//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2023 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
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

// NOTE: Types in this file should be self-contained and should not depend on any non-stdlib types.

@_spi(PluginMessage)
public enum HostToPluginMessage: Codable {
  /// Send capability of the host, and get capability of the plugin.
  case getCapability(
    capability: PluginMessage.HostCapability?
  )

  /// Expand a '@freestanding' macro.
  case expandFreestandingMacro(
    macro: PluginMessage.MacroReference,
    macroRole: PluginMessage.MacroRole? = nil,
    discriminator: String,
    syntax: PluginMessage.Syntax,
    lexicalContext: [PluginMessage.Syntax]? = nil,
    staticBuildConfiguration: String? = nil
  )

  /// Expand an '@attached' macro.
  case expandAttachedMacro(
    macro: PluginMessage.MacroReference,
    macroRole: PluginMessage.MacroRole,
    discriminator: String,
    attributeSyntax: PluginMessage.Syntax,
    declSyntax: PluginMessage.Syntax,
    parentDeclSyntax: PluginMessage.Syntax?,
    extendedTypeSyntax: PluginMessage.Syntax?,
    conformanceListSyntax: PluginMessage.Syntax?,
    lexicalContext: [PluginMessage.Syntax]? = nil,
    staticBuildConfiguration: String? = nil
  )

  /// Optionally implemented message to load a dynamic link library.
  /// 'moduleName' can be used as a hint indicating that the library
  /// provides the specified module.
  case loadPluginLibrary(
    libraryPath: String,
    moduleName: String
  )
}

@_spi(PluginMessage)
public enum PluginToHostMessage: Codable {
  case getCapabilityResult(
    capability: PluginMessage.PluginCapability
  )

  /// Unified response for freestanding/attached macro expansion.
  case expandMacroResult(
    expandedSource: String?,
    diagnostics: [PluginMessage.Diagnostic]
  )

  // @available(*, deprecated: "use expandMacroResult() instead")
  case expandFreestandingMacroResult(
    expandedSource: String?,
    diagnostics: [PluginMessage.Diagnostic]
  )

  // @available(*, deprecated: "use expandMacroResult() instead")
  case expandAttachedMacroResult(
    expandedSources: [String]?,
    diagnostics: [PluginMessage.Diagnostic]
  )

  case loadPluginLibraryResult(
    loaded: Bool,
    diagnostics: [PluginMessage.Diagnostic]
  )
}

@_spi(PluginMessage)
public enum PluginMessage {
  public static var PROTOCOL_VERSION_NUMBER: Int { 8 }  // Syntax.Kind.accessor

  public struct HostCapability: Codable {
    var protocolVersion: Int

    public init(protocolVersion: Int) {
      self.protocolVersion = protocolVersion
    }
  }

  public struct PluginCapability: Codable {
    public var protocolVersion: Int

    /// Optional features this plugin provides.
    ///  * 'load-plugin-library': 'loadPluginLibrary' message is implemented.
    public var features: [String]?

    public init(protocolVersion: Int, features: [String]? = nil) {
      self.protocolVersion = protocolVersion
      self.features = features
    }
  }

  public struct MacroReference: Codable, Sendable {
    public var moduleName: String
    public var typeName: String

    // The name of 'macro' declaration the client is using.
    public var name: String

    public init(moduleName: String, typeName: String, name: String) {
      self.moduleName = moduleName
      self.typeName = typeName
      self.name = name
    }
  }

  public enum MacroRole: String, Codable, Sendable {
    case expression
    case declaration
    case accessor
    case memberAttribute
    case member
    case peer
    case conformance
    case codeItem
    case `extension`
    @_spi(ExperimentalLanguageFeatures) case preamble
    case body
  }

  public struct SourceLocation: Codable {
    /// A file ID consisting of the module name and file name (without full path),
    /// as would be generated by the macro expansion `#fileID`.
    public var fileID: String

    /// A full path name as would be generated by the macro expansion `#filePath`,
    /// e.g., `/home/taylor/alison.swift`.
    public var fileName: String

    /// UTF-8 offset of the location in the file.
    public var offset: Int

    public var line: Int
    public var column: Int

    public init(fileID: String, fileName: String, offset: Int, line: Int, column: Int) {
      self.fileID = fileID
      self.fileName = fileName
      self.offset = offset
      self.line = line
      self.column = column
    }
  }

  public struct Diagnostic: Codable {
    public enum Severity: String, Codable {
      case error
      case warning
      case note
      case remark
    }
    public struct Position: Codable {
      public var fileName: String
      /// UTF-8 offset in the file.
      public var offset: Int

      public init(fileName: String, offset: Int) {
        self.fileName = fileName
        self.offset = offset
      }

      public static var invalid: Self {
        .init(fileName: "", offset: 0)
      }
    }
    public struct PositionRange: Codable {
      public var fileName: String
      /// UTF-8 offset of the start of the range in the file.
      public var startOffset: Int
      /// UTF-8 offset of the end of the range in the file.
      public var endOffset: Int

      public init(fileName: String, startOffset: Int, endOffset: Int) {
        self.fileName = fileName
        self.startOffset = startOffset
        self.endOffset = endOffset
      }

      public static var invalid: Self {
        .init(fileName: "", startOffset: 0, endOffset: 0)
      }
    }
    public struct Note: Codable {
      public var position: Position
      public var message: String

      public init(position: Position, message: String) {
        self.position = position
        self.message = message
      }
    }
    public struct FixIt: Codable {
      public struct Change: Codable {
        public var range: PositionRange
        public var newText: String

        internal init(range: PositionRange, newText: String) {
          self.range = range
          self.newText = newText
        }
      }
      public var message: String
      public var changes: [Change]

      internal init(message: String, changes: [Change]) {
        self.message = message
        self.changes = changes
      }
    }
    public var message: String
    public var severity: Severity
    public var position: Position
    public var highlights: [PositionRange]
    public var notes: [Note]
    public var fixIts: [FixIt]

    public init(
      message: String,
      severity: Severity,
      position: Position,
      highlights: [PositionRange],
      notes: [Note],
      fixIts: [FixIt]
    ) {
      self.message = message
      self.severity = severity
      self.position = position
      self.highlights = highlights
      self.notes = notes
      self.fixIts = fixIts
    }
  }

  public struct Syntax: Codable {
    public enum Kind: String, Codable {
      case declaration
      case statement
      case expression
      case type
      case pattern
      case attribute
      case accessor
    }
    public var kind: Kind
    public var source: String
    public var location: SourceLocation

    public init(kind: Kind, source: String, location: SourceLocation) {
      self.kind = kind
      self.source = source
      self.location = location
    }
  }
}
