// Copyright 2018 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 checker

import (
	"reflect"

	"github.com/google/cel-go/common"
	"github.com/google/cel-go/common/ast"
	"github.com/google/cel-go/common/types"

	exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
)

// typeErrors is a specialization of Errors.
type typeErrors struct {
	errs *common.Errors
}

func (e *typeErrors) fieldTypeMismatch(id int64, l common.Location, name string, field, value *types.Type) {
	e.errs.ReportErrorAtID(id, l, "expected type of field '%s' is '%s' but provided type is '%s'",
		name, FormatCELType(field), FormatCELType(value))
}

func (e *typeErrors) incompatibleType(id int64, l common.Location, ex *exprpb.Expr, prev, next *types.Type) {
	e.errs.ReportErrorAtID(id, l,
		"incompatible type already exists for expression: %v(%d) old:%v, new:%v", ex, ex.GetId(), prev, next)
}

func (e *typeErrors) noMatchingOverload(id int64, l common.Location, name string, args []*types.Type, isInstance bool) {
	signature := formatFunctionDeclType(nil, args, isInstance)
	e.errs.ReportErrorAtID(id, l, "found no matching overload for '%s' applied to '%s'", name, signature)
}

func (e *typeErrors) notAComprehensionRange(id int64, l common.Location, t *types.Type) {
	e.errs.ReportErrorAtID(id, l, "expression of type '%s' cannot be range of a comprehension (must be list, map, or dynamic)",
		FormatCELType(t))
}

func (e *typeErrors) notAnOptionalFieldSelection(id int64, l common.Location, field *exprpb.Expr) {
	e.errs.ReportErrorAtID(id, l, "unsupported optional field selection: %v", field)
}

func (e *typeErrors) notAType(id int64, l common.Location, typeName string) {
	e.errs.ReportErrorAtID(id, l, "'%s' is not a type", typeName)
}

func (e *typeErrors) notAMessageType(id int64, l common.Location, typeName string) {
	e.errs.ReportErrorAtID(id, l, "'%s' is not a message type", typeName)
}

func (e *typeErrors) referenceRedefinition(id int64, l common.Location, ex *exprpb.Expr, prev, next *ast.ReferenceInfo) {
	e.errs.ReportErrorAtID(id, l,
		"reference already exists for expression: %v(%d) old:%v, new:%v", ex, ex.GetId(), prev, next)
}

func (e *typeErrors) typeDoesNotSupportFieldSelection(id int64, l common.Location, t *types.Type) {
	e.errs.ReportErrorAtID(id, l, "type '%s' does not support field selection", FormatCELType(t))
}

func (e *typeErrors) typeMismatch(id int64, l common.Location, expected, actual *types.Type) {
	e.errs.ReportErrorAtID(id, l, "expected type '%s' but found '%s'",
		FormatCELType(expected), FormatCELType(actual))
}

func (e *typeErrors) undefinedField(id int64, l common.Location, field string) {
	e.errs.ReportErrorAtID(id, l, "undefined field '%s'", field)
}

func (e *typeErrors) undeclaredReference(id int64, l common.Location, container string, name string) {
	e.errs.ReportErrorAtID(id, l, "undeclared reference to '%s' (in container '%s')", name, container)
}

func (e *typeErrors) unexpectedFailedResolution(id int64, l common.Location, typeName string) {
	e.errs.ReportErrorAtID(id, l, "unexpected failed resolution of '%s'", typeName)
}

func (e *typeErrors) unexpectedASTType(id int64, l common.Location, ex *exprpb.Expr) {
	e.errs.ReportErrorAtID(id, l, "unrecognized ast type: %v", reflect.TypeOf(ex))
}