/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

%{

#include "Annotation.h"
#include "AST.h"
#include "ArrayType.h"
#include "CompoundType.h"
#include "ConstantExpression.h"
#include "EnumType.h"
#include "FQName.h"
#include "GenericBinder.h"
#include "Interface.h"
#include "Method.h"
#include "VectorType.h"
#include "RefType.h"

#include "hidl-gen_y.h"

#include <android-base/logging.h>
#include <stdio.h>

using namespace android;

extern int yylex(yy::parser::semantic_type *, yy::parser::location_type *, void *);

#define scanner ast->scanner()

%}

%initial-action {
    // Initialize the initial location.
    @$.begin.filename = @$.end.filename =
        const_cast<std::string *>(&ast->getFilename());
}

%parse-param { android::AST *ast }
%lex-param { void *scanner }
%pure-parser
%glr-parser
%skeleton "glr.cc"

%expect-rr 0

%token<str> ENUM
%token<str> EXTENDS
%token<str> FQNAME
%token<str> GENERATES
%token<str> IDENTIFIER
%token<str> IMPORT
%token<str> INTEGER
%token<str> FLOAT
%token<str> INTERFACE
%token<str> PACKAGE
%token<type> SCALAR
%token<str> STRUCT
%token<str> STRING_LITERAL
%token<str> TYPEDEF
%token<str> UNION
%token<templatedType> TEMPLATED
%token<void> ONEWAY

/* Operator precedence and associativity, as per
 * http://en.cppreference.com/w/cpp/language/operator_precedence */
/* Precedence level 15 ternary operator */
%right '?' ':'
/* Precedence level 13 - 14, LTR, logical operators*/
%left LOGICAL_OR
%left LOGICAL_AND
/* Precedence level 10 - 12, LTR, bitwise operators*/
%left '|'
%left '^'
%left '&'
/* Precedence level 9, LTR */
%left EQUALITY NEQ
/* Precedence level 8, LTR */
%left '<' '>' LEQ GEQ
/* Precedence level 7, LTR */
%left LSHIFT RSHIFT
/* Precedence level 6, LTR */
%left '+' '-'
/* Precedence level 5, LTR */
%left '*' '/' '%'
/* Precedence level 3, RTL; but we have to use %left here */
%left UNARY_MINUS UNARY_PLUS '!' '~'

%type<str> package
%type<fqName> fqname
%type<type> fqtype

%type<type> type opt_storage_type
%type<type> opt_extends
%type<type> type_declaration_body interface_declaration typedef_declaration
%type<type> named_struct_or_union_declaration named_enum_declaration
%type<type> compound_declaration annotated_compound_declaration

%type<field> field_declaration
%type<fields> field_declarations struct_or_union_body
%type<constantExpression> const_expr
%type<enumValue> enum_value
%type<enumValues> enum_values enum_declaration_body
%type<typedVars> typed_vars
%type<typedVar> typed_var
%type<method> method_declaration
%type<compoundStyle> struct_or_union_keyword
%type<stringVec> annotation_string_values annotation_string_value
%type<constExprVec> annotation_const_expr_values annotation_const_expr_value
%type<annotationParam> annotation_param
%type<annotationParams> opt_annotation_params annotation_params
%type<annotation> annotation
%type<annotations> opt_annotations

%start program

%union {
    const char *str;
    android::Type *type;
    android::TemplatedType *templatedType;
    android::FQName *fqName;
    android::CompoundType *compoundType;
    android::CompoundField *field;
    std::vector<android::CompoundField *> *fields;
    android::EnumValue *enumValue;
    android::ConstantExpression *constantExpression;
    std::vector<android::EnumValue *> *enumValues;
    android::TypedVar *typedVar;
    std::vector<android::TypedVar *> *typedVars;
    android::Method *method;
    android::CompoundType::Style compoundStyle;
    std::vector<std::string> *stringVec;
    std::vector<android::ConstantExpression *> *constExprVec;
    android::AnnotationParam *annotationParam;
    android::AnnotationParamVector *annotationParams;
    android::Annotation *annotation;
    std::vector<android::Annotation *> *annotations;
}

%%

opt_annotations
    : /* empty */
      {
          $$ = new std::vector<Annotation *>;
      }
    | opt_annotations annotation
      {
          $$ = $1;
          $$->push_back($2);
      }
    ;

annotation
    : '@' IDENTIFIER opt_annotation_params
      {
          $$ = new Annotation($2, $3);
      }
    ;

opt_annotation_params
    : /* empty */
      {
          $$ = new AnnotationParamVector;
      }
    | '(' annotation_params ')'
      {
          $$ = $2;
      }
    ;

annotation_params
    : annotation_param
      {
          $$ = new AnnotationParamVector;
          $$->push_back($1);
      }
    | annotation_params ',' annotation_param
      {
          $$ = $1;
          $$->push_back($3);
      }
    ;

annotation_param
    : IDENTIFIER '=' annotation_string_value
      {
          $$ = new AnnotationParam($1, $3);
      }
    | IDENTIFIER '=' annotation_const_expr_value
      {
          $$ = new AnnotationParam($1, $3);
      }
    ;

annotation_string_value
    : STRING_LITERAL
      {
          $$ = new std::vector<std::string>;
          $$->push_back($1);
      }
    | '{' annotation_string_values '}' { $$ = $2; }
    ;

annotation_string_values
    : STRING_LITERAL
      {
          $$ = new std::vector<std::string>;
          $$->push_back($1);
      }
    | annotation_string_values ',' STRING_LITERAL
      {
          $$ = $1;
          $$->push_back($3);
      }
    ;

annotation_const_expr_value
    : const_expr
      {
          $$ = new std::vector<ConstantExpression *>;
          $$->push_back($1);
      }
    | '{' annotation_const_expr_values '}' { $$ = $2; }
    ;

annotation_const_expr_values
    : const_expr
      {
          $$ = new std::vector<ConstantExpression *>;
          $$->push_back($1);
      }
    | annotation_const_expr_values ',' const_expr
      {
          $$ = $1;
          $$->push_back($3);
      }
    ;

program
    : package imports body
    ;

fqname
    : FQNAME
      {
          $$ = new FQName($1);
          if(!$$->isValid()) {
              std::cerr << "ERROR: FQName '" << $1 << "' is not valid at "
                        << @1
                        << ".\n";
              YYERROR;
          }
      }
    | IDENTIFIER
      {
          $$ = new FQName($1);
          if(!$$->isValid()) {
              std::cerr << "ERROR: FQName '" << $1 << "' is not valid at "
                        << @1
                        << ".\n";
              YYERROR;
          }
      }
    ;

fqtype
    : fqname
      {
          $$ = ast->lookupType(*($1));
          if ($$ == NULL) {
              std::cerr << "ERROR: Failed to lookup type '" << $1->string() << "' at "
                        << @1
                        << "\n";

              YYERROR;
          }
      }
    | SCALAR
    ;

package
    : PACKAGE FQNAME ';'
      {
          if (!ast->setPackage($2)) {
              std::cerr << "ERROR: Malformed package identifier '"
                        << $2
                        << "' at "
                        << @2
                        << "\n";

              YYERROR;
          }
      }

imports
    : /* empty */
    | imports IMPORT FQNAME ';'
      {
          if (!ast->addImport($3)) {
              std::cerr << "ERROR: Unable to import '" << $3 << "' at " << @3
                        << "\n";

              YYERROR;
          }
      }
    | imports IMPORT IDENTIFIER ';'
      {
          if (!ast->addImport($3)) {
              std::cerr << "ERROR: Unable to import '" << $3 << "' at " << @3
                        << "\n";

              YYERROR;
          }
      }
    ;

opt_extends
    : /* empty */ { $$ = NULL; }
    | EXTENDS fqtype { $$ = $2; }

body
    : type_declarations
    ;

interface_declarations
    : /* empty */
    | interface_declarations type_declaration
    | interface_declarations method_declaration
      {
          Interface *iface = static_cast<Interface *>(ast->scope());
          iface->addMethod($2);
      }
    ;

type_declarations
    : /* empty */
    | type_declarations type_declaration
    ;

type_declaration
    : opt_annotations type_declaration_body
      {
          if ($2 != nullptr) {
              $2->setAnnotations($1);
          } else if (!$1->empty()) {
              // Since typedefs are always resolved to their target it makes
              // little sense to annotate them and have their annotations
              // impose semantics other than their target type.
              std::cerr << "ERROR: typedefs cannot be annotated. at " << @2
                        << "\n";

              YYERROR;
          }
      }
    ;

type_declaration_body
    : named_struct_or_union_declaration ';'
    | named_enum_declaration ';'
    | typedef_declaration ';'
    | interface_declaration ';'
    ;

interface_declaration
    : INTERFACE IDENTIFIER opt_extends
      {
          if ($3 != NULL && !$3->isInterface()) {
              std::cerr << "ERROR: You can only extend interfaces. at" << @3
                        << "\n";

              YYERROR;
          }

          if ($2[0] != 'I') {
              std::cerr << "ERROR: All interface names must start with an 'I' "
                        << "prefix. at " << @2 << "\n";

              YYERROR;
          }

          Interface *iface = new Interface($2, static_cast<Interface *>($3));

          // Register interface immediately so it can be referenced inside
          // definition.
          std::string errorMsg;
          if (!ast->addScopedType(iface, &errorMsg)) {
              std::cerr << "ERROR: " << errorMsg << " at " << @2 << "\n";
              YYERROR;
          }

          ast->enterScope(iface);
      }
      '{' interface_declarations '}'
      {
          Interface *iface = static_cast<Interface *>(ast->scope());

          ast->leaveScope();

          $$ = iface;
      }
    ;

typedef_declaration
    : TYPEDEF type IDENTIFIER
      {
          std::string errorMsg;
          if (!ast->addTypeDef($3, $2, &errorMsg)) {
              std::cerr << "ERROR: " << errorMsg << " at " << @3 << "\n";
              YYERROR;
          }

          $$ = nullptr;
      }
    ;

const_expr
    : INTEGER                   { $$ = new ConstantExpression($1); }
    | fqname
      {
          if(!$1->isValidValueName()) {
              std::cerr << "ERROR: '" << $1->string()
                        << "' does not refer to an enum value at "
                        << @1 << ".\n";
              YYERROR;
          }
          if($1->isIdentifier()) {
              std::string identifier = $1->name();
              LocalIdentifier *iden = ast->scope()->lookupIdentifier(identifier);
              if(!iden) {
                  std::cerr << "ERROR: at " << @1 << ", identifier " << $1->string()
                            << " could not be found.\n";
                  YYERROR;
              }
              if(!iden->isEnumValue()) {
                  std::cerr << "ERROR: at " << @1 << ", identifier " << $1->string()
                            << " is not an enum value.\n";
                  YYERROR;
              }
              $$ = new ConstantExpression(
                      *(static_cast<EnumValue *>(iden)->constExpr()), $1->string());
          } else {
              std::string errorMsg;
              EnumValue *v = ast->lookupEnumValue(*($1), &errorMsg);
              if(v == nullptr) {
                  std::cerr << "ERROR: " << errorMsg << " at " << @1 << ".\n";
                  YYERROR;
              }
              $$ = new ConstantExpression(*(v->constExpr()), $1->string());
          }
      }
    | const_expr '?' const_expr ':' const_expr
      {
          $$ = new ConstantExpression($1, $3, $5);
      }
    | const_expr LOGICAL_OR const_expr  { $$ = new ConstantExpression($1, "||", $3); }
    | const_expr LOGICAL_AND const_expr { $$ = new ConstantExpression($1, "&&", $3); }
    | const_expr '|' const_expr { $$ = new ConstantExpression($1, "|" , $3); }
    | const_expr '^' const_expr { $$ = new ConstantExpression($1, "^" , $3); }
    | const_expr '&' const_expr { $$ = new ConstantExpression($1, "&" , $3); }
    | const_expr EQUALITY const_expr { $$ = new ConstantExpression($1, "==", $3); }
    | const_expr NEQ const_expr { $$ = new ConstantExpression($1, "!=", $3); }
    | const_expr '<' const_expr { $$ = new ConstantExpression($1, "<" , $3); }
    | const_expr '>' const_expr { $$ = new ConstantExpression($1, ">" , $3); }
    | const_expr LEQ const_expr { $$ = new ConstantExpression($1, "<=", $3); }
    | const_expr GEQ const_expr { $$ = new ConstantExpression($1, ">=", $3); }
    | const_expr LSHIFT const_expr { $$ = new ConstantExpression($1, "<<", $3); }
    | const_expr RSHIFT const_expr { $$ = new ConstantExpression($1, ">>", $3); }
    | const_expr '+' const_expr { $$ = new ConstantExpression($1, "+" , $3); }
    | const_expr '-' const_expr { $$ = new ConstantExpression($1, "-" , $3); }
    | const_expr '*' const_expr { $$ = new ConstantExpression($1, "*" , $3); }
    | const_expr '/' const_expr { $$ = new ConstantExpression($1, "/" , $3); }
    | const_expr '%' const_expr { $$ = new ConstantExpression($1, "%" , $3); }
    | '+' const_expr %prec UNARY_PLUS  { $$ = new ConstantExpression("+", $2); }
    | '-' const_expr %prec UNARY_MINUS { $$ = new ConstantExpression("-", $2); }
    | '!' const_expr { $$ = new ConstantExpression("!", $2); }
    | '~' const_expr { $$ = new ConstantExpression("~", $2); }
    | '(' const_expr ')' { $$ = $2; }
    ;

method_declaration
    : opt_annotations IDENTIFIER '(' typed_vars ')' ';'
      {
          $$ = new Method($2, $4, new std::vector<TypedVar *>, false, $1);
      }
    | opt_annotations ONEWAY IDENTIFIER '(' typed_vars ')' ';'
      {
          $$ = new Method($3, $5, new std::vector<TypedVar *>, true, $1);
      }
    | opt_annotations IDENTIFIER '(' typed_vars ')' GENERATES '(' typed_vars ')' ';'
      {
          $$ = new Method($2, $4, $8, false, $1);
      }
    ;

typed_vars
    : /* empty */
      {
          $$ = new std::vector<TypedVar *>;
      }
    | typed_var
      {
          $$ = new std::vector<TypedVar *>;
          $$->push_back($1);
      }
    | typed_vars ',' typed_var
      {
          $$ = $1;
          $$->push_back($3);
      }
    ;

typed_var : type IDENTIFIER { $$ = new TypedVar($2, $1); }
    ;


struct_or_union_keyword
    : STRUCT { $$ = CompoundType::STYLE_STRUCT; }
    | UNION { $$ = CompoundType::STYLE_UNION; }
    ;

named_struct_or_union_declaration
    : struct_or_union_keyword IDENTIFIER
      {
          CompoundType *container = new CompoundType($1, $2);
          ast->enterScope(container);
      }
      struct_or_union_body
      {
          CompoundType *container = static_cast<CompoundType *>(ast->scope());

          std::string errorMsg;
          if (!container->setFields($4, &errorMsg)) {
              std::cerr << "ERROR: " << errorMsg << " at " << @4 << "\n";
              YYERROR;
          }

          ast->leaveScope();

          if (!ast->addScopedType(container, &errorMsg)) {
              std::cerr << "ERROR: " << errorMsg << " at " << @2 << "\n";
              YYERROR;
          }

          $$ = container;
      }
    ;

struct_or_union_body
    : '{' field_declarations '}' { $$ = $2; }
    ;

field_declarations
    : /* empty */ { $$ = new std::vector<CompoundField *>; }
    | field_declarations field_declaration
      {
          $$ = $1;

          if ($2 != NULL) {
              $$->push_back($2);
          }
      }
    ;

field_declaration
    : type IDENTIFIER ';' { $$ = new CompoundField($2, $1); }
    | annotated_compound_declaration ';' { $$ = NULL; }
    ;

annotated_compound_declaration
    : opt_annotations compound_declaration
      {
          $2->setAnnotations($1);
          $$ = $2;
      }
    ;

compound_declaration
    : named_struct_or_union_declaration { $$ = $1; }
    | named_enum_declaration { $$ = $1; }
    ;

opt_storage_type
    : /* empty */ { $$ = NULL; }
    | ':' fqtype
      {
          $$ = $2;

          if ($$ != NULL && !$$->isValidEnumStorageType()) {
              std::cerr << "ERROR: Invalid enum storage type specified. at "
                        << @2 << "\n";

              YYABORT;
          }
      }
    ;

opt_comma
    : /* empty */
    | ','
    ;

named_enum_declaration
    : ENUM IDENTIFIER opt_storage_type
      {
          ast->enterScope(new EnumType($2, $3));
      }
      enum_declaration_body
      {
          EnumType *enumType = static_cast<EnumType *>(ast->scope());
          ast->leaveScope();

          std::string errorMsg;
          if (!ast->addScopedType(enumType, &errorMsg)) {
              std::cerr << "ERROR: " << errorMsg << " at " << @2 << "\n";
              YYERROR;
          }

          $$ = enumType;
      }
    ;

enum_declaration_body
    : '{' enum_values opt_comma '}' { $$ = $2; }
    ;

enum_value
    : IDENTIFIER { $$ = new EnumValue($1); }
    | IDENTIFIER '=' const_expr { $$ = new EnumValue($1, $3); }
    ;

enum_values
    : /* empty */
      { /* do nothing */ }
    | enum_value
      {
          static_cast<EnumType *>(ast->scope())->addValue($1);
      }
    | enum_values ',' enum_value
      {
          static_cast<EnumType *>(ast->scope())->addValue($3);
      }
    ;

type
    : fqtype { $$ = $1; }
    | type '[' const_expr ']'
      {
          if ($1->isBinder()) {
              std::cerr << "ERROR: Arrays of interface types are not supported."
                        << " at " << @1 << "\n";

              YYERROR;
          }

          if ($1->isArray()) {
              $$ = new ArrayType(static_cast<ArrayType *>($1), $3);
          } else {
              $$ = new ArrayType($1, $3);
          }
      }
    | TEMPLATED '<' type '>'
      {
          if ($3->isBinder()) {
              std::cerr << "ERROR: TemplatedType of interface types are not "
                        << "supported. at " << @3 << "\n";

              YYERROR;
          }
          $1->setElementType($3);
          $$ = $1;
      }
    | TEMPLATED '<' TEMPLATED '<' type RSHIFT
      {
          if ($5->isBinder()) {
              std::cerr << "ERROR: TemplatedType of interface types are not "
                        << "supported. at " << @5 << "\n";

              YYERROR;
          }
          $3->setElementType($5);
          $1->setElementType($3);
          $$ = $1;
      }
    | annotated_compound_declaration { $$ = $1; }
    | INTERFACE { $$ = new GenericBinder; }
    ;

%%

#include <android-base/logging.h>

void yy::parser::error(
        const yy::parser::location_type &where,
        const std::string &errstr) {
    std::cerr << "ERROR: " << errstr << " at " << where << "\n";
}