#include "swift/Basic/LangOptions.h"
#include "swift/Basic/SourceManager.h"
#include "swift/Parse/Lexer.h"
#include "swift/Subsystems.h"
#include "llvm/Support/MemoryBuffer.h"
#include "gtest/gtest.h"

using namespace swift;
using namespace swift::syntax;
using namespace llvm;

class LexerTriviaTest : public ::testing::Test {};

TEST_F(LexerTriviaTest, RestoreWithTrivia) {
  using namespace swift::syntax;
  StringRef SourceStr = "aaa \n bbb /*C*/ccc";

  LangOptions LangOpts;
  SourceManager SourceMgr;
  unsigned BufferID = SourceMgr.addMemBufferCopy(SourceStr);

  Lexer L(LangOpts, SourceMgr, BufferID, /*Diags=*/nullptr, /*InSILMode=*/false,
          CommentRetentionMode::AttachToNextToken,
          TriviaRetentionMode::WithTrivia);

  Token Tok;
  Trivia LeadingTrivia, TrailingTrivia;

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("aaa", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ(LeadingTrivia, Trivia());
  ASSERT_EQ(TrailingTrivia, (Trivia{{TriviaPiece::spaces(1)}}));

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("bbb", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ(LeadingTrivia,
            (Trivia{{TriviaPiece::newlines(1), TriviaPiece::spaces(1)}}));
  ASSERT_EQ(TrailingTrivia, (Trivia{{TriviaPiece::spaces(1)}}));

  LexerState S = L.getStateForBeginningOfToken(Tok, LeadingTrivia);

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("ccc", Tok.getText());
  ASSERT_FALSE(Tok.isAtStartOfLine());
  ASSERT_EQ(LeadingTrivia, (Trivia{{TriviaPiece::blockComment("/*C*/")}}));
  ASSERT_EQ(TrailingTrivia, Trivia());

  L.restoreState(S);
  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("bbb", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ(LeadingTrivia,
            (Trivia{{TriviaPiece::newlines(1), TriviaPiece::spaces(1)}}));
  ASSERT_EQ(TrailingTrivia, (Trivia{{TriviaPiece::spaces(1)}}));
}

TEST_F(LexerTriviaTest, TriviaHashbang) {
  StringRef SourceStr = "#!/bin/swift\naaa";

  LangOptions LangOpts;
  SourceManager SourceMgr;
  unsigned BufferID = SourceMgr.addMemBufferCopy(SourceStr);

  Lexer L(LangOpts, SourceMgr, BufferID, /*Diags=*/nullptr, /*InSILMode=*/false,
          CommentRetentionMode::AttachToNextToken,
          TriviaRetentionMode::WithTrivia);

  Token Tok;
  Trivia LeadingTrivia, TrailingTrivia;
  L.lex(Tok, LeadingTrivia, TrailingTrivia);

  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("aaa", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ(LeadingTrivia,
            (Trivia{{TriviaPiece::garbageText("#!/bin/swift"),
                     TriviaPiece::newlines(1)}}));
}

TEST_F(LexerTriviaTest, TriviaHashbangAfterBOM) {
  StringRef SourceStr = "\xEF\xBB\xBF" "#!/bin/swift\naaa";

  LangOptions LangOpts;
  SourceManager SourceMgr;
  unsigned BufferID = SourceMgr.addMemBufferCopy(SourceStr);

  Lexer L(LangOpts, SourceMgr, BufferID, /*Diags=*/nullptr, /*InSILMode=*/false,
          CommentRetentionMode::AttachToNextToken,
          TriviaRetentionMode::WithTrivia);

  Token Tok;
  Trivia LeadingTrivia, TrailingTrivia;
  L.lex(Tok, LeadingTrivia, TrailingTrivia);

  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("aaa", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());

  // FIXME: This should include UTF8-BOM as a GarbargeText trivia.
  ASSERT_EQ(LeadingTrivia,
            (Trivia{{TriviaPiece::garbageText("#!/bin/swift"),
                     TriviaPiece::newlines(1)}}));
}

TEST_F(LexerTriviaTest, TriviaConflictMarker) {
  using namespace swift::syntax;
  StringRef SourceStr =
      "aaa\n"
      "<<<<<<< HEAD:conflict_markers.swift\n"
      "new\n"
      "=======\n"
      "old\n"
      ">>>>>>> 18844bc65229786b96b89a9fc7739c0f:conflict_markers.swift\n"
      "bbb\n";

  LangOptions LangOpts;
  SourceManager SourceMgr;
  unsigned BufferID = SourceMgr.addMemBufferCopy(SourceStr);

  Lexer L(LangOpts, SourceMgr, BufferID, /*Diags=*/nullptr, /*InSILMode=*/false,
          CommentRetentionMode::AttachToNextToken,
          TriviaRetentionMode::WithTrivia);

  Token Tok;
  Trivia LeadingTrivia, TrailingTrivia;

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("aaa", Tok.getText());

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("bbb", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  StringRef expectedTrivia =
      "<<<<<<< HEAD:conflict_markers.swift\n"
      "new\n"
      "=======\n"
      "old\n"
      ">>>>>>> 18844bc65229786b96b89a9fc7739c0f:conflict_markers.swift";
  ASSERT_EQ(LeadingTrivia, (Trivia{{TriviaPiece::newlines(1),
                                    TriviaPiece::garbageText(expectedTrivia),
                                    TriviaPiece::newlines(1)}}));
}

TEST_F(LexerTriviaTest, TriviaCarriageReturn) {
  using namespace swift::syntax;
  StringRef SourceStr = "aaa\r\rbbb\r";

  LangOptions LangOpts;
  SourceManager SourceMgr;
  unsigned BufferID = SourceMgr.addMemBufferCopy(SourceStr);

  Lexer L(LangOpts, SourceMgr, BufferID, /*Diags=*/nullptr, /*InSILMode=*/false,
          CommentRetentionMode::AttachToNextToken,
          TriviaRetentionMode::WithTrivia);

  Token Tok;
  Trivia LeadingTrivia, TrailingTrivia;

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("aaa", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ(LeadingTrivia, Trivia());
  ASSERT_EQ(TrailingTrivia, Trivia());

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("bbb", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ(LeadingTrivia, (Trivia{{TriviaPiece::carriageReturns(2)}}));
  ASSERT_EQ(TrailingTrivia, Trivia());

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::eof, Tok.getKind());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ(LeadingTrivia, (Trivia{{TriviaPiece::carriageReturns(1)}}));
  ASSERT_EQ(TrailingTrivia, Trivia());
}

TEST_F(LexerTriviaTest, TriviaNewLines) {
  using namespace swift::syntax;
  StringRef SourceStr = "\n\r\r\n\r\r\r\n\r\n\n\n"
                        "aaa"
                        "\n\r\r\n\r\r\r\n\r\n\n\n"
                        "bbb"
                        "\n\r\r\n\r\r\r\n\r\n\n\n";

  LangOptions LangOpts;
  SourceManager SourceMgr;
  unsigned BufferID = SourceMgr.addMemBufferCopy(SourceStr);

  Lexer L(LangOpts, SourceMgr, BufferID, /*Diags=*/nullptr, /*InSILMode=*/false,
          CommentRetentionMode::AttachToNextToken,
          TriviaRetentionMode::WithTrivia);

  Token Tok;
  Trivia LeadingTrivia, TrailingTrivia;

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("aaa", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ((Trivia{{
    TriviaPiece::newlines(1),
    TriviaPiece::carriageReturns(1),
    TriviaPiece::carriageReturnLineFeeds(1),
    TriviaPiece::carriageReturns(2),
    TriviaPiece::carriageReturnLineFeeds(2),
    TriviaPiece::newlines(2)
  }}), LeadingTrivia);
  ASSERT_EQ(Trivia(), TrailingTrivia);

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::identifier, Tok.getKind());
  ASSERT_EQ("bbb", Tok.getText());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ((Trivia{{
    TriviaPiece::newlines(1),
    TriviaPiece::carriageReturns(1),
    TriviaPiece::carriageReturnLineFeeds(1),
    TriviaPiece::carriageReturns(2),
    TriviaPiece::carriageReturnLineFeeds(2),
    TriviaPiece::newlines(2)
  }}), LeadingTrivia);
  ASSERT_EQ(Trivia(), TrailingTrivia);

  L.lex(Tok, LeadingTrivia, TrailingTrivia);
  ASSERT_EQ(tok::eof, Tok.getKind());
  ASSERT_TRUE(Tok.isAtStartOfLine());
  ASSERT_EQ((Trivia{{
    TriviaPiece::newlines(1),
    TriviaPiece::carriageReturns(1),
    TriviaPiece::carriageReturnLineFeeds(1),
    TriviaPiece::carriageReturns(2),
    TriviaPiece::carriageReturnLineFeeds(2),
    TriviaPiece::newlines(2)
  }}), LeadingTrivia);
  ASSERT_EQ(Trivia(), TrailingTrivia);
}