//===--- Index.swift.gyb - tests for Index types and operations -----------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
// -*- swift -*-
// RUN: rm -rf %t ; mkdir -p %t
// RUN: %S/../../utils/gyb %s -o %t/Index.swift
// RUN: %S/../../utils/line-directive %t/Index.swift -- %target-build-swift %t/Index.swift -o %t/a.out
// RUN: %S/../../utils/line-directive %t/Index.swift -- %target-run %t/a.out
// REQUIRES: executable_test

import StdlibUnittest
import StdlibCollectionUnittest

// Also import modules which are used by StdlibUnittest internally. This
// workaround is needed to link all required libraries in case we compile
// StdlibUnittest with -sil-serialize-all.
import SwiftPrivate
#if _runtime(_ObjC)
import ObjectiveC
#endif

struct DistanceToTest {
  let startIndex: Int
  let endIndex: Int
  let expectedDistance: Int
  let loc: SourceLoc

  init(
    startIndex: Int, endIndex: Int, expectedDistance: Int,
    file: String = #file, line: UInt = #line
  ) {
    self.startIndex = startIndex
    self.endIndex = endIndex
    self.expectedDistance = expectedDistance
    self.loc = SourceLoc(file, line, comment: "distance(to:) test data")
  }
}

struct AdvancedByTest {
  let startIndex: Int
  let distance: Int
  let limit: Int?
  let expectedIndex: Int
  let loc: SourceLoc
  init(
    startIndex: Int, distance: Int, expectedIndex: Int,
    limit: Int? = nil,
    file: String = #file, line: UInt = #line
  ) {
    self.startIndex = startIndex
    self.distance = distance
    self.expectedIndex = expectedIndex
    self.limit = limit
    self.loc = SourceLoc(file, line, comment: "advanced(by:) test data")
  }
}

let distanceToTests = [
  DistanceToTest(
    startIndex: 0,
    endIndex: 0,
    expectedDistance: 0
  ),
  DistanceToTest(
    startIndex: 10,
    endIndex: 10,
    expectedDistance: 0
  ),
  DistanceToTest(
    startIndex: 10,
    endIndex: 13,
    expectedDistance: 3
  ),
  DistanceToTest(
    startIndex: 7,
    endIndex: 10,
    expectedDistance: 3
  ),
]

let advancedByTests = [
  AdvancedByTest(
    startIndex: 0,
    distance: 0,
    expectedIndex: 0
  ),
  AdvancedByTest(
    startIndex: 0,
    distance: -1,
    expectedIndex: -1
  ),
  AdvancedByTest(
    startIndex: 0,
    distance: 0,
    expectedIndex: 0,
    limit: 0
  ),
  AdvancedByTest(
    startIndex: 0,
    distance: 0,
    expectedIndex: 0,
    limit: 10
  ),
  AdvancedByTest(
    startIndex: 0,
    distance: 10,
    expectedIndex: 0,
    limit: 0
  ),
  AdvancedByTest(
    startIndex: 0,
    distance: -10,
    expectedIndex: 0,
    limit: 0
  ),
  AdvancedByTest(
    startIndex: 0,
    distance: 10,
    expectedIndex: 10,
    limit: 10
  ),
  AdvancedByTest(
    startIndex: 0,
    distance: 20,
    expectedIndex: 10,
    limit: 10
  ),
  AdvancedByTest(
    startIndex: 10,
    distance: -20,
    expectedIndex: 0,
    limit: 0
  ),
]

var Index = TestSuite("Index")

% for Traversal in ['Forward', 'Bidirectional', 'RandomAccess']:

Index.test("${Traversal}Index/distance(to:)/dispatch") {
  var start = ${Traversal}IndexLog.dispatchTester(0)
  var end = ${Traversal}IndexLog.dispatchTester(10)
  _ = start.distance(to: end)
  expectCustomizable(start, start.log.distanceTo)
}

Index.test("${Traversal}Index/advanced(by:)/dispatch") {
  var start = ${Traversal}IndexLog.dispatchTester(0)
  _ = start.advanced(by: 10)
  expectCustomizable(start, start.log.advancedBy)
}

Index.test("${Traversal}Index/advanced(by: n, limit:)/dispatch") {
  let start = ${Traversal}IndexLog.dispatchTester(0)
  let limit = ${Traversal}IndexLog.dispatchTester(5)
  _ = start.advanced(by: 10, limit: limit)
  expectCustomizable(start, start.log.advancedByWithLimit)
}

%   for Base in ['Minimal', 'Defaulted']:
%     Kind = '{}{}'.format(Base, Traversal)

Index.test("${Kind}Index/distance(to:)/semantics") {
  for test in distanceToTests {
    let start = ${Kind}Index(
      position: test.startIndex,
      startIndex: -20,
      endIndex: 20)
    let end = ${Kind}Index(
      position: test.endIndex,
      startIndex: -20,
      endIndex: 20)
    let d = start.distance(to: end)
    expectEqual(test.expectedDistance, d,
      stackTrace: SourceLocStack().with(test.loc))
  }
}

Index.test("${Kind}Index/advanced(by: n)/semantics") {
  for test in advancedByTests.filter({$0.limit == nil}) {
    let start = ${Kind}Index(
      position: test.startIndex,
      startIndex: -20,
      endIndex: 20)
    let expected = ${Kind}Index(
      position: test.expectedIndex,
      startIndex: -20,
      endIndex: 20)

%     if Traversal == 'Forward':

    if test.distance < 0 {
      // Negative distance trap tests are handled in
      // advanced(by:-n)/semantics
      continue
    }

%     end

    let new = start.advanced(by: test.distance)
    expectEqual(expected, new,
      stackTrace: SourceLocStack().with(test.loc))
  }
}

%     if Traversal == 'Forward':
Index.test("${Kind}Index/advanced(by: -n)/semantics") {
  for test in advancedByTests.filter({$0.limit == nil && $0.distance < 0}) {
    let start = ${Kind}Index(
      position: test.startIndex,
      startIndex: -20,
      endIndex: 20)
    let expected = ${Kind}Index(
      position: test.expectedIndex,
      startIndex: -20,
      endIndex: 20)
    expectCrashLater()
    let new = start.advanced(by: test.distance)
  }
}
%     end

%     if Traversal == 'Forward':
Index.test("${Kind}Index/advanced(by: -n, limit:)/semantics") {
  for test in advancedByTests.filter({$0.limit != nil && $0.distance < 0}) {
    let start = ${Kind}Index(
      position: test.startIndex,
      startIndex: -20,
      endIndex: 20)
    let expected = ${Kind}Index(
      position: test.expectedIndex,
      startIndex: -20,
      endIndex: 20)
    expectCrashLater()
    let new = start.advanced(by: test.distance)
  }
}
%     end

Index.test("${Kind}Index/advanced(by: n, limit:)/semantics") {
  for test in advancedByTests.filter({$0.limit != nil}) {
    let startIndex = test.startIndex
    let endIndex = test.startIndex + test.distance
    let start = ${Kind}Index(
      position: test.startIndex,
      startIndex: -20,
      endIndex: 20)
    let limit = ${Kind}Index(
      position: test.limit!,
      startIndex: -20,
      endIndex: 20)

%     if Traversal == 'Forward':

    if test.distance < 0 {
      expectCrashLater()
    }

%     end

    let new = start.advanced(by: test.distance, limit: limit)
    let expected = ${Kind}Index(
      position: test.expectedIndex,
      startIndex: -20,
      endIndex: 20)
    expectEqual(expected, new,
      stackTrace: SourceLocStack().with(test.loc))
  }
}

// Check that a random access index doesn't call into O(n) predecessor calls
// when it has a more efficient implementation.

%     if Traversal == 'RandomAccess' and Base == 'Defaulted':
Index.test(
  "${Kind}Index/advanced(by: n)/avoidsSuccessorAndPredecessor/dispatch"
) {
  for test in advancedByTests.filter({$0.limit == nil}) {
    let i = ${Kind}Index(test.startIndex)
    let result  = i.advanced(by: test.distance)
    expectEqual(test.expectedIndex, result.base)
    expectEqual(0, ${Kind}Index.timesSuccessorCalled.value)
    expectEqual(0, ${Kind}Index.timesPredecessorCalled.value)
  }
}

Index.test(
  "${Kind}Index/advanced(by: n, limit:)/avoidsSuccessorAndPredecessor/dispatch"
) {
  for test in advancedByTests.filter({$0.limit != nil}) {
    let i = ${Kind}Index(test.startIndex)
    let result  = i.advanced(by: test.distance, limit: ${Kind}Index(test.limit!))
    expectEqual(test.expectedIndex, result.base)
    expectEqual(0, ${Kind}Index.timesSuccessorCalled.value)
    expectEqual(0, ${Kind}Index.timesPredecessorCalled.value)
  }
}
%     end
%   end
% end

runAllTests()