// Copyright 2023 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 cel

import (
	"reflect"
	"testing"

	celenv "github.com/google/cel-go/common/env"
	"github.com/google/cel-go/common/operators"
	"github.com/google/cel-go/common/overloads"
	"github.com/google/cel-go/common/types"
	"github.com/google/cel-go/common/types/ref"
	"github.com/google/cel-go/common/types/traits"
	"github.com/google/cel-go/test"
)

func TestValidateDurationLiterals(t *testing.T) {
	env, err := NewEnv(
		Variable("x", types.StringType),
		ASTValidators(ValidateDurationLiterals()))
	if err != nil {
		t.Fatalf("NewEnv(ValidateDurationLiterals()) failed: %v", err)
	}

	tests := []struct {
		expr string
		iss  string
	}{
		{
			expr: `duration('1')`,
			iss: `ERROR: <input>:1:10: invalid duration argument
			| duration('1')
			| .........^`,
		},
		{
			expr: `duration('1d')`,
			iss: `ERROR: <input>:1:10: invalid duration argument
			| duration('1d')
			| .........^`,
		},
		{
			expr: "duration('1us')\n < duration('1nns')",
			iss: `ERROR: <input>:2:13: invalid duration argument
			|  < duration('1nns')
			| ............^`,
		},
		{
			expr: `duration('2h3m4s5us')`,
		},
		{
			expr: `duration(x)`,
		},
	}
	for _, tst := range tests {
		tc := tst
		t.Run(tc.expr, func(t *testing.T) {
			_, iss := env.Compile(tc.expr)
			if tc.iss != "" {
				if iss.Err() == nil {
					t.Fatalf("e.Compile(%v) returned ast, expected error: %v", tc.expr, tc.iss)
				}
				if !test.Compare(iss.Err().Error(), tc.iss) {
					t.Fatalf("e.Compile(%v) returned %v, expected error: %v", tc.expr, iss.Err(), tc.iss)
				}
				return
			}
			if iss.Err() != nil {
				t.Fatalf("e.Compile(%v) failed: %v", tc.expr, iss.Err())
			}
		})
	}
}

func TestValidateTimestampLiterals(t *testing.T) {
	env, err := NewEnv(
		Variable("x", types.StringType),
		ASTValidators(ValidateTimestampLiterals()))
	if err != nil {
		t.Fatalf("NewEnv(ValidateTimestampLiterals()) failed: %v", err)
	}

	tests := []struct {
		expr string
		iss  string
	}{
		{
			expr: `timestamp('1000-00-00T00:00:00Z')`,
			iss: `ERROR: <input>:1:11: invalid timestamp argument
			| timestamp('1000-00-00T00:00:00Z')
			| ..........^`,
		},
		{
			expr: `timestamp('1000-01-01T00:00:00ZZ')`,
			iss: `ERROR: <input>:1:11: invalid timestamp argument
			| timestamp('1000-01-01T00:00:00ZZ')
			| ..........^`,
		},
		{
			expr: `timestamp('1000-01-01T00:00:00Z')`,
		},
		{
			expr: `timestamp(-6213559680)`, // min unix epoch time.
		},
		{
			expr: `timestamp(-62135596801)`,
			iss: `ERROR: <input>:1:11: invalid timestamp argument
			| timestamp(-62135596801)
			| ..........^`,
		},
		{
			expr: `timestamp(x)`,
		},
	}
	for _, tst := range tests {
		tc := tst
		t.Run(tc.expr, func(t *testing.T) {
			_, iss := env.Compile(tc.expr)
			if tc.iss != "" {
				if iss.Err() == nil {
					t.Fatalf("e.Compile(%v) returned ast, expected error: %v", tc.expr, tc.iss)
				}
				if !test.Compare(iss.Err().Error(), tc.iss) {
					t.Fatalf("e.Compile(%v) returned %v, expected error: %v", tc.expr, iss.Err(), tc.iss)
				}
				return
			}
			if iss.Err() != nil {
				t.Fatalf("e.Compile(%v) failed: %v", tc.expr, iss.Err())
			}
		})
	}
}

func TestValidateRegexLiterals(t *testing.T) {
	env, err := NewEnv(
		Variable("x", types.StringType),
		ASTValidators(ValidateRegexLiterals()))
	if err != nil {
		t.Fatalf("NewEnv(ValidateRegexLiterals()) failed: %v", err)
	}

	tests := []struct {
		expr string
		iss  string
	}{
		{
			expr: `'hello'.matches('el*')`,
		},
		{
			expr: `'hello'.matches('x++')`,
			iss: `
			ERROR: <input>:1:17: invalid matches argument
             | 'hello'.matches('x++')
             | ................^`,
		},
		{
			expr: `'hello'.matches('(?<name%>el*)')`,
			iss: `
			ERROR: <input>:1:17: invalid matches argument
			 | 'hello'.matches('(?<name%>el*)')
			 | ................^`,
		},
		{
			expr: `'hello'.matches('??el*')`,
			iss: `
			ERROR: <input>:1:17: invalid matches argument
             | 'hello'.matches('??el*')
             | ................^`,
		},
		{
			expr: `'hello'.matches(x)`,
		},
	}
	for _, tst := range tests {
		tc := tst
		t.Run(tc.expr, func(t *testing.T) {
			_, iss := env.Compile(tc.expr)
			if tc.iss != "" {
				if iss.Err() == nil {
					t.Fatalf("e.Compile(%v) returned ast, expected error: %v", tc.expr, tc.iss)
				}
				if !test.Compare(iss.Err().Error(), tc.iss) {
					t.Fatalf("e.Compile(%v) returned %v, expected error: %v", tc.expr, iss.Err(), tc.iss)
				}
				return
			}
			if iss.Err() != nil {
				t.Fatalf("e.Compile(%v) failed: %v", tc.expr, iss.Err())
			}
		})
	}
}

func TestValidateHomogeneousAggregateLiterals(t *testing.T) {
	env, err := NewCustomEnv(
		Variable("name", StringType),
		Function(operators.In,
			Overload(overloads.InList, []*Type{StringType, ListType(StringType)}, BoolType,
				BinaryBinding(func(lhs, rhs ref.Val) ref.Val {
					return rhs.(traits.Container).Contains(lhs)
				}),
			),
			Overload(overloads.InMap, []*Type{StringType, MapType(StringType, BoolType)}, BoolType,
				BinaryBinding(func(lhs, rhs ref.Val) ref.Val {
					return rhs.(traits.Container).Contains(lhs)
				}),
			),
		),
		OptionalTypes(),
		HomogeneousAggregateLiterals(),
		ASTValidators(ValidateHomogeneousAggregateLiterals()),
	)
	if err != nil {
		t.Fatalf("NewCustomEnv() failed: %v", err)
	}

	tests := []struct {
		expr string
		iss  string
	}{
		{
			expr: `name in ['hello', 0]`,
			iss: `
			ERROR: <input>:1:19: expected type 'string' but found 'int'
             | name in ['hello', 0]
             | ..................^`,
		},
		{
			expr: `{'hello':'world', 1:'!'}`,
			iss: `
			ERROR: <input>:1:19: expected type 'string' but found 'int'
             | {'hello':'world', 1:'!'}
             | ..................^`,
		},
		{
			expr: `name in {'hello':'world', 'goodbye':true}`,
			iss: `
			ERROR: <input>:1:37: expected type 'string' but found 'bool'
             | name in {'hello':'world', 'goodbye':true}
             | ....................................^`,
		},
		{
			expr: `name in ['hello', 'world']`,
		},
		{
			expr: `name in ['hello', ?optional.ofNonZeroValue('')]`,
		},
		{
			expr: `name in [?optional.ofNonZeroValue(''), 'hello', ?optional.of('')]`,
		},
		{
			expr: `name in {'hello': false, 'world': true}`,
		},
		{
			expr: `{'hello': false, ?'world': optional.ofNonZeroValue(true)}`,
		},
		{
			expr: `{?'hello': optional.ofNonZeroValue(false), 'world': true}`,
		},
	}
	for _, tst := range tests {
		tc := tst
		t.Run(tc.expr, func(t *testing.T) {
			_, iss := env.Compile(tc.expr)
			if tc.iss != "" {
				if iss.Err() == nil {
					t.Fatalf("e.Compile(%v) returned ast, expected error: %v", tc.expr, tc.iss)
				}
				if !test.Compare(iss.Err().Error(), tc.iss) {
					t.Fatalf("e.Compile(%v) returned %v, expected error: %v", tc.expr, iss.Err(), tc.iss)
				}
				return
			}
			if iss.Err() != nil {
				t.Fatalf("e.Compile(%v) failed: %v", tc.expr, iss.Err())
			}
		})
	}
}

func TestValidateComprehensionNestingLimit(t *testing.T) {
	env, err := NewEnv(
		ASTValidators(ValidateComprehensionNestingLimit(2)),
	)
	if err != nil {
		t.Fatalf("NewEnv() failed: %v", err)
	}
	tests := []struct {
		expr string
		iss  string
	}{
		{
			expr: `[1, 2, 3].exists(i, i < 1)`,
		},
		{
			expr: `[1, 2, 3].exists(i, [4, 5, 6].filter(j, j % i != 0).size() > 0)`,
		},
		{
			// three comprehensions, but not three levels deep
			expr: `[1, 2, 3].exists(i, [4, 5, 6].filter(j, j % i != 0).size() > 0) && [1, 2, 3].exists(i, i < 1)`,
		},
		{
			// the empty iteration range in [].all(k, k) does not impact the actual runtime complexity,
			// so it does not trip the comprehension limit.
			expr: `[1, 2, 3].exists(i, [4, 5, 6].filter(j, [].all(k, k) && j % i != 0).size() > 0)`,
		},
		{
			// three comprehensions, three levels deep
			expr: `[1, 2, 3].map(i, [4, 5, 6].map(j, [7, 8, 9].map(k, i * j * k)))`,
			iss: `
			ERROR: <input>:1:48: comprehension exceeds nesting limit
             | [1, 2, 3].map(i, [4, 5, 6].map(j, [7, 8, 9].map(k, i * j * k)))
             | ...............................................^`,
		},
	}
	for _, tst := range tests {
		tc := tst
		t.Run(tc.expr, func(t *testing.T) {
			_, iss := env.Compile(tc.expr)
			if tc.iss != "" {
				if iss.Err() == nil {
					t.Fatalf("e.Compile(%v) returned ast, expected error: %v", tc.expr, tc.iss)
				}
				if !test.Compare(iss.Err().Error(), tc.iss) {
					t.Fatalf("e.Compile(%v) returned %v, expected error: %v", tc.expr, iss.Err(), tc.iss)
				}
				return
			}
			if iss.Err() != nil {
				t.Fatalf("e.Compile(%v) failed: %v", tc.expr, iss.Err())
			}
		})
	}
}

func TestExtendedValidations(t *testing.T) {
	env, err := NewEnv(
		Variable("x", types.StringType),
		ExtendedValidations(),
	)
	if err != nil {
		t.Fatalf("NewEnv(ExtendedValidations()) failed: %v", err)
	}
	tests := []struct {
		expr string
		iss  string
	}{
		{
			expr: `x in ['hello', 0] 
			&& duration(x) < duration('1d') 
			&& timestamp(x) != timestamp('1000-01-00T00:00:00Z')
			&& x.matches('x++')`,
			iss: `
			ERROR: <input>:1:16: expected type 'string' but found 'int'
             | x in ['hello', 0] 
             | ...............^
            ERROR: <input>:2:30: invalid duration argument
             |    && duration(x) < duration('1d') 
             | .............................^
            ERROR: <input>:3:33: invalid timestamp argument
             |    && timestamp(x) != timestamp('1000-01-00T00:00:00Z')
             | ................................^
            ERROR: <input>:4:17: invalid matches argument
             |    && x.matches('x++')
             | ................^`,
		},
	}
	for _, tst := range tests {
		tc := tst
		t.Run(tc.expr, func(t *testing.T) {
			_, iss := env.Compile(tc.expr)
			if tc.iss != "" {
				if iss.Err() == nil {
					t.Fatalf("e.Compile(%v) returned ast, expected error: %v", tc.expr, tc.iss)
				}
				if !test.Compare(iss.Err().Error(), tc.iss) {
					t.Fatalf("e.Compile(%v) returned %v, expected error: %v", tc.expr, iss.Err(), tc.iss)
				}
				return
			}
			if iss.Err() != nil {
				t.Fatalf("e.Compile(%v) failed: %v", tc.expr, iss.Err())
			}
		})
	}
}

func TestValidatorConfig(t *testing.T) {
	config := newValidatorConfig()
	result := config.GetOrDefault("ext.validate.custom", 2)
	if result != 2 {
		t.Errorf("config.GetOrDefault() got %v, wanted default of 2", result)
	}
	result = config.GetOrDefault(HomogeneousAggregateLiteralExemptFunctions, []string{})
	if reflect.TypeOf(result) != reflect.TypeOf([]string{}) {
		t.Errorf("config.GetOrDefault() got %T, wanted type %T", result, []string{})
	}
	err := config.Set(HomogeneousAggregateLiteralExemptFunctions, []string{"_==_"})
	if err != nil {
		t.Errorf("config.Set() failed: %v", err)
	}
	err = config.Set(HomogeneousAggregateLiteralExemptFunctions, map[string]any{})
	if err == nil {
		t.Error("config.Set() with incorrect value type did not fail")
	}
}

func TestOverrideValidator(t *testing.T) {
	// Base environment configured with comprehension nesting limit of 2.
	baseEnv, err := NewEnv(
		ASTValidators(ValidateComprehensionNestingLimit(2)),
	)
	if err != nil {
		t.Fatalf("NewEnv() failed: %v", err)
	}

	expr := `[1, 2, 3].map(i, [4, 5, 6].map(j, [7, 8, 9].map(k, i * j * k)))`

	// Fails in base environment with limit 2.
	_, iss := baseEnv.Compile(expr)
	if iss.Err() == nil {
		t.Fatalf("baseEnv.Compile() succeeded, expected nesting limit error")
	}

	// Extend environment overriding limit to 3.
	extEnv, err := baseEnv.Extend(
		ASTValidators(ValidateComprehensionNestingLimit(3)),
	)
	if err != nil {
		t.Fatalf("baseEnv.Extend() failed: %v", err)
	}

	// Succeeds in extended environment with limit 3.
	_, iss = extEnv.Compile(expr)
	if iss.Err() != nil {
		t.Fatalf("extEnv.Compile() failed: %v", iss.Err())
	}

	// Verify base environment still fails (immutability check).
	_, iss = baseEnv.Compile(expr)
	if iss.Err() == nil {
		t.Fatalf("baseEnv.Compile() succeeded after Extend, expected baseEnv to remain unchanged")
	}

	// Extend environment overriding limit to 1 (stricter limit).
	stricterEnv, err := extEnv.Extend(
		ASTValidators(ValidateComprehensionNestingLimit(1)),
	)
	if err != nil {
		t.Fatalf("extEnv.Extend() failed: %v", err)
	}

	expr2 := `[1, 2, 3].exists(i, [4, 5, 6].filter(j, j % i != 0).size() > 0)`
	// 2 levels deep: succeeds in extEnv (limit 3), fails in stricterEnv (limit 1).
	_, iss = extEnv.Compile(expr2)
	if iss.Err() != nil {
		t.Fatalf("extEnv.Compile() for 2 levels failed: %v", iss.Err())
	}
	_, iss = stricterEnv.Compile(expr2)
	if iss.Err() == nil {
		t.Fatalf("stricterEnv.Compile() for 2 levels succeeded, expected error")
	}
}

func TestOverrideValidatorFromConfig(t *testing.T) {
	baseEnv, err := NewEnv(
		ASTValidators(ValidateComprehensionNestingLimit(2)),
	)
	if err != nil {
		t.Fatalf("NewEnv() failed: %v", err)
	}

	conf := celenv.NewConfig("override_validator").
		AddValidators(celenv.NewValidator(nestingLimitValidatorName).SetConfig(map[string]any{"limit": 3}))

	extEnv, err := baseEnv.Extend(FromConfig(conf))
	if err != nil {
		t.Fatalf("baseEnv.Extend(FromConfig) failed: %v", err)
	}

	expr := `[1, 2, 3].map(i, [4, 5, 6].map(j, [7, 8, 9].map(k, i * j * k)))`
	_, iss := extEnv.Compile(expr)
	if iss.Err() != nil {
		t.Fatalf("extEnv.Compile() failed: %v", iss.Err())
	}
}

func TestOverrideValidatorPreservesOrder(t *testing.T) {
	v1 := ValidateDurationLiterals()
	v2 := ValidateComprehensionNestingLimit(2)
	v3 := ValidateTimestampLiterals()

	env1, err := NewEnv(ASTValidators(v1, v2, v3))
	if err != nil {
		t.Fatalf("NewEnv() failed: %v", err)
	}

	v2New := ValidateComprehensionNestingLimit(5)
	env2, err := env1.Extend(ASTValidators(v2New))
	if err != nil {
		t.Fatalf("Extend() failed: %v", err)
	}

	validators := env2.Validators()
	if len(validators) != 3 {
		t.Fatalf("got %d validators, wanted 3", len(validators))
	}
	if validators[0].Name() != v1.Name() || validators[1].Name() != v2.Name() || validators[2].Name() != v3.Name() {
		t.Fatalf("validator order or names unexpected: %v, %v, %v", validators[0].Name(), validators[1].Name(), validators[2].Name())
	}
	if val, ok := validators[1].(nestingLimitValidator); !ok || val.limit != 5 {
		t.Fatalf("expected overridden nesting limit validator with limit 5, got %v", validators[1])
	}
}