/**
 * utest.h
 *   Sam's favorite unit testing macros.  Make sure to link your file
 *   with utest.o and the various *-utils.o.
 */

#ifndef __UTEST_H__
#define __UTEST_H__

// +---------+--------------------------------------------------------
// | Headers |
// +---------+

#include <stdio.h>      // For FILE 

#include "misc-utils.h"


// +--------+---------------------------------------------------------
// | Macros |
// +--------+

/**
 * Macro:
 *   CHECK
 * Parameters:
 *   EXPRESSION, an expression
 *   EXPECTED, another expression, preferably a constant
 *   TYPE, the type of the two expressions
 *   COMPARE, a function that compares two values of type TYPE
 *   PRINT, a function that prints values of type TYPE
 * Purpose:
 *   Evaluate EXPRESSION and ensure that its value matches EXPECTED.
 *   If not, report an error.
 * Produces:
 *   [Nothing; Called for the side effects.
 * Problems:
 *   If the evaluation or expression or expected would cause the program
 *   to crash, it crashes.  (Ideally, this would catch the error.)
 */
#define CHECK (EXPRESSION, EXPECTED, TYPE, COMPARE, PRINT)      \
  BLOCK (                                                       \
    utest_test (#EXPRESSION);                                   \
    TYPE _v1_ = EXPECTED;                                       \
    TYPE _v2_ = EXPRESSION;                                     \
    if (COMPARE (_v1_, _v2_) != 0)                              \
      {                                                         \
        utest_error (#EXPRESSION);                              \
        fprintf (stderr, "ERROR\n");                            \
        fprintf (stderr, "  Expression:  %s\n", expression);    \
        fprintf (stderr, "  Expected: ");                       \
        PRINT (stderr, _v1_);                                   \
        fprintf (stderr, "\n");                                 \
        fprintf (stderr, "  Result:   ");                       \
        PRINT (stderr, _v2_);                                   \
        fprintf (stderr, "\n");                                 \
      }                                                         \
  )

/**
 * Macros:
 *   CHECK_INT
 *   CHECK_INT_ARRAY
 *   CHECK_STRING
 *   CHECK_STRING_ARRAY
 * Parameters:
 *   EXPRESSION, an expression 
 *   EXPECTED, another expression
 * Purpose:
 *   Evaluate EXPRESSION and ensure that its value matches EXPECTED.
 *   If not, report an error.
 * Produces:
 *   [Nothing; Called for the side effects.]
 * Philosophy:
 *   Easier to read (and use) versions of CHECK.
 */
#define CHECK_INT(EXPRESSION, EXPECTED) \
  CHECK (EXPRESSION, EXPECTED, int, int_compare, int_fprint)

#define CHECK_INT_ARRAY(EXPRESSION, EXPECTED) \
  CHECK (EXPRESSION, EXPECTED, int *, int_array_compare, int_array_fprint)

#define CHECK_STRING(EXPRESSION, EXPECTED) \
  CHECK (EXPRESSION, EXPECTED, char *, string_compare, string_fprint)

#define CHECK_STRING_ARRAY(EXPRESSION, EXPECTED) \
  CHECK (EXPRESSION, EXPECTED, char **, string_array_compare, string_array_fprint)


// +-----------+------------------------------------------------------
// | Functions |
// +-----------+

/**
 * Procedure:
 *   utest_count
 * Parameters:
 *   [None]
 * Purpose:
 *   Determine how many errors have been encountered so far.
 * Produces:
 *   errors, an integer.
 */
int utest_count (void);

/**
 * Procedure:
 *   utest_error
 * Parameters:
 *   expression, a string
 * Purpose:
 *   Reports that the evaluation of expression gave an unexpected result.
 * Produces:
 *   [Nothing; Called for the side effect]
 */
void utest_error (char *expression);

/**
 * Procedure:
 *   utest_report
 * Parameters:
 *   fp, a FILE *
 * Purpose:
 *   Report on the errors encountered.
 * Produces:
 *   [Nothing; Called for the side effect]
 */
void utest_report (FILE *fp);

/**
 * Procedure:
 *   utest_reset
 * Parameters:
 *   [None]
 * Purpose:
 *   Reset testing.
 * Produces:
 *   [Nothing; Called for the side effect.]
 */
void utest_reset ();

/**
 * Procedure:
 *   utest_test
 * Parameters:
 *   test, a string
 * Purpose:
 *   Note that a test that is about to be conducted.
 * Produces:
 *   [Nothing; Called for the side effect.]
 */
void utest_test (char *test);

#endif // __UTEST_H__