void generate(ASTNode* node) {
	switch (node.kind) {
		case NODE_FUNCTION:
			gen_function(&node.fn);
			break;
		case NODE_TYPEDEF:
			printf("typedef %s %s;\n", node.td.type, node.td.alias);
			break;
		case NODE_STRUCT:
			gen_struct(&node.str);
			break;
		case NODE_VAR_DECL:
			gen_var_decl(&node.var);
			break;
		case NODE_BLOCK:
			gen_block(&node.block);
			break;
		default:
			error("unsupported node");
	}
}

void gen_function(FunctionNode* fn) {
	if (fn->is_inline) printf("inline ");
	else if (fn->is_static) printf("static ");
	else if (fn->is_extern) printf("extern ");
	else if (fn->is_export) printf("__attribute__((visibility(\"default\"))) ");

	printf("%s %s(", fn->return_type, fn->name);
	for (i = 0; i < fn->params.len; i++) {
		gen_var_decl(&fn->params[i]);
		if (i < fn->params.len - 1) printf(", ");
	}
	printf(") ");
	gen_block(&fn->body);
}

void gen_block(BlockNode* block) {
	printf("{\n");
	for (stmt in block.statements) {
		generate(stmt);
	}
	printf("}\n");
}

void gen_var_decl(VarDeclNode* var) {
	printf("%s %s", var->type, var->name);
	if (var->init != NULL) {
		printf(" = ");
		gen_expr(var->init);
	}
	printf(";");
}

void gen_struct(StructNode* str) {
	printf("typedef struct {\n");
	for (field in str.fields) {
		printf("\t%s %s", field.type, field.name);
		if (field.init != NULL) {
			printf(" = ");
			gen_expr(field.init);
		}
		printf(";\n");
	}
	printf("} %s;\n", str.name);
}

void gen_expr(ExprNode* expr) {
	switch (expr.kind) {
		case EXPR_LITERAL:
			printf("%s", expr.lit.value);
			break;
		case EXPR_IDENTIFIER:
			printf("%s", expr.ident);
			break;
		case EXPR_BINARY:
			gen_expr(expr.bin.lhs);
			printf(" %s ", expr.bin.op);
			gen_expr(expr.bin.rhs);
			break;
		case EXPR_CALL:
			printf("%s(", expr.call.callee);
			for (i = 0; i < expr.call.args.len; i++) {
				gen_expr(expr.call.args[i]);
				if (i < expr.call.args.len - 1) printf(", ");
			}
			printf(")");
			break;
		case EXPR_CAST:
			printf("(%s)", expr.cast.to_type);
			gen_expr(expr.cast.value);
			break;
	}
}