labels.Matcher{
					labels.MustNewMatcher(labels.MatchEqual, labels.MetricName, "foobar"),
				},
			},
			expected: `{__name__="foobar"}`,
		},
		{
			name: "empty name matcher",
			vs: VectorSelector{
				LabelMatchers: []*labels.Matcher{
					labels.MustNewMatcher(labels.MatchEqual, labels.MetricName, ""),
					labels.MustNewMatcher(labels.MatchEqual, "a", "x"),
				},
			},
			expected: `{__name__="",a="x"}`,
		},
	} {
		t.Run(tc.name, func(t *testing.T) {
			require.Equal(t, tc.expected, tc.vs.String())
		})
	}
}
