/*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <stdio.h>
  #include <stdarg.h>
  #include <string.h>
  #include <assert.h>
  
  #include "py/mpconfig.h"
  #include "py/runtime.h"
  #include "py/mpprint.h"
  
  // returned value is always at least 1 greater than argument
  #define ROUND_ALLOC(a) (((a) & ((~0U) - 7)) + 8)
  
  // Init the vstr so it allocs exactly given number of bytes.  Set length to zero.
  void vstr_init(vstr_t *vstr, size_t alloc) {
      if (alloc < 1) {
          alloc = 1;
      }
      vstr->alloc = alloc;
      vstr->len = 0;
      vstr->buf = m_new(char, vstr->alloc);
      vstr->fixed_buf = false;
  }
  
  // Init the vstr so it allocs exactly enough ram to hold a null-terminated
  // string of the given length, and set the length.
  void vstr_init_len(vstr_t *vstr, size_t len) {
      vstr_init(vstr, len + 1);
      vstr->len = len;
  }
  
  void vstr_init_fixed_buf(vstr_t *vstr, size_t alloc, char *buf) {
      vstr->alloc = alloc;
      vstr->len = 0;
      vstr->buf = buf;
      vstr->fixed_buf = true;
  }
  
  void vstr_init_print(vstr_t *vstr, size_t alloc, mp_print_t *print) {
      vstr_init(vstr, alloc);
      print->data = vstr;
      print->print_strn = (mp_print_strn_t)vstr_add_strn;
  }
  
  void vstr_clear(vstr_t *vstr) {
      if (!vstr->fixed_buf) {
          m_del(char, vstr->buf, vstr->alloc);
      }
      vstr->buf = NULL;
  }
  
  vstr_t *vstr_new(size_t alloc) {
      vstr_t *vstr = m_new_obj(vstr_t);
      vstr_init(vstr, alloc);
      return vstr;
  }
  
  void vstr_free(vstr_t *vstr) {
      if (vstr != NULL) {
          if (!vstr->fixed_buf) {
              m_del(char, vstr->buf, vstr->alloc);
          }
          m_del_obj(vstr_t, vstr);
      }
  }
  
  // Extend vstr strictly by requested size, return pointer to newly added chunk.
  char *vstr_extend(vstr_t *vstr, size_t size) {
      if (vstr->fixed_buf) {
          // We can't reallocate, and the caller is expecting the space to
          // be there, so the only safe option is to raise an exception.
          mp_raise_msg(&mp_type_RuntimeError, NULL);
      }
      char *new_buf = m_renew(char, vstr->buf, vstr->alloc, vstr->alloc + size);
      char *p = new_buf + vstr->alloc;
      vstr->alloc += size;
      vstr->buf = new_buf;
      return p;
  }
  
  STATIC void vstr_ensure_extra(vstr_t *vstr, size_t size) {
      if (vstr->len + size > vstr->alloc) {
          if (vstr->fixed_buf) {
              // We can't reallocate, and the caller is expecting the space to
              // be there, so the only safe option is to raise an exception.
              mp_raise_msg(&mp_type_RuntimeError, NULL);
          }
          size_t new_alloc = ROUND_ALLOC((vstr->len + size) + 16);
          char *new_buf = m_renew(char, vstr->buf, vstr->alloc, new_alloc);
          vstr->alloc = new_alloc;
          vstr->buf = new_buf;
      }
  }
  
  void vstr_hint_size(vstr_t *vstr, size_t size) {
      vstr_ensure_extra(vstr, size);
  }
  
  char *vstr_add_len(vstr_t *vstr, size_t len) {
      vstr_ensure_extra(vstr, len);
      char *buf = vstr->buf + vstr->len;
      vstr->len += len;
      return buf;
  }
  
  // Doesn't increase len, just makes sure there is a null byte at the end
  char *vstr_null_terminated_str(vstr_t *vstr) {
      // If there's no more room, add single byte
      if (vstr->alloc == vstr->len) {
          vstr_extend(vstr, 1);
      }
      vstr->buf[vstr->len] = '\0';
      return vstr->buf;
  }
  
  void vstr_add_byte(vstr_t *vstr, byte b) {
      byte *buf = (byte*)vstr_add_len(vstr, 1);
      buf[0] = b;
  }
  
  void vstr_add_char(vstr_t *vstr, unichar c) {
  #if MICROPY_PY_BUILTINS_STR_UNICODE
      // TODO: Can this be simplified and deduplicated?
      // Is it worth just calling vstr_add_len(vstr, 4)?
      if (c < 0x80) {
          byte *buf = (byte*)vstr_add_len(vstr, 1);
          *buf = (byte)c;
      } else if (c < 0x800) {
          byte *buf = (byte*)vstr_add_len(vstr, 2);
          buf[0] = (c >> 6) | 0xC0;
          buf[1] = (c & 0x3F) | 0x80;
      } else if (c < 0x10000) {
          byte *buf = (byte*)vstr_add_len(vstr, 3);
          buf[0] = (c >> 12) | 0xE0;
          buf[1] = ((c >> 6) & 0x3F) | 0x80;
          buf[2] = (c & 0x3F) | 0x80;
      } else {
          assert(c < 0x110000);
          byte *buf = (byte*)vstr_add_len(vstr, 4);
          buf[0] = (c >> 18) | 0xF0;
          buf[1] = ((c >> 12) & 0x3F) | 0x80;
          buf[2] = ((c >> 6) & 0x3F) | 0x80;
          buf[3] = (c & 0x3F) | 0x80;
      }
  #else
      vstr_add_byte(vstr, c);
  #endif
  }
  
  void vstr_add_str(vstr_t *vstr, const char *str) {
      vstr_add_strn(vstr, str, strlen(str));
  }
  
  void vstr_add_strn(vstr_t *vstr, const char *str, size_t len) {
      vstr_ensure_extra(vstr, len);
      memmove(vstr->buf + vstr->len, str, len);
      vstr->len += len;
  }
  
  STATIC char *vstr_ins_blank_bytes(vstr_t *vstr, size_t byte_pos, size_t byte_len) {
      size_t l = vstr->len;
      if (byte_pos > l) {
          byte_pos = l;
      }
      if (byte_len > 0) {
          // ensure room for the new bytes
          vstr_ensure_extra(vstr, byte_len);
          // copy up the string to make room for the new bytes
          memmove(vstr->buf + byte_pos + byte_len, vstr->buf + byte_pos, l - byte_pos);
          // increase the length
          vstr->len += byte_len;
      }
      return vstr->buf + byte_pos;
  }
  
  void vstr_ins_byte(vstr_t *vstr, size_t byte_pos, byte b) {
      char *s = vstr_ins_blank_bytes(vstr, byte_pos, 1);
      *s = b;
  }
  
  void vstr_ins_char(vstr_t *vstr, size_t char_pos, unichar chr) {
      // TODO UNICODE
      char *s = vstr_ins_blank_bytes(vstr, char_pos, 1);
      *s = chr;
  }
  
  void vstr_cut_head_bytes(vstr_t *vstr, size_t bytes_to_cut) {
      vstr_cut_out_bytes(vstr, 0, bytes_to_cut);
  }
  
  void vstr_cut_tail_bytes(vstr_t *vstr, size_t len) {
      if (len > vstr->len) {
          vstr->len = 0;
      } else {
          vstr->len -= len;
      }
  }
  
  void vstr_cut_out_bytes(vstr_t *vstr, size_t byte_pos, size_t bytes_to_cut) {
      if (byte_pos >= vstr->len) {
          return;
      } else if (byte_pos + bytes_to_cut >= vstr->len) {
          vstr->len = byte_pos;
      } else {
          memmove(vstr->buf + byte_pos, vstr->buf + byte_pos + bytes_to_cut, vstr->len - byte_pos - bytes_to_cut);
          vstr->len -= bytes_to_cut;
      }
  }
  
  void vstr_printf(vstr_t *vstr, const char *fmt, ...) {
      va_list ap;
      va_start(ap, fmt);
      vstr_vprintf(vstr, fmt, ap);
      va_end(ap);
  }
  
  void vstr_vprintf(vstr_t *vstr, const char *fmt, va_list ap) {
      mp_print_t print = {vstr, (mp_print_strn_t)vstr_add_strn};
      mp_vprintf(&print, fmt, ap);
  }