// Copyright 2020 Google LLC
//
// 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 ext

import (
	"fmt"
	"testing"

	"github.com/google/cel-go/cel"
)

func TestEncoders(t *testing.T) {
	var tests = []struct {
		expr      string
		err       string
		parseOnly bool
	}{
		{expr: "base64.decode('aGVsbG8=') == b'hello'"},
		{
			expr: "base64.decode('aGVsbG8') == b'error'",
			err:  "illegal base64 data at input byte 4",
		},
		{
			expr:      "base64.decode(b'aGVsbG8=') == b'hello'",
			err:       "no such overload",
			parseOnly: true,
		},
		{expr: "base64.encode(b'hello') == 'aGVsbG8='"},
		{
			expr:      "base64.encode('hello') == b'aGVsbG8='",
			err:       "no such overload",
			parseOnly: true,
		},
	}

	env, err := cel.NewEnv(Encoders())
	if err != nil {
		t.Fatal(err)
	}
	for i, tst := range tests {
		tc := tst
		t.Run(fmt.Sprintf("[%d]", i), func(tt *testing.T) {
			var asts []*cel.Ast
			pAst, iss := env.Parse(tc.expr)
			if iss.Err() != nil {
				tt.Fatal(iss.Err())
			}
			asts = append(asts, pAst)
			if !tc.parseOnly {
				cAst, iss := env.Check(pAst)
				if iss.Err() != nil {
					tt.Fatal(iss.Err())
				}
				asts = append(asts, cAst)
			}
			for _, ast := range asts {
				prg, err := env.Program(ast)
				if err != nil {
					tt.Fatal(err)
				}
				out, _, err := prg.Eval(cel.NoVars())
				if tc.err != "" {
					if err == nil {
						tt.Fatalf("got %v, wanted error %s for expr: %s",
							out.Value(), tc.err, tc.expr)
					}
					if tc.err != err.Error() {
						tt.Errorf("got error %v, wanted error %s for expr: %s",
							err, tc.err, tc.expr)
					}
				} else if err != nil {
					tt.Fatal(err)
				} else if out.Value() != true {
					tt.Errorf("got %v, wanted true for expr: %s", out.Value(), tc.expr)
				}
			}
		})
	}
}
