/*
Copyright 2017-2020 Gravitational, Inc.

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 parse

import (
	"regexp"
	"testing"

	"github.com/google/go-cmp/cmp"
	"github.com/gravitational/trace"
	"github.com/stretchr/testify/require"
)

// TestVariable tests variable parsing
func TestVariable(t *testing.T) {
	t.Parallel()
	var tests = []struct {
		title string
		in    string
		err   error
		out   Expression
	}{
		{
			title: "no curly bracket prefix",
			in:    "external.foo}}",
			err:   trace.BadParameter(""),
		},
		{
			title: "invalid syntax",
			in:    `{{external.foo("bar")`,
			err:   trace.BadParameter(""),
		},
		{
			title: "invalid variable syntax",
			in:    "{{internal.}}",
			err:   trace.BadParameter(""),
		},
		{
			title: "invalid dot syntax",
			in:    "{{external..foo}}",
			err:   trace.BadParameter(""),
		},
		{
			title: "empty variable",
			in:    "{{}}",
			err:   trace.BadParameter(""),
		},
		{
			title: "no curly bracket suffix",
			in:    "{{internal.foo",
			err:   trace.BadParameter(""),
		},
		{
			title: "too many levels of nesting in the variable",
			in:    "{{internal.foo.bar}}",
			err:   trace.BadParameter(""),
		},
		{
			title: "regexp function call not allowed",
			in:    `{{regexp.match(".*")}}`,
			err:   trace.BadParameter(""),
		},
		{
			title: "valid with brackets",
			in:    `{{internal["foo"]}}`,
			out:   Expression{namespace: "internal", variable: "foo"},
		},
		{
			title: "string literal",
			in:    `foo`,
			out:   Expression{namespace: LiteralNamespace, variable: "foo"},
		},
		{
			title: "external with no brackets",
			in:    "{{external.foo}}",
			out:   Expression{namespace: "external", variable: "foo"},
		},
		{
			title: "internal with no brackets",
			in:    "{{internal.bar}}",
			out:   Expression{namespace: "internal", variable: "bar"},
		},
		{
			title: "internal with spaces removed",
			in:    "  {{  internal.bar  }}  ",
			out:   Expression{namespace: "internal", variable: "bar"},
		},
		{
			title: "variable with prefix and suffix",
			in:    "  hello,  {{  internal.bar  }}  there! ",
			out:   Expression{prefix: "hello,  ", namespace: "internal", variable: "bar", suffix: "  there!"},
		},
		{
			title: "variable with local function",
			in:    "{{email.local(internal.bar)}}",
			out:   Expression{namespace: "internal", variable: "bar", transform: emailLocalTransformer{}},
		},
		{
			title: "regexp replace",
			in:    `{{regexp.replace(internal.foo, "bar-(.*)", "$1")}}`,
			out: Expression{
				namespace: "internal",
				variable:  "foo",
				transform: &regexpReplaceTransformer{
					re:          regexp.MustCompile("bar-(.*)"),
					replacement: "$1",
				},
			},
		},
		{
			title: "regexp replace with variable expression",
			in:    `{{regexp.replace(internal.foo, internal.bar, "baz")}}`,
			err:   trace.BadParameter(""),
		},
		{
			title: "regexp replace with variable replacement",
			in:    `{{regexp.replace(internal.foo, "bar", internal.baz)}}`,
			err:   trace.BadParameter(""),
		},
	}

	for _, tt := range tests {
		t.Run(tt.title, func(t *testing.T) {
			variable, err := NewExpression(tt.in)
			if tt.err != nil {
				require.IsType(t, tt.err, err)
				return
			}
			require.NoError(t, err)
			require.Equal(t, tt.out, *variable)
		})
	}
}

// TestInterpolate tests variable interpolation
func TestInterpolate(t *testing.T) {
	t.Parallel()
	type result struct {
		values []string
		err    error
	}
	var tests = []struct {
		title  string
		in     Expression
		traits map[string][]string
		res    result
	}{
		{
			title:  "mapped traits",
			in:     Expression{variable: "foo"},
			traits: map[string][]string{"foo": []string{"a", "b"}, "bar": []string{"c"}},
			res:    result{values: []string{"a", "b"}},
		},
		{
			title:  "mapped traits with email.local",
			in:     Expression{variable: "foo", transform: emailLocalTransformer{}},
			traits: map[string][]string{"foo": []string{"Alice <alice@example.com>", "bob@example.com"}, "bar": []string{"c"}},
			res:    result{values: []string{"alice", "bob"}},
		},
		{
			title:  "missed traits",
			in:     Expression{variable: "baz"},
			traits: map[string][]string{"foo": []string{"a", "b"}, "bar": []string{"c"}},
			res:    result{err: trace.NotFound("not found"), values: []string{}},
		},
		{
			title:  "traits with prefix and suffix",
			in:     Expression{prefix: "IAM#", variable: "foo", suffix: ";"},
			traits: map[string][]string{"foo": []string{"a", "b"}, "bar": []string{"c"}},
			res:    result{values: []string{"IAM#a;", "IAM#b;"}},
		},
		{
			title:  "error in mapping traits",
			in:     Expression{variable: "foo", transform: emailLocalTransformer{}},
			traits: map[string][]string{"foo": []string{"Alice <alice"}},
			res:    result{err: trace.BadParameter("")},
		},
		{
			title:  "literal expression",
			in:     Expression{namespace: LiteralNamespace, variable: "foo"},
			traits: map[string][]string{"foo": []string{"a", "b"}, "bar": []string{"c"}},
			res:    result{values: []string{"foo"}},
		},
		{
			title: "regexp replacement with numeric match",
			in: Expression{
				variable: "foo",
				transform: regexpReplaceTransformer{
					re:          regexp.MustCompile("bar-(.*)"),
					replacement: "$1",
				},
			},
			traits: map[string][]string{"foo": []string{"bar-baz"}},
			res:    result{values: []string{"baz"}},
		},
		{
			title: "regexp replacement with named match",
			in: Expression{
				variable: "foo",
				transform: regexpReplaceTransformer{
					re:          regexp.MustCompile("bar-(?P<suffix>.*)"),
					replacement: "${suffix}",
				},
			},
			traits: map[string][]string{"foo": []string{"bar-baz"}},
			res:    result{values: []string{"baz"}},
		},
		{
			title: "regexp replacement with multiple matches",
			in: Expression{
				variable: "foo",
				transform: regexpReplaceTransformer{
					re:          regexp.MustCompile("foo-(.*)-(.*)"),
					replacement: "$1.$2",
				},
			},
			traits: map[string][]string{"foo": []string{"foo-bar-baz"}},
			res:    result{values: []string{"bar.baz"}},
		},
		{
			title: "regexp replacement with no match",
			in: Expression{
				variable: "foo",
				transform: regexpReplaceTransformer{
					re:          regexp.MustCompile("^bar-(.*)$"),
					replacement: "$1-matched",
				},
			},
			traits: map[string][]string{"foo": []string{"foo-test1", "bar-test2"}},
			res:    result{values: []string{"test2-matched"}},
		},
	}

	for _, tt := range tests {
		t.Run(tt.title, func(t *testing.T) {
			values, err := tt.in.Interpolate(tt.traits)
			if tt.res.err != nil {
				require.IsType(t, tt.res.err, err)
				require.Empty(t, values)
				return
			}
			require.NoError(t, err)
			require.Equal(t, tt.res.values, values)
		})
	}
}

func TestMatch(t *testing.T) {
	t.Parallel()
	tests := []struct {
		title string
		in    string
		err   error
		out   Matcher
	}{
		{
			title: "no curly bracket prefix",
			in:    `regexp.match(".*")}}`,
			err:   trace.BadParameter(""),
		},
		{
			title: "no curly bracket suffix",
			in:    `{{regexp.match(".*")`,
			err:   trace.BadParameter(""),
		},
		{
			title: "unknown function",
			in:    `{{regexp.surprise(".*")}}`,
			err:   trace.BadParameter(""),
		},
		{
			title: "bad regexp",
			in:    `{{regexp.match("+foo")}}`,
			err:   trace.BadParameter(""),
		},
		{
			title: "unknown namespace",
			in:    `{{surprise.match(".*")}}`,
			err:   trace.BadParameter(""),
		},
		{
			title: "unsupported namespace",
			in:    `{{email.local(external.email)}}`,
			err:   trace.BadParameter(""),
		},
		{
			title: "unsupported variable syntax",
			in:    `{{external.email}}`,
			err:   trace.BadParameter(""),
		},
		{
			title: "string literal",
			in:    `foo`,
			out:   &regexpMatcher{re: regexp.MustCompile(`^foo$`)},
		},
		{
			title: "wildcard",
			in:    `foo*`,
			out:   &regexpMatcher{re: regexp.MustCompile(`^foo(.*)$`)},
		},
		{
			title: "raw regexp",
			in:    `^foo.*$`,
			out:   &regexpMatcher{re: regexp.MustCompile(`^foo.*$`)},
		},
		{
			title: "regexp.match call",
			in:    `foo-{{regexp.match("bar")}}-baz`,
			out: prefixSuffixMatcher{
				prefix: "foo-",
				suffix: "-baz",
				m:      &regexpMatcher{re: regexp.MustCompile(`bar`)},
			},
		},
		{
			title: "regexp.not_match call",
			in:    `foo-{{regexp.not_match("bar")}}-baz`,
			out: prefixSuffixMatcher{
				prefix: "foo-",
				suffix: "-baz",
				m:      notMatcher{&regexpMatcher{re: regexp.MustCompile(`bar`)}},
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.title, func(t *testing.T) {
			matcher, err := NewMatcher(tt.in)
			if tt.err != nil {
				require.IsType(t, tt.err, err, err)
				return
			}
			require.NoError(t, err)
			require.Empty(t, cmp.Diff(tt.out, matcher, cmp.AllowUnexported(
				regexpMatcher{}, prefixSuffixMatcher{}, notMatcher{}, regexp.Regexp{},
			)))
		})
	}
}

func TestMatchers(t *testing.T) {
	t.Parallel()
	tests := []struct {
		title   string
		matcher Matcher
		in      string
		want    bool
	}{
		{
			title:   "regexp matcher positive",
			matcher: regexpMatcher{re: regexp.MustCompile(`foo`)},
			in:      "foo",
			want:    true,
		},
		{
			title:   "regexp matcher negative",
			matcher: regexpMatcher{re: regexp.MustCompile(`bar`)},
			in:      "foo",
			want:    false,
		},
		{
			title:   "not matcher",
			matcher: notMatcher{regexpMatcher{re: regexp.MustCompile(`bar`)}},
			in:      "foo",
			want:    true,
		},
		{
			title:   "prefix/suffix matcher positive",
			matcher: prefixSuffixMatcher{prefix: "foo-", m: regexpMatcher{re: regexp.MustCompile(`bar`)}, suffix: "-baz"},
			in:      "foo-bar-baz",
			want:    true,
		},
		{
			title:   "prefix/suffix matcher negative",
			matcher: prefixSuffixMatcher{prefix: "foo-", m: regexpMatcher{re: regexp.MustCompile(`bar`)}, suffix: "-baz"},
			in:      "foo-foo-baz",
			want:    false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.title, func(t *testing.T) {
			got := tt.matcher.Match(tt.in)
			require.Equal(t, tt.want, got)
		})
	}
}