//===----------------------------------------------------------*- swift -*-===//
//
// This source file is part of the Swift Argument Parser open source project
//
// Copyright (c) 2020 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
//
//===----------------------------------------------------------------------===//

/// Gets thrown while parsing and will be handled by the error output generation.
enum ParserError: Error {
  case helpRequested(visibility: ArgumentVisibility)
  case versionRequested
  case dumpHelpRequested
  
  case completionScriptRequested(shell: String?)
  case completionScriptCustomResponse(String)
  case unsupportedShell(String? = nil)
  
  case notImplemented
  case invalidState
  case unknownOption(InputOrigin.Element, Name)
  case invalidOption(String)
  case nonAlphanumericShortOption(Character)
  /// The option was there, but its value is missing, e.g. `--name` but no value for the `name`.
  case missingValueForOption(InputOrigin, Name)
  case unexpectedValueForOption(InputOrigin.Element, Name, String)
  case unexpectedExtraValues([(InputOrigin, String)])
  case duplicateExclusiveValues(previous: InputOrigin, duplicate: InputOrigin, originalInput: [String])
  /// We need a value for the given key, but it’s not there. Some non-optional option or argument is missing.
  case noValue(forKey: InputKey)
  case unableToParseValue(InputOrigin, Name?, String, forKey: InputKey, originalError: Error? = nil)
  case missingSubcommand
  case userValidationError(Error)
  case noArguments(Error)
}

/// These are errors used internally to the parsing, and will not be exposed to the help generation.
enum InternalParseError: Error {
  case wrongType(Any?, forKey: InputKey)
  case subcommandNameMismatch
  case subcommandLevelMismatch(Int, Int)
  case subcommandLevelMissing(Int)
  case subcommandLevelDuplicated(Int)
  case expectedCommandButNoneFound
}
