Composer.swift

//
// Created by Krzysztof Zablocki on 31/12/2016.
// Copyright (c) 2016 Pixle. All rights reserved.
//

import Foundation

private func currentTimestamp() -> TimeInterval {
    return CFAbsoluteTimeGetCurrent()
}

/// Responsible for composing results of `FileParser`.
public enum Composer {
    internal final class State {
        private(set) var typeMap = [String: Type]()
        private(set) var modules = [String: [String: Type]]()
        let parsedTypes: [Type]
        let functions: [SourceryMethod]
        let resolvedTypealiases: [String: Typealias]
        let unresolvedTypealiases: [String: Typealias]

        init(parserResult: FileParserResult) {
            // TODO: This logic should really be more complicated
            // For any resolution we need to be looking at accessLevel and module boundaries
            // e.g. there might be a typealias `private typealias Something = MyType` in one module and same name in another with public modifier, one could be accessed and the other could not
            self.functions = parserResult.functions
            let aliases = Self.typealiases(parserResult)
            resolvedTypealiases = aliases.resolved
            unresolvedTypealiases = aliases.unresolved
            parsedTypes = parserResult.types

            // set definedInType for all methods and variables
            parsedTypes
              .forEach { type in
                type.variables.forEach { $0.definedInType = type }
                type.methods.forEach { $0.definedInType = type }
                type.subscripts.forEach { $0.definedInType = type }
            }

            // map all known types to their names
            parsedTypes
              .filter { $0.isExtension == false }
              .forEach {
                  typeMap[$0.globalName] = $0
                  if let module = $0.module {
                      var typesByModules = modules[module, default: [:]]
                      typesByModules[$0.name] = $0
                      modules[module] = typesByModules
                  }
              }
        }

        func unifyTypes() -> [Type] {
            /// Resolve actual names of extensions, as they could have been done on typealias and note updated child names in uniques if needed
            parsedTypes
              .filter { $0.isExtension == true }
              .forEach {
                  let oldName = $0.globalName

                  if let resolved = resolveGlobalName(for: oldName, containingType: $0.parent, unique: typeMap, modules: modules, typealiases: resolvedTypealiases)?.name {
                      $0.localName = resolved.replacingOccurrences(of: "\($0.module != nil ? "\($0.module!)." : "")", with: "")
                  } else {
                      return
                  }

                  // nothing left to do
                  guard oldName != $0.globalName else {
                      return
                  }

                  // if it had contained types, they might have been fully defined and so their name has to be noted in uniques
                  func rewriteChildren(of type: Type) {
                      // child is never an extension so no need to check
                      for child in type.containedTypes {
                          typeMap[child.globalName] = child
                          rewriteChildren(of: child)
                      }
                  }
                  rewriteChildren(of: $0)
              }

            // extend all types with their extensions
            parsedTypes.forEach { type in
                type.inheritedTypes = type.inheritedTypes.map { inheritedName in
                    resolveGlobalName(for: inheritedName, containingType: type.parent, unique: typeMap, modules: modules, typealiases: resolvedTypealiases)?.name ?? inheritedName
                }

                let uniqueType = typeMap[type.globalName] ?? // this check will only fail on an extension?
                  typeFromComposedName(type.name, modules: modules) ?? // this can happen for an extension on unknown type, this case should probably be handled by the inferTypeNameFromModules
                  (inferTypeNameFromModules(from: type.localName, containedInType: type.parent, uniqueTypes: typeMap, modules: modules).flatMap { typeMap[$0] })

                guard let current = uniqueType else {
                    assert(type.isExtension)

                    // for unknown types we still store their extensions but mark them as unknown
                    type.isUnknownExtension = true
                    if let existingType = typeMap[type.globalName] {
                        existingType.extend(type)
                        typeMap[type.globalName] = existingType
                    } else {
                        typeMap[type.globalName] = type
                    }

                    let inheritanceClause = type.inheritedTypes.isEmpty ? "" :
                      ": \(type.inheritedTypes.joined(separator: ", "))"

                    Log.astWarning("Found \"extension \(type.name)\(inheritanceClause)\" of type for which there is no original type declaration information.")
                    return
                }

                if current == type { return }

                current.extend(type)
                typeMap[current.globalName] = current
            }

            let values = typeMap.values
            var processed = Set<String>(minimumCapacity: values.count)
            return typeMap.values.filter({
                let name = $0.globalName
                let wasProcessed = processed.contains(name)
                processed.insert(name)
                return !wasProcessed
            })
        }

        /// returns typealiases map to their full names, with `resolved` removing intermediate
        /// typealises and `unresolved` including typealiases that reference other typealiases.
        private static func typealiases(_ parserResult: FileParserResult) -> (resolved: [String: Typealias], unresolved: [String: Typealias]) {
            var typealiasesByNames = [String: Typealias]()
            parserResult.typealiases.forEach { typealiasesByNames[$0.name] = $0 }
            parserResult.types.forEach { type in
                type.typealiases.forEach({ (_, alias) in
                    // TODO: should I deal with the fact that alias.name depends on type name but typenames might be updated later on
                    // maybe just handle non extension case here and extension aliases after resolving them?
                    typealiasesByNames[alias.name] = alias
                })
            }

            let unresolved = typealiasesByNames

            // ! if a typealias leads to another typealias, follow through and replace with final type
            typealiasesByNames.forEach { _, alias in
                var aliasNamesToReplace = [alias.name]
                var finalAlias = alias
                while let targetAlias = typealiasesByNames[finalAlias.typeName.name] {
                    aliasNamesToReplace.append(targetAlias.name)
                    finalAlias = targetAlias
                }

                // ! replace all keys
                aliasNamesToReplace.forEach { typealiasesByNames[$0] = finalAlias }
            }

            return (resolved: typealiasesByNames, unresolved: unresolved)
        }

        /// Resolves type identifier for name
        func resolveGlobalName(for type: String,
                                              containingType: Type? = nil,
                                              unique: [String: Type]? = nil,
                                              modules: [String: [String: Type]],
                                              typealiases: [String: Typealias]) -> (name: String, typealias: Typealias?)? {
            // if the type exists for this name and isn't an extension just return it's name
            // if it's extension we need to check if there aren't other options TODO: verify
            if let realType = unique?[type], realType.isExtension == false {
                return (name: realType.globalName, typealias: nil)
            }

            if let alias = typealiases[type] {
                return (name: alias.type?.globalName ?? alias.typeName.name, typealias: alias)
            }

            if let containingType = containingType {
                if type == "Self" {
                    return (name: containingType.globalName, typealias: nil)
                }

                var currentContainer: Type? = containingType
                while currentContainer != nil, let parentName = currentContainer?.globalName {
                    /// TODO: no parent for sure?
                    /// manually walk the containment tree
                    if let name = resolveGlobalName(for: "\(parentName).\(type)", containingType: nil, unique: unique, modules: modules, typealiases: typealiases) {
                        return name
                    }

                    currentContainer = currentContainer?.parent
                }

//            if let name = resolveGlobalName(for: "\(containingType.globalName).\(type)", containingType: containingType.parent, unique: unique, modules: modules, typealiases: typealiases) {
//                return name
//            }

//             last check it's via module
//            if let module = containingType.module, let name = resolveGlobalName(for: "\(module).\(type)", containingType: nil, unique: unique, modules: modules, typealiases: typealiases) {
//                return name
//            }
            }

            // TODO: is this needed?
            if let inferred = inferTypeNameFromModules(from: type, containedInType: containingType, uniqueTypes: unique ?? [:], modules: modules) {
                return (name: inferred, typealias: nil)
            }

            return typeFromComposedName(type, modules: modules).map { (name: $0.globalName, typealias: nil) }
        }

        private func inferTypeNameFromModules(from typeIdentifier: String, containedInType: Type?, uniqueTypes: [String: Type], modules: [String: [String: Type]]) -> String? {
            func fullName(for module: String) -> String {
                "\(module).\(typeIdentifier)"
            }

            func type(for module: String) -> Type? {
                return modules[module]?[typeIdentifier]
            }

            func ambiguousErrorMessage(from types: [Type]) -> String? {
                Log.astWarning("Ambiguous type \(typeIdentifier), found \(types.map { $0.globalName }.joined(separator: ", ")). Specify module name at declaration site to disambiguate.")
                return nil
            }

            let explicitModulesAtDeclarationSite: [String] = [
                containedInType?.module.map { [$0] } ?? [],    // main module for this typename
                containedInType?.imports.map { $0.moduleName } ?? []    // imported modules
            ]
              .flatMap { $0 }

            let remainingModules = Set(modules.keys).subtracting(explicitModulesAtDeclarationSite)

            /// We need to check whether we can find type in one of the modules but we need to be careful to avoid amibiguity
            /// First checking explicit modules available at declaration site (so source module + all imported ones)
            /// If there is no ambigiuity there we can assume that module will be resolved by the compiler
            /// If that's not the case we look after remaining modules in the application and if the typename has no ambigiuity we use that
            /// But if there is more than 1 typename duplication across modules we have no way to resolve what is the compiler going to use so we fail
            let moduleSetsToCheck: [[String]] = [
                explicitModulesAtDeclarationSite,
                Array(remainingModules)
            ]

            for modules in moduleSetsToCheck {
                let possibleTypes = modules
                  .compactMap { type(for: $0) }

                if possibleTypes.count > 1 {
                    return ambiguousErrorMessage(from: possibleTypes)
                }

                if let type = possibleTypes.first {
                    return type.globalName
                }
            }

            // as last result for unknown types / extensions
            // try extracting type from unique array
            if let module = containedInType?.module {
                return uniqueTypes[fullName(for: module)]?.globalName
            }
            return nil
        }

        func typeFromComposedName(_ name: String, modules: [String: [String: Type]]) -> Type? {
            guard name.contains(".") else { return nil }
            let nameComponents = name.components(separatedBy: ".")
            let moduleName = nameComponents[0]
            let typeName = nameComponents.suffix(from: 1).joined(separator: ".")
            return modules[moduleName]?[typeName]
        }
    }

    /// Performs final processing of discovered types:
    /// - extends types with their corresponding extensions;
    /// - replaces typealiases with actual types
    /// - finds actual types for variables and enums raw values
    /// - filters out any private types and extensions
    ///
    /// - Parameter parserResult: Result of parsing source code.
    /// - Returns: Final types and extensions of unknown types.
    public static func uniqueTypesAndFunctions(_ parserResult: FileParserResult) -> (types: [Type], functions: [SourceryMethod], typealiases: [Typealias]) {
        let state = State(parserResult: parserResult)

        let resolveType = { (typeName: TypeName, containingType: Type?) -> Type? in
            return self.resolveType(typeName: typeName, containingType: containingType, state: state)
        }

        /// Resolve typealiases
        let typealiases = Array(state.unresolvedTypealiases.values)
        typealiases.forEach { alias in
            alias.type = resolveType(alias.typeName, alias.parent)
        }

        let types = state.unifyTypes()

        let resolutionStart = currentTimestamp()

        types.parallelPerform { type in
            type.variables.forEach {
                resolveVariableTypes($0, of: type, resolve: resolveType)
            }
            type.methods.forEach {
                resolveMethodTypes($0, of: type, resolve: resolveType)
            }
            type.subscripts.forEach {
                resolveSubscriptTypes($0, of: type, resolve: resolveType)
            }

            if let enumeration = type as? Enum {
                resolveEnumTypes(enumeration, types: state.typeMap, resolve: resolveType)
            }

            if let composition = type as? ProtocolComposition {
                resolveProtocolCompositionTypes(composition, resolve: resolveType)
            }

            if let sourceryProtocol = type as? SourceryProtocol {
                resolveProtocolTypes(sourceryProtocol, resolve: resolveType)
            }
        }

        state.functions.parallelPerform { function in
            resolveMethodTypes(function, of: nil, resolve: resolveType)
        }

        Log.benchmark("resolution took \(currentTimestamp() - resolutionStart)")

        updateTypeRelationships(types: types)

        return (
            types: types.sorted { $0.globalName < $1.globalName },
            functions: state.functions.sorted { $0.name < $1.name },
            typealiases: typealiases.sorted(by: { $0.name < $1.name })
        )
    }

    private static func resolveType(typeName: TypeName, containingType: Type?, state: State) -> Type? {
        let resolveTypeWithName = { (typeName: TypeName) -> Type? in
            return self.resolveType(typeName: typeName, containingType: containingType, state: state)
        }

        let unique = state.typeMap
        let modules = state.modules
        let typealiases = state.resolvedTypealiases

        if let name = typeName.actualTypeName {
            let resolvedIdentifier = name.generic?.name ?? name.unwrappedTypeName
            return unique[resolvedIdentifier]
        }

        let retrievedName = self.actualTypeName(for: typeName, containingType: containingType, state: state)
        let lookupName = retrievedName ?? typeName

        if let tuple = lookupName.tuple {
            var needsUpdate = false

            tuple.elements.forEach { tupleElement in
                tupleElement.type = resolveTypeWithName(tupleElement.typeName)
                if tupleElement.typeName.actualTypeName != nil {
                    needsUpdate = true
                }
            }

            if needsUpdate || retrievedName != nil {
                let tupleCopy = TupleType(name: tuple.name, elements: tuple.elements)
                tupleCopy.elements.forEach {
                    $0.typeName = $0.actualTypeName ?? $0.typeName
                    $0.typeName.actualTypeName = nil
                }
                tupleCopy.name = tupleCopy.elements.asTypeName

                typeName.tuple = tupleCopy // TODO: really don't like this old behaviour
                typeName.actualTypeName = TypeName(name: tupleCopy.name,
                                                   isOptional: typeName.isOptional,
                                                   isImplicitlyUnwrappedOptional: typeName.isImplicitlyUnwrappedOptional,
                                                   tuple: tupleCopy,
                                                   array: lookupName.array,
                                                   dictionary: lookupName.dictionary,
                                                   closure: lookupName.closure,
                                                   generic: lookupName.generic
                )
            }
            return nil
        } else
        if let array = lookupName.array {
            array.elementType = resolveTypeWithName(array.elementTypeName)

            if array.elementTypeName.actualTypeName != nil || retrievedName != nil {
                let array = ArrayType(name: array.name, elementTypeName: array.elementTypeName, elementType: array.elementType)
                array.elementTypeName = array.elementTypeName.actualTypeName ?? array.elementTypeName
                array.elementTypeName.actualTypeName = nil
                array.name = array.asSource
                typeName.array = array // TODO: really don't like this old behaviour
                typeName.generic = array.asGeneric // TODO: really don't like this old behaviour

                typeName.actualTypeName = TypeName(name: array.name,
                                                   isOptional: typeName.isOptional,
                                                   isImplicitlyUnwrappedOptional: typeName.isImplicitlyUnwrappedOptional,
                                                   tuple: lookupName.tuple,
                                                   array: array,
                                                   dictionary: lookupName.dictionary,
                                                   closure: lookupName.closure,
                                                   generic: typeName.generic
                )
            }
        } else
        if let dictionary = lookupName.dictionary {
            dictionary.keyType = resolveTypeWithName(dictionary.keyTypeName)
            dictionary.valueType = resolveTypeWithName(dictionary.valueTypeName)

            if dictionary.keyTypeName.actualTypeName != nil || dictionary.valueTypeName.actualTypeName != nil || retrievedName != nil {
                let dictionary = DictionaryType(name: dictionary.name, valueTypeName: dictionary.valueTypeName, valueType: dictionary.valueType, keyTypeName: dictionary.keyTypeName, keyType: dictionary.keyType)
                dictionary.keyTypeName = dictionary.keyTypeName.actualTypeName ?? dictionary.keyTypeName
                dictionary.keyTypeName.actualTypeName = nil // TODO: really don't like this old behaviour
                dictionary.valueTypeName = dictionary.valueTypeName.actualTypeName ?? dictionary.valueTypeName
                dictionary.valueTypeName.actualTypeName = nil // TODO: really don't like this old behaviour

                dictionary.name = dictionary.asSource

                typeName.dictionary = dictionary // TODO: really don't like this old behaviour
                typeName.generic = dictionary.asGeneric // TODO: really don't like this old behaviour

                typeName.actualTypeName = TypeName(name: dictionary.asSource,
                                                   isOptional: typeName.isOptional,
                                                   isImplicitlyUnwrappedOptional: typeName.isImplicitlyUnwrappedOptional,
                                                   tuple: lookupName.tuple,
                                                   array: lookupName.array,
                                                   dictionary: dictionary,
                                                   closure: lookupName.closure,
                                                   generic: dictionary.asGeneric
                )
            }
        } else
        if let closure = lookupName.closure {
            var needsUpdate = false

            closure.returnType = resolveTypeWithName(closure.returnTypeName)
            closure.parameters.forEach { parameter in
                parameter.type = resolveTypeWithName(parameter.typeName)
                if parameter.typeName.actualTypeName != nil {
                    needsUpdate = true
                }
            }

            if closure.returnTypeName.actualTypeName != nil || needsUpdate || retrievedName != nil {
                typeName.closure = closure // TODO: really don't like this old behaviour

                typeName.actualTypeName = TypeName(name: closure.asSource,
                                                   isOptional: typeName.isOptional,
                                                   isImplicitlyUnwrappedOptional: typeName.isImplicitlyUnwrappedOptional,
                                                   tuple: lookupName.tuple,
                                                   array: lookupName.array,
                                                   dictionary: lookupName.dictionary,
                                                   closure: closure,
                                                   generic: lookupName.generic
                )
            }

            return nil
        } else
        if let generic = lookupName.generic {
            var needsUpdate = false

            generic.typeParameters.forEach { parameter in
                parameter.type = resolveTypeWithName(parameter.typeName)
                if parameter.typeName.actualTypeName != nil {
                    needsUpdate = true
                }
            }

            if needsUpdate || retrievedName != nil {
                let generic = GenericType(name: generic.name, typeParameters: generic.typeParameters)
                generic.typeParameters.forEach {
                    $0.typeName = $0.typeName.actualTypeName ?? $0.typeName
                    $0.typeName.actualTypeName = nil // TODO: really don't like this old behaviour
                }
                typeName.generic = generic // TODO: really don't like this old behaviour
                typeName.array = lookupName.array // TODO: really don't like this old behaviour
                typeName.dictionary = lookupName.dictionary // TODO: really don't like this old behaviour

                let params = generic.typeParameters.map { $0.typeName.asSource }.joined(separator: ", ")

                typeName.actualTypeName = TypeName(name: "\(generic.name)<\(params)>",
                                                   isOptional: typeName.isOptional,
                                                   isImplicitlyUnwrappedOptional: typeName.isImplicitlyUnwrappedOptional,
                                                   tuple: lookupName.tuple,
                                                   array: lookupName.array, // TODO: asArray
                                                   dictionary: lookupName.dictionary, // TODO: asDictionary
                                                   closure: lookupName.closure,
                                                   generic: generic
                )
            }
        }

        if let aliasedName = (typeName.actualTypeName ?? retrievedName), aliasedName.unwrappedTypeName != typeName.unwrappedTypeName {
            typeName.actualTypeName = aliasedName
        }

        let finalLookup = typeName.actualTypeName ?? typeName
        let resolvedIdentifier = finalLookup.generic?.name ?? finalLookup.unwrappedTypeName

        // should we cache resolved typenames?
        return unique[resolvedIdentifier]
    }

    typealias TypeResolver = (TypeName, Type?) -> Type?

    private static func resolveVariableTypes(_ variable: Variable, of type: Type, resolve: TypeResolver) {
        variable.type = resolve(variable.typeName, type)

        /// The actual `definedInType` is assigned in `uniqueTypes` but we still
        /// need to resolve the type to correctly parse typealiases
        /// @see https://github.com/krzysztofzablocki/Sourcery/pull/374
        if let definedInTypeName = variable.definedInTypeName {
            _ = resolve(definedInTypeName, type)
        }
    }

    private static func resolveSubscriptTypes(_ subscript: Subscript, of type: Type, resolve: TypeResolver) {
        `subscript`.parameters.forEach { (parameter) in
            parameter.type = resolve(parameter.typeName, type)
        }

        `subscript`.returnType = resolve(`subscript`.returnTypeName, type)
        if let definedInTypeName = `subscript`.definedInTypeName {
            _ = resolve(definedInTypeName, type)
        }
    }

    private static func resolveMethodTypes(_ method: SourceryMethod, of type: Type?, resolve: TypeResolver) {
        method.parameters.forEach { parameter in
            parameter.type = resolve(parameter.typeName, type)
        }

        /// The actual `definedInType` is assigned in `uniqueTypes` but we still
        /// need to resolve the type to correctly parse typealiases
        /// @see https://github.com/krzysztofzablocki/Sourcery/pull/374
        var definedInType: Type?
        if let definedInTypeName = method.definedInTypeName {
            definedInType = resolve(definedInTypeName, type)
        }

        guard !method.returnTypeName.isVoid else { return }

        if method.isInitializer || method.isFailableInitializer {
            method.returnType = definedInType
            if let type = method.actualDefinedInTypeName {
                if method.isFailableInitializer {
                    method.returnTypeName = TypeName(
                        name: type.name,
                        isOptional: true,
                        isImplicitlyUnwrappedOptional: false,
                        tuple: type.tuple,
                        array: type.array,
                        dictionary: type.dictionary,
                        closure: type.closure,
                        generic: type.generic,
                        isProtocolComposition: type.isProtocolComposition
                    )
                } else if method.isInitializer {
                    method.returnTypeName = type
                }
            }
        } else {
            method.returnType = resolve(method.returnTypeName, type)
        }
    }

    private static func resolveEnumTypes(_ enumeration: Enum, types: [String: Type], resolve: TypeResolver) {
        enumeration.cases.forEach { enumCase in
            enumCase.associatedValues.forEach { associatedValue in
                associatedValue.type = resolve(associatedValue.typeName, enumeration)
            }
        }

        guard enumeration.hasRawType else { return }

        if let rawValueVariable = enumeration.variables.first(where: { $0.name == "rawValue" && !$0.isStatic }) {
            enumeration.rawTypeName = rawValueVariable.actualTypeName
            enumeration.rawType = rawValueVariable.type
        } else if let rawTypeName = enumeration.inheritedTypes.first {
            // enums with no cases or enums with cases that contain associated values can't have raw type
            guard !enumeration.cases.isEmpty,
                  !enumeration.hasAssociatedValues else {
                return enumeration.rawTypeName = nil
            }

            if let rawTypeCandidate = types[rawTypeName] {
                if !((rawTypeCandidate is SourceryProtocol) || (rawTypeCandidate is ProtocolComposition)) {
                    enumeration.rawTypeName = TypeName(rawTypeName)
                    enumeration.rawType = rawTypeCandidate
                }
            } else {
                enumeration.rawTypeName = TypeName(rawTypeName)
            }
        }
    }

    private static func resolveProtocolCompositionTypes(_ protocolComposition: ProtocolComposition, resolve: TypeResolver) {
        let composedTypes = protocolComposition.composedTypeNames.compactMap { typeName in
            resolve(typeName, protocolComposition)
        }

        protocolComposition.composedTypes = composedTypes
    }

    private static func resolveProtocolTypes(_ sourceryProtocol: SourceryProtocol, resolve: TypeResolver) {
        sourceryProtocol.associatedTypes.forEach { (_, value) in
            guard let typeName = value.typeName,
                  let type = resolve(typeName, sourceryProtocol)
            else { return }
            value.type = type
        }

        sourceryProtocol.genericRequirements.forEach { requirment in
            if let knownAssociatedType = sourceryProtocol.associatedTypes[requirment.leftType.name] {
                requirment.leftType = knownAssociatedType
            }
            requirment.rightType.type = resolve(requirment.rightType.typeName, sourceryProtocol)
        }
    }

    private static func actualTypeName(for typeName: TypeName,
                                       containingType: Type? = nil,
                                       state: State) -> TypeName? {
        let unique = state.typeMap
        let modules = state.modules
        let typealiases = state.resolvedTypealiases

        var unwrapped = typeName.unwrappedTypeName
        if let generic = typeName.generic {
            unwrapped = generic.name
        }

        guard let aliased = state.resolveGlobalName(for: unwrapped, containingType: containingType, unique: unique, modules: modules, typealiases: typealiases) else {
            return nil
        }

        /// TODO: verify
        let generic = typeName.generic.map { GenericType(name: $0.name, typeParameters: $0.typeParameters) }
        generic?.name = aliased.name
        let dictionary = typeName.dictionary.map { DictionaryType(name: $0.name, valueTypeName: $0.valueTypeName, valueType: $0.valueType, keyTypeName: $0.keyTypeName, keyType: $0.keyType) }
        dictionary?.name = aliased.name
        let array = typeName.array.map { ArrayType(name: $0.name, elementTypeName: $0.elementTypeName, elementType: $0.elementType) }
        array?.name = aliased.name

        return TypeName(name: aliased.name,
                        isOptional: typeName.isOptional,
                        isImplicitlyUnwrappedOptional: typeName.isImplicitlyUnwrappedOptional,
                        tuple: aliased.typealias?.typeName.tuple ?? typeName.tuple, // TODO: verify
                        array: aliased.typealias?.typeName.array ?? array,
                        dictionary: aliased.typealias?.typeName.dictionary ?? dictionary,
                        closure: aliased.typealias?.typeName.closure ?? typeName.closure,
                        generic: aliased.typealias?.typeName.generic ?? generic
        )
    }

    private static func updateTypeRelationships(types: [Type]) {
        var typesByName = [String: Type]()
        types.forEach { typesByName[$0.globalName] = $0 }

        var processed = [String: Bool]()
        types.forEach { type in
            if let type = type as? Class, let supertype = type.inheritedTypes.first.flatMap({ typesByName[$0] }) as? Class {
                type.supertype = supertype
            }
            processed[type.globalName] = true
            updateTypeRelationship(for: type, typesByName: typesByName, processed: &processed)
        }
    }

    private static func findBaseType(for type: Type, name: String, typesByName: [String: Type]) -> Type? {
        if let baseType = typesByName[name] {
            return baseType
        }
        if let module = type.module, let baseType = typesByName["\(module).\(name)"] {
            return baseType
        }
        for importModule in type.imports {
            if let baseType = typesByName["\(importModule).\(name)"] {
                return baseType
            }
        }
        return nil
    }

    private static func updateTypeRelationship(for type: Type, typesByName: [String: Type], processed: inout [String: Bool]) {
        type.based.keys.forEach { name in
            guard let baseType = findBaseType(for: type, name: name, typesByName: typesByName) else { return }
            let globalName = baseType.globalName
            if processed[globalName] != true {
                processed[globalName] = true
                updateTypeRelationship(for: baseType, typesByName: typesByName, processed: &processed)
            }

            baseType.based.keys.forEach { type.based[$0] = $0 }
            baseType.basedTypes.forEach { type.basedTypes[$0.key] = $0.value }
            baseType.inherits.forEach { type.inherits[$0.key] = $0.value }
            baseType.implements.forEach { type.implements[$0.key] = $0.value }

            if baseType is Class {
                type.inherits[globalName] = baseType
            } else if let baseProtocol = baseType as? SourceryProtocol {
                type.implements[globalName] = baseProtocol
                if let extendingProtocol = type as? SourceryProtocol {
                    baseProtocol.associatedTypes.forEach {
                        if extendingProtocol.associatedTypes[$0.key] == nil {
                            extendingProtocol.associatedTypes[$0.key] = $0.value
                        }
                    }
                }
            } else if baseType is ProtocolComposition {
                // TODO: associated types?
                type.implements[globalName] = baseType
            }

            type.basedTypes[globalName] = baseType
        }
    }
}