/* 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 "serializer.h"
#include "utils.h"

#include <iosfwd>
#include <unordered_map>

using MethodType = const char *;
extern MethodType kMethodType_Exit;

struct lsRequestId {
  // The client can send the request id as an int or a string. We should output
  // the same format we received.
  enum Type { kNone, kInt, kString };
  Type type = kNone;

  int value = -1;

  bool Valid() const { return type != kNone; }
};
void Reflect(Reader &visitor, lsRequestId &value);
void Reflect(Writer &visitor, lsRequestId &value);

struct InMessage {
  virtual ~InMessage();

  virtual MethodType GetMethodType() const = 0;
  virtual lsRequestId GetRequestId() const { return {}; }
};

struct NotificationMessage : InMessage {};

struct RequestMessage : public InMessage {
  lsRequestId id;
  lsRequestId GetRequestId() const override { return id; }
};

#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));
        };
  }
};

enum class lsErrorCodes {
  // Defined by JSON RPC
  ParseError = -32700,
  InvalidRequest = -32600,
  MethodNotFound = -32601,
  InvalidParams = -32602,
  InternalError = -32603,
  serverErrorStart = -32099,
  serverErrorEnd = -32000,
  ServerNotInitialized = -32002,
  UnknownErrorCode = -32001,

  // Defined by the protocol.
  RequestCancelled = -32800,
};
MAKE_REFLECT_TYPE_PROXY(lsErrorCodes);

struct lsResponseError {
  // A number indicating the error type that occurred.
  lsErrorCodes code;

  // A string providing a short description of the error.
  std::string message;

  // A Primitive or Structured value that contains additional
  // information about the error. Can be omitted.
  // std::optional<D> data;
};
MAKE_REFLECT_STRUCT(lsResponseError, code, message);

constexpr char ccls_xref[] = "ccls.xref";
constexpr char window_showMessage[] = "window/showMessage";

/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
////////////////////////////// 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);

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);

struct lsWorkspaceFolder {
  lsDocumentUri uri;
  std::string name;
};
MAKE_REFLECT_STRUCT(lsWorkspaceFolder, uri, name);

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

enum class lsDiagnosticSeverity {
  // Reports an error.
  Error = 1,
  // Reports a warning.
  Warning = 2,
  // Reports an information.
  Information = 3,
  // Reports a hint.
  Hint = 4
};
MAKE_REFLECT_TYPE_PROXY(lsDiagnosticSeverity);

struct lsDiagnostic {
  // The range at which the message applies.
  lsRange range;

  // The diagnostic's severity. Can be omitted. If omitted it is up to the
  // client to interpret diagnostics as error, warning, info or hint.
  std::optional<lsDiagnosticSeverity> severity;

  // The diagnostic's code. Can be omitted.
  int code = 0;

  // A human-readable string describing the source of this
  // diagnostic, e.g. 'typescript' or 'super lint'.
  std::string source = "ccls";

  // The diagnostic's message.
  std::string message;

  // Non-serialized set of fixits.
  std::vector<lsTextEdit> fixits_;
};
MAKE_REFLECT_STRUCT(lsDiagnostic, range, severity, source, message);

struct lsPublishDiagnosticsParams {
  // The URI for which diagnostic information is reported.
  lsDocumentUri uri;

  // An array of diagnostic information items.
  std::vector<lsDiagnostic> diagnostics;
};
MAKE_REFLECT_STRUCT(lsPublishDiagnosticsParams, uri, diagnostics);

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

// Used to identify the language at a file level. The ordering is important, as
// a file previously identified as `C`, will be changed to `Cpp` if it
// encounters a c++ declaration.
enum class LanguageId { Unknown = -1, C = 0, Cpp = 1, ObjC = 2, ObjCpp = 3 };
MAKE_REFLECT_TYPE_PROXY(LanguageId);