// BoxingCasts.swift - Tests for boxing/unboxing casts
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 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
//
// -----------------------------------------------------------------------------
///
/// Contains tests for existential, optional, and other casts that box/unbox values.
///
// -----------------------------------------------------------------------------

import StdlibUnittest
#if _runtime(_ObjC)
import Foundation
#endif

fileprivate func runtimeCast<From, To> (_ x: From, to: To.Type) -> To? {
  return x as? To
}

fileprivate func optional<T>(_ x: T) -> Optional<T> {
  return runtimeCast(x, to: Optional<T>.self)!
}

fileprivate protocol FilePrivateProtocol {}
internal protocol InternalProtocol {}
public protocol PublicProtocol {}
protocol UnimplementedProtocol {}

fileprivate enum EmptyEnum: FilePrivateProtocol, InternalProtocol, PublicProtocol { }

fileprivate enum SingleCaseEnum: FilePrivateProtocol, InternalProtocol, PublicProtocol {
case case0
  init() {self = .case0}
}

fileprivate enum TrivialPayloadEnum: FilePrivateProtocol, InternalProtocol, PublicProtocol {
case payloadCase(Int)
  init() {self = .payloadCase(42)}
}

extension TrivialPayloadEnum: Hashable {}

fileprivate enum MultiPayloadEnum: FilePrivateProtocol, InternalProtocol, PublicProtocol {
case case0(String)
case case1(Int)
  init() {self = .case1(42)}
}

extension MultiPayloadEnum: Hashable {}

fileprivate class ClassInt: FilePrivateProtocol, InternalProtocol, PublicProtocol {
  public var value: Int
  private var tracker = LifetimeTracked(77)
  init(_ v: Int = 42) {value = v}
}

extension ClassInt: Equatable, Hashable {
  static func ==(left: ClassInt, right: ClassInt) -> Bool {left.value == right.value}
  func hash(into hasher: inout Hasher) { value.hash(into: &hasher) }
}

fileprivate struct StructInt: FilePrivateProtocol, InternalProtocol, PublicProtocol {
  public var value: Int
  private var tracker = LifetimeTracked(77)
  init(_ v: Int = 42) { value = v}
}

extension StructInt: Hashable, Equatable { }

#if _runtime(_ObjC)
fileprivate class OCClassInt: NSObject, FilePrivateProtocol, InternalProtocol, PublicProtocol {
  public var value: Int
  private var tracker = LifetimeTracked(77)
  init(_ v: Int = 42) { value = v}
}
#endif

let BoxingCasts = TestSuite("BoxingCasts")

%{
import random
# The test body goes into a named function and the test case just invokes that
# function by name.  This makes debugging easier, since it's easier to set break
# points on named functions than on arbitrary closures.
# The function names are included in the test name
# for ease of reference.
testNumber = 0
def testFunctionName():
  return "test{number}".format(number=testNumber)
def nextTestNumber():
  global testNumber
  testNumber += 1

# Type used for intermediate casts.  The base object gets
# cast to one or more of these before the final test.
class Box:
  def __init__(self, name, typeName=None, cast=None):
    self.name = name
    self.typeName = typeName or name
    self.cast_template = cast or "runtimeCast({expr}, to: {typeName}.self)!"
  def cast_oper(self, expr):
    return self.cast_template.format(expr=expr, typeName=self.typeName)

anyHashableBox = Box(name="AnyHashable")
all_boxes = [
    Box(name="Any", typeName="Any"),
    Box(name="AnyStatic", cast="({expr} as Any)"),
    Box(name="AnyObject"),
    Box(name="SwiftValueBox", cast="_bridgeAnythingToObjectiveC({expr})"),
    Box(name="Optional", cast="optional({expr})")
]
protocol_boxes = [
    Box(name="PublicProtocol"),
#    Box(name="FilePrivateProtocol"), # FIXME: Blocked by https://github.com/apple/swift/issues/45225 (rdar://28281488)
    Box(name="InternalProtocol"),
]

# Describes a base object that will be subject to a variety of casts
default_protocols = [
  "PublicProtocol",
  "InternalProtocol",
  # "FilePrivateProtocol" # FIXME: Blocked by https://github.com/apple/swift/issues/45225 (rdar://28281488)
]

class Contents:
  def __init__(self, name, constructor=None, extra_targets=[], hashable=True, roundtrips=True, protocols=default_protocols, objc_only=False):
    self.name = name
    self.constructor = constructor or "{name}()".format(name=name)
    self.objc_only = objc_only

    self.targets = ["Any"]
    self.targets.extend(protocols)
    self.targets.extend(extra_targets)
    if roundtrips:
      self.targets.append(self.name)

    self.boxes = []
    self.boxes.extend(all_boxes)
    self.boxes.extend([Box(name=n) for n in protocols])
    if hashable:
      self.boxes.append(anyHashableBox)

contents = [
  Contents(name="StructInt",
    # extra_targets=["StructInt?"],
  ),
  Contents(name="StructInt?",
    constructor="Optional<StructInt>.some(StructInt())",
    extra_targets=["StructInt"],
    roundtrips=False, # Compiler bug rejects roundtrip cast T? => Any => T?
  ),
  Contents(name="ClassInt"),
  Contents(name="OCClassInt", objc_only=True),
  Contents(name="SingleCaseEnum"),
  Contents(name="TrivialPayloadEnum"),
  Contents(name="TrivialPayloadEnum"),
  Contents(name="MultiPayloadEnum"),
  Contents(name="StructInt.Type",
    constructor="StructInt.self",
    hashable=False,
    protocols=[],
  ),
  Contents(name="StructInt.Type?",
    constructor="Optional<StructInt.Type>.some(StructInt.self)",
    hashable=False,
    protocols=[],
    extra_targets=["StructInt.Type"],
    roundtrips=False, # Compiler bug rejects roundtrip cast T? => Any => T?
  ),
  Contents(name="ClassInt.Type",
    constructor="ClassInt.self",
    hashable=False,
    protocols=[],
  ),
  Contents(name="PublicProtocol.Protocol",
    constructor="PublicProtocol.self",
    hashable=False,
    protocols=[],
  ),
]

# Code below generates a separate test case for each combination of content,
# target type, and one or more box/intermediate types.
}%

% for content in contents:
%   if content.objc_only:
#if _runtime(_ObjC)
%   end
%   for target in content.targets:
%     for box in content.boxes:
%       nextTestNumber()
BoxingCasts.test("${testFunctionName()}(): Casting ${box.name}(${content.name}) to ${target}") {
  // TODO: Selectively enable/disable cases that work with earlier stdlib
  if #available(SwiftStdlib 5.5, *) {
    ${testFunctionName()}()
  }
}
func ${testFunctionName()}() {
  let a = ${content.constructor}
  let b = ${box.cast_oper("a")}
%       # // Skip trivial cast from T? to T
%       if not (content.name == target and box.name == "Optional"):
%         # // Skip trivial cast from protocol box to protocol
%         if box.name != target:
%           # // Skip trivial cast from T? => P
%           if not (target.endswith("Protocol") and box.name == "Optional"):
  let c = /* ${box.name}(${content.name})) */ b as? ${target}
  expectNotNil(c)
%           end
%         end
%       end
  let d = runtimeCast(/* ${box.name}(${content.name}) */ b, to: ${target}.self)
  expectNotNil(d)
}

%       for innerBox in [random.choice(content.boxes)]:
%         nextTestNumber()
BoxingCasts.test("${testFunctionName()}(): Casting ${box.name}(${innerBox.name}(${content.name})) to ${target}") {
  // TODO: Selectively enable/disable cases that work with earlier stdlib
  if #available(SwiftStdlib 5.5, *) {
    ${testFunctionName()}()
  }
}
func ${testFunctionName()}() {
  let a = ${content.constructor}
  let b = ${innerBox.cast_oper("a")}
  let c = ${box.cast_oper("b")}
%         # // Skip trivial cast from T? to T
%         if not (innerBox.name == target and box.name == "Optional"):
%           # // Skip trivial cast from protocol box to protocol
%           if box.name != target:
  let d = /* ${box.name}(${innerBox.name}(${content.name})) */ c as? ${target}
  expectNotNil(d)
%           end
%         end
  let e = runtimeCast(/* ${box.name}(${innerBox.name}(${content.name})) */ c, to: ${target}.self)
  expectNotNil(e)
}
%       end
%     end
%   end
%   if content.objc_only:
#endif
%   end
% end

runAllTests()