/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Copyright (C) 2018 Blender Foundation.
 */

/** \file
 * \ingroup DNA
 *
 * Utilities for stand-alone makesdna.c and Blender to share.
 */

#include <string.h>

#include "MEM_guardedalloc.h"

#include "BLI_sys_types.h"
#include "BLI_utildefines.h"
#include "BLI_assert.h"
#include "BLI_ghash.h"

#include "BLI_memarena.h"

#include "dna_utils.h"

/* -------------------------------------------------------------------- */
/** \name Struct Member Evaluation
 * \{ */

/**
 * Parses the `[n1][n2]...` on the end of an array name
 * and returns the number of array elements `n1 * n2 ...`.
 */
int DNA_elem_array_size(const char *str)
{
  int result = 1;
  int current = 0;
  while (true) {
    char c = *str++;
    switch (c) {
      case '\0':
        return result;
      case '[':
        current = 0;
        break;
      case ']':
        result *= current;
        break;
      case '0':
      case '1':
      case '2':
      case '3':
      case '4':
      case '5':
      case '6':
      case '7':
      case '8':
      case '9':
        current = current * 10 + (c - '0');
        break;
      default:
        break;
    }
  }
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Struct Member Manipulation
 * \{ */

static bool is_identifier(const char c)
{
  return ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') ||
          (c == '_'));
}

uint DNA_elem_id_offset_start(const char *elem_full)
{
  uint elem_full_offset = 0;
  while (!is_identifier(elem_full[elem_full_offset])) {
    elem_full_offset++;
  }
  return elem_full_offset;
}

uint DNA_elem_id_offset_end(const char *elem_full)
{
  uint elem_full_offset = 0;
  while (is_identifier(elem_full[elem_full_offset])) {
    elem_full_offset++;
  }
  return elem_full_offset;
}

/**
 * \a elem_dst must be at least the size of \a elem_src.
 */
uint DNA_elem_id_strip_copy(char *elem_dst, const char *elem_src)
{
  const uint elem_src_offset = DNA_elem_id_offset_start(elem_src);
  const char *elem_src_trim = elem_src + elem_src_offset;
  const uint elem_src_trim_len = DNA_elem_id_offset_end(elem_src_trim);
  memcpy(elem_dst, elem_src_trim, elem_src_trim_len);
  elem_dst[elem_src_trim_len] = '\0';
  return elem_src_trim_len;
}

uint DNA_elem_id_strip(char *elem)
{
  const uint elem_offset = DNA_elem_id_offset_start(elem);
  const char *elem_trim = elem + elem_offset;
  const uint elem_trim_len = DNA_elem_id_offset_end(elem_trim);
  memmove(elem, elem_trim, elem_trim_len);
  elem[elem_trim_len] = '\0';
  return elem_trim_len;
}

/**
 * Check if 'var' matches '*var[3]' for eg,
 * return true if it does, with start/end offsets.
 */
bool DNA_elem_id_match(const char *elem_search,
                       const int elem_search_len,
                       const char *elem_full,
                       uint *r_elem_full_offset)
{
  BLI_assert(strlen(elem_search) == elem_search_len);
  const uint elem_full_offset = DNA_elem_id_offset_start(elem_full);
  const char *elem_full_trim = elem_full + elem_full_offset;
  if (strncmp(elem_search, elem_full_trim, elem_search_len) == 0) {
    const char c = elem_full_trim[elem_search_len];
    if (c == '\0' || !is_identifier(c)) {
      *r_elem_full_offset = elem_full_offset;
      return true;
    }
  }
  return false;
}

/**
 * Return a renamed dna name, allocated from \a mem_arena.
 */
char *DNA_elem_id_rename(struct MemArena *mem_arena,
                         const char *elem_src,
                         const int elem_src_len,
                         const char *elem_dst,
                         const int elem_dst_len,
                         const char *elem_src_full,
                         const int elem_src_full_len,
                         const uint elem_src_full_offset_len)
{
  BLI_assert(strlen(elem_src) == elem_src_len);
  BLI_assert(strlen(elem_dst) == elem_dst_len);
  BLI_assert(strlen(elem_src_full) == elem_src_full_len);
  BLI_assert(DNA_elem_id_offset_start(elem_src_full) == elem_src_full_offset_len);
  UNUSED_VARS_NDEBUG(elem_src);

  const int elem_final_len = (elem_src_full_len - elem_src_len) + elem_dst_len;
  char *elem_dst_full = BLI_memarena_alloc(mem_arena, elem_final_len + 1);
  uint i = 0;
  if (elem_src_full_offset_len != 0) {
    memcpy(elem_dst_full, elem_src_full, elem_src_full_offset_len);
    i = elem_src_full_offset_len;
  }
  memcpy(&elem_dst_full[i], elem_dst, elem_dst_len + 1);
  i += elem_dst_len;
  uint elem_src_full_offset_end = elem_src_full_offset_len + elem_src_len;
  if (elem_src_full[elem_src_full_offset_end] != '\0') {
    const int elem_full_tail_len = (elem_src_full_len - elem_src_full_offset_end);
    memcpy(&elem_dst_full[i], &elem_src_full[elem_src_full_offset_end], elem_full_tail_len + 1);
    i += elem_full_tail_len;
  }
  BLI_assert((strlen(elem_dst_full) == elem_final_len) && (i == elem_final_len));
  return elem_dst_full;
}

/** \} */

/* -------------------------------------------------------------------- */
/** \name Versioning
 * \{ */

static uint strhash_pair_p(const void *ptr)
{
  const char *const *pair = ptr;
  return (BLI_ghashutil_strhash_p(pair[0]) ^ BLI_ghashutil_strhash_p(pair[1]));
}

static bool strhash_pair_cmp(const void *a, const void *b)
{
  const char *const *pair_a = a;
  const char *const *pair_b = b;
  return (STREQ(pair_a[0], pair_b[0]) && STREQ(pair_a[1], pair_b[1])) ? false : true;
}

void DNA_alias_maps(enum eDNA_RenameDir version_dir, GHash **r_struct_map, GHash **r_elem_map)
{
  GHash *struct_map_local = NULL;
  if (r_struct_map) {
    const char *data[][2] = {
#define DNA_STRUCT_RENAME(old, new) {#old, #new},
#define DNA_STRUCT_RENAME_ELEM(struct_name, old, new)
#include "dna_rename_defs.h"
#undef DNA_STRUCT_RENAME
#undef DNA_STRUCT_RENAME_ELEM
    };

    int elem_key, elem_val;
    if (version_dir == DNA_RENAME_ALIAS_FROM_STATIC) {
      elem_key = 0;
      elem_val = 1;
    }
    else {
      elem_key = 1;
      elem_val = 0;
    }
    GHash *struct_map = BLI_ghash_str_new_ex(__func__, ARRAY_SIZE(data));
    for (int i = 0; i < ARRAY_SIZE(data); i++) {
      BLI_ghash_insert(struct_map, (void *)data[i][elem_key], (void *)data[i][elem_val]);
    }
    *r_struct_map = struct_map;

    /* We know the direction of this, for local use. */
    struct_map_local = BLI_ghash_str_new_ex(__func__, ARRAY_SIZE(data));
    for (int i = 0; i < ARRAY_SIZE(data); i++) {
      BLI_ghash_insert(struct_map_local, (void *)data[i][1], (void *)data[i][0]);
    }
  }

  if (r_elem_map != NULL) {
    const char *data[][3] = {
#define DNA_STRUCT_RENAME(old, new)
#define DNA_STRUCT_RENAME_ELEM(struct_name, old, new) {#struct_name, #old, #new},
#include "dna_rename_defs.h"
#undef DNA_STRUCT_RENAME
#undef DNA_STRUCT_RENAME_ELEM
    };

    int elem_key, elem_val;
    if (version_dir == DNA_RENAME_ALIAS_FROM_STATIC) {
      elem_key = 1;
      elem_val = 2;
    }
    else {
      elem_key = 2;
      elem_val = 1;
    }
    GHash *elem_map = BLI_ghash_new_ex(
        strhash_pair_p, strhash_pair_cmp, __func__, ARRAY_SIZE(data));
    for (int i = 0; i < ARRAY_SIZE(data); i++) {
      const char **str_pair = MEM_mallocN(sizeof(char *) * 2, __func__);
      str_pair[0] = BLI_ghash_lookup_default(struct_map_local, data[i][0], (void *)data[i][0]);
      str_pair[1] = data[i][elem_key];
      BLI_ghash_insert(elem_map, (void *)str_pair, (void *)data[i][elem_val]);
    }
    *r_elem_map = elem_map;
  }

  if (struct_map_local) {
    BLI_ghash_free(struct_map_local, NULL, NULL);
  }
}

#undef DNA_MAKESDNA

/** \} */

/* -------------------------------------------------------------------- */
/** \name Struct Name Legacy Hack
 * \{ */

/**
 * DNA Compatibility Hack
 * ======================
 *
 * Only keep this for compatibility: **NEVER ADD NEW STRINGS HERE**.
 *
 * The renaming here isn't complete, references to the old struct names
 * are still included in DNA, now fixing these struct names properly
 * breaks forward compatibility. Leave these as-is, but don't add to them!
 * See D4342#98780
 */
const char *DNA_struct_rename_legacy_hack_static_from_alias(const char *name)
{
  /* 'bScreen' replaces the old IrisGL 'Screen' struct */
  if (STREQ("bScreen", name)) {
    return "Screen";
  }
  /* Groups renamed to collections in 2.8 */
  if (STREQ("Collection", name)) {
    return "Group";
  }
  if (STREQ("CollectionObject", name)) {
    return "GroupObject";
  }
  return name;
}

const char *DNA_struct_rename_legacy_hack_alias_from_static(const char *name)
{
  /* 'bScreen' replaces the old IrisGL 'Screen' struct */
  if (STREQ("Screen", name)) {
    return "bScreen";
  }
  /* Groups renamed to collections in 2.8 */
  if (STREQ("Group", name)) {
    return "Collection";
  }
  if (STREQ("GroupObject", name)) {
    return "CollectionObject";
  }
  return name;
}

/** \} */