package promrelabel

import (
	"bytes"
	"fmt"
	"testing"

	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus"
	"gopkg.in/yaml.v2"
)

func TestIfExpressionUnmarshalFailure(t *testing.T) {
	f := func(s string) {
		t.Helper()
		var ie IfExpression
		err := yaml.UnmarshalStrict([]byte(s), &ie)
		if err == nil {
			t.Fatalf("expecting non-nil error")
		}
	}
	f(`{`)
	f(`{x:y}`)
	f(`[]`)
	f(`"{"`)
	f(`'{'`)
	f(`foo{bar`)
	f(`foo{bar}`)
	f(`foo{bar=`)
	f(`foo{bar="`)
	f(`foo{bar='`)
	f(`foo{bar=~"("}`)
	f(`foo{bar!~"("}`)
	f(`foo{bar==aaa}`)
	f(`foo{bar=="b"}`)
	f(`'foo+bar'`)
	f(`'foo{bar=~"a[b"}'`)
}

func TestIfExpressionUnmarshalSuccess(t *testing.T) {
	f := func(s string) {
		t.Helper()
		var ie IfExpression
		if err := yaml.UnmarshalStrict([]byte(s), &ie); err != nil {
			t.Fatalf("unexpected error during unmarshal: %s", err)
		}
		b, err := yaml.Marshal(&ie)
		if err != nil {
			t.Fatalf("unexpected error during marshal: %s", err)
		}
		b = bytes.TrimSpace(b)
		if string(b) != s {
			t.Fatalf("unexpected marshaled data;\ngot\n%s\nwant\n%s", b, s)
		}
	}
	f(`'{}'`)
	f(`foo`)
	f(`foo{bar="baz"}`)
	f(`'{a="b", c!="d", e=~"g", h!~"d"}'`)
	f(`foo{bar="zs",a=~"b|c"}`)
}

func TestIfExpressionMatch(t *testing.T) {
	f := func(ifExpr, metricWithLabels string) {
		t.Helper()
		var ie IfExpression
		if err := yaml.UnmarshalStrict([]byte(ifExpr), &ie); err != nil {
			t.Fatalf("unexpected error during unmarshal: %s", err)
		}
		labels, err := parseMetricWithLabels(metricWithLabels)
		if err != nil {
			t.Fatalf("cannot parse %s: %s", metricWithLabels, err)
		}
		if !ie.Match(labels) {
			t.Fatalf("unexpected mismatch of ifExpr=%s for %s", ifExpr, metricWithLabels)
		}
	}
	f(`foo`, `foo`)
	f(`foo`, `foo{bar="baz",a="b"}`)
	f(`foo{bar="a"}`, `foo{bar="a"}`)
	f(`foo{bar="a"}`, `foo{x="y",bar="a",baz="b"}`)
	f(`'{a=~"x|abc",y!="z"}'`, `m{x="aa",a="abc"}`)
	f(`'{a=~"x|abc",y!="z"}'`, `m{x="aa",a="abc",y="qwe"}`)
	f(`'{__name__="foo"}'`, `foo{bar="baz"}`)
	f(`'{__name__=~"foo|bar"}'`, `bar`)
	f(`'{__name__!=""}'`, `foo`)
	f(`'{__name__!=""}'`, `bar{baz="aa",b="c"}`)
	f(`'{__name__!~"a.+"}'`, `bar{baz="aa",b="c"}`)
	f(`foo{a!~"a.+"}`, `foo{a="baa"}`)
	f(`'{foo=""}'`, `bar`)
	f(`'{foo!=""}'`, `aa{foo="b"}`)
	f(`'{foo=~".*"}'`, `abc`)
	f(`'{foo=~".*"}'`, `abc{foo="bar"}`)
	f(`'{foo!~".+"}'`, `abc`)
	f(`'{foo=~"bar|"}'`, `abc`)
	f(`'{foo=~"bar|"}'`, `abc{foo="bar"}`)
	f(`'{foo!~"bar|"}'`, `abc{foo="baz"}`)
}

func TestIfExpressionMismatch(t *testing.T) {
	f := func(ifExpr, metricWithLabels string) {
		t.Helper()
		var ie IfExpression
		if err := yaml.UnmarshalStrict([]byte(ifExpr), &ie); err != nil {
			t.Fatalf("unexpected error during unmarshal: %s", err)
		}
		labels, err := parseMetricWithLabels(metricWithLabels)
		if err != nil {
			t.Fatalf("cannot parse %s: %s", metricWithLabels, err)
		}
		if ie.Match(labels) {
			t.Fatalf("unexpected match of ifExpr=%s for %s", ifExpr, metricWithLabels)
		}
	}
	f(`foo`, `bar`)
	f(`foo`, `a{foo="bar"}`)
	f(`foo{bar="a"}`, `foo`)
	f(`foo{bar="a"}`, `foo{bar="b"}`)
	f(`foo{bar="a"}`, `foo{baz="b",a="b"}`)
	f(`'{a=~"x|abc",y!="z"}'`, `m{x="aa",a="xabc"}`)
	f(`'{a=~"x|abc",y!="z"}'`, `m{x="aa",a="abc",y="z"}`)
	f(`'{__name__!~".+"}'`, `foo`)
	f(`'{a!~"a.+"}'`, `foo{a="abc"}`)
	f(`'{foo=""}'`, `bar{foo="aa"}`)
	f(`'{foo!=""}'`, `aa`)
	f(`'{foo=~".+"}'`, `abc`)
	f(`'{foo!~".+"}'`, `abc{foo="x"}`)
	f(`'{foo=~"bar|"}'`, `abc{foo="baz"}`)
	f(`'{foo!~"bar|"}'`, `abc`)
	f(`'{foo!~"bar|"}'`, `abc{foo="bar"}`)
}

func parseMetricWithLabels(metricWithLabels string) ([]prompbmarshal.Label, error) {
	// add a value to metricWithLabels, so it could be parsed by prometheus protocol parser.
	s := metricWithLabels + " 123"
	var rows prometheus.Rows
	var err error
	rows.UnmarshalWithErrLogger(s, func(s string) {
		err = fmt.Errorf("error during metric parse: %s", s)
	})
	if err != nil {
		return nil, err
	}
	if len(rows.Rows) != 1 {
		return nil, fmt.Errorf("unexpected number of rows parsed; got %d; want 1", len(rows.Rows))
	}
	r := rows.Rows[0]
	var lfs []prompbmarshal.Label
	if r.Metric != "" {
		lfs = append(lfs, prompbmarshal.Label{
			Name:  "__name__",
			Value: r.Metric,
		})
	}
	for _, tag := range r.Tags {
		lfs = append(lfs, prompbmarshal.Label{
			Name:  tag.Key,
			Value: tag.Value,
		})
	}
	return lfs, nil
}