#include "postgres.h"

#include "extern.h"

struct variable * allvariables = NULL;

struct variable *
new_variable(const char * name, struct ECPGtype * type)
{
    struct variable * p = (struct variable*) mm_alloc(sizeof(struct variable));

    p->name = mm_strdup(name);
    p->type = type;
    p->brace_level = braces_open;

    p->next = allvariables;
    allvariables = p;

    return(p);
}

static struct variable *
find_struct_member(char *name, char *str, struct ECPGstruct_member *members)
{
    char *next = strchr(++str, '.'), c = '\0';

    if (next != NULL)
    {
	c = *next;
	*next = '\0';
    }

    for (; members; members = members->next)
    {
        if (strcmp(members->name, str) == 0)
	{
		if (c == '\0')
		{
			/* found the end */
			switch (members->typ->typ)
			{
			   case ECPGt_array:
				return(new_variable(name, ECPGmake_array_type(members->typ->u.element, members->typ->size)));
			   case ECPGt_struct:
			   case ECPGt_union:
				return(new_variable(name, ECPGmake_struct_type(members->typ->u.members, members->typ->typ)));
			   default:
				return(new_variable(name, ECPGmake_simple_type(members->typ->typ, members->typ->size)));
			}
		}
		else
		{
			*next = c;
			if (c == '-')
			{
				next++;
				return(find_struct_member(name, next, members->typ->u.element->u.members));
			}
			else return(find_struct_member(name, next, members->typ->u.members));
		}
	}
    }

    return(NULL);
}

static struct variable *
find_struct(char * name, char *next)
{
    struct variable * p;
    char c = *next;

    /* first get the mother structure entry */
    *next = '\0';
    p = find_variable(name);

    if (c == '-')
    {
	if (p->type->typ != ECPGt_struct && p->type->typ != ECPGt_union)
        {
                sprintf(errortext, "variable %s is not a pointer", name);
                mmerror(ET_FATAL, errortext);
        }

	if (p->type->u.element->typ  != ECPGt_struct && p->type->u.element->typ != ECPGt_union)
        {
                sprintf(errortext, "variable %s is not a pointer to a structure or a union", name);
                mmerror(ET_FATAL, errortext);
        }

	/* restore the name, we will need it later on */
	*next = c;
	next++;

	return find_struct_member(name, next, p->type->u.element->u.members);
    }
    else
    {
	if (p->type->typ != ECPGt_struct && p->type->typ != ECPGt_union)
	{
		sprintf(errortext, "variable %s is neither a structure nor a union", name);
		mmerror(ET_FATAL, errortext);
	}

	/* restore the name, we will need it later on */
	*next = c;

	return find_struct_member(name, next, p->type->u.members);
    }
}

static struct variable *
find_simple(char * name)
{
    struct variable * p;

    for (p = allvariables; p; p = p->next)
    {
        if (strcmp(p->name, name) == 0)
	    return p;
    }

    return(NULL);
}

/* Note that this function will end the program in case of an unknown */
/* variable */
struct variable *
find_variable(char * name)
{
    char * next;
    struct variable * p;

    if ((next = strchr(name, '.')) != NULL)
	p = find_struct(name, next);
    else if ((next = strstr(name, "->")) != NULL)
	p = find_struct(name, next);
    else
	p = find_simple(name);

    if (p == NULL)
    {
	sprintf(errortext, "The variable %s is not declared", name);
	mmerror(ET_FATAL, errortext);
    }

    return(p);
}

void
remove_variables(int brace_level)
{
    struct variable * p, *prev;

    for (p = prev = allvariables; p; p = p ? p->next : NULL)
    {
	if (p->brace_level >= brace_level)
	{
	    /* remove it */
	    if (p == allvariables)
		prev = allvariables = p->next;
	    else
		prev->next = p->next;

	    ECPGfree_type(p->type);
	    free(p->name);
	    free(p);
	    p = prev;
	}
	else
	    prev = p;
    }
}


/*
 * Here are the variables that need to be handled on every request.
 * These are of two kinds: input and output.
 * I will make two lists for them.
 */

struct arguments * argsinsert = NULL;
struct arguments * argsresult = NULL;

void
reset_variables(void)
{
    argsinsert = NULL;
    argsresult = NULL;
}


/* Add a variable to a request. */
void
add_variable(struct arguments ** list, struct variable * var, struct variable * ind)
{
    struct arguments * p = (struct arguments *)mm_alloc(sizeof(struct arguments));
    p->variable = var;
    p->indicator = ind;
    p->next = *list;
    *list = p;
}


/* Dump out a list of all the variable on this list.
   This is a recursive function that works from the end of the list and
   deletes the list as we go on.
 */
void
dump_variables(struct arguments * list, int mode)
{
    if (list == NULL)
    {
        return;
    }

    /* The list is build up from the beginning so lets first dump the
       end of the list:
     */

    dump_variables(list->next, mode);

    /* Then the current element and its indicator */
    ECPGdump_a_type(yyout, list->variable->name, list->variable->type,
	(list->indicator->type->typ != ECPGt_NO_INDICATOR) ? list->indicator->name : NULL,
	(list->indicator->type->typ != ECPGt_NO_INDICATOR) ? list->indicator->type : NULL, NULL, NULL);

    /* Then release the list element. */
    if (mode != 0)
    	free(list);
}

void
check_indicator(struct ECPGtype *var)
{
	/* make sure this is a valid indicator variable */
	switch (var->typ)
	{
		struct ECPGstruct_member *p;

		case ECPGt_short:
		case ECPGt_int:
		case ECPGt_long:
		case ECPGt_unsigned_short:
		case ECPGt_unsigned_int:
		case ECPGt_unsigned_long:
			break;

		case ECPGt_struct:
		case ECPGt_union:
			for (p = var->u.members; p; p = p->next)
				check_indicator(p->typ);
			break;

		case ECPGt_array:
			check_indicator(var->u.element);
			break;
		default: 
			mmerror(ET_ERROR, "indicator variable must be integer type");
			break;
	}
}

struct typedefs *
get_typedef(char *name)
{
	struct typedefs *this;

	for (this = types; this && strcmp(this->name, name); this = this->next);
	if (!this)
	{
		sprintf(errortext, "invalid datatype '%s'", name);
		mmerror(ET_FATAL, errortext);
	}

	return(this);
}

void
adjust_array(enum ECPGttype type_enum, int *dimension, int *length, int type_dimension, int type_index, bool pointer)
{
	if (type_index >= 0) 
	{
		if (*length >= 0)
                      	mmerror(ET_FATAL, "No multi-dimensional array support");

		*length = type_index;
	}
		       
	if (type_dimension >= 0)
	{
		if (*dimension >= 0 && *length >= 0)
			mmerror(ET_FATAL, "No multi-dimensional array support");

		if (*dimension >= 0)
			*length = *dimension;

		*dimension = type_dimension;
	}

	if (*length >= 0 && *dimension >= 0 && pointer)
		mmerror(ET_FATAL, "No multi-dimensional array support");

	switch (type_enum)
	{
	   case ECPGt_struct:
	   case ECPGt_union:
	        /* pointer has to get dimension 0 */
                if (pointer)
	        {
		    *length = *dimension;
                    *dimension = 0;
	        }

                if (*length >= 0)
                   mmerror(ET_FATAL, "No multi-dimensional array support for structures");

                break;
           case ECPGt_varchar:
	        /* pointer has to get dimension 0 */
                if (pointer)
                    *dimension = 0;

                /* one index is the string length */
                if (*length < 0)
                {
                   *length = *dimension;
                   *dimension = -1;
                }

                break;
           case ECPGt_char:
           case ECPGt_unsigned_char:
	        /* pointer has to get length 0 */
                if (pointer)
                    *length=0;

                /* one index is the string length */
                if (*length < 0)
                {
                   *length = (*dimension < 0) ? 1 : *dimension;
                   *dimension = -1;
                }

                break;
           default:
 	        /* a pointer has dimension = 0 */
                if (pointer) {
                    *length = *dimension;
		    *dimension = 0;
	        }

                if (*length >= 0)
                   mmerror(ET_FATAL, "No multi-dimensional array support for simple data types");

                break;
	}
}
