/*
*
*   Copyright (c) 2000-2001, Darren Hiebert
*
*   This source code is released for free distribution under the terms of the
*   GNU General Public License.
*
*   This module contains functions for generating tags for PERL language
*   files.
*/

/*
*   INCLUDE FILES
*/
#include "general.h"	/* must always come first */

#include <string.h>

#include "read.h"
#include "vstring.h"

/*
*   DATA DEFINITIONS
*/
typedef enum {
    K_SUBROUTINE,
    K_PACKAGE,
    K_LOCAL,
    K_MY,
    K_OUR
} perlKind;

static kindOption PerlKinds [] = {
    { TRUE, 'f', "function", "functions" },
    { TRUE, 'c', "class", "packages" },
    { TRUE, 'l', "macro", "local variables" },
    { TRUE, 'm', "member", "my variables" },
    { TRUE, 'v', "variable", "our variables" }
};

/*
*   FUNCTION DEFINITIONS
*/

static const unsigned char *createTagString(const unsigned char *str, int type)
{
    vString *n = vStringNew();
    while (! isspace ((int) *str) && *str != '\0' && *str != '=' && *str != ';' &&
			*str != ',' && *str != ')' && *str != '$')
    {
		vStringPut (n, (int) *str);
		str++;
    }

    vStringTerminate (n);
    if (vStringLength (n) > 0)
	makeSimpleTag (n, PerlKinds, type);
    vStringDelete (n);

/*    if ((*(const char*)str) == ')')
		return str-1;
	else
*/		return str;
}

/* Algorithm adapted from from GNU etags.
 * Perl support by Bart Robinson <lomew@cs.utah.edu>
 * Perl sub names: look for /^ [ \t\n]sub [ \t\n]+ [^ \t\n{ (]+/
 */
static void findPerlTags (void)
{
    vString *name = vStringNew ();
    boolean skipPodDoc = FALSE;
    const unsigned char *line;
    perlKind kind;

    while ((line = fileReadLine ()) != NULL)
    {
	const unsigned char *cp = line;

	if (skipPodDoc)
	{
	    if (strcmp ((const char*) line, "=cut") == 0)
		skipPodDoc = FALSE;
	    continue;
	}
	else if (line [0] == '=')
	{
	    skipPodDoc = (boolean) (strncmp (
			(const char*) line + 1, "cut", (size_t) 3) != 0);
	    continue;
	}
	else if (strcmp ((const char*) line, "__DATA__") == 0)
	    break;
	else if (strcmp ((const char*) line, "__END__") == 0)
	    break;
	else if (line [0] == '#')
	    continue;

	while (isspace (*cp))
	    cp++;

	if (strncmp((const char*) cp, "my", (size_t) 2) == 0)
	{
		cp += 2;
		while (isspace (*cp)) cp++;

	    /* parse something like my($bla) */
	    if (*(const char*) cp == '(')
	    {
			cp++;
			while (*(const char*) cp != ')')
			{
				while (isspace (*(const char*) cp)) cp++;
				if (*(const char*) cp == ',') cp++;  /* to skip ',' */
				while (isspace (*(const char*) cp)) cp++;
				cp++; /* to skip $ sign */
				cp = createTagString(cp, K_MY);
				while (isspace (*(const char*) cp)) cp++;
			}
	    }
		/* parse my $bla */
		else
		{
			cp++; /* to skip the $ sign */

			if (! isalpha (*(const char*) cp)) continue;

			createTagString (cp, K_MY);
		}
	}
	else if (strncmp((const char*) cp, "our", (size_t) 3) == 0)
	{
		cp += 3;
		while (isspace (*cp)) cp++;

	    /* parse something like my($bla) */
	    if (*(const char*) cp == '(')
	    {
			cp++;
			while (*(const char*) cp != ')')
			{
				while (isspace (*(const char*) cp)) cp++;
				if (*(const char*) cp == ',') cp++;  /* to skip ',' */
				while (isspace (*(const char*) cp)) cp++;
				cp++; /* to skip $ sign */
				cp = createTagString(cp, K_OUR);
				while (isspace (*(const char*) cp)) cp++;
			}
	    }
		/* parse my $bla */
		else
		{
			cp++; /* to skip the $ sign */

			if (! isalpha (*(const char*) cp)) continue;

			createTagString (cp, K_OUR);
		}
	}
	else if (strncmp((const char*) cp, "local", (size_t) 5) == 0)
	{
		cp += 5;
		while (isspace (*cp)) cp++;

	    /* parse something like my($bla) */
	    if (*(const char*) cp == '(')
	    {
			cp++;
			while (*(const char*) cp != ')')
			{
				while (isspace (*(const char*) cp)) cp++;
				if (*(const char*) cp == ',') cp++;  /* to skip ',' */
				while (isspace (*(const char*) cp)) cp++;
				cp++; /* to skip $ sign */
				cp = createTagString(cp, K_LOCAL);
				while (isspace (*(const char*) cp)) cp++;
			}
	    }
		/* parse my $bla */
		else
		{
			cp++; /* to skip the $ sign */

			if (! isalpha (*(const char*) cp)) continue;

			createTagString (cp, K_LOCAL);
		}
	}
	else if (strncmp((const char*) cp, "sub", (size_t) 3) == 0 ||
			 strncmp((const char*) cp, "package", (size_t) 7) == 0)
	{
	    if (strncmp((const char*) cp, "sub", (size_t) 3) == 0)
	    {
	    	cp += 3;
		kind = K_SUBROUTINE;
	    } else {
	    	cp += 7;
		kind = K_PACKAGE;
	    }
	    if (!isspace(*cp))		/* woops, not followed by a space */
	        continue;

	    while (isspace (*cp))
		cp++;
	    while (! isspace ((int) *cp) && *cp != '\0' && *cp != '{' && *cp != '(' && *cp != ';')
	    {
		vStringPut (name, (int) *cp);
		cp++;
	    }
	    vStringTerminate (name);
	    if (vStringLength (name) > 0)
		makeSimpleTag (name, PerlKinds, kind);
	    vStringClear (name);
	}
    }
    vStringDelete (name);
}

extern parserDefinition* PerlParser (void)
{
    static const char *const extensions [] = { "pl", "pm", "perl", NULL };
    parserDefinition* def = parserNew ("Perl");
    def->kinds      = PerlKinds;
    def->kindCount  = KIND_COUNT (PerlKinds);
    def->extensions = extensions;
    def->parser     = findPerlTags;
    return def;
}

/* vi:set tabstop=8 shiftwidth=4: */
