//
// Copyright (C) 2011-15 DyND Developers
// BSD 2-Clause License, see LICENSE.txt
//

#pragma once

#include <iostream>
#include <string>

#include <dynd/config.hpp>

namespace dynd {
namespace ndt {

  class type;

} // namespace dynd::ndt

enum string_encoding_t : uint32_t {
  string_encoding_ascii,
  string_encoding_ucs_2,
  string_encoding_utf_8,
  string_encoding_utf_16,
  string_encoding_utf_32,

  string_encoding_latin1,
  // TODO: more codepages here

  string_encoding_invalid
};

/**
 * A table of the individual character sizes for
 * the various encodings.
 */
extern DYNDT_API int string_encoding_char_size_table[6];

/**
 * Returns true if the provided encoding uses a variable-length encoding
 * for each character, for example UTF-8.
 */
inline bool is_variable_length_string_encoding(string_encoding_t encoding)
{
  return encoding == string_encoding_utf_8 || encoding == string_encoding_utf_16;
}

inline std::ostream &operator<<(std::ostream &o, string_encoding_t encoding)
{
  switch (encoding) {
  case string_encoding_ascii:
    o << "ascii";
    break;
  case string_encoding_ucs_2:
    o << "ucs2";
    break;
  case string_encoding_utf_8:
    o << "utf8";
    break;
  case string_encoding_utf_16:
    o << "utf16";
    break;
  case string_encoding_utf_32:
    o << "utf32";
    break;
  case string_encoding_latin1:
    o << "latin1";
    break;
  default:
    o << "unknown string encoding";
    break;
  }

  return o;
}

/**
 * Typedef for getting the next unicode codepoint from a string of a particular
 * encoding.
 *
 * On entry, this function assumes that 'it' and 'end' are appropriately aligned
 * and that (it < end). The variable 'it' is updated in-place to be after the
 * character data representing the returned code point.
 *
 * This function may raise an exception if there is an error.
 */
typedef uint32_t (*next_unicode_codepoint_t)(const char *&it, const char *end);

/**
 * Typedef for appending a unicode codepoint to a string of a particular
 * encoding.
 *
 * On entry, this function assumes that 'it' and 'end' are appropriately aligned
 * and that (it < end). The variable 'it' is updated in-place to be after the
 * character data representing the appended code point.
 *
 * This function may raise an exception if there is an error.
 */
typedef void (*append_unicode_codepoint_t)(uint32_t cp, char *&it, char *end);

DYNDT_API next_unicode_codepoint_t get_next_unicode_codepoint_function(string_encoding_t encoding,
                                                                      assign_error_mode errmode);
DYNDT_API append_unicode_codepoint_t get_append_unicode_codepoint_function(string_encoding_t encoding,
                                                                          assign_error_mode errmode);

/**
 * Converts a string buffer provided as a range of bytes into a std::string as UTF8.
 */
DYNDT_API std::string string_range_as_utf8_string(string_encoding_t encoding, const char *begin, const char *end,
                                                 assign_error_mode errmode);

/**
 * Prints the given code point to the output stream, escaping it as necessary.
 */
DYNDT_API void print_escaped_unicode_codepoint(std::ostream &o, uint32_t cp, bool single_quote);

/**
 * Prints the utf8 string, escaping as necessary.
 */
DYNDT_API void print_escaped_utf8_string(std::ostream &o, const char *str_begin, const char *str_end,
                                        bool single_quote = false);

/**
 * Prints the utf8 string, escaping as necessary.
 */
inline void print_escaped_utf8_string(std::ostream &o, const std::string &str, bool single_quote = false)
{
  print_escaped_utf8_string(o, str.data(), str.data() + str.size(), single_quote);
}

DYNDT_API void append_utf8_codepoint(uint32_t cp, std::string &out_str);

/**
 * Returns the char type corresponding to the encoding. For fixed-sized
 * encodings, this is "char_type[encoding]", and for variable-sized
 * encodings, this is "bytes[1]" or "bytes[2,2]".
 */
DYNDT_API ndt::type char_type_of_encoding(string_encoding_t encoding);

} // namespace dynd