/**
 * Copyright (c) 2020-present, Goldman Sachs
 *
 * 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.
 */

import {
  PackageableElementExplicitReference,
  type PackageableElementReference,
  type PackageableElementImplicitReference,
} from '../../../PackageableElementReference.js';
import { ReferenceWithOwner } from '../../../../Reference.js';
import type { Database } from './Database.js';
import type { Column } from './Column.js';
import type { Relation } from './RelationalOperationElement.js';
import type { Schema } from './Schema.js';
import { View } from './View.js';
import { Table } from './Table.js';
import { UnsupportedOperationError } from '@finos/legend-shared';

const getSchemaFromRelation = (value: Relation): Schema => {
  if (value instanceof Table || value instanceof View) {
    return value.schema;
  }
  throw new UnsupportedOperationError(
    `Can't derive schema for relation`,
    value,
  );
};

export abstract class ColumnReference extends ReferenceWithOwner {
  override readonly ownerReference: PackageableElementReference<Database>;
  value: Column;

  protected constructor(
    ownerReference: PackageableElementReference<Database>,
    value: Column,
  ) {
    super(ownerReference);
    this.ownerReference = ownerReference;
    this.value = value;
  }
}

export class ColumnExplicitReference extends ColumnReference {
  override readonly ownerReference: PackageableElementExplicitReference<Database>;

  private constructor(value: Column) {
    const ownerReference = PackageableElementExplicitReference.create(
      getSchemaFromRelation(value.owner)._OWNER,
    );
    super(ownerReference, value);
    this.ownerReference = ownerReference;
  }

  static create(value: Column): ColumnExplicitReference {
    return new ColumnExplicitReference(value);
  }
}

export class ColumnImplicitReference extends ColumnReference {
  override readonly ownerReference: PackageableElementImplicitReference<Database>;

  private constructor(
    ownerReference: PackageableElementImplicitReference<Database>,
    value: Column,
  ) {
    super(ownerReference, value);
    this.ownerReference = ownerReference;
  }

  static create(
    ownerReference: PackageableElementImplicitReference<Database>,
    value: Column,
  ): ColumnImplicitReference {
    return new ColumnImplicitReference(ownerReference, value);
  }
}