brightdigit/Options

//
//  OptionsMacro.swift
//  SimulatorServices
//
//  Created by Leo Dion.
//  Copyright © 2024 BrightDigit.
//
//  Permission is hereby granted, free of charge, to any person
//  obtaining a copy of this software and associated documentation
//  files (the “Software”), to deal in the Software without
//  restriction, including without limitation the rights to use,
//  copy, modify, merge, publish, distribute, sublicense, and/or
//  sell copies of the Software, and to permit persons to whom the
//  Software is furnished to do so, subject to the following
//  conditions:
//
//  The above copyright notice and this permission notice shall be
//  included in all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
//  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
//  OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
//  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
//  HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
//  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
//  OTHER DEALINGS IN THE SOFTWARE.
//

import SwiftSyntax
import SwiftSyntaxMacros

public struct OptionsMacro: ExtensionMacro, PeerMacro {
  public static func expansion(
    of _: SwiftSyntax.AttributeSyntax,
    providingPeersOf declaration: some SwiftSyntax.DeclSyntaxProtocol,
    in _: some SwiftSyntaxMacros.MacroExpansionContext
  ) throws -> [SwiftSyntax.DeclSyntax] {
    guard let enumDecl = declaration.as(EnumDeclSyntax.self) else {
      throw InvalidDeclError.kind(declaration.kind)
    }
    let typeName = enumDecl.name

    let aliasName: TokenSyntax = "\(typeName.trimmed)Set"

    let initializerName: TokenSyntax = "EnumSet<\(typeName)>"

    return [
      .init(TypeAliasDeclSyntax(name: aliasName, for: initializerName))
    ]
  }

  public static func expansion(
    of _: SwiftSyntax.AttributeSyntax,
    attachedTo declaration: some SwiftSyntax.DeclGroupSyntax,
    providingExtensionsOf _: some SwiftSyntax.TypeSyntaxProtocol,
    conformingTo protocols: [SwiftSyntax.TypeSyntax],
    in _: some SwiftSyntaxMacros.MacroExpansionContext
  ) throws -> [SwiftSyntax.ExtensionDeclSyntax] {
    guard let enumDecl = declaration.as(EnumDeclSyntax.self) else {
      throw InvalidDeclError.kind(declaration.kind)
    }

    let extensionDecl = try ExtensionDeclSyntax(
      enumDecl: enumDecl, conformingTo: protocols
    )
    return [extensionDecl]
  }
}