/*
 * $LynxId: LYJump.c,v 1.43 2012/02/09 13:02:30 tom Exp $
 */
#include <HTUtils.h>
#include <HTAlert.h>
#include <LYUtils.h>
#include <LYStrings.h>
#include <LYGlobalDefs.h>
#include <LYJump.h>
#include <LYKeymap.h>
#include <GridText.h>

#include <LYLeaks.h>

#ifdef _WINDOWS
#include <stdlib.h>		/* bsearch() */
#endif

#ifdef VMS
#include <fab.h>
#endif /* VMS */

struct JumpTable *JThead = NULL;

static int LYCompare(const void *e1, const void *e2);
static unsigned LYRead_Jumpfile(struct JumpTable *jtp);

void LYJumpTable_free(void)
{
    struct JumpTable *cur = JThead;
    struct JumpTable *next;

    while (cur) {
	next = cur->next;
	FREE(cur->msg);
	FREE(cur->file);
	FREE(cur->shortcut);
	if (cur->history) {
	    LYFreeStringList(cur->history);
	    cur->history = NULL;
	}
	FREE(cur->table);
	FREE(cur->mp);
	FREE(cur);
	cur = next;
    }
    JThead = NULL;
    return;
}

/*
 * Utility for listing shortcuts, making any repeated
 * shortcut the most current in the list. - FM
 */
void LYAddJumpShortcut(HTList *historyp, char *shortcut)
{
    char *tmp = NULL;
    char *old;
    HTList *cur = historyp;

    if (!historyp || isEmpty(shortcut))
	return;

    StrAllocCopy(tmp, shortcut);

    while (NULL != (old = (char *) HTList_nextObject(cur))) {
	if (!strcmp(old, tmp)) {
	    HTList_removeObject(historyp, old);
	    FREE(old);
	    break;
	}
    }
    HTList_addObject(historyp, tmp);

    return;
}

BOOL LYJumpInit(char *config)
{
    struct JumpTable *jtp;
    char *cp;

    /*
     * Create a JumpTable structure.
     */
    jtp = typecalloc(struct JumpTable);

    if (jtp == NULL) {
	outofmem(__FILE__, "LYJumpInit");
    }

    assert(jtp != NULL);

    /*
     * config is JUMPFILE:path[:optional_key[:optional_prompt]]
     *
     * Skip JUMPFILE.
     */
    cp = strtok(config, ":\n");
    if (!cp) {
	FREE(jtp);
	return FALSE;
    }

    /*
     * Get the path.
     */
    cp = strtok(NULL, ":\n");
    if (!cp) {
	FREE(jtp);
	return FALSE;
    }
    StrAllocCopy(jtp->file, cp);
#ifdef LY_FIND_LEAKS
    if (!JThead)
	atexit(LYJumpTable_free);
#endif /* LY_FIND_LEAKS */

    /*
     * Get the key, if present.
     */
    cp = strtok(NULL, ":\n");

    /*
     * If no key, check whether we are resetting the default jumps file.
     */
    if (!cp && JThead) {
	struct JumpTable *jtptmp = JThead;

	jumpfile = jtp->file;
	FREE(jtp);
	while (jtptmp && jtptmp->key)
	    jtptmp = jtptmp->next;
	if (!jtptmp)
	    return FALSE;
	StrAllocCopy(jtptmp->file, jumpfile);
	StrAllocCopy(jtptmp->msg, jumpprompt);
	return TRUE;
    }

    /*
     * If a key is present and we have no default, create one,
     * using the path from config, and the current jumpprompt.
     */
    if (cp && !JThead) {
	JThead = jtp;
	StrAllocCopy(JThead->msg, jumpprompt);
	if (!jumpfile)
	    StrAllocCopy(jumpfile, JThead->file);
	jtp = typecalloc(struct JumpTable);

	if (jtp == NULL) {
	    outofmem(__FILE__, "LYJumpInit");
	}

	assert(jtp != NULL);

	StrAllocCopy(jtp->file, JThead->file);
    }

    /*
     * Complete the initialization of config.
     */
    if (cp) {
	jtp->key = remap(cp, "JUMP", FALSE);	/* key is present, (re)map it */
	cp = strtok(NULL, "\n");	/* get prompt, if present */
	if (non_empty(cp))
	    StrAllocCopy(jtp->msg, cp);		/* prompt is present, load it */
	else
	    cp = NULL;
    }
    if (!cp)			/* no prompt, use default */
	StrAllocCopy(jtp->msg, jumpprompt);
    if (jtp->msg[strlen(jtp->msg) - 1] != ' ')	/* ensure a trailing space */
	StrAllocCat(jtp->msg, " ");
    jtp->history = HTList_new();
    jtp->next = JThead;
    JThead = jtp;
    return TRUE;
}

char *LYJump(int key)
{
    static bstring *buf = NULL;

    JumpDatum seeking;
    JumpDatum *found;
    char *bp, *cp;
    struct JumpTable *jtp;
    int ch;
    RecallType recall;
    int ShortcutTotal;
    int ShortcutNum;
    BOOLEAN FirstShortcutRecall = TRUE;

    if (!JThead)
	return NULL;
    jtp = JThead;
    while (jtp && jtp->key && jtp->key != key)
	jtp = jtp->next;
    if (!jtp) {
	char *msg = 0;

	HTSprintf0(&msg, KEY_NOT_MAPPED_TO_JUMP_FILE, key);
	HTAlert(msg);
	FREE(msg);
	return NULL;
    }
    if (!jtp->table)
	jtp->nel = LYRead_Jumpfile(jtp);
    if (jtp->nel == 0)
	return NULL;

    if (!jump_buffer || isEmpty(jtp->shortcut)) {
	BStrCopy0(buf, "");
    } else if (non_empty(jtp->shortcut)) {
	size_t len = (size_t) BStrLen(buf);

	if (strlen(jtp->shortcut) > len) {
	    jtp->shortcut[len] = '\0';
	    BStrCopy0(buf, jtp->shortcut);
	}
    }

    ShortcutTotal = (jtp->history ? HTList_count(jtp->history) : 0);
    if (jump_buffer && !isBEmpty(buf)) {
	recall = ((ShortcutTotal > 1) ? RECALL_URL : NORECALL);
	ShortcutNum = 0;
	FirstShortcutRecall = FALSE;
    } else {
	recall = ((ShortcutTotal >= 1) ? RECALL_URL : NORECALL);
	ShortcutNum = ShortcutTotal;
	FirstShortcutRecall = TRUE;
    }

    statusline(jtp->msg);
    if ((ch = LYgetBString(&buf, VISIBLE, 0, recall)) < 0) {
	/*
	 * User cancelled the Jump via ^G. - FM
	 */
	HTInfoMsg(CANCELLED);
	return NULL;
    }

  check_recall:
    bp = buf->str;
    if (TOUPPER(key) == 'G' && StrNCmp(buf->str, "o ", 2) == 0)
	bp++;
    bp = LYSkipBlanks(bp);
    if (*bp == '\0' &&
	!(recall && (ch == UPARROW || ch == DNARROW))) {
	/*
	 * User cancelled the Jump via a zero-length string. - FM
	 */
	BStrCopy0(buf, "");
	StrAllocCopy(jtp->shortcut, buf->str);
	HTInfoMsg(CANCELLED);
	return NULL;
    }
#ifdef PERMIT_GOTO_FROM_JUMP
    if (strchr(bp, ':') || strchr(bp, '/')) {
	char *temp = NULL;

	LYJumpFileURL = FALSE;
	if (no_goto) {
	    BStrCopy0(buf, "");
	    StrAllocCopy(jtp->shortcut, buf->str);
	    HTUserMsg(RANDOM_URL_DISALLOWED);
	    return NULL;
	}
	HTSprintf0(&temp, "Go %s", bp);
	BStrCopy0(buf, temp);
	FREE(temp);
	return (bp = buf->str);
    }
#endif /* PERMIT_GOTO_FROM_JUMP */

    if (recall && ch == UPARROW) {
	if (FirstShortcutRecall) {
	    /*
	     * Use last Shortcut in the list. - FM
	     */
	    FirstShortcutRecall = FALSE;
	    ShortcutNum = 0;
	} else {
	    /*
	     * Go back to the previous Shortcut in the list. - FM
	     */
	    ShortcutNum++;
	}
	if (ShortcutNum >= ShortcutTotal)
	    /*
	     * Roll around to the last Shortcut in the list. - FM
	     */
	    ShortcutNum = 0;
	if ((cp = (char *) HTList_objectAt(jtp->history,
					   ShortcutNum)) != NULL) {
	    BStrCopy0(buf, cp);
	    if (jump_buffer && jtp->shortcut &&
		!strcmp(buf->str, jtp->shortcut)) {
		_statusline(EDIT_CURRENT_SHORTCUT);
	    } else if ((jump_buffer && ShortcutTotal == 2) ||
		       (!jump_buffer && ShortcutTotal == 1)) {
		_statusline(EDIT_THE_PREV_SHORTCUT);
	    } else {
		_statusline(EDIT_A_PREV_SHORTCUT);
	    }
	    if ((ch = LYgetBString(&buf, VISIBLE, 0, recall)) < 0) {
		/*
		 * User cancelled the jump via ^G.
		 */
		HTInfoMsg(CANCELLED);
		return NULL;
	    }
	    goto check_recall;
	}
    } else if (recall && ch == DNARROW) {
	if (FirstShortcutRecall) {
	    /*
	     * Use the first Shortcut in the list. - FM
	     */
	    FirstShortcutRecall = FALSE;
	    ShortcutNum = ShortcutTotal - 1;
	} else {
	    /*
	     * Advance to the next Shortcut in the list. - FM
	     */
	    ShortcutNum--;
	}
	if (ShortcutNum < 0)
	    /*
	     * Roll around to the first Shortcut in the list. - FM
	     */
	    ShortcutNum = ShortcutTotal - 1;
	if ((cp = (char *) HTList_objectAt(jtp->history,
					   ShortcutNum)) != NULL) {
	    BStrCopy0(buf, cp);
	    if (jump_buffer && jtp->shortcut &&
		!strcmp(buf->str, jtp->shortcut)) {
		_statusline(EDIT_CURRENT_SHORTCUT);
	    } else if ((jump_buffer && ShortcutTotal == 2) ||
		       (!jump_buffer && ShortcutTotal == 1)) {
		_statusline(EDIT_THE_PREV_SHORTCUT);
	    } else {
		_statusline(EDIT_A_PREV_SHORTCUT);
	    }
	    if ((ch = LYgetBString(&buf, VISIBLE, 0, recall)) < 0) {
		/*
		 * User cancelled the jump via ^G.
		 */
		HTInfoMsg(CANCELLED);
		return NULL;
	    }
	    goto check_recall;
	}
    }

    seeking.key = bp;
    found = (JumpDatum *) bsearch((char *) &seeking, (char *) jtp->table,
				  (size_t) jtp->nel, sizeof(JumpDatum), LYCompare);
    if (!found) {
	user_message("Unknown target '%s'", buf->str);
	LYSleepAlert();
    }

    StrAllocCopy(jtp->shortcut, bp);
    LYAddJumpShortcut(jtp->history, jtp->shortcut);
    return found ? found->url : NULL;
}

static unsigned LYRead_Jumpfile(struct JumpTable *jtp)
{
    struct stat st;
    unsigned int nel;
    char *mp;
    int fd;

#ifdef VMS
    int blocksize = 1024;
    FILE *fp;
    BOOL IsStream_LF = TRUE;
#endif /* VMS */
    char *cp;
    unsigned i;

    if (isEmpty(jtp->file))
	return 0;

    CTRACE((tfp, "Read Jumpfile %s\n", jtp->file));
    if (stat(jtp->file, &st) < 0) {
	HTAlert(CANNOT_LOCATE_JUMP_FILE);
	return 0;
    }

    /* allocate storage to read entire file */
    if ((mp = typecallocn(char, (size_t) st.st_size + 1)) == NULL) {
	HTAlert(OUTOF_MEM_FOR_JUMP_FILE);
	return 0;
    }
#ifdef VMS
    if (st.st_fab_rfm != (char) FAB$C_STMLF) {
	/** It's a record-oriented file. **/
	IsStream_LF = FALSE;
	if ((fp = fopen(jtp->file, "r", "mbc=32")) == NULL) {
	    HTAlert(CANNOT_OPEN_JUMP_FILE);
	    FREE(mp);
	    return 0;
	}
    } else if ((fd = open(jtp->file, O_RDONLY, "mbc=32")) < 0)
#else
    if ((fd = open(jtp->file, O_RDONLY)) < 0)
#endif /* VMS */
    {
	HTAlert(CANNOT_OPEN_JUMP_FILE);
	FREE(mp);
	return 0;
    }
#ifdef VMS
    if (IsStream_LF) {
    /** Handle as a stream. **/
#endif /* VMS */
	if (read(fd, mp, (size_t) st.st_size) < st.st_size) {
	    HTAlert(ERROR_READING_JUMP_FILE);
	    FREE(mp);
	    return 0;
	}
	mp[st.st_size] = '\0';
	close(fd);
#ifdef VMS
    } else {
	/** Handle as a series of records. **/
	if (fgets(mp, blocksize, fp) == NULL) {
	    HTAlert(ERROR_READING_JUMP_FILE);
	    FREE(mp);
	    return 0;
	} else
	    while (fgets(mp + strlen(mp), blocksize, fp) != NULL) {
		;
	    }
	LYCloseInput(fp);
    }
#endif /* VMS */

    /* quick scan for approximate number of entries */
    nel = 0;
    cp = mp;
    while ((cp = strchr(cp, '\n')) != NULL) {
	nel++;
	cp++;
    }

    jtp->table = (JumpDatum *) malloc((nel + 1) * sizeof(JumpDatum));
    if (jtp->table == NULL) {
	HTAlert(OUTOF_MEM_FOR_JUMP_TABLE);
	FREE(mp);
	return 0;
    }

    cp = jtp->mp = mp;
    for (i = 0; i < nel;) {
	if (StrNCmp(cp, "<!--", 4) == 0 || StrNCmp(cp, "<dl>", 4) == 0) {
	    cp = strchr(cp, '\n');
	    if (cp == NULL)
		break;
	    cp++;
	    continue;
	}
	cp = LYstrstr(cp, "<dt>");
	if (cp == NULL)
	    break;
	cp += 4;
	jtp->table[i].key = cp;
	cp = LYstrstr(cp, "<dd>");
	if (cp == NULL)
	    break;
	*cp = '\0';
	cp += 4;
	cp = LYstrstr(cp, "href=\"");
	if (cp == NULL)
	    break;
	cp += 6;
	jtp->table[i].url = cp;
	cp = strchr(cp, '"');
	if (cp == NULL)
	    break;
	*cp = '\0';
	cp++;
	cp = strchr(cp, '\n');
	if (cp == NULL)
	    break;
	cp++;
	CTRACE((tfp, "Read jumpfile[%u] key='%s', url='%s'\n",
		i, jtp->table[i].key, jtp->table[i].url));
	i++;
	if (!cp)
	    break;
    }

    return i;
}

static int LYCompare(const void *e1, const void *e2)
{
    return strcasecomp(((const JumpDatum *) e1)->key,
		       ((const JumpDatum *) e2)->key);
}
