/**
 * See Copyright Notice in picrin.h
 */

#include <string.h>

#include "picrin.h"
#include "picrin/string.h"
#include "picrin/pair.h"
#include "picrin/port.h"

static pic_str *
make_str_rope(pic_state *pic, xrope *rope)
{
  pic_str *str;

  str = (pic_str *)pic_obj_alloc(pic, sizeof(pic_str), PIC_TT_STRING);
  str->rope = rope;             /* delegate ownership */
  return str;
}

pic_str *
pic_make_str(pic_state *pic, const char *imbed, size_t len)
{
  if (imbed == NULL && len > 0) {
    pic_errorf(pic, "zero length specified against NULL ptr");
  }
  return make_str_rope(pic, xr_new_copy(imbed, len));
}

pic_str *
pic_make_str_cstr(pic_state *pic, const char *cstr)
{
  return pic_make_str(pic, cstr, strlen(cstr));
}

pic_str *
pic_make_str_fill(pic_state *pic, size_t len, char fill)
{
  size_t i;
  char buf[len + 1];

  for (i = 0; i < len; ++i) {
    buf[i] = fill;
  }
  buf[i] = '\0';

  return pic_make_str(pic, buf, len);
}

size_t
pic_strlen(pic_str *str)
{
  return xr_len(str->rope);
}

char
pic_str_ref(pic_state *pic, pic_str *str, size_t i)
{
  int c;

  c = xr_at(str->rope, i);
  if (c == -1) {
    pic_errorf(pic, "index out of range %d", i);
  }
  return (char)c;
}

pic_str *
pic_strcat(pic_state *pic, pic_str *a, pic_str *b)
{
  return make_str_rope(pic, xr_cat(a->rope, b->rope));
}

pic_str *
pic_substr(pic_state *pic, pic_str *str, size_t s, size_t e)
{
  return make_str_rope(pic, xr_sub(str->rope, s, e));
}

int
pic_strcmp(pic_str *str1, pic_str *str2)
{
  return strcmp(xr_cstr(str1->rope), xr_cstr(str2->rope));
}

const char *
pic_str_cstr(pic_str *str)
{
  return xr_cstr(str->rope);
}

pic_value
pic_xvfformat(pic_state *pic, xFILE *file, const char *fmt, va_list ap)
{
  char c;
  pic_value irrs = pic_nil_value();

  while ((c = *fmt++)) {
    switch (c) {
    default:
      xfputc(c, file);
      break;
    case '%':
      c = *fmt++;
      if (! c)
        goto exit;
      switch (c) {
      default:
        xfputc(c, file);
        break;
      case '%':
        xfputc('%', file);
        break;
      case 'c':
        xfprintf(file, "%c", va_arg(ap, int));
        break;
      case 's':
        xfprintf(file, "%s", va_arg(ap, const char *));
        break;
      case 'd':
        xfprintf(file, "%d", va_arg(ap, int));
        break;
      case 'p':
        xfprintf(file, "%p", va_arg(ap, void *));
        break;
      case 'f':
        xfprintf(file, "%f", va_arg(ap, double));
        break;
      }
      break;
    case '~':
      c = *fmt++;
      if (! c)
        goto exit;
      switch (c) {
      default:
        xfputc(c, file);
        break;
      case '~':
        xfputc('~', file);
        break;
      case '%':
        xfputc('\n', file);
        break;
      case 'a':
        irrs = pic_cons(pic, pic_fdisplay(pic, va_arg(ap, pic_value), file), irrs);
        break;
      case 's':
        irrs = pic_cons(pic, pic_fwrite(pic, va_arg(ap, pic_value), file), irrs);
        break;
      }
      break;
    }
  }
 exit:

  return pic_reverse(pic, irrs);
}

pic_value
pic_xvformat(pic_state *pic, const char *fmt, va_list ap)
{
  struct pic_port *port;
  pic_value irrs;

  port = pic_open_output_string(pic);

  irrs = pic_xvfformat(pic, port->file, fmt, ap);
  irrs = pic_cons(pic, pic_obj_value(pic_get_output_string(pic, port)), irrs);

  pic_close_port(pic, port);
  return irrs;
}

pic_value
pic_xformat(pic_state *pic, const char *fmt, ...)
{
  va_list ap;
  pic_value objs;

  va_start(ap, fmt);
  objs = pic_xvformat(pic, fmt, ap);
  va_end(ap);

  return objs;
}

void
pic_vfformat(pic_state *pic, xFILE *file, const char *fmt, va_list ap)
{
  pic_xvfformat(pic, file, fmt, ap);
}

pic_str *
pic_vformat(pic_state *pic, const char *fmt, va_list ap)
{
  struct pic_port *port;
  pic_str *str;

  port = pic_open_output_string(pic);

  pic_vfformat(pic, port->file, fmt, ap);
  str = pic_get_output_string(pic, port);

  pic_close_port(pic, port);
  return str;
}

pic_str *
pic_format(pic_state *pic, const char *fmt, ...)
{
  va_list ap;
  pic_str *str;

  va_start(ap, fmt);
  str = pic_vformat(pic, fmt, ap);
  va_end(ap);

  return str;
}

static pic_value
pic_str_string_p(pic_state *pic)
{
  pic_value v;

  pic_get_args(pic, "o", &v);

  return pic_bool_value(pic_str_p(v));
}

static pic_value
pic_str_string(pic_state *pic)
{
  size_t argc, i;
  pic_value *argv;
  pic_str *str;
  char *buf;

  pic_get_args(pic, "*", &argc, &argv);

  buf = pic_alloc(pic, (size_t)argc);

  for (i = 0; i < argc; ++i) {
    pic_assert_type(pic, argv[i], char);
    buf[i] = pic_char(argv[i]);
  }

  str = pic_make_str(pic, buf, (size_t)argc);
  pic_free(pic, buf);

  return pic_obj_value(str);
}

static pic_value
pic_str_make_string(pic_state *pic)
{
  size_t len;
  char c = ' ';

  pic_get_args(pic, "k|c", &len, &c);

  return pic_obj_value(pic_make_str_fill(pic, len, c));
}

static pic_value
pic_str_string_length(pic_state *pic)
{
  pic_str *str;

  pic_get_args(pic, "s", &str);

  return pic_size_value(pic_strlen(str));
}

static pic_value
pic_str_string_ref(pic_state *pic)
{
  pic_str *str;
  size_t k;

  pic_get_args(pic, "sk", &str, &k);

  return pic_char_value(pic_str_ref(pic, str, k));
}

#define DEFINE_STRING_CMP(name, op)                                     \
  static pic_value                                                      \
  pic_str_string_##name(pic_state *pic)                                 \
  {                                                                     \
    size_t argc, i;                                                     \
    pic_value *argv;                                                    \
                                                                        \
    pic_get_args(pic, "*", &argc, &argv);                               \
                                                                        \
    if (argc < 1 || ! pic_str_p(argv[0])) {                             \
      return pic_false_value();                                         \
    }                                                                   \
                                                                        \
    for (i = 1; i < argc; ++i) {                                        \
      if (! pic_str_p(argv[i])) {                                       \
	return pic_false_value();                                       \
      }                                                                 \
      if (! (pic_strcmp(pic_str_ptr(argv[i-1]), pic_str_ptr(argv[i])) op 0)) { \
	return pic_false_value();                                       \
      }                                                                 \
    }                                                                   \
    return pic_true_value();                                            \
  }

DEFINE_STRING_CMP(eq, ==)
DEFINE_STRING_CMP(lt, <)
DEFINE_STRING_CMP(gt, >)
DEFINE_STRING_CMP(le, <=)
DEFINE_STRING_CMP(ge, >=)

static pic_value
pic_str_string_copy(pic_state *pic)
{
  pic_str *str;
  int n;
  size_t start, end;

  n = pic_get_args(pic, "s|kk", &str, &start, &end);

  switch (n) {
  case 1:
    start = 0;
  case 2:
    end = pic_strlen(str);
  }

  return pic_obj_value(pic_substr(pic, str, start, end));
}

static pic_value
pic_str_string_append(pic_state *pic)
{
  size_t argc, i;
  pic_value *argv;
  pic_str *str;

  pic_get_args(pic, "*", &argc, &argv);

  str = pic_make_str(pic, NULL, 0);
  for (i = 0; i < argc; ++i) {
    if (! pic_str_p(argv[i])) {
      pic_errorf(pic, "type error");
    }
    str = pic_strcat(pic, str, pic_str_ptr(argv[i]));
  }
  return pic_obj_value(str);
}

static pic_value
pic_str_string_map(pic_state *pic)
{
  struct pic_proc *proc;
  pic_value *argv, vals, val;
  size_t argc, i, len, j;

  pic_get_args(pic, "l*", &proc, &argc, &argv);

  len = SIZE_MAX;
  for (i = 0; i < argc; ++i) {
    pic_assert_type(pic, argv[i], str);

    len = len < pic_strlen(pic_str_ptr(argv[i]))
      ? len
      : pic_strlen(pic_str_ptr(argv[i]));
  }
  if (len == SIZE_MAX) {
    pic_errorf(pic, "string-map: one or more strings expected, but got zero");
  }
  else {
    char buf[len];

    for (i = 0; i < len; ++i) {
      vals = pic_nil_value();
      for (j = 0; j < argc; ++j) {
        pic_push(pic, pic_char_value(pic_str_ref(pic, pic_str_ptr(argv[j]), i)), vals);
      }
      val = pic_apply(pic, proc, vals);

      pic_assert_type(pic, val, char);
      buf[i] = pic_char(val);
    }

    return pic_obj_value(pic_make_str(pic, buf, len));
  }
}

static pic_value
pic_str_string_for_each(pic_state *pic)
{
  struct pic_proc *proc;
  size_t argc, len, i, j;
  pic_value *argv, vals, val;

  pic_get_args(pic, "l*", &proc, &argc, &argv);

  len = SIZE_MAX;
  for (i = 0; i < argc; ++i) {
    pic_assert_type(pic, argv[i], str);

    len = len < pic_strlen(pic_str_ptr(argv[i]))
      ? len
      : pic_strlen(pic_str_ptr(argv[i]));
  }
  if (len == SIZE_MAX) {
    pic_errorf(pic, "string-map: one or more strings expected, but got zero");
  }

  for (i = 0; i < len; ++i) {
    vals = pic_nil_value();
    for (j = 0; j < argc; ++j) {
      pic_push(pic, pic_char_value(pic_str_ref(pic, pic_str_ptr(argv[j]), i)), vals);
    }
    val = pic_apply(pic, proc, vals);
  }

  return pic_none_value();
}

static pic_value
pic_str_list_to_string(pic_state *pic)
{
  pic_str *str;
  pic_value list, e;
  size_t i = 0;

  pic_get_args(pic, "o", &list);

  if (pic_length(pic, list) == 0) {
    return pic_obj_value(pic_make_str(pic, NULL, 0));
  } else {
    char buf[pic_length(pic, list)];

    pic_for_each (e, list) {
      pic_assert_type(pic, e, char);

      buf[i++] = pic_char(e);
    }

    str = pic_make_str(pic, buf, i);

    return pic_obj_value(str);
  }
}

static pic_value
pic_str_string_to_list(pic_state *pic)
{
  pic_str *str;
  pic_value list;
  int n;
  size_t start, end, i;

  n = pic_get_args(pic, "s|kk", &str, &start, &end);

  switch (n) {
  case 1:
    start = 0;
  case 2:
    end = pic_strlen(str);
  }

  list = pic_nil_value();

  for (i = start; i < end; ++i) {
    pic_push(pic, pic_char_value(pic_str_ref(pic, str, i)), list);
  }
  return pic_reverse(pic, list);
}

void
pic_init_str(pic_state *pic)
{
  pic_defun(pic, "string?", pic_str_string_p);
  pic_defun(pic, "string", pic_str_string);
  pic_defun(pic, "make-string", pic_str_make_string);
  pic_defun(pic, "string-length", pic_str_string_length);
  pic_defun(pic, "string-ref", pic_str_string_ref);
  pic_defun(pic, "string-copy", pic_str_string_copy);
  pic_defun(pic, "string-append", pic_str_string_append);
  pic_defun(pic, "string-map", pic_str_string_map);
  pic_defun(pic, "string-for-each", pic_str_string_for_each);
  pic_defun(pic, "list->string", pic_str_list_to_string);
  pic_defun(pic, "string->list", pic_str_string_to_list);

  pic_defun(pic, "string=?", pic_str_string_eq);
  pic_defun(pic, "string<?", pic_str_string_lt);
  pic_defun(pic, "string>?", pic_str_string_gt);
  pic_defun(pic, "string<=?", pic_str_string_le);
  pic_defun(pic, "string>=?", pic_str_string_ge);
}