/*
  Copyright (C) 2019 Leo Tenenbaum.
  This file is part of toc. toc is distributed under version 3 of the GNU General Public License, without any warranty whatsoever.
  You should have received a copy of the GNU General Public License along with toc. If not, see <https://www.gnu.org/licenses/>.
*/
static void exptr_create(Exporter *exptr, FILE *out) {
	exptr->out = out;
	exptr->export_locations = true;
}

static void export_u8(Exporter *ex, U8 u8) {
	write_u8(ex->out, u8);
}

static void export_u16(Exporter *ex, U16 u16) {
	write_u16(ex->out, u16);
}

static void export_u32(Exporter *ex, U32 u32) {
	write_u32(ex->out, u32);
}

static void export_u64(Exporter *ex, U64 u64) {
	write_u64(ex->out, u64);
}

static void export_location(Exporter *ex, Location where) {
	if (ex->export_locations) {
		export_u32(ex, where.line);
		export_u32(ex, where.pos);
	}
}

static void export_ident(Exporter *ex, Identifier i) {
	assert(i->id);
	export_u64(ex, i->id);
}

static inline bool type_contains_reference(Type *type) {
	assert(type->flags & TYPE_IS_RESOLVED);
	switch (type->kind) {
	case TYPE_PTR:
	case TYPE_SLICE:
	case TYPE_FN:
		return true;
	case TYPE_TUPLE:
		arr_foreach(type->tuple, Type, sub)
			if (type_contains_reference(sub))
				return true;
		return false;
	case TYPE_STRUCT:
		arr_foreach(type->struc->fields, Field, field) {
			if (type_contains_reference(field->type))
				return true;
		}
		return false;
	case TYPE_ARR:
		return type_contains_reference(type->arr.of);
	case TYPE_BUILTIN:
	case TYPE_VOID:
	case TYPE_UNKNOWN:
	case TYPE_TYPE:
		return false;
	case TYPE_EXPR: break;
	}
	assert(0);
	return false;
}

static void export_type(Exporter *ex, Type *type) {
}

static void export_val(Exporter *ex, Value val, Type *type) {
	assert(!type_contains_reference(type));
	export_type(ex, type);
	switch (type->kind) {
    case TYPE_VOID: break;
	case TYPE_TYPE:
		export_type(ex, val.type);
		break;
	case TYPE_UNKNOWN:
	case TYPE_EXPR:
		assert(0);
		break;
	}
}

static void export_expr(Exporter *ex, Expression *e) {
}

enum {
	  DECL_EXPORT_NONE,
	  DECL_EXPORT_EXPR,
	  DECL_EXPORT_VAL
};

static void export_decl(Exporter *ex, Declaration *d) {
	if (d->type.kind == TYPE_UNKNOWN) {
		warn_print(d->where, "Can't export declaration of unknown type.");
		return;
	}
	export_location(ex, d->where);
	export_u16(ex, (U16)arr_len(d->idents));
	arr_foreach(d->idents, Identifier, ident) {
		export_ident(ex, *ident);
	}

	U8 constness = 0;
	if (d->flags & DECL_IS_CONST) constness = 1;
	else if (d->flags & DECL_SEMI_CONST) constness = 2;
	export_u8(ex, constness);

	U8 expr_kind = 0;
	if (d->flags & DECL_HAS_EXPR) expr_kind = DECL_EXPORT_EXPR;
	if (d->flags & DECL_FOUND_VAL) {
		if (type_contains_reference(&d->type))
			expr_kind = DECL_EXPORT_EXPR;
		else
			expr_kind = DECL_EXPORT_VAL;
	}
	
	export_u8(ex, expr_kind);

	if (expr_kind == DECL_EXPORT_EXPR) {
		export_expr(ex, &d->expr);
	} else if (expr_kind == DECL_EXPORT_VAL) {
		export_val(ex, d->val, &d->type);
	}
}