//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// Basic round-trip tests for POSIX regex functions.
///
//===----------------------------------------------------------------------===//

#include "src/regex/regcomp.h"
#include "src/regex/regexec.h"
#include "src/regex/regfree.h"
#include "test/UnitTest/Test.h"

#include "hdr/regex_macros.h"
#include "hdr/types/regex_t.h"

TEST(LlvmLibcRegexTest, BasicLiteralRoundTrip) {
  regex_t preg;
  ASSERT_EQ(0,
            LIBC_NAMESPACE::regcomp(&preg, "hello", REG_EXTENDED | REG_NOSUB));
  ASSERT_EQ(0,
            LIBC_NAMESPACE::regexec(&preg, "say hello world", 0, nullptr, 0));
  ASSERT_EQ(REG_NOMATCH,
            LIBC_NAMESPACE::regexec(&preg, "goodbye", 0, nullptr, 0));
  LIBC_NAMESPACE::regfree(&preg);
}

TEST(LlvmLibcRegexTest, MismatchCases) {
  regex_t preg;
  // Partial match
  ASSERT_EQ(0,
            LIBC_NAMESPACE::regcomp(&preg, "hello", REG_EXTENDED | REG_NOSUB));
  ASSERT_EQ(REG_NOMATCH, LIBC_NAMESPACE::regexec(&preg, "hell", 0, nullptr, 0));
  LIBC_NAMESPACE::regfree(&preg);

  // Case sensitivity
  ASSERT_EQ(0,
            LIBC_NAMESPACE::regcomp(&preg, "Hello", REG_EXTENDED | REG_NOSUB));
  ASSERT_EQ(REG_NOMATCH,
            LIBC_NAMESPACE::regexec(&preg, "hello", 0, nullptr, 0));
  LIBC_NAMESPACE::regfree(&preg);

  // Empty string vs non-empty pattern
  ASSERT_EQ(0, LIBC_NAMESPACE::regcomp(&preg, "a", REG_EXTENDED | REG_NOSUB));
  ASSERT_EQ(REG_NOMATCH, LIBC_NAMESPACE::regexec(&preg, "", 0, nullptr, 0));
  LIBC_NAMESPACE::regfree(&preg);
}

TEST(LlvmLibcRegexTest, EmptyString) {
  regex_t preg;
  ASSERT_EQ(0, LIBC_NAMESPACE::regcomp(&preg, "", REG_EXTENDED | REG_NOSUB));
  ASSERT_EQ(0, LIBC_NAMESPACE::regexec(&preg, "anything", 0, nullptr, 0));
  ASSERT_EQ(0, LIBC_NAMESPACE::regexec(&preg, "", 0, nullptr, 0));
  LIBC_NAMESPACE::regfree(&preg);
}

TEST(LlvmLibcRegexTest, ExactMatch) {
  regex_t preg;
  ASSERT_EQ(0,
            LIBC_NAMESPACE::regcomp(&preg, "test", REG_EXTENDED | REG_NOSUB));
  ASSERT_EQ(0, LIBC_NAMESPACE::regexec(&preg, "test", 0, nullptr, 0));
  LIBC_NAMESPACE::regfree(&preg);
}

TEST(LlvmLibcRegexTest, NullByteStopsParsing) {
  regex_t preg;
  ASSERT_EQ(0,
            LIBC_NAMESPACE::regcomp(&preg, "match", REG_EXTENDED | REG_NOSUB));
  ASSERT_EQ(REG_NOMATCH,
            LIBC_NAMESPACE::regexec(&preg, "doesn't \0 match", 0, nullptr, 0));
  LIBC_NAMESPACE::regfree(&preg);
}