//===-- ExtractVariableTests.cpp --------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "TweakTesting.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

namespace clang {
namespace clangd {
namespace {

TWEAK_TEST(ExtractVariable);

TEST_F(ExtractVariableTest, Test) {
  const char *AvailableCases = R"cpp(
    int xyz(int a = 1) {
      struct T {
        int bar(int a = 1);
        int z;
      } t;
      // return statement
      return [[[[t.b[[a]]r]]([[t.z]])]];
    }
    void f() {
      int a = [[5 +]] [[4 * [[[[xyz]]()]]]];
      // multivariable initialization
      if(1)
        int x = [[1]], y = [[a + 1]], a = [[1]], z = a + 1;
      // if without else
      if([[1]])
        a = [[1]] + 1;
      // if with else
      if(a < [[3]])
        if(a == [[4]])
          a = [[5]] + 1;
        else
          a = [[5]] + 1;
      else if (a < [[4]])
        a = [[4]] + 1;
      else
        a = [[5]] + 1;
      // for loop
      for(a = [[1]] + 1; a > [[[[3]] + [[4]]]]; a++)
        a = [[2]] + 1;
      // while
      while(a < [[1]])
        a = [[1]] + 1;
      // do while
      do
        a = [[1]] + 1;
      while(a < [[3]]);
    }
  )cpp";
  EXPECT_AVAILABLE(AvailableCases);

  ExtraArgs = {"-xc"};
  const char *AvailableC = R"cpp(
    void foo() {
      int x = [[1]];
    })cpp";
  EXPECT_AVAILABLE(AvailableC);
  ExtraArgs = {"-xobjective-c"};
  const char *AvailableObjC = R"cpp(
    __attribute__((objc_root_class))
    @interface Foo
    @end
    @implementation Foo
    - (void)method {
      int x = [[1 + 2]];
    }
    @end)cpp";
  EXPECT_AVAILABLE(AvailableObjC);
  ExtraArgs = {};

  const char *NoCrashCases = R"cpp(
    // error-ok: broken code, but shouldn't crash
    template<typename T, typename ...Args>
    struct Test<T, Args...> {
    Test(const T &v) :val[[(^]]) {}
      T val;
    };
  )cpp";
  EXPECT_UNAVAILABLE(NoCrashCases);

  const char *UnavailableCases = R"cpp(
    int xyz(int a = [[1]]) {
      struct T {
        int bar(int a = [[1]]) {
          int b = [[z]];
        }
        int z = [[1]];
      } t;
      return [[t]].bar([[t]].z);
    }
    void v() { return; }
    // function default argument
    void f(int b = [[1]]) {
      // empty selection
      int a = ^1 ^+ ^2;
      // void expressions
      auto i = new int, j = new int;
      [[[[delete i]], delete j]];
      [[v]]();
      // if
      if(1)
        int x = 1, y = a + 1, a = 1, z = [[a + 1]];
      if(int a = 1)
        if([[a + 1]] == 4)
          a = [[[[a]] +]] 1;
      // for loop
      for(int a = 1, b = 2, c = 3; a > [[b + c]]; [[a++]])
        a = [[a + 1]];
      // lambda
      auto lamb = [&[[a]], &[[b]]](int r = [[1]]) {return 1;};
      // assignment
      xyz([[a = 5]]);
      xyz([[a *= 5]]);
      // Variable DeclRefExpr
      a = [[b]];
      a = [[xyz()]];
      // statement expression
      [[xyz()]];
      while (a)
        [[++a]];
      // label statement
      goto label;
      label:
        a = [[1]];
    }
  )cpp";
  EXPECT_UNAVAILABLE(UnavailableCases);

  // vector of pairs of input and output strings
  std::vector<std::pair<std::string, std::string>> InputOutputs = {
      // extraction from variable declaration/assignment
      {R"cpp(void varDecl() {
                   int a = 5 * (4 + (3 [[- 1)]]);
                 })cpp",
       R"cpp(void varDecl() {
                   auto placeholder = (3 - 1); int a = 5 * (4 + placeholder);
                 })cpp"},
      // FIXME: extraction from switch case
      /*{R"cpp(void f(int a) {
               if(1)
                 while(a < 1)
                   switch (1) {
                       case 1:
                         a = [[1 + 2]];
                         break;
                       default:
                         break;
                   }
             })cpp",
       R"cpp(void f(int a) {
               auto placeholder = 1 + 2; if(1)
                 while(a < 1)
                   switch (1) {
                       case 1:
                         a = placeholder;
                         break;
                       default:
                         break;
                   }
             })cpp"},*/
      // Macros
      {R"cpp(#define PLUS(x) x++
                 void f(int a) {
                   int y = PLUS([[1+a]]);
                 })cpp",
       /*FIXME: It should be extracted like this.
        R"cpp(#define PLUS(x) x++
              void f(int a) {
                auto placeholder = 1+a; int y = PLUS(placeholder);
              })cpp"},*/
       R"cpp(#define PLUS(x) x++
                 void f(int a) {
                   auto placeholder = PLUS(1+a); int y = placeholder;
                 })cpp"},
      // ensure InsertionPoint isn't inside a macro
      {R"cpp(#define LOOP(x) while (1) {a = x;}
                 void f(int a) {
                   if(1)
                    LOOP(5 + [[3]])
                 })cpp",
       R"cpp(#define LOOP(x) while (1) {a = x;}
                 void f(int a) {
                   auto placeholder = 3; if(1)
                    LOOP(5 + placeholder)
                 })cpp"},
      {R"cpp(#define LOOP(x) do {x;} while(1);
                 void f(int a) {
                   if(1)
                    LOOP(5 + [[3]])
                 })cpp",
       R"cpp(#define LOOP(x) do {x;} while(1);
                 void f(int a) {
                   auto placeholder = 3; if(1)
                    LOOP(5 + placeholder)
                 })cpp"},
      // attribute testing
      {R"cpp(void f(int a) {
                    [ [gsl::suppress("type")] ] for (;;) a = [[1]] + 1;
                 })cpp",
       R"cpp(void f(int a) {
                    auto placeholder = 1; [ [gsl::suppress("type")] ] for (;;) a = placeholder + 1;
                 })cpp"},
      // MemberExpr
      {R"cpp(class T {
                   T f() {
                     return [[T().f()]].f();
                   }
                 };)cpp",
       R"cpp(class T {
                   T f() {
                     auto placeholder = T().f(); return placeholder.f();
                   }
                 };)cpp"},
      // Function DeclRefExpr
      {R"cpp(int f() {
                   return [[f]]();
                 })cpp",
       R"cpp(int f() {
                   auto placeholder = f(); return placeholder;
                 })cpp"},
      // FIXME: Wrong result for \[\[clang::uninitialized\]\] int b = [[1]];
      // since the attr is inside the DeclStmt and the bounds of
      // DeclStmt don't cover the attribute.

      // Binary subexpressions
      {R"cpp(void f() {
                   int x = 1 + [[2 + 3 + 4]] + 5;
                 })cpp",
       R"cpp(void f() {
                   auto placeholder = 2 + 3 + 4; int x = 1 + placeholder + 5;
                 })cpp"},
      {R"cpp(void f() {
                   int x = [[1 + 2 + 3]] + 4 + 5;
                 })cpp",
       R"cpp(void f() {
                   auto placeholder = 1 + 2 + 3; int x = placeholder + 4 + 5;
                 })cpp"},
      {R"cpp(void f() {
                   int x = 1 + 2 + [[3 + 4 + 5]];
                 })cpp",
       R"cpp(void f() {
                   auto placeholder = 3 + 4 + 5; int x = 1 + 2 + placeholder;
                 })cpp"},
      // Non-associative operations have no special support
      {R"cpp(void f() {
                   int x = 1 - [[2 - 3 - 4]] - 5;
                 })cpp",
       R"cpp(void f() {
                   auto placeholder = 1 - 2 - 3 - 4; int x = placeholder - 5;
                 })cpp"},
      // A mix of associative operators isn't associative.
      {R"cpp(void f() {
                   int x = 0 + 1 * [[2 + 3]] * 4 + 5;
                 })cpp",
       R"cpp(void f() {
                   auto placeholder = 1 * 2 + 3 * 4; int x = 0 + placeholder + 5;
                 })cpp"},
      // Overloaded operators are supported, we assume associativity
      // as if they were built-in.
      {R"cpp(struct S {
                   S(int);
                 };
                 S operator+(S, S);

                 void f() {
                   S x = S(1) + [[S(2) + S(3) + S(4)]] + S(5);
                 })cpp",
       R"cpp(struct S {
                   S(int);
                 };
                 S operator+(S, S);

                 void f() {
                   auto placeholder = S(2) + S(3) + S(4); S x = S(1) + placeholder + S(5);
                 })cpp"},
      // Don't try to analyze across macro boundaries
      // FIXME: it'd be nice to do this someday (in a safe way)
      {R"cpp(#define ECHO(X) X
                 void f() {
                   int x = 1 + [[ECHO(2 + 3) + 4]] + 5;
                 })cpp",
       R"cpp(#define ECHO(X) X
                 void f() {
                   auto placeholder = 1 + ECHO(2 + 3) + 4; int x = placeholder + 5;
                 })cpp"},
      {R"cpp(#define ECHO(X) X
                 void f() {
                   int x = 1 + [[ECHO(2) + ECHO(3) + 4]] + 5;
                 })cpp",
       R"cpp(#define ECHO(X) X
                 void f() {
                   auto placeholder = 1 + ECHO(2) + ECHO(3) + 4; int x = placeholder + 5;
                 })cpp"},
  };
  for (const auto &IO : InputOutputs) {
    EXPECT_EQ(IO.second, apply(IO.first)) << IO.first;
  }

  ExtraArgs = {"-xc"};
  InputOutputs = {
      // Function Pointers
      {R"cpp(struct Handlers {
               void (*handlerFunc)(int);
             };
             void runFunction(void (*func)(int)) {}
             void f(struct Handlers *handler) {
               runFunction([[handler->handlerFunc]]);
             })cpp",
       R"cpp(struct Handlers {
               void (*handlerFunc)(int);
             };
             void runFunction(void (*func)(int)) {}
             void f(struct Handlers *handler) {
               void (*placeholder)(int) = handler->handlerFunc; runFunction(placeholder);
             })cpp"},
      {R"cpp(int (*foo(char))(int);
             void bar() {
               (void)[[foo('c')]];
             })cpp",
       R"cpp(int (*foo(char))(int);
             void bar() {
               int (*placeholder)(int) = foo('c'); (void)placeholder;
             })cpp"},
      // Arithmetic on typedef types preserves typedef types
      {R"cpp(typedef long NSInteger;
             void varDecl() {
                NSInteger a = 2 * 5;
                NSInteger b = [[a * 7]] + 3;
             })cpp",
       R"cpp(typedef long NSInteger;
             void varDecl() {
                NSInteger a = 2 * 5;
                NSInteger placeholder = a * 7; NSInteger b = placeholder + 3;
             })cpp"},
  };
  for (const auto &IO : InputOutputs) {
    EXPECT_EQ(IO.second, apply(IO.first)) << IO.first;
  }

  ExtraArgs = {"-xobjective-c"};
  EXPECT_UNAVAILABLE(R"cpp(
      __attribute__((objc_root_class))
      @interface Foo
      - (void)setMethod1:(int)a;
      - (int)method1;
      @property int prop1;
      @end
      @implementation Foo
      - (void)method {
        [[self.method1]] = 1;
        [[self.method1]] += 1;
        [[self.prop1]] = 1;
        [[self.prop1]] += 1;
      }
      @end)cpp");
  InputOutputs = {
      // Support ObjC property references (explicit property getter).
      {R"cpp(__attribute__((objc_root_class))
             @interface Foo
             @property int prop1;
             @end
             @implementation Foo
             - (void)method {
               int x = [[self.prop1]] + 1;
             }
             @end)cpp",
       R"cpp(__attribute__((objc_root_class))
             @interface Foo
             @property int prop1;
             @end
             @implementation Foo
             - (void)method {
               int placeholder = self.prop1; int x = placeholder + 1;
             }
             @end)cpp"},
      // Support ObjC property references (implicit property getter).
      {R"cpp(__attribute__((objc_root_class))
             @interface Foo
             - (int)method1;
             @end
             @implementation Foo
             - (void)method {
               int x = [[self.method1]] + 1;
             }
             @end)cpp",
       R"cpp(__attribute__((objc_root_class))
             @interface Foo
             - (int)method1;
             @end
             @implementation Foo
             - (void)method {
               int placeholder = self.method1; int x = placeholder + 1;
             }
             @end)cpp"},
  };
  for (const auto &IO : InputOutputs) {
    EXPECT_EQ(IO.second, apply(IO.first)) << IO.first;
  }
}

} // namespace
} // namespace clangd
} // namespace clang