// Copyright (c) 1999-2008 by Digital Mars
// All Rights Reserved
// written by Walter Bright
// http://www.digitalmars.com
// License for redistribution is by either the Artistic License
// in artistic.txt, or the GNU General Public License in gnu.txt.
// See the included readme.txt for details.

#include <stdio.h>
#include <assert.h>

#include "root.h"
#include "enum.h"
#include "mtype.h"
#include "scope.h"
#include "id.h"
#include "expression.h"
#include "module.h"
#include "declaration.h"

/********************************* EnumDeclaration ****************************/

EnumDeclaration::EnumDeclaration(Loc loc, Identifier *id, Type *memtype)
    : ScopeDsymbol(id)
{
    this->loc = loc;
    type = new TypeEnum(this);
    this->memtype = memtype;
    maxval = NULL;
    minval = NULL;
    defaultval = NULL;
    sinit = NULL;
    scope = NULL;
    isdeprecated = 0;
}

Dsymbol *EnumDeclaration::syntaxCopy(Dsymbol *s)
{
    Type *t = NULL;
    if (memtype)
	t = memtype->syntaxCopy();

    EnumDeclaration *ed;
    if (s)
    {	ed = (EnumDeclaration *)s;
	ed->memtype = t;
    }
    else
	ed = new EnumDeclaration(loc, ident, t);
    ScopeDsymbol::syntaxCopy(ed);
    return ed;
}

void EnumDeclaration::semantic(Scope *sc)
{
    Type *t;
    Scope *sce;

    //printf("EnumDeclaration::semantic(sd = %p, '%s') %s\n", sc->scopesym, sc->scopesym->toChars(), toChars());
    //printf("EnumDeclaration::semantic() %s\n", toChars());
    if (!members)		// enum ident;
	return;

    if (!memtype && !isAnonymous())
    {	// Set memtype if we can to reduce fwd reference errors
	memtype = Type::tint32;	// case 1)  enum ident { ... }
    }

    if (symtab)			// if already done
    {	if (!scope)
	    return;		// semantic() already completed
    }
    else
	symtab = new DsymbolTable();

    Scope *scx = NULL;
    if (scope)
    {   sc = scope;
        scx = scope;            // save so we don't make redundant copies
        scope = NULL;
    }

    if (sc->stc & STCdeprecated)
	isdeprecated = 1;

    parent = sc->parent;

    /* The separate, and distinct, cases are:
     *  1. enum { ... }
     *  2. enum : memtype { ... }
     *  3. enum ident { ... }
     *  4. enum ident : memtype { ... }
     */

    if (memtype)
    {
	memtype = memtype->semantic(loc, sc);

	/* Check to see if memtype is forward referenced
	 */
	if (memtype->ty == Tenum)
	{   EnumDeclaration *sym = (EnumDeclaration *)memtype->toDsymbol(sc);
	    if (!sym->memtype || !sym->members || !sym->symtab || sym->scope)
	    {	// memtype is forward referenced, so try again later
		scope = scx ? scx : new Scope(*sc);
		scope->setNoFree();
		scope->module->addDeferredSemantic(this);
		printf("\tdeferring %s\n", toChars());
		return;
	    }
	}
#if 0	// Decided to abandon this restriction for D 2.0
	if (!memtype->isintegral())
	{   error("base type must be of integral type, not %s", memtype->toChars());
	    memtype = Type::tint32;
	}
#endif
    }

    type = type->semantic(loc, sc);
    if (isAnonymous())
    	sce = sc;
    else
    {	sce = sc->push(this);
	sce->parent = this;
    }
    if (members->dim == 0)
	error("enum %s must have at least one member", toChars());
    int first = 1;
    Expression *elast = NULL;
    for (int i = 0; i < members->dim; i++)
    {
	EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
	Expression *e;

	if (!em)
	    /* The e->semantic(sce) can insert other symbols, such as
	     * template instances and function literals.
	     */
	    continue;

	//printf("  Enum member '%s'\n",em->toChars());
	if (em->type)
	    em->type = em->type->semantic(em->loc, sce);
	e = em->value;
	if (e)
	{
	    assert(e->dyncast() == DYNCAST_EXPRESSION);
	    e = e->semantic(sce);
	    e = e->optimize(WANTvalue | WANTinterpret);
	    if (memtype)
	    {
		e = e->implicitCastTo(sce, memtype);
		e = e->optimize(WANTvalue | WANTinterpret);
		if (!isAnonymous())
		    e = e->castTo(sce, type);
		t = memtype;
	    }
	    else if (em->type)
	    {
		e = e->implicitCastTo(sce, em->type);
		e = e->optimize(WANTvalue | WANTinterpret);
		assert(isAnonymous());
		t = e->type;
	    }
	    else
		t = e->type;
	}
	else if (first)
	{
	    if (memtype)
		t = memtype;
	    else if (em->type)
		t = em->type;
	    else
		t = Type::tint32;
	    e = new IntegerExp(em->loc, 0, Type::tint32);
	    e = e->implicitCastTo(sce, t);
	    e = e->optimize(WANTvalue | WANTinterpret);
	    if (!isAnonymous())
		e = e->castTo(sce, type);
	}
	else
	{
	    // Set value to (elast + 1).
	    // But first check that (elast != t.max)
	    assert(elast);
	    e = new EqualExp(TOKequal, em->loc, elast, t->getProperty(0, Id::max));
	    e = e->semantic(sce);
	    e = e->optimize(WANTvalue | WANTinterpret);
	    if (e->toInteger())
		error("overflow of enum value %s", elast->toChars());

	    // Now set e to (elast + 1)
	    e = new AddExp(em->loc, elast, new IntegerExp(em->loc, 1, Type::tint32));
	    e = e->semantic(sce);
	    e = e->castTo(sce, elast->type);
	    e = e->optimize(WANTvalue | WANTinterpret);
	}
	elast = e;
	em->value = e;

	// Add to symbol table only after evaluating 'value'
	if (isAnonymous())
	{
	    /* Anonymous enum members get added to enclosing scope.
	     */
	    for (Scope *scx = sce; scx; scx = scx->enclosing)
	    {
		if (scx->scopesym)
		{
		    if (!scx->scopesym->symtab)
			scx->scopesym->symtab = new DsymbolTable();
		    em->addMember(sce, scx->scopesym, 1);
		    break;
		}
	    }
	}
	else
	    em->addMember(sc, this, 1);

	/* Compute .min, .max and .default values.
	 * If enum doesn't have a name, we can never identify the enum type,
	 * so there is no purpose for a .min, .max or .default
	 */
	if (!isAnonymous())
	{
	    if (first)
	    {	defaultval = e;
		minval = e;
		maxval = e;
	    }
	    else
	    {	Expression *ec;

		/* In order to work successfully with UDTs,
		 * build expressions to do the comparisons,
		 * and let the semantic analyzer and constant
		 * folder give us the result.
		 */

		// Compute if(e < minval)
		ec = new CmpExp(TOKlt, em->loc, e, minval);
		ec = ec->semantic(sce);
		ec = ec->optimize(WANTvalue | WANTinterpret);
		if (ec->toInteger())
		    minval = e;

		ec = new CmpExp(TOKgt, em->loc, e, maxval);
		ec = ec->semantic(sce);
		ec = ec->optimize(WANTvalue | WANTinterpret);
		if (ec->toInteger())
		    maxval = e;
	    }
	}
	first = 0;
    }
    //printf("defaultval = %lld\n", defaultval);

    //if (defaultval) printf("defaultval: %s %s\n", defaultval->toChars(), defaultval->type->toChars());
    if (sc != sce)
	sce->pop();
    //members->print();
}

int EnumDeclaration::oneMember(Dsymbol **ps)
{
    if (isAnonymous())
	return Dsymbol::oneMembers(members, ps);
    return Dsymbol::oneMember(ps);
}

void EnumDeclaration::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{   int i;

    buf->writestring("enum ");
    if (ident)
    {	buf->writestring(ident->toChars());
	buf->writeByte(' ');
    }
    if (memtype)
    {
	buf->writestring(": ");
	memtype->toCBuffer(buf, NULL, hgs);
    }
    if (!members)
    {
	buf->writeByte(';');
	buf->writenl();
	return;
    }
    buf->writenl();
    buf->writeByte('{');
    buf->writenl();
    for (i = 0; i < members->dim; i++)
    {
	EnumMember *em = ((Dsymbol *)members->data[i])->isEnumMember();
	if (!em)
	    continue;
	//buf->writestring("    ");
	em->toCBuffer(buf, hgs);
	buf->writeByte(',');
	buf->writenl();
    }
    buf->writeByte('}');
    buf->writenl();
}

Type *EnumDeclaration::getType()
{
    return type;
}

const char *EnumDeclaration::kind()
{
    return "enum";
}

int EnumDeclaration::isDeprecated()
{
    return isdeprecated;
}

Dsymbol *EnumDeclaration::search(Loc loc, Identifier *ident, int flags)
{
    //printf("%s.EnumDeclaration::search('%s')\n", toChars(), ident->toChars());
    if (scope)
	// Try one last time to resolve this enum
        semantic(scope);

    if (!members || !symtab || scope)
    {   error("is forward referenced when looking for '%s'", ident->toChars());
        //*(char*)0=0;
        return NULL;
    }

    Dsymbol *s = ScopeDsymbol::search(loc, ident, flags);
    return s;
}

/********************************* EnumMember ****************************/

EnumMember::EnumMember(Loc loc, Identifier *id, Expression *value, Type *type)
    : Dsymbol(id)
{
    this->value = value;
    this->type = type;
    this->loc = loc;
}

Dsymbol *EnumMember::syntaxCopy(Dsymbol *s)
{
    Expression *e = NULL;
    if (value)
	e = value->syntaxCopy();

    Type *t = NULL;
    if (type)
	t = type->syntaxCopy();

    EnumMember *em;
    if (s)
    {	em = (EnumMember *)s;
	em->loc = loc;
	em->value = e;
	em->type = t;
    }
    else
	em = new EnumMember(loc, ident, e, t);
    return em;
}

void EnumMember::toCBuffer(OutBuffer *buf, HdrGenState *hgs)
{
    if (type)
	type->toCBuffer(buf, ident, hgs);
    else
	buf->writestring(ident->toChars());
    if (value)
    {
	buf->writestring(" = ");
	value->toCBuffer(buf, hgs);
    }
}

const char *EnumMember::kind()
{
    return "enum member";
}