/*

 * Copyright (C) 2005 Junio C Hamano

 */

#include "git-compat-util.h"

#include "gettext.h"

#include "diff.h"

#include "diffcore.h"

#include "wildmatch.h"

static char **order;

static int order_cnt;

static void prepare_order(const char *orderfile)

{

  int cnt, pass;

  struct strbuf sb = STRBUF_INIT;

  const char *cp, *endp;

  ssize_t sz;

  if (order)

    return;

  sz = strbuf_read_file(&sb, orderfile, 0);

  if (sz < 0)

    die_errno(_("failed to read orderfile '%s'"), orderfile);

  endp = sb.buf + sz;

  for (pass = 0; pass < 2; pass++) {

    cnt = 0;

    cp = sb.buf;

    while (cp < endp) {

      const char *ep;

      for (ep = cp; ep < endp && *ep != '\n'; ep++)

        ;

      /* cp to ep has one line */

      if (*cp == '\n' || *cp == '#')

        ; /* comment */

      else if (pass == 0)

        cnt++;

      else {

        order[cnt] = xmemdupz(cp, ep - cp);

        cnt++;

      }

      if (ep < endp)

        ep++;

      cp = ep;

    }

    if (pass == 0) {

      order_cnt = cnt;

      ALLOC_ARRAY(order, cnt);

    }

  }

  strbuf_release(&sb);

}

static int match_order(const char *path)

{

  int i;

  static struct strbuf p = STRBUF_INIT;

  for (i = 0; i < order_cnt; i++) {

    strbuf_reset(&p);

    strbuf_addstr(&p, path);

    while (p.buf[0]) {

      char *cp;

      if (!wildmatch(order[i], p.buf, 0))

        return i;

      cp = strrchr(p.buf, '/');

      if (!cp)

        break;

      *cp = 0;

    }

  }

  return order_cnt;

}

static int compare_objs_order(const void *a_, const void *b_)

{

  struct obj_order const *a, *b;

  a = (struct obj_order const *)a_;

  b = (struct obj_order const *)b_;

  if (a->order != b->order)

    return a->order - b->order;

  return a->orig_order - b->orig_order;

}

void order_objects(const char *orderfile, obj_path_fn_t obj_path,

       struct obj_order *objs, int nr)

{

  int i;

  if (!nr)

    return;

  prepare_order(orderfile);

  for (i = 0; i < nr; i++) {

    objs[i].orig_order = i;

    objs[i].order = match_order(obj_path(objs[i].obj));

  }

  QSORT(objs, nr, compare_objs_order);

}

static const char *pair_pathtwo(void *obj)

{

  struct diff_filepair *pair = (struct diff_filepair *)obj;

  return pair->two->path;

}

void diffcore_order(const char *orderfile)

{

  struct diff_queue_struct *q = &diff_queued_diff;

  struct obj_order *o;

  int i;

  if (!q->nr)

    return;

  ALLOC_ARRAY(o, q->nr);

  for (i = 0; i < q->nr; i++)

    o[i].obj = q->queue[i];

  order_objects(orderfile, pair_pathtwo, o, q->nr);

  for (i = 0; i < q->nr; i++)

    q->queue[i] = o[i].obj;

  free(o);

  return;

}