#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <strings.h>

extern const char *__progname;

#include "seq.h"
#include "folder.h"
#include "system.h"
#include "context.h"

static int nfolders;
static FOLDER **folders;

static void get_folder_list(int ac, char **av)
{
 int errs;

 errs = 0;
 nfolders = 0;
 folders = 0;
 for (ac--,av++;ac;ac--,av++)
  { FOLDER *f;
    char *ep;
    if ((**av == '+') && folder_lookup(1+*av,&f,&ep) && !*ep)
     { nfolders ++;
       folders = realloc(folders,nfolders*sizeof(FOLDER *));
       folders[nfolders-1] = f;
     }
    else
     { fprintf(stderr,"%s: `%s': not a folder\n",__progname,*av);
       errs ++;
     }
  }
 if (errs) exit(1);
 if (nfolders == 0)
  { char *curfname;
    FOLDER *f;
    curfname = context_lookup("folder");
    if (curfname == 0)
     { fprintf(stderr,"%s: no current folder\n",__progname);
       exit(1);
     }
    if (! folder_lookup(curfname,&f,0))
     { fprintf(stderr,"%s: current folder name (%s) is invalid\n",__progname,curfname);
       exit(1);
     }
    nfolders = 1;
    folders = malloc(sizeof(FOLDER *));
    *folders = f;
  }
}

static int seq_renumber(SEQ *s, void *mnvv)
{
 if (seq_test(s,((int *)mnvv)[0]))
  { seq_remove(s,((int *)mnvv)[0]);
    seq_add(s,((int *)mnvv)[1]);
  }
 return(0);
}

static void pack_folder(FOLDER *f)
{
 int nmsgs;
 int *msgs;
 char *mf;
 int i;
 SEQS *ss;
 int mnv[2];

 if (folder_lock(f,FOLDER_WAIT|FOLDER_EXCLUSIVE) < 0)
  { fprintf(stderr,"%s: can't lock +%s: %s\n",__progname,folder_name(f),strerror(errno));
    return;
  }
 nmsgs = folder_get_msgnos(f,0,-1,0);
 if (nmsgs < 1)
  { folder_unlock(f);
    return;
  }
 ss = seqs_open(f);
 msgs = malloc(nmsgs*2*sizeof(int));
 mf = malloc(nmsgs);
 if (folder_get_msgnos(f,nmsgs,0,msgs) != nmsgs)
  { fprintf(stderr,"%s: folder phase error on +%s\n",__progname,folder_name(f));
    exit(1);
  }
 for (i=0;i<nmsgs;i++)
  { if (msgs[i] != i+1)
     { MESSAGE *om;
       MESSAGE *nm;
       if (msgs[i] < i+1)
	{ fprintf(stderr,"%s: impossible message number in +%s\n",__progname,folder_name(f));
punt:;
	  seqs_abort(ss);
	  folder_unlock(f);
	  return;
	}
       om = message_make(f,msgs[i]);
       nm = message_make(f,i+1);
       if (message_open(nm,O_RDONLY,0) >= 0)
	{ fprintf(stderr,"%s: packing onto existing message in +%s?\n",__progname,folder_name(f));
punt2:;
	  message_close(nm);
	  message_free(om);
	  message_free(nm);
	  goto punt;
	}
       if (rename(message_path(om),message_path(nm)) < 0)
	{ fprintf(stderr,"%s: can't rename %d to %d in +%s: %s\n",__progname,message_number(om),message_number(nm),folder_name(f),strerror(errno));
	  goto punt2;
	}
       mnv[0] = msgs[i];
       mnv[1] = i + 1;
       seqs_forall(ss,&mnv[0],seq_renumber);
       message_free(om);
       message_free(nm);
     }
  }
 seqs_close(ss);
 folder_unlock(f);
}

static void pack_folders(void)
{
 int fno;

 for (fno=0;fno<nfolders;fno++) pack_folder(folders[fno]);
}

int main(int, char **);
int main(int ac, char **av)
{
 if (system_lock(SYS_SHARED|SYS_WAIT) < 0)
  { fprintf(stderr,"%s: can't lock system: %s\n",__progname,strerror(errno));
    exit(1);
  }
 get_folder_list(ac,av);
 pack_folders();
 system_unlock();
 exit(0);
}