/*
    CUTest - A unit test runner for C
    Copyright (C) 2022 Pascal Baillehache baillehache.pascal@gmail.com
    https://baillehachepascal.dev
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.
    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <stddef.h>
#include <time.h>

// Conversion from macro to string
#define CUTEST_TO_STR_(x) #x
#define CUTEST_TO_STR(x) CUTEST_TO_STR_(x)

// Escape sequence to colorize the output
#define CUTEST_START_RED "\033[38;2;255;0;0m"
#define CUTEST_END_RED "\033[39m"
#define CUTEST_START_GREEN "\033[38;2;0;255;0m"
#define CUTEST_END_GREEN "\033[39m"
#define CUTEST_START_BOLD "\033[1m"
#define CUTEST_END_BOLD "\033[0m"

// Print current date and time
#define CUTEST_TIME \
  { time_t now = time(NULL); printf("%.19s\n", asctime(localtime(&now))); }

// Variables to memorise the number of tests and failed test
size_t cutestIdxTest;
size_t cutestNbTest;
size_t cutestNbTestFailed;
bool cutestTestSuccess;

// Wrapper for the test condition in the unit tests. To be used as follow:
// CUTEST_ASSERT(cond, msg, msg_arg1, msg_arg2, ...)
// where 'cond' is the condition to be respected by the test, and 'msg', etc...
// are the arguments passed to a 'printf' call in case the condition
// is not satisfy with the view to explain why the condition wasn't satisfied.
#define CUTEST_ASSERT(cond, ...)                                      \
  if(!(cond)) {                                                       \
    if(cutestTestSuccess)                                             \
      printf(CUTEST_START_RED "NG" CUTEST_END_RED "\n");              \
    printf(                                                           \
      CUTEST_START_RED " -- Unsatisfied condition on line %u:\n%s\n", \
      __LINE__, CUTEST_TO_STR(cond));                                 \
    printf("While:\n");                                               \
    printf(__VA_ARGS__);                                              \
    printf(CUTEST_END_RED "\n");                                      \
    cutestTestSuccess = false;                                        \
  }

// Print the OK result for a successful test and increase the counter of
// failed test for an unsuccessful test
#define CUTEST_OK                                                \
  if(cutestTestSuccess) {                                        \
    printf(CUTEST_START_GREEN "OK" CUTEST_END_GREEN "\n");       \
  } else {                                                       \
    ++cutestNbTestFailed;                                        \
  }

// Unit tests declarations macro. To be used in the unit tests file as follow:
// CUTEST(test002, "Second unit test") {
//   int a = 2;
//   a *= a;
//   CUTEST_ASSERT(a == 4, "a equals to %d", a);
// }
#define CUTEST(name, lbl) void name(void)
#include CUTEST_TO_STR(CUTEST_FILE)

// Helper function to print and pad the label of the executed tests
void CutestPrintLbl(char const* const lbl) {
  size_t length = strlen(lbl);
  size_t lengthMax = 80;
  printf("%03lu/%03lu ", cutestIdxTest, cutestNbTest);
  size_t i = 0;
  for(; i < length; ++i) {
    if(i > 0 && (i % lengthMax) == 0) printf("\n        ");
    printf("%c", lbl[i]);
  }
  i %= lengthMax;
  if(i != 0) for(; i < lengthMax; ++i) printf(".");
  printf(" ");
  fflush(stdout);
}

// Main function
int main(int argc, char** argv) {

  // Variable to memorise the unit test to be executed
  // (if null, all are executed)
  char* nameTestToExecute = NULL;
  for(int iArg = 0; iArg < argc; ++iArg) {
    if(strcmp(argv[iArg], "-t") == 0 && (iArg + 1) < argc)
      nameTestToExecute = argv[iArg + 1];
  }

  // Print the unit test file name and start time
  printf(
    CUTEST_START_BOLD "\n  ==== %s ====" CUTEST_END_BOLD "\n",
    CUTEST_TO_STR(CUTEST_FILE));
  CUTEST_TIME

  // Init the counters
  cutestIdxTest = 0;
  cutestNbTest = 0;
  cutestNbTestFailed = 0;

  // Calculate the number of test
  #undef CUTEST
  #define CUTEST(name, lbl)                               \
    if(                                                   \
      nameTestToExecute == NULL ||                        \
      strcmp(nameTestToExecute, CUTEST_TO_STR(name)) == 0 \
    ) {                                                   \
      ++cutestNbTest;                                     \
    } if(0)
  #include CUTEST_TO_STR(CUTEST_FILE)

  // Unit tests call
  #undef CUTEST
  #define CUTEST(name, lbl)                               \
    if(                                                   \
      nameTestToExecute == NULL ||                        \
      strcmp(nameTestToExecute, CUTEST_TO_STR(name)) == 0 \
    ) {                                                   \
      ++cutestIdxTest; cutestTestSuccess = true;          \
      CutestPrintLbl(lbl); name(); CUTEST_OK              \
    }                                                     \
    if(0)
  #include CUTEST_TO_STR(CUTEST_FILE)

  // Variable to memorise the returned code
  int ret = 0;

  // Print a summary
  if(cutestNbTestFailed == 0) {
    printf(
      CUTEST_START_GREEN "All tests succeeded." CUTEST_END_GREEN "\n");
    ret = EXIT_SUCCESS;
  } else {
    printf(
      CUTEST_START_RED "%03lu/%03lu test(s) failed." CUTEST_END_RED "\n",
      cutestNbTestFailed, cutestNbTest);
    ret = EXIT_FAILURE;
  }

  // Print the end time and return the exit code
  CUTEST_TIME
  return ret;
}

// Example of Makefile:
// test:
//   for file in `ls UnitTests/test_*.c`; do
//   gcc -o cutest cutest.c -DCUTEST_FILE=$$file && cutest; \rm -f cutest; done
//
// To execute only the unit test 'test002', you can use:
// cutest -t test002