/**
 * @file braces.cpp
 * Adds or removes braces.
 *
 * @author  Ben Gardner
 * @license GPL v2+
 *
 * $Id: sorting.cpp 1034 2007-11-27 00:24:40Z bengardner $
 */
#include "uncrustify_types.h"
#include "chunk_list.h"
#include "prototypes.h"


/**
 * Compare two series of chunks, starting with the given ones.
 */
static int compare_chunks(chunk_t *pc1, chunk_t *pc2)
{
   if (pc1 == pc2)
   {
      return(0);
   }

   while ((pc1 != NULL) && (pc2 != NULL))
   {
      int min_len = (pc1->len < pc2->len) ? pc1->len : pc2->len;
      int ret_val = memcmp(pc1->str, pc2->str, min_len);

      if (ret_val != 0)
      {
         return(ret_val);
      }
      if (pc1->len != pc2->len)
      {
         return(pc1->len - pc2->len);
      }

      /* Same word, same length. Step to the next chunk. */
      pc1 = chunk_get_next(pc1);
      pc2 = chunk_get_next(pc2);

      /* If we hit a newline or NULL, we are done */
      if ((pc1 == NULL) || chunk_is_newline(pc1) ||
          (pc2 == NULL) || chunk_is_newline(pc2))
      {
         break;
      }
   }

   if ((pc1 == NULL) || !chunk_is_newline(pc2))
   {
      return(-1);
   }
   if (!chunk_is_newline(pc1))
   {
      return(1);
   }
   return(0);
}

/**
 * Sorting should be pretty rare and should usually only include a few chunks.
 * We need to minimize the number of swaps, as those are expensive.
 * So, we do a min sort.
 */
static void do_the_sort(chunk_t **chunks, int num_chunks)
{
   int start_idx, min_idx, idx;

   LOG_FMT(LSORT, "%s: %d chunks:", __func__, num_chunks);
   for (idx = 0; idx < num_chunks; idx++)
   {
      LOG_FMT(LSORT, " [%.*s]", chunks[idx]->len, chunks[idx]->str);
   }
   LOG_FMT(LSORT, "\n");

   for (start_idx = 0; start_idx < (num_chunks - 1); start_idx++)
   {
      /* Find the index of the minimum value */
      min_idx = start_idx;
      for (idx = start_idx + 1; idx < num_chunks; idx++)
      {
         if (compare_chunks(chunks[idx], chunks[min_idx]) < 0)
         {
            min_idx = idx;
         }
      }

      /* Swap the lines if the minimum isn't the first entry */
      if (min_idx != start_idx)
      {
         chunk_swap_lines(chunks[start_idx], chunks[min_idx]);

         /* Don't need to swap, since we only want the side-effects */
         chunks[min_idx] = chunks[start_idx];
      }
   }
}

void sort_imports(void)
{
   chunk_t *chunks[256];  /* 256 should be enough, right? */
   int     num_chunks = 0;
   chunk_t *pc;
   chunk_t *next;
   chunk_t *p_last = NULL;
   chunk_t *p_imp  = NULL;

   pc = chunk_get_head();
   while (pc != NULL)
   {
      next = chunk_get_next(pc);

      if (chunk_is_newline(pc))
      {
         bool did_import = false;

         if ((p_imp != NULL) && (p_last != NULL) &&
             ((p_last->type == CT_SEMICOLON) ||
              (p_imp->flags & PCF_IN_PREPROC)))
         {
            if (num_chunks < (int)ARRAY_SIZE(chunks))
            {
               chunks[num_chunks++] = p_imp;
            }
            did_import = true;
         }
         if (!did_import || (pc->nl_count > 1))
         {
            if (num_chunks > 1)
            {
               do_the_sort(chunks, num_chunks);
            }
            num_chunks = 0;
            memset(chunks, 0, sizeof(chunks));
         }
         p_imp  = NULL;
         p_last = NULL;
      }
      else if (pc->type == CT_IMPORT)
      {
         if (cpd.settings[UO_mod_sort_import].b)
         {
            p_imp = chunk_get_next(pc);
         }
      }
      else if (pc->type == CT_USING)
      {
         if (cpd.settings[UO_mod_sort_using].b)
         {
            p_imp = chunk_get_next(pc);
         }
      }
      else if (pc->type == CT_PP_INCLUDE)
      {
         if (cpd.settings[UO_mod_sort_include].b)
         {
            p_imp  = chunk_get_next(pc);
            p_last = pc;
         }
      }
      else if (!chunk_is_comment(pc))
      {
         p_last = pc;
      }
      pc = next;
   }
}