/*
 * Copyright (C) 2015 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.
 */

#ifndef AAPT_RESOURCE_VALUES_H
#define AAPT_RESOURCE_VALUES_H

#include <array>
#include <ostream>
#include <vector>

#include "androidfw/ResourceTypes.h"

#include "Diagnostics.h"
#include "Resource.h"
#include "StringPool.h"
#include "io/File.h"
#include "util/Maybe.h"

namespace aapt {

struct RawValueVisitor;

/**
 * A resource value. This is an all-encompassing representation
 * of Item and Map and their subclasses. The way to do
 * type specific operations is to check the Value's type() and
 * cast it to the appropriate subclass. This isn't super clean,
 * but it is the simplest strategy.
 */
struct Value {
  virtual ~Value() = default;

  /**
   * Whether this value is weak and can be overridden without
   * warning or error. Default is false.
   */
  bool IsWeak() const { return weak_; }

  void SetWeak(bool val) { weak_ = val; }

  // Whether the value is marked as translateable.
  // This does not persist when flattened.
  // It is only used during compilation phase.
  void SetTranslateable(bool val) { translateable_ = val; }

  // Default true.
  bool IsTranslateable() const { return translateable_; }

  /**
   * Returns the source where this value was defined.
   */
  const Source& GetSource() const { return source_; }

  void SetSource(const Source& source) { source_ = source; }

  void SetSource(Source&& source) { source_ = std::move(source); }

  /**
   * Returns the comment that was associated with this resource.
   */
  const std::string& GetComment() const { return comment_; }

  void SetComment(const StringPiece& str) { comment_ = str.ToString(); }

  void SetComment(std::string&& str) { comment_ = std::move(str); }

  virtual bool Equals(const Value* value) const = 0;

  /**
   * Calls the appropriate overload of ValueVisitor.
   */
  virtual void Accept(RawValueVisitor* visitor) = 0;

  /**
   * Clone the value. new_pool is the new StringPool that
   * any resources with strings should use when copying their string.
   */
  virtual Value* Clone(StringPool* new_pool) const = 0;

  /**
   * Human readable printout of this value.
   */
  virtual void Print(std::ostream* out) const = 0;

 protected:
  Source source_;
  std::string comment_;
  bool weak_ = false;
  bool translateable_ = true;
};

/**
 * Inherit from this to get visitor accepting implementations for free.
 */
template <typename Derived>
struct BaseValue : public Value {
  void Accept(RawValueVisitor* visitor) override;
};

/**
 * A resource item with a single value. This maps to android::ResTable_entry.
 */
struct Item : public Value {
  /**
   * Clone the Item.
   */
  virtual Item* Clone(StringPool* new_pool) const override = 0;

  /**
   * Fills in an android::Res_value structure with this Item's binary
   * representation.
   * Returns false if an error occurred.
   */
  virtual bool Flatten(android::Res_value* out_value) const = 0;
};

/**
 * Inherit from this to get visitor accepting implementations for free.
 */
template <typename Derived>
struct BaseItem : public Item {
  void Accept(RawValueVisitor* visitor) override;
};

/**
 * A reference to another resource. This maps to
 * android::Res_value::TYPE_REFERENCE.
 *
 * A reference can be symbolic (with the name set to a valid resource name) or
 * be
 * numeric (the id is set to a valid resource ID).
 */
struct Reference : public BaseItem<Reference> {
  enum class Type {
    kResource,
    kAttribute,
  };

  Maybe<ResourceName> name;
  Maybe<ResourceId> id;
  Reference::Type reference_type;
  bool private_reference = false;

  Reference();
  explicit Reference(const ResourceNameRef& n, Type type = Type::kResource);
  explicit Reference(const ResourceId& i, Type type = Type::kResource);
  Reference(const ResourceNameRef& n, const ResourceId& i);

  bool Equals(const Value* value) const override;
  bool Flatten(android::Res_value* out_value) const override;
  Reference* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

bool operator<(const Reference&, const Reference&);
bool operator==(const Reference&, const Reference&);

/**
 * An ID resource. Has no real value, just a place holder.
 */
struct Id : public BaseItem<Id> {
  Id() { weak_ = true; }
  bool Equals(const Value* value) const override;
  bool Flatten(android::Res_value* out) const override;
  Id* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

/**
 * A raw, unprocessed string. This may contain quotations,
 * escape sequences, and whitespace. This shall *NOT*
 * end up in the final resource table.
 */
struct RawString : public BaseItem<RawString> {
  StringPool::Ref value;

  explicit RawString(const StringPool::Ref& ref);

  bool Equals(const Value* value) const override;
  bool Flatten(android::Res_value* out_value) const override;
  RawString* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

struct String : public BaseItem<String> {
  StringPool::Ref value;

  explicit String(const StringPool::Ref& ref);

  bool Equals(const Value* value) const override;
  bool Flatten(android::Res_value* out_value) const override;
  String* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

struct StyledString : public BaseItem<StyledString> {
  StringPool::StyleRef value;

  explicit StyledString(const StringPool::StyleRef& ref);

  bool Equals(const Value* value) const override;
  bool Flatten(android::Res_value* out_value) const override;
  StyledString* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

struct FileReference : public BaseItem<FileReference> {
  StringPool::Ref path;

  /**
   * A handle to the file object from which this file can be read.
   */
  io::IFile* file = nullptr;

  FileReference() = default;
  explicit FileReference(const StringPool::Ref& path);

  bool Equals(const Value* value) const override;
  bool Flatten(android::Res_value* out_value) const override;
  FileReference* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

/**
 * Represents any other android::Res_value.
 */
struct BinaryPrimitive : public BaseItem<BinaryPrimitive> {
  android::Res_value value;

  BinaryPrimitive() = default;
  explicit BinaryPrimitive(const android::Res_value& val);
  BinaryPrimitive(uint8_t dataType, uint32_t data);

  bool Equals(const Value* value) const override;
  bool Flatten(android::Res_value* out_value) const override;
  BinaryPrimitive* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

struct Attribute : public BaseValue<Attribute> {
  struct Symbol {
    Reference symbol;
    uint32_t value;
  };

  uint32_t type_mask;
  int32_t min_int;
  int32_t max_int;
  std::vector<Symbol> symbols;

  explicit Attribute(bool w, uint32_t t = 0u);

  bool Equals(const Value* value) const override;
  Attribute* Clone(StringPool* new_pool) const override;
  void PrintMask(std::ostream* out) const;
  void Print(std::ostream* out) const override;
  bool Matches(const Item* item, DiagMessage* out_msg) const;
};

struct Style : public BaseValue<Style> {
  struct Entry {
    Reference key;
    std::unique_ptr<Item> value;
  };

  Maybe<Reference> parent;

  /**
   * If set to true, the parent was auto inferred from the
   * style's name.
   */
  bool parent_inferred = false;

  std::vector<Entry> entries;

  bool Equals(const Value* value) const override;
  Style* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

struct Array : public BaseValue<Array> {
  std::vector<std::unique_ptr<Item>> items;

  bool Equals(const Value* value) const override;
  Array* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

struct Plural : public BaseValue<Plural> {
  enum { Zero = 0, One, Two, Few, Many, Other, Count };

  std::array<std::unique_ptr<Item>, Count> values;

  bool Equals(const Value* value) const override;
  Plural* Clone(StringPool* new_pool) const override;
  void Print(std::ostream* out) const override;
};

struct Styleable : public BaseValue<Styleable> {
  std::vector<Reference> entries;

  bool Equals(const Value* value) const override;
  Styleable* Clone(StringPool* newPool) const override;
  void Print(std::ostream* out) const override;
  void MergeWith(Styleable* styleable);
};

/**
 * Stream operator for printing Value objects.
 */
inline ::std::ostream& operator<<(::std::ostream& out, const Value& value) {
  value.Print(&out);
  return out;
}

inline ::std::ostream& operator<<(::std::ostream& out,
                                  const Attribute::Symbol& s) {
  if (s.symbol.name) {
    out << s.symbol.name.value().entry;
  } else {
    out << "???";
  }
  return out << "=" << s.value;
}

}  // namespace aapt

#endif  // AAPT_RESOURCE_VALUES_H