/* Copyright 2017-2018 ccls Authors

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.
==============================================================================*/

#pragma once

#include "config.h"
#include "method.h"
#include "serializer.h"
#include "utils.h"

#include <iosfwd>
#include <unordered_map>

#define REGISTER_IN_MESSAGE(type)                                              \
  static MessageRegistryRegister<type> type##message_handler_instance_;

struct MessageRegistry {
  static MessageRegistry *instance_;
  static MessageRegistry *instance();

  using Allocator =
      std::function<void(Reader &visitor, std::unique_ptr<InMessage> *)>;
  std::unordered_map<std::string, Allocator> allocators;

  std::optional<std::string>
  ReadMessageFromStdin(std::unique_ptr<InMessage> *message);
  std::optional<std::string> Parse(Reader &visitor,
                                   std::unique_ptr<InMessage> *message);
};

template <typename T> struct MessageRegistryRegister {
  MessageRegistryRegister() {
    T dummy;
    std::string method_name = dummy.GetMethodType();
    MessageRegistry::instance()->allocators[method_name] =
        [](Reader &visitor, std::unique_ptr<InMessage> *message) {
          *message = std::make_unique<T>();
          // Reflect may throw and *message will be partially deserialized.
          Reflect(visitor, static_cast<T &>(**message));
        };
  }
};

struct lsBaseOutMessage {
  virtual ~lsBaseOutMessage();
  virtual void ReflectWriter(Writer &) = 0;

  // Send the message to the language client by writing it to stdout.
  void Write(std::ostream &out);
};

template <typename TDerived> struct lsOutMessage : lsBaseOutMessage {
  // All derived types need to reflect on the |jsonrpc| member.
  std::string jsonrpc = "2.0";

  void ReflectWriter(Writer &writer) override {
    Reflect(writer, static_cast<TDerived &>(*this));
  }
};

struct lsResponseError {
  enum class lsErrorCodes : int {
    ParseError = -32700,
    InvalidRequest = -32600,
    MethodNotFound = -32601,
    InvalidParams = -32602,
    InternalError = -32603,
    serverErrorStart = -32099,
    serverErrorEnd = -32000,
    ServerNotInitialized = -32002,
    UnknownErrorCode = -32001,
    RequestCancelled = -32800,
  };

  lsErrorCodes code;
  // Short description.
  std::string message;

  void Write(Writer &visitor);
};

constexpr std::string_view ccls_xref("ccls.xref");

/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
////////////////////////////// PRIMITIVE TYPES //////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////

struct lsDocumentUri {
  static lsDocumentUri FromPath(const std::string &path);

  bool operator==(const lsDocumentUri &other) const;

  void SetPath(const std::string &path);
  std::string GetPath() const;

  std::string raw_uri;
};

template <typename TVisitor>
void Reflect(TVisitor &visitor, lsDocumentUri &value) {
  Reflect(visitor, value.raw_uri);
}

struct lsPosition {
  int line = 0;
  int character = 0;
  bool operator==(const lsPosition &o) const {
    return line == o.line && character == o.character;
  }
  bool operator<(const lsPosition &o) const {
    return line != o.line ? line < o.line : character < o.character;
  }
  std::string ToString() const;
};
MAKE_REFLECT_STRUCT(lsPosition, line, character);

struct lsRange {
  lsPosition start;
  lsPosition end;
  bool operator==(const lsRange &o) const {
    return start == o.start && end == o.end;
  }
  bool operator<(const lsRange &o) const {
    return !(start == o.start) ? start < o.start : end < o.end;
  }
};
MAKE_REFLECT_STRUCT(lsRange, start, end);

struct lsLocation {
  lsDocumentUri uri;
  lsRange range;
  bool operator==(const lsLocation &o) const {
    return uri == o.uri && range == o.range;
  }
  bool operator<(const lsLocation &o) const {
    return !(uri.raw_uri == o.uri.raw_uri) ? uri.raw_uri < o.uri.raw_uri
                                           : range < o.range;
  }
};
MAKE_REFLECT_STRUCT(lsLocation, uri, range);

enum class lsSymbolKind : uint8_t {
  Unknown = 0,

  File = 1,
  Module = 2,
  Namespace = 3,
  Package = 4,
  Class = 5,
  Method = 6,
  Property = 7,
  Field = 8,
  Constructor = 9,
  Enum = 10,
  Interface = 11,
  Function = 12,
  Variable = 13,
  Constant = 14,
  String = 15,
  Number = 16,
  Boolean = 17,
  Array = 18,
  Object = 19,
  Key = 20,
  Null = 21,
  EnumMember = 22,
  Struct = 23,
  Event = 24,
  Operator = 25,

  // For C++, this is interpreted as "template parameter" (including
  // non-type template parameters).
  TypeParameter = 26,

  // ccls extensions
  // See also https://github.com/Microsoft/language-server-protocol/issues/344
  // for new SymbolKind clang/Index/IndexSymbol.h clang::index::SymbolKind
  TypeAlias = 252,
  Parameter = 253,
  StaticMethod = 254,
  Macro = 255,
};
MAKE_REFLECT_TYPE_PROXY(lsSymbolKind);

// ccls extension
struct lsLocationEx : lsLocation {
  std::optional<std::string_view> containerName;
  std::optional<lsSymbolKind> parentKind;
  // Avoid circular dependency on symbol.h
  std::optional<uint16_t> role;
};
MAKE_REFLECT_STRUCT(lsLocationEx, uri, range, containerName, parentKind, role);

struct lsTextDocumentIdentifier {
  lsDocumentUri uri;
};
MAKE_REFLECT_STRUCT(lsTextDocumentIdentifier, uri);

struct lsVersionedTextDocumentIdentifier {
  lsDocumentUri uri;
  // The version number of this document.  number | null
  std::optional<int> version;

  lsTextDocumentIdentifier AsTextDocumentIdentifier() const;
};
MAKE_REFLECT_STRUCT(lsVersionedTextDocumentIdentifier, uri, version);

struct lsTextDocumentPositionParams {
  // The text document.
  lsTextDocumentIdentifier textDocument;

  // The position inside the text document.
  lsPosition position;
};
MAKE_REFLECT_STRUCT(lsTextDocumentPositionParams, textDocument, position);

struct lsTextEdit {
  // The range of the text document to be manipulated. To insert
  // text into a document create a range where start === end.
  lsRange range;

  // The string to be inserted. For delete operations use an
  // empty string.
  std::string newText;

  bool operator==(const lsTextEdit &that);
};
MAKE_REFLECT_STRUCT(lsTextEdit, range, newText);

struct lsTextDocumentItem {
  // The text document's URI.
  lsDocumentUri uri;

  // The text document's language identifier.
  std::string languageId;

  // The version number of this document (it will strictly increase after each
  // change, including undo/redo).
  int version;

  // The content of the opened text document.
  std::string text;
};
MAKE_REFLECT_STRUCT(lsTextDocumentItem, uri, languageId, version, text);

struct lsTextDocumentEdit {
  // The text document to change.
  lsVersionedTextDocumentIdentifier textDocument;

  // The edits to be applied.
  std::vector<lsTextEdit> edits;
};
MAKE_REFLECT_STRUCT(lsTextDocumentEdit, textDocument, edits);

struct lsWorkspaceEdit {
  // Holds changes to existing resources.
  // changes ? : { [uri:string]: TextEdit[]; };
  // std::unordered_map<lsDocumentUri, std::vector<lsTextEdit>> changes;

  // An array of `TextDocumentEdit`s to express changes to specific a specific
  // version of a text document. Whether a client supports versioned document
  // edits is expressed via `WorkspaceClientCapabilites.versionedWorkspaceEdit`.
  std::vector<lsTextDocumentEdit> documentChanges;
};
MAKE_REFLECT_STRUCT(lsWorkspaceEdit, documentChanges);

// MarkedString can be used to render human readable text. It is either a
// markdown string or a code-block that provides a language and a code snippet.
// The language identifier is sematically equal to the std::optional language
// identifier in fenced code blocks in GitHub issues. See
// https://help.github.com/articles/creating-and-highlighting-code-blocks/#syntax-highlighting
//
// The pair of a language and a value is an equivalent to markdown:
// ```${language}
// ${value}
// ```
//
// Note that markdown strings will be sanitized - that means html will be
// escaped.
struct lsMarkedString {
  std::optional<std::string> language;
  std::string value;
};
void Reflect(Writer &visitor, lsMarkedString &value);

struct lsTextDocumentContentChangeEvent {
  // The range of the document that changed.
  std::optional<lsRange> range;
  // The length of the range that got replaced.
  std::optional<int> rangeLength;
  // The new text of the range/document.
  std::string text;
};
MAKE_REFLECT_STRUCT(lsTextDocumentContentChangeEvent, range, rangeLength, text);

struct lsTextDocumentDidChangeParams {
  lsVersionedTextDocumentIdentifier textDocument;
  std::vector<lsTextDocumentContentChangeEvent> contentChanges;
};
MAKE_REFLECT_STRUCT(lsTextDocumentDidChangeParams, textDocument,
                    contentChanges);

// Show a message to the user.
enum class lsMessageType : int { Error = 1, Warning = 2, Info = 3, Log = 4 };
MAKE_REFLECT_TYPE_PROXY(lsMessageType)

struct Out_ShowLogMessageParams {
  lsMessageType type = lsMessageType::Error;
  std::string message;
};
MAKE_REFLECT_STRUCT(Out_ShowLogMessageParams, type, message);

struct Out_ShowLogMessage : public lsOutMessage<Out_ShowLogMessage> {
  enum class DisplayType { Show, Log };
  DisplayType display_type = DisplayType::Show;

  std::string method();
  Out_ShowLogMessageParams params;
};

template <typename TVisitor>
void Reflect(TVisitor &visitor, Out_ShowLogMessage &value) {
  REFLECT_MEMBER_START();
  REFLECT_MEMBER(jsonrpc);
  std::string method = value.method();
  REFLECT_MEMBER2("method", method);
  REFLECT_MEMBER(params);
  REFLECT_MEMBER_END();
}

struct Out_LocationList : public lsOutMessage<Out_LocationList> {
  lsRequestId id;
  std::vector<lsLocationEx> result;
};
MAKE_REFLECT_STRUCT(Out_LocationList, jsonrpc, id, result);