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

/* setUp and tearDown are required by Unity */
void setUp(void) {
  /* Disable order checking to avoid dereferencing any stale prevline pointers
     left from previous tests, since we free lines after each test. */
  check_input_order = CHECK_ORDER_DISABLED;
  /* Reset the unpairable flag just in case any logic consults it. */
  seen_unpairable = false;
}

void tearDown(void) {
  /* Ensure any spare lines are freed to avoid leaks across tests. */
  free_spareline();
}

/* Helper: create a temporary file preloaded with 'content' and rewound. */
static FILE* make_tempfile_with(const char* content) {
  FILE *fp = tmpfile();
  TEST_ASSERT_NOT_NULL_MESSAGE(fp, "tmpfile() failed");
  if (content && *content) {
    size_t len = strlen(content);
    TEST_ASSERT_EQUAL_MESSAGE(len, fwrite(content, 1, len, fp),
                              "Failed to write content to tmp file");
  }
  fflush(fp);
  rewind(fp);
  return fp;
}

/* Validate a field equals the given string (length and bytes). */
static void assert_field_equals(const struct field *f, const char *s) {
  size_t slen = strlen(s);
  TEST_ASSERT_EQUAL_size_t(slen, (size_t)f->len);
  if (slen > 0) {
    TEST_ASSERT_NOT_NULL(f->beg);
    TEST_ASSERT_EQUAL_INT(0, memcmp(f->beg, s, slen));
  }
}

/* Test: getseq reads a single line and parses three fields separated by blanks. */
void test_getseq_reads_single_line_and_fields(void) {
  FILE *fp = make_tempfile_with("a b c\n");

  struct seq s;
  initseq(&s);

  bool ok = getseq(fp, &s, 1);
  TEST_ASSERT_TRUE(ok);
  TEST_ASSERT_TRUE(s.count == 1);
  TEST_ASSERT_NOT_NULL(s.lines);
  TEST_ASSERT_TRUE(s.alloc >= 1);
  TEST_ASSERT_NOT_NULL(s.lines[0]);

  struct line *l = s.lines[0];
  TEST_ASSERT_NOT_NULL(l);
  TEST_ASSERT_TRUE(l->nfields == 3);

  TEST_ASSERT_NOT_NULL(l->fields);
  assert_field_equals(&l->fields[0], "a");
  assert_field_equals(&l->fields[1], "b");
  assert_field_equals(&l->fields[2], "c");

  delseq(&s);
  fclose(fp);
}

/* Test: getseq returns false on EOF and does not increment count. */
void test_getseq_returns_false_on_empty_file(void) {
  FILE *fp = make_tempfile_with("");

  struct seq s;
  initseq(&s);

  bool ok = getseq(fp, &s, 1);
  TEST_ASSERT_FALSE(ok);
  TEST_ASSERT_TRUE(s.count == 0);
  /* Storage should have been allocated, and the first slot initialized to NULL. */
  TEST_ASSERT_NOT_NULL(s.lines);
  TEST_ASSERT_TRUE(s.alloc >= 1);
  TEST_ASSERT_NULL(s.lines[0]);

  delseq(&s);
  fclose(fp);
}

/* Test: getseq reads multiple lines and increments count appropriately. */
void test_getseq_reads_multiple_lines(void) {
  FILE *fp = make_tempfile_with("x\ny\nz\n");

  struct seq s;
  initseq(&s);

  bool ok1 = getseq(fp, &s, 1);
  TEST_ASSERT_TRUE(ok1);
  TEST_ASSERT_TRUE(s.count == 1);
  TEST_ASSERT_NOT_NULL(s.lines[0]);
  TEST_ASSERT_TRUE(s.lines[0]->nfields == 1);
  assert_field_equals(&s.lines[0]->fields[0], "x");

  bool ok2 = getseq(fp, &s, 1);
  TEST_ASSERT_TRUE(ok2);
  TEST_ASSERT_TRUE(s.count == 2);
  TEST_ASSERT_NOT_NULL(s.lines[1]);
  TEST_ASSERT_TRUE(s.lines[1]->nfields == 1);
  assert_field_equals(&s.lines[1]->fields[0], "y");

  bool ok3 = getseq(fp, &s, 1);
  TEST_ASSERT_TRUE(ok3);
  TEST_ASSERT_TRUE(s.count == 3);
  TEST_ASSERT_NOT_NULL(s.lines[2]);
  TEST_ASSERT_TRUE(s.lines[2]->nfields == 1);
  assert_field_equals(&s.lines[2]->fields[0], "z");

  /* Next call should hit EOF and return false; count should remain unchanged. */
  bool ok4 = getseq(fp, &s, 1);
  TEST_ASSERT_FALSE(ok4);
  TEST_ASSERT_TRUE(s.count == 3);

  delseq(&s);
  fclose(fp);
}

/* Test: getseq works for both whichfile values independently. */
void test_getseq_works_for_both_files(void) {
  FILE *fp1 = make_tempfile_with("a\nb\n");
  FILE *fp2 = make_tempfile_with("c\nd\n");

  struct seq s1, s2;
  initseq(&s1);
  initseq(&s2);

  /* Read first line from file 1 */
  TEST_ASSERT_TRUE(getseq(fp1, &s1, 1));
  TEST_ASSERT_TRUE(s1.count == 1);
  TEST_ASSERT_TRUE(s1.lines[0]->nfields == 1);
  assert_field_equals(&s1.lines[0]->fields[0], "a");

  /* Read first line from file 2 */
  TEST_ASSERT_TRUE(getseq(fp2, &s2, 2));
  TEST_ASSERT_TRUE(s2.count == 1);
  TEST_ASSERT_TRUE(s2.lines[0]->nfields == 1);
  assert_field_equals(&s2.lines[0]->fields[0], "c");

  /* Read second line from each */
  TEST_ASSERT_TRUE(getseq(fp1, &s1, 1));
  TEST_ASSERT_TRUE(s1.count == 2);
  assert_field_equals(&s1.lines[1]->fields[0], "b");

  TEST_ASSERT_TRUE(getseq(fp2, &s2, 2));
  TEST_ASSERT_TRUE(s2.count == 2);
  assert_field_equals(&s2.lines[1]->fields[0], "d");

  /* EOF on both */
  TEST_ASSERT_FALSE(getseq(fp1, &s1, 1));
  TEST_ASSERT_FALSE(getseq(fp2, &s2, 2));

  delseq(&s1);
  delseq(&s2);
  fclose(fp1);
  fclose(fp2);
}

/* Test: handle a line without a trailing newline */
void test_getseq_handles_line_without_trailing_newline(void) {
  FILE *fp = make_tempfile_with("no-trailing-newline");

  struct seq s;
  initseq(&s);

  TEST_ASSERT_TRUE(getseq(fp, &s, 1));
  TEST_ASSERT_TRUE(s.count == 1);
  TEST_ASSERT_NOT_NULL(s.lines[0]);
  TEST_ASSERT_TRUE(s.lines[0]->nfields == 1);
  assert_field_equals(&s.lines[0]->fields[0], "no-trailing-newline");

  /* Next should be EOF */
  TEST_ASSERT_FALSE(getseq(fp, &s, 1));

  delseq(&s);
  fclose(fp);
}

int main(void) {
  UNITY_BEGIN();
  RUN_TEST(test_getseq_reads_single_line_and_fields);
  RUN_TEST(test_getseq_returns_false_on_empty_file);
  RUN_TEST(test_getseq_reads_multiple_lines);
  RUN_TEST(test_getseq_works_for_both_files);
  RUN_TEST(test_getseq_handles_line_without_trailing_newline);
  return UNITY_END();
}