#include "../../unity/unity.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

/* Unity setup/teardown */
void setUp(void) {
  /* Reset key globals to a known state before each test */
  in_column = 0;
  tabs = false;
}

void tearDown(void) {
  /* Nothing to cleanup */
}

/* Helper to create a tmp file with content s, rewound for reading */
static FILE* make_tmp_with(const char* s) {
  FILE* f = tmpfile();
  TEST_ASSERT_NOT_NULL(f);
  if (s && *s) {
    size_t len = strlen(s);
    TEST_ASSERT_EQUAL_size_t(len, fwrite(s, 1, len, f));
  }
  rewind(f);
  return f;
}

/* 1) Non-blank initial character: should return c, not change in_column or tabs, and not consume further. */
static void test_get_space_nonblank_initial(void) {
  FILE* f = make_tmp_with("A");
  int first = getc(f);
  TEST_ASSERT_EQUAL_INT('A', first);

  in_column = 5;
  tabs = false;

  int r = get_space(f, first);
  TEST_ASSERT_EQUAL_INT('A', r);
  TEST_ASSERT_EQUAL_INT(5, in_column);
  TEST_ASSERT_FALSE(tabs);

  /* Next char should be EOF because only 'A' was present and already consumed before call */
  int next = getc(f);
  TEST_ASSERT_EQUAL_INT(EOF, next);

  fclose(f);
}

/* 2) Spaces then non-blank: should consume spaces, update in_column, return first non-blank, and consume it. */
static void test_get_space_spaces_then_nonblank(void) {
  FILE* f = make_tmp_with("    XZ"); /* 4 spaces, 'X', 'Z' */
  int first = getc(f);
  TEST_ASSERT_EQUAL_INT(' ', first);

  in_column = 0;
  tabs = false;

  int r = get_space(f, first);
  TEST_ASSERT_EQUAL_INT('X', r);
  TEST_ASSERT_EQUAL_INT(4, in_column);
  TEST_ASSERT_FALSE(tabs);

  /* X has been consumed by get_space; next should be 'Z' */
  int next = getc(f);
  TEST_ASSERT_EQUAL_INT('Z', next);

  fclose(f);
}

/* 3) Tabs and spaces mixed with non-zero initial in_column: verify tab stops and tabs flag. */
static void test_get_space_tabs_and_spaces_mixed_initial_incol(void) {
  FILE* f = make_tmp_with("\t\t  XZ"); /* tab, tab, space, space, 'X', 'Z' */
  int first = getc(f);
  TEST_ASSERT_EQUAL_INT('\t', first);

  in_column = 3; /* Start not on tab stop */
  tabs = false;

  int r = get_space(f, first);
  TEST_ASSERT_EQUAL_INT('X', r);

  /* Computation:
     start 3
     '\t' -> 8
     '\t' -> 16
     ' '  -> 17
     ' '  -> 18
  */
  TEST_ASSERT_EQUAL_INT(18, in_column);
  TEST_ASSERT_TRUE(tabs);

  /* 'X' consumed; next should be 'Z' */
  int next = getc(f);
  TEST_ASSERT_EQUAL_INT('Z', next);

  fclose(f);
}

/* 4) Only spaces to EOF: should return EOF and update in_column accordingly, tabs remains false. */
static void test_get_space_only_spaces_to_eof(void) {
  FILE* f = make_tmp_with("   "); /* three spaces, then EOF */
  int first = getc(f);
  TEST_ASSERT_EQUAL_INT(' ', first);

  in_column = 10;
  tabs = false;

  int r = get_space(f, first);
  TEST_ASSERT_EQUAL_INT(EOF, r);
  TEST_ASSERT_EQUAL_INT(13, in_column);
  TEST_ASSERT_FALSE(tabs);

  /* Stream should now be at EOF */
  int next = getc(f);
  TEST_ASSERT_EQUAL_INT(EOF, next);

  fclose(f);
}

/* 5) Initial EOF: should return EOF without changing state or reading. */
static void test_get_space_initial_eof(void) {
  FILE* f = make_tmp_with(""); /* empty file */

  in_column = 7;
  tabs = false;

  int r = get_space(f, EOF);
  TEST_ASSERT_EQUAL_INT(EOF, r);
  TEST_ASSERT_EQUAL_INT(7, in_column);
  TEST_ASSERT_FALSE(tabs);

  int next = getc(f);
  TEST_ASSERT_EQUAL_INT(EOF, next);

  fclose(f);
}

/* 6) Newline treated as non-blank: should return '\n' immediately, no changes to in_column or tabs. */
static void test_get_space_newline_nonblank(void) {
  FILE* f = make_tmp_with("\nA");
  int first = getc(f);
  TEST_ASSERT_EQUAL_INT('\n', first);

  in_column = 2;
  tabs = false;

  int r = get_space(f, first);
  TEST_ASSERT_EQUAL_INT('\n', r);
  TEST_ASSERT_EQUAL_INT(2, in_column);
  TEST_ASSERT_FALSE(tabs);

  int next = getc(f);
  TEST_ASSERT_EQUAL_INT('A', next);

  fclose(f);
}

/* 7) Tab when at a tab stop boundary: should advance to next tab stop correctly. */
static void test_get_space_tab_at_tabstop(void) {
  FILE* f = make_tmp_with("\tY");
  int first = getc(f);
  TEST_ASSERT_EQUAL_INT('\t', first);

  in_column = 8; /* at a tab stop already */
  tabs = false;

  int r = get_space(f, first);
  TEST_ASSERT_EQUAL_INT('Y', r);
  TEST_ASSERT_EQUAL_INT(16, in_column);
  TEST_ASSERT_TRUE(tabs);

  int next = getc(f);
  TEST_ASSERT_EQUAL_INT(EOF, next); /* after 'Y', file ends */

  fclose(f);
}

int main(void) {
  UNITY_BEGIN();

  RUN_TEST(test_get_space_nonblank_initial);
  RUN_TEST(test_get_space_spaces_then_nonblank);
  RUN_TEST(test_get_space_tabs_and_spaces_mixed_initial_incol);
  RUN_TEST(test_get_space_only_spaces_to_eof);
  RUN_TEST(test_get_space_initial_eof);
  RUN_TEST(test_get_space_newline_nonblank);
  RUN_TEST(test_get_space_tab_at_tabstop);

  return UNITY_END();
}