#include "../../unity/unity.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>

/* Note:
   - This test file is included into the nl source, so it has access to
     all internal globals and functions, including proc_text, line_buf, etc.
   - Do not use Unity assertions while stdout is redirected.
*/

/* Forward declare the target function for clarity (it is visible as it's in the same TU). */
/* static void proc_text(void);  -- not redeclared to avoid conflicts */

/* Helper: begin capturing stdout to a temporary file. */
typedef struct {
  int saved_fd;
  int tmp_fd;
  char path[64];
} capture_ctx;

static int begin_capture(capture_ctx *ctx) {
  strcpy(ctx->path, "/tmp/nl_cap_XXXXXX");
  ctx->tmp_fd = mkstemp(ctx->path);
  if (ctx->tmp_fd < 0) return -1;

  ctx->saved_fd = dup(fileno(stdout));
  if (ctx->saved_fd < 0) {
    close(ctx->tmp_fd);
    unlink(ctx->path);
    return -1;
  }

  fflush(stdout);
  if (dup2(ctx->tmp_fd, fileno(stdout)) < 0) {
    close(ctx->tmp_fd);
    close(ctx->saved_fd);
    unlink(ctx->path);
    return -1;
  }
  return 0;
}

/* Helper: end capturing stdout and return the captured output as a malloc'd string. */
static char *end_capture(capture_ctx *ctx) {
  fflush(stdout);

  /* Restore stdout first, then read and clean up. */
  dup2(ctx->saved_fd, fileno(stdout));
  close(ctx->saved_fd);

  /* Read back file */
  struct stat st;
  if (fstat(ctx->tmp_fd, &st) != 0) {
    close(ctx->tmp_fd);
    unlink(ctx->path);
    return NULL;
  }

  off_t sz = st.st_size;
  if (lseek(ctx->tmp_fd, 0, SEEK_SET) < 0) {
    close(ctx->tmp_fd);
    unlink(ctx->path);
    return NULL;
  }

  char *buf = (char *)malloc((size_t)sz + 1);
  if (!buf) {
    close(ctx->tmp_fd);
    unlink(ctx->path);
    return NULL;
  }

  ssize_t rd = read(ctx->tmp_fd, buf, (size_t)sz);
  if (rd < 0) {
    free(buf);
    close(ctx->tmp_fd);
    unlink(ctx->path);
    return NULL;
  }
  buf[rd] = '\0';

  close(ctx->tmp_fd);
  unlink(ctx->path);
  return buf;
}

/* Helper: set the global line buffer to the given content (must include '\n').
   Returns pointer that must be freed by caller after proc_text call. */
static char *set_line(const char *s) {
  size_t len = strlen(s);
  char *copy = (char *)malloc(len);
  memcpy(copy, s, len);
  line_buf.buffer = copy;
  line_buf.length = len;
  return copy;
}

/* Helper: call proc_text on provided content and capture output. */
static char *call_and_capture_proc_text(const char *content) {
  capture_ctx ctx;
  if (begin_capture(&ctx) != 0) {
    return NULL;
  }
  char *mem = set_line(content);
  /* Do not use Unity asserts while redirected */
  proc_text();
  char *out = end_capture(&ctx);
  free(mem);
  return out;
}

/* Reset the static blank_lines inside proc_text to a known state.
   We do this by forcing an 'a' mode call on a non-empty line, which sets blank_lines = 0.
   Output is discarded. */
static void reset_proc_text_static_state(void) {
  const char *saved_type = current_type;
  intmax_t saved_blank_join = blank_join;
  char const *saved_sep = separator_str;
  char const *saved_fmt = lineno_format;
  int saved_width = lineno_width;
  char const *saved_no_line_fmt = print_no_line_fmt;
  intmax_t saved_line_no = line_no;
  intmax_t saved_incr = page_incr;

  current_type = "a";
  blank_join = 2; /* >1 to ensure the path sets blank_lines=0 for non-empty line */
  separator_str = "|";
  lineno_format = FORMAT_RIGHT_NOLZ;
  lineno_width = 2;
  print_no_line_fmt = "";
  line_no = 1;
  page_incr = 1;

  capture_ctx ctx;
  if (begin_capture(&ctx) == 0) {
    char *mem = set_line("R\n");
    proc_text(); /* does a numbered non-empty line -> blank_lines becomes 0 */
    char *d = end_capture(&ctx);
    free(mem);
    free(d);
  }

  /* restore */
  current_type = saved_type;
  blank_join = saved_blank_join;
  separator_str = saved_sep;
  lineno_format = saved_fmt;
  lineno_width = saved_width;
  print_no_line_fmt = saved_no_line_fmt;
  line_no = saved_line_no;
  page_incr = saved_incr;
}

void setUp(void) {
  /* Set deterministic defaults; reset internal static state in proc_text */
  separator_str = "|";
  lineno_format = FORMAT_RIGHT_NOLZ;
  lineno_width = 3;
  page_incr = 1;
  line_no = 1;
  line_no_overflow = false;
  print_no_line_fmt = "U";
  current_type = "n";
  blank_join = 1;
  reset_proc_text_static_state();
}

void tearDown(void) {
  /* Nothing to clean specifically */
}

/* Test: 'a' mode with blank_join == 1 numbers all lines, including blank. */
static void test_proc_text_a_blank_join_1(void) {
  current_type = "a";
  blank_join = 1;
  separator_str = "|";
  lineno_width = 3;
  lineno_format = FORMAT_RIGHT_NOLZ;
  print_no_line_fmt = "<>";
  line_no = 7;
  page_incr = 1;

  char *out1 = call_and_capture_proc_text("X\n");
  TEST_ASSERT_NOT_NULL(out1);
  TEST_ASSERT_EQUAL_STRING("  7|X\n", out1);
  free(out1);
  TEST_ASSERT_EQUAL_INT64(8, line_no);

  char *out2 = call_and_capture_proc_text("\n");
  TEST_ASSERT_NOT_NULL(out2);
  TEST_ASSERT_EQUAL_STRING("  8|\n", out2);
  free(out2);
  TEST_ASSERT_EQUAL_INT64(9, line_no);
}

/* Test: 'a' mode with blank_join > 1 groups consecutive blank lines.
   For blank_join=3 and starting line_no=1:
   - first blank -> unnumbered
   - second blank -> unnumbered
   - third blank -> numbered " 1|"
   - fourth blank -> unnumbered
   Then a non-empty line resets the blank counter and is numbered " 2|".
*/
static void test_proc_text_a_blank_join_gt1_sequence(void) {
  current_type = "a";
  blank_join = 3;
  separator_str = "|";
  lineno_width = 2;
  lineno_format = FORMAT_RIGHT_NOLZ;
  print_no_line_fmt = "U";
  line_no = 1;
  page_incr = 1;

  char *o1 = call_and_capture_proc_text("\n");
  TEST_ASSERT_NOT_NULL(o1);
  TEST_ASSERT_EQUAL_STRING("U\n", o1);
  free(o1);
  TEST_ASSERT_EQUAL_INT64(1, line_no);

  char *o2 = call_and_capture_proc_text("\n");
  TEST_ASSERT_NOT_NULL(o2);
  TEST_ASSERT_EQUAL_STRING("U\n", o2);
  free(o2);
  TEST_ASSERT_EQUAL_INT64(1, line_no);

  char *o3 = call_and_capture_proc_text("\n");
  TEST_ASSERT_NOT_NULL(o3);
  TEST_ASSERT_EQUAL_STRING(" 1|\n", o3);
  free(o3);
  TEST_ASSERT_EQUAL_INT64(2, line_no);

  char *o4 = call_and_capture_proc_text("\n");
  TEST_ASSERT_NOT_NULL(o4);
  TEST_ASSERT_EQUAL_STRING("U\n", o4);
  free(o4);
  TEST_ASSERT_EQUAL_INT64(2, line_no);

  char *o5 = call_and_capture_proc_text("abc\n");
  TEST_ASSERT_NOT_NULL(o5);
  TEST_ASSERT_EQUAL_STRING(" 2|abc\n", o5);
  free(o5);
  TEST_ASSERT_EQUAL_INT64(3, line_no);
}

/* Test: 't' mode numbers only non-empty lines. */
static void test_proc_text_t_type(void) {
  current_type = "t";
  print_no_line_fmt = "X";
  separator_str = "|";
  lineno_width = 2;
  lineno_format = FORMAT_RIGHT_NOLZ;
  line_no = 42;
  page_incr = 1;

  char *o1 = call_and_capture_proc_text("hello\n");
  TEST_ASSERT_NOT_NULL(o1);
  TEST_ASSERT_EQUAL_STRING("42|hello\n", o1);
  free(o1);
  TEST_ASSERT_EQUAL_INT64(43, line_no);

  char *o2 = call_and_capture_proc_text("\n");
  TEST_ASSERT_NOT_NULL(o2);
  TEST_ASSERT_EQUAL_STRING("X\n", o2);
  free(o2);
  /* line_no unchanged for unnumbered line */
  TEST_ASSERT_EQUAL_INT64(43, line_no);
}

/* Test: 'n' mode numbers no lines. */
static void test_proc_text_n_type(void) {
  current_type = "n";
  print_no_line_fmt = "Z";
  separator_str = "|";
  lineno_width = 2;
  lineno_format = FORMAT_RIGHT_NOLZ;
  line_no = 5;
  page_incr = 1;

  char *o1 = call_and_capture_proc_text("q\n");
  TEST_ASSERT_NOT_NULL(o1);
  TEST_ASSERT_EQUAL_STRING("Zq\n", o1);
  free(o1);
  TEST_ASSERT_EQUAL_INT64(5, line_no);

  char *o2 = call_and_capture_proc_text("\n");
  TEST_ASSERT_NOT_NULL(o2);
  TEST_ASSERT_EQUAL_STRING("Z\n", o2);
  free(o2);
  TEST_ASSERT_EQUAL_INT64(5, line_no);
}

/* Test: 'p' mode numbers only lines matching regex.
   Use the program's regex engine and buffers. */
static void test_proc_text_p_type_regex(void) {
  /* Prepare regex: "foo" */
  current_type = "p";
  current_regex = &body_regex;

  /* Initialize pattern buffer similarly to build_type_arg. */
  body_regex.buffer = NULL;
  body_regex.allocated = 0;
  body_regex.fastmap = body_fastmap;
  body_regex.translate = NULL;
  re_syntax_options =
    RE_SYNTAX_POSIX_BASIC & ~RE_CONTEXT_INVALID_DUP & ~RE_NO_EMPTY_RANGES;
  const char *errmsg = re_compile_pattern("foo", strlen("foo"), &body_regex);
  TEST_ASSERT_NULL_MESSAGE(errmsg, "Failed to compile regex pattern");

  print_no_line_fmt = "N";
  separator_str = "|";
  lineno_width = 2;
  lineno_format = FORMAT_RIGHT_NOLZ;
  line_no = 5;
  page_incr = 1;

  char *o1 = call_and_capture_proc_text("foo\n");
  TEST_ASSERT_NOT_NULL(o1);
  TEST_ASSERT_EQUAL_STRING(" 5|foo\n", o1);
  free(o1);
  TEST_ASSERT_EQUAL_INT64(6, line_no);

  char *o2 = call_and_capture_proc_text("bar\n");
  TEST_ASSERT_NOT_NULL(o2);
  TEST_ASSERT_EQUAL_STRING("Nbar\n", o2);
  free(o2);
  TEST_ASSERT_EQUAL_INT64(6, line_no);
}

/* Test: page_incr affects line_no increment. */
static void test_proc_text_page_incr(void) {
  current_type = "a";
  blank_join = 1;
  separator_str = "|";
  lineno_width = 3;
  lineno_format = FORMAT_RIGHT_NOLZ;
  print_no_line_fmt = "";
  line_no = 10;
  page_incr = 10;

  char *o = call_and_capture_proc_text("X\n");
  TEST_ASSERT_NOT_NULL(o);
  TEST_ASSERT_EQUAL_STRING(" 10|X\n", o);
  free(o);
  TEST_ASSERT_EQUAL_INT64(20, line_no);
}

int main(void) {
  UNITY_BEGIN();

  RUN_TEST(test_proc_text_a_blank_join_1);
  RUN_TEST(test_proc_text_a_blank_join_gt1_sequence);
  RUN_TEST(test_proc_text_t_type);
  RUN_TEST(test_proc_text_n_type);
  RUN_TEST(test_proc_text_p_type_regex);
  RUN_TEST(test_proc_text_page_incr);

  return UNITY_END();
}