/*
 *  Empire - A multi-player, client/server Internet based war game.
 *  Copyright (C) 1986-2006, Dave Pare, Jeff Bailey, Thomas Ruschak,
 *                           Ken Stevens, Steve McClure
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  ---
 *
 *  See files README, COPYING and CREDITS in the root of the source
 *  tree for related information and legal notices.  It is expected
 *  that future projects/authors will amend these files as needed.
 *
 *  ---
 *
 *  xundump.c: Load back xdump output
 * 
 *  Known contributors to this file:
 *     Ron Koenderink, 2005
 *     Markus Armbruster, 2005-2006
 */

/*
 * FIXME:
 * - Normalize terminology: table/rows/columns or file/records/fields
 * - Loading tables with NSC_STRING elements more than once leaks memory
 * TODO:
 * - Check each partial table supplies the same rows
 * - Check EFF_CFG tables are dense
 * - Symbolic references to non-symbol tables
 * - Symbolic array indexes
 * TODO, but hardly worth the effort:
 * - Permit reordering of array elements
 * - Permit repetition of array elements in split tables
 */

#include <config.h>

#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <time.h>
#include "file.h"
#include "match.h"
#include "nsc.h"
#include "optlist.h"
#include "prototypes.h"

static char *fname;
static int lineno;
static int human;
static int ellipsis, is_partial;
static int cur_type, cur_id;
static void *cur_obj;
static int cur_obj_is_blank;
static int nflds;
static struct castr **fldca;
static int *fldidx;
static int *caflds;
static unsigned char *caseen;

static int gripe(char *, ...) ATTRIBUTE((format (printf, 1, 2)));
static int deffld(int, char *, int);
static int defellipsis(int fldno);
static int chkflds(void);
static int setnum(int, double);
static int setstr(int, char *);
static int xunsymbol(char *, struct castr *, int);
static int setsym(int, char *);
static int mtsymset(int, long *);
static int add2symset(int, long *, char *);
static int xundump1(FILE *, int, struct castr *);
static int xundump2(FILE *, int, struct castr *);

static int
gripe(char *fmt, ...)
{
    va_list ap;

    fprintf(stderr, "%s:%d: ", fname, lineno);
    va_start(ap, fmt);
    vfprintf(stderr, fmt, ap);
    va_end(ap);
    putc('\n', stderr);

    return -1;
}

static int
skipfs(FILE *fp)
{
    int ch;

    do {
	ch = getc(fp);
    } while (ch == ' ' || ch == '\t');

    if (ch == '#') {
	do {
	    ch = getc(fp);
	} while (ch != EOF && ch != '\n');
    }

    return ch;
}

static int
getid(FILE *fp, char *buf)
{
    int n;
    if (fscanf(fp, "%1023[^#()<>=#\" \t\n]%n", buf, &n) != 1
	|| !isalpha(buf[0]))
	return -1;
    return n;
}

static char *
xuesc(char *buf)
{
    char *src, *dst;
    int octal_chr, n;

    dst = buf;
    src = buf;
    while (*src) {
	if (*src == '\\') {
	    if (sscanf(++src, "%3o%n", &octal_chr, &n) != 1 || n != 3)
		return NULL;
	    *dst++ = (char)octal_chr;
	    src += 3;
	} else
	    *dst++ = *src++;
    }
    *dst = '\0';
    return buf;
}

static int
xufldname(FILE *fp, int i)
{
    int ch, idx;
    char buf[1024];

    ch = skipfs(fp);
    switch (ch) {
    case EOF:
	return gripe("Unexpected EOF");
    case '\n':
	if (chkflds() < 0)
	    return -1;
	lineno++;
	return 0;
    case '.':
	if (getc(fp) != '.' || getc(fp) != '.')
	    return gripe("Junk in header field %d", i + 1);
	if (i == 0)
	    return gripe("... not allowed in field 1");
	if (defellipsis(i) < 0)
	    return -1;
	ch = skipfs(fp);
	if (ch != EOF && ch != '\n')
	    return gripe("Junk after ...");
	ungetc(ch, fp);
	return 1;
    default:
	ungetc(ch, fp);
	if (getid(fp, buf) < 0)
	    return gripe("Junk in header field %d", i + 1);
	ch = getc(fp);
	if (ch != '(') {
	    ungetc(ch, fp);
	    return deffld(i, buf, -1);
	}
	ch = getc(fp);
	ungetc(ch, fp);
	if (isdigit(ch) || ch == '-' || ch == '+') {
	    if (fscanf(fp, "%d", &idx) != 1)
		return gripe("Malformed number in index of header field %d",
			     i + 1);
	    if (idx < 0)
		return gripe("Index must not be negative in header field %d",
			     i + 1);
	} else {
	    if (getid(fp, buf) < 0)
		return gripe("Malformed index in header field %d", i + 1);
	    return gripe("Symbolic index in header field %d not yet implemented",
			 i + 1);
	}
	ch = getc(fp);
	if (ch != ')')
	    return gripe("Malformed index in header field %d", i + 1);
	return deffld(i, buf, idx);
    }
}

static int
xufld(FILE *fp, int i)
{
    int ch;
    char buf[1024];
    double dbl;
    long set;

    ch = skipfs(fp);
    switch (ch) {
    case EOF:
	return gripe("Unexpected EOF");
    case '\n':
	if (i != nflds) {
	    if (fldca[i]->ca_type != NSC_STRINGY && fldca[i]->ca_len)
		return gripe("Field %s(%d) missing",
			     fldca[i]->ca_name, fldidx[i]);
	    return gripe("Field %s missing", fldca[i]->ca_name);
	}
	lineno++;
	return 0;
    case '+': case '-': case '.':
    case '0': case '1': case '2': case '3': case '4':
    case '5': case '6': case '7': case '8': case '9':
	ungetc(ch, fp);
	if (fscanf(fp, "%lg", &dbl) != 1)
	    return gripe("Malformed number in field %d", i + 1);
	return setnum(i, dbl);
    case '"':
	ch = getc(fp);
	if (ch == '"')
	    buf[0] = 0;
	else {
	    ungetc(ch, fp);
	    if (fscanf(fp, "%1023[^\"\n]", buf) != 1 || getc(fp) != '"')
		return gripe("Malformed string in field %d", i + 1);
	    if (!xuesc(buf))
		return gripe("Invalid escape sequence in field %d",
			     i + 1);
	}
	return setstr(i, buf);
    case '(':
	if (mtsymset(i, &set) < 0)
	    return -1;
	for (;;) {
	    ch = skipfs(fp);
	    if (ch == EOF || ch == '\n')
		return gripe("Unmatched '(' in field %d", i + 1);
	    if (ch == ')')
		break;
	    ungetc(ch, fp);
	    if (getid(fp, buf) < 0)
		return gripe("Junk in field %d", i + 1);
	    if (add2symset(i, &set, buf) < 0)
		return -1;
	}
	return setnum(i, set);
    default:
	ungetc(ch, fp);
	if (getid(fp, buf) < 0)
	    return gripe("Junk in field %d", i + 1);
	if (!strcmp(buf, "nil"))
	    return setstr(i, NULL);
	else
	    return setsym(i, buf);
    }
}

static int
xuflds(FILE *fp, int (*parse)(FILE *, int))
{
    int i, ch, res;

    for (i = 0; ; i++) {
	res = parse(fp, i);
	if (res < 0)
	    return -1;
	if (res == 0)
	    return i;
	ch = getc(fp);
	if (ch == '\n')
	    ungetc(ch, fp);
	else if (ch != ' ' && ch != '\t')
	    return gripe("Bad field separator after field %d", i + 1);
    }
}

static int
deffld(int fldno, char *name, int idx)
{
    struct castr *ca = ef_cadef(cur_type);
    int res;

    res = stmtch(name, ca, offsetof(struct castr, ca_name),
		     sizeof(struct castr));
    if (res < 0)
	return gripe("Header %s of field %d is %s", name, fldno + 1,
		     res == M_NOTUNIQUE ? "ambiguous" : "unknown");
    if (ca[res].ca_type != NSC_STRINGY && ca[res].ca_len != 0) {
	if (idx < 0)
	    return gripe("Header %s requires an index in field %d",
			 ca[res].ca_name, fldno + 1);
	if (idx >= ca[res].ca_len)
	    return gripe("Header %s(%d) index out of bounds in field %d",
			 ca[res].ca_name, idx, fldno + 1);
	if (idx < caflds[res])
	    return gripe("Duplicate header %s(%d) in field %d",
			 ca[res].ca_name, idx, fldno + 1);
	if (idx > caflds[res])
	    return gripe("Expected header %s(%d) in field %d",
			 ca[res].ca_name, caflds[res], fldno + 1);
    } else {
	if (idx >= 0)
	    return gripe("Header %s doesn't take an index in field %d",
			 ca[res].ca_name, fldno + 1);
	idx = 0;
	if (caflds[res] && !caseen[res])
	    /* FIXME doesn't catch dupes within table part when caseen[res] */
	    return gripe("Duplicate header %s in field %d",
			 ca[res].ca_name, fldno + 1);
    }
    fldca[fldno] = &ca[res];
    fldidx[fldno] = idx;
    if (!caseen[res])
	caflds[res]++;
    return 1;
}

static int
defellipsis(int fldno)
{
    struct castr *ca = ef_cadef(cur_type);

    if (ca[0].ca_table != cur_type)
	return gripe("Table %s doesn't support ...", ef_nameof(cur_type));
    ellipsis = fldno;
    is_partial = 1;
    return 0;
}

static int
chkflds(void)
{
    struct castr *ca = ef_cadef(cur_type);
    int i, len, res = 0;

    if (is_partial) {
	/* Require index field */
	if (!caflds[0])
	    return gripe("Header field %s required with ...", ca[0].ca_name);
	/* Want the index field again in continued table: */
	caflds[0] = 0;
	return 0;
    }

    for (i = 0; ca[i].ca_name; i++) {
	if (ca[i].ca_flags & NSC_EXTRA)
	    continue;
	len = ca[i].ca_type != NSC_STRINGY ? ca[i].ca_len : 0;
	if (!len && !caflds[i])
	    res = gripe("Header field %s missing", ca[i].ca_name);
	else if (len && caflds[i] == len - 1)
	    res = gripe("Header field %s(%d) missing",
			ca[i].ca_name, len - 1);
	else if (len && caflds[i] < len - 1)
	    res = gripe("Header fields %s(%d) ... %s(%d) missing",
			ca[i].ca_name, caflds[i], ca[i].ca_name, len - 1);
    }

    return res;
}

static struct castr *
getfld(int fldno, int *idx)
{
    if (fldno >= nflds) {
	gripe("Too many fields, expected only %d", nflds);
	return NULL;
    }
    if (CANT_HAPPEN(fldno < 0))
	return NULL;
    if (idx)
	*idx = fldidx[fldno];
    return fldca[fldno];
}

static int
fldval_must_match(int fldno)
{
    struct castr *ca = ef_cadef(cur_type);
    int i = fldca[fldno] - ca;

    return (!cur_obj_is_blank && (fldca[fldno]->ca_flags & NSC_CONST))
	|| caseen[i];
}

static void *
getobj(struct castr *ca, int altid)
{
    struct empfile *ep = &empfile[cur_type];
    int need_sentinel = !EF_IS_GAME_STATE(cur_type);

    if (!cur_obj) {
	if (ca->ca_table == cur_type)
	    cur_id = altid;
	cur_obj_is_blank = cur_id >= ep->fids;
	if (cur_obj_is_blank) {
	    /* TODO grow cache (and posssibly file) unless EFF_STATIC */
	    if (cur_id < ep->csize - !!need_sentinel)
		ep->cids = ep->fids = cur_id + 1;
	    /* else: ef_ptr() will fail */
	}
	cur_obj = ef_ptr(cur_type, cur_id);
    	if (!cur_obj)
	    gripe("Can't put ID %d into table %s, it holds only 0..%d.",
		  cur_id, ep->name, ep->fids - 1);
    }

    return cur_obj;
}

static int
setnum(int fldno, double dbl)
{
    struct castr *ca;
    int idx;
    char *memb_ptr;
    double old;

    ca = getfld(fldno, &idx);
    if (!ca)
	return -1;

    memb_ptr = getobj(ca, (int)dbl);
    if (!memb_ptr)
	return -1;
    memb_ptr += ca->ca_off;

    /* FIXME check assignment preserves value */
    switch (ca->ca_type) {
    case NSC_CHAR:
	old = ((signed char *)memb_ptr)[idx];
	((signed char *)memb_ptr)[idx] = (signed char)dbl;
	break;
    case NSC_UCHAR:
    case NSC_HIDDEN:
	old = ((unsigned char *)memb_ptr)[idx];
	((unsigned char *)memb_ptr)[idx] = (unsigned char)dbl;
	break;
    case NSC_SHORT:
	old = ((short *)memb_ptr)[idx];
	((short *)memb_ptr)[idx] = (short)dbl;
	break;
    case NSC_USHORT:
	old = ((unsigned short *)memb_ptr)[idx];
	((unsigned short *)memb_ptr)[idx] = (unsigned short)dbl;
	break;
    case NSC_INT:
	old = ((int *)memb_ptr)[idx];
	((int *)memb_ptr)[idx] = (int)dbl;
	break;
    case NSC_LONG:
	old = ((long *)memb_ptr)[idx];
	((long *)memb_ptr)[idx] = (long)dbl;
	break;
    case NSC_XCOORD:
	old = ((coord *)memb_ptr)[idx];
	/* FIXME use variant of xrel() that takes orig instead of nation */
	if (old >= WORLD_X / 2)
	    old -= WORLD_X;
	((coord *)memb_ptr)[idx] = XNORM((coord)dbl);
	break;
    case NSC_YCOORD:
	old = ((coord *)memb_ptr)[idx];
	/* FIXME use variant of yrel() that takes orig instead of nation */
	if (old >= WORLD_Y / 2)
	    old -= WORLD_Y;
	((coord *)memb_ptr)[idx] = YNORM((coord)dbl);
	break;
    case NSC_FLOAT:
	old = ((float *)memb_ptr)[idx];
	((float *)memb_ptr)[idx] = (float)dbl;
	break;
    case NSC_DOUBLE:
	old = ((double *)memb_ptr)[idx];
	((double *)memb_ptr)[idx] = dbl;
	break;
    case NSC_TIME:
	old = ((time_t *)memb_ptr)[idx];
	((time_t *)memb_ptr)[idx] = (time_t)dbl;
	break;
    default:
	return gripe("Field %d doesn't take numbers", fldno + 1);
    }

    if (fldval_must_match(fldno) && old != dbl)
	return gripe("Value for field %d must be %g", fldno + 1, old);

    return 1;
}

static int
setstr(int fldno, char *str)
{
    struct castr *ca;
    int must_match, idx;
    size_t len;
    char *memb_ptr, *old;

    ca = getfld(fldno, &idx);
    if (!ca)
	return -1;

    memb_ptr = getobj(ca, cur_id);
    if (!memb_ptr)
	return -1;
    memb_ptr += ca->ca_off;
    must_match = fldval_must_match(fldno);

    switch (ca->ca_type) {
    case NSC_STRING:
	old = ((char **)memb_ptr)[idx];
	if (!must_match)
	    ((char **)memb_ptr)[idx] = str ? strdup(str) : NULL;
	len = 65535;		/* really SIZE_MAX, but that's C99 */
	break;
    case NSC_STRINGY:
	if (CANT_HAPPEN(idx))
	    return -1;
	if (!str)
	    return gripe("Field %d doesn't take nil", fldno + 1);
	len = ca->ca_len;
	if (strlen(str) > len)
	    return gripe("Field %d takes at most %d characters",
			 fldno + 1, len);
	old = memb_ptr;
	if (!must_match)
	    strncpy(memb_ptr, str, len);
	break;
    default:
	return gripe("Field %d doesn't take strings", fldno + 1);
    }

    if (must_match) {
	if (old && (!str || strncmp(old, str, len)))
	    return gripe("Value for field %d must be \"%.*s\"",
			 fldno + 1, (int)len, old);
	if (!old && str)
	    return gripe("Value for field %d must be nil", fldno + 1);
    }

    return 1;
}

static int
xunsymbol(char *id, struct castr *ca, int n)
{
    int i = ef_elt_byname(ca->ca_table, id);
    if (i < 0)
	return gripe("%s %s symbol `%s' in field %d",
		     i == M_NOTUNIQUE ? "Ambiguous" : "Unknown",
		     ca->ca_name, id, n + 1);
    return i;
}

static int
symval(struct castr *ca, int i)
{
    int type = ca->ca_table;

    if (ef_check(type) < 0)
	return -1;
    if (ef_cadef(type) == symbol_ca)
	/* symbol table, value is in the table */
	return ((struct symbol *)ef_ptr(type, i))->value;
    /* value is the table index */
    return i;
}

static int
setsym(int fldno, char *sym)
{
    struct castr *ca;
    int i;

    ca = getfld(fldno, NULL);
    if (!ca)
	return -1;

    if (ca->ca_table == EF_BAD || (ca->ca_flags & NSC_BITS))
	return gripe("Field %d doesn't take symbols", fldno + 1);

    i = xunsymbol(sym, ca, fldno);
    if (i < 0)
	return -1;
    return setnum(fldno, symval(ca, i));
}

static int
mtsymset(int fldno, long *set)
{
    struct castr *ca;

    ca = getfld(fldno, NULL);
    if (!ca)
	return -1;

    if (ca->ca_table == EF_BAD || ef_cadef(ca->ca_table) != symbol_ca
	|| !(ca->ca_flags & NSC_BITS))
	return gripe("Field %d doesn't take symbol sets", fldno + 1);
    *set = 0;
    return 0;
}

static int
add2symset(int fldno, long *set, char *sym)
{
    struct castr *ca;
    int i;

    ca = getfld(fldno, NULL);
    if (!ca)
	return -1;

    i = xunsymbol(sym, ca, fldno);
    if (i < 0)
	return -1;
    *set |= symval(ca, i);
    return 0;
}

static int
xuheader(FILE *fp, int expected_table)
{
    char name[64];
    int res, ch;
    int type;

    while ((ch = skipfs(fp)) == '\n')
	lineno++;
    if (ch == EOF && expected_table == EF_BAD)
	return -2;
    ungetc(ch, fp);

    human = ch == 'c';
    res = -1;
    if ((human
         ? fscanf(fp, "config%*[ \t]%63[^ \t#\n]%n", name, &res) != 1
         : fscanf(fp, "XDUMP%*[ \t]%63[^ \t#\n]%*[ \t]%*[^ \t#\n]%n",
                  name, &res) != 1) || res < 0)
	return gripe("Expected xdump header");

    type = ef_byname(name);
    if (type < 0)
	return gripe("Unknown table `%s'", name);
    if (expected_table != EF_BAD && expected_table != type)
	return gripe("Expected table `%s', not `%s'",
		     ef_nameof(expected_table), name);

    if (!ef_cadef(type) || !(ef_flags(type) & EFF_MEM)) {
	CANT_HAPPEN(expected_table != EF_BAD);
	return gripe("Table `%s' is not permitted here", name);
    }

    if (skipfs(fp) != '\n')
	return gripe("Junk after xdump header");
    lineno++;

    return type;
}

static int
xuheader1(FILE *fp, int type, struct castr ca[])
{
    struct castr **fca;
    int *fidx;
    int ch, i, j, n;

    if (human) {
	while ((ch = skipfs(fp)) == '\n')
	    lineno++;
	ungetc(ch, fp);
	ellipsis = 0;
	nflds = xuflds(fp, xufldname);
	if (nflds < 0)
	    return -1;
	nflds -= ellipsis != 0;
    } else {
	fca = fldca;
	fidx = fldidx;

	for (i = 0; ca[i].ca_name; i++) {
	    if ((ca[i].ca_flags & NSC_EXTRA))
		continue;
	    n = ca[i].ca_type != NSC_STRINGY ? ca[i].ca_len : 0;
	    j = 0;
	    do {
		*fca++ = &ca[i];
		*fidx++ = j;
	    } while (++j < n);
	}

	nflds = fidx - fldidx;
    }

    return 0;
}

static int
xutrailer(FILE *fp, int type, int row)
{
    int rows, res;

    res = -1;
    if (human) {
	if (fscanf(fp, "config%n",  &res) != 0 || res < 0)
	    return gripe("Malformed table footer");
    } else {
	if (fscanf(fp, "%d", &rows) != 1)
	    return gripe("Malformed table footer");
	if (row != rows)
	    return gripe("Read %d rows, which doesn't match footer "
			 "%d rows", row, rows);
    }
    if (skipfs(fp) != '\n')
	return gripe("Junk after table footer");
    lineno++;

    return 0;
}

int
xundump(FILE *fp, char *file, int expected_table)
{
    struct castr *ca;
    int type, nca, nf, i, ch;

    if (fname != file) {
        fname = file;
	lineno = 1;
    }

    if ((type = xuheader(fp, expected_table)) < 0)
	return type;

    ca = ef_cadef(type);
    if (CANT_HAPPEN(!ca))
	return -1;

    nca = nf = 0;
    for (i = 0; ca[i].ca_name; i++) {
	nca++;
	if (!(ca[i].ca_flags & NSC_EXTRA))
	    nf += MAX(1, ca[i].ca_type != NSC_STRINGY ? ca[i].ca_len : 0);
    }
    fldca = calloc(nf, sizeof(*fldca));
    fldidx = calloc(nf, sizeof(*fldidx));
    caflds = calloc(nca, sizeof(*caflds));
    caseen = calloc(nca, sizeof(*caseen));
    cur_type = type;

    if (xundump2(fp, type, ca) < 0)
	type = EF_BAD;

    free(caseen);
    free(caflds);
    free(fldidx);
    free(fldca);

    /* Skip empty lines so that callers can easily check for EOF */
    while ((ch = skipfs(fp)) == '\n')
	lineno++;
    ungetc(ch, fp);

    return type;
}

static int
xundump2(FILE *fp, int type, struct castr *ca)
{
    int i;

    is_partial = 0;
    for (;;) {
	if (xuheader1(fp, type, ca) < 0)
	    return -1;
	if (xundump1(fp, type, ca) < 0)
	    return -1;
	if (!ellipsis)
	    return 0;
	for (i = 0; ca[i].ca_name; i++)
	    caseen[i] = caflds[i] != 0;
	if (xuheader(fp, type) < 0)
	    return -1;
    }
}

static int
xundump1(FILE *fp, int type, struct castr *ca)
{
    struct empfile *ep = &empfile[type];
    int need_sentinel = !EF_IS_GAME_STATE(type);
    int row, n, ch;

    n = 0;
    for (row = 0;; ++row) {
	while ((ch = skipfs(fp)) == '\n')
	    lineno++;
	if (ch == '/')
	    break;
	ungetc(ch, fp);
	cur_obj = NULL;
	cur_id = row;
	if (xuflds(fp, xufld) < 0)
	    return -1;
	n = MAX(n, cur_id + 1);
    }

    if (CANT_HAPPEN(n > ep->fids))
	n = ep->fids;
    if (n < ep->fids) {
	if (EF_IS_GAME_STATE(type) && n != ep->csize)
	    /* TODO truncate file */
	    gripe("Warning: should resize table %s from %d to %d, not implemented",
		  ef_nameof(type), ep->csize, n);
	else if (type >= EF_SHIP_CHR && type <= EF_NUKE_CHR)
	    ep->cids = ep->fids = n;
	else
	    return gripe("Table %s requires %d rows, got %d",
			 ef_nameof(type), ep->fids, n);
    }

    if (need_sentinel) {
	if (CANT_HAPPEN(n >= ep->csize))
	    return gripe("No space for sentinel");
	memset(ep->cache + ep->size * n, 0, ep->size);
    }

    if (xutrailer(fp, type, row) < 0)
	return -1;

    return 0;
}