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

#include "message_handler.hh"
#include "pipeline.hh"
#include "query_utils.h"
#include "serializers/json.h"

#include <llvm/Support/FormatVariadic.h>

#include <unordered_set>

namespace ccls {
namespace {
struct CodeAction {
  std::string title;
  const char *kind = "quickfix";
  lsWorkspaceEdit edit;
};
MAKE_REFLECT_STRUCT(CodeAction, title, kind, edit);
}
void MessageHandler::textDocument_codeAction(CodeActionParam &param,
                                             ReplyOnce &reply) {
  WorkingFile *wfile =
      working_files->GetFileByFilename(param.textDocument.uri.GetPath());
  if (!wfile) {
    return;
  }
  std::vector<CodeAction> result;
  std::vector<lsDiagnostic> diagnostics;
  working_files->DoAction([&]() { diagnostics = wfile->diagnostics_; });
  for (lsDiagnostic &diag : diagnostics)
    if (diag.fixits_.size()) {
      CodeAction &cmd = result.emplace_back();
      cmd.title = "FixIt: " + diag.message;
      auto &edit = cmd.edit.documentChanges.emplace_back();
      edit.textDocument.uri = param.textDocument.uri;
      edit.textDocument.version = wfile->version;
      edit.edits = diag.fixits_;
    }
  reply(result);
}

namespace {
struct Cmd_xref {
  Usr usr;
  SymbolKind kind;
  std::string field;
};
struct lsCommand {
  std::string title;
  std::string command;
  std::vector<std::string> arguments;
};
struct lsCodeLens {
  lsRange range;
  std::optional<lsCommand> command;
};
MAKE_REFLECT_STRUCT(Cmd_xref, usr, kind, field);
MAKE_REFLECT_STRUCT(lsCommand, title, command, arguments);
MAKE_REFLECT_STRUCT(lsCodeLens, range, command);

template <typename T>
std::string ToString(T &v) {
  rapidjson::StringBuffer output;
  rapidjson::Writer<rapidjson::StringBuffer> writer(output);
  JsonWriter json_writer(&writer);
  Reflect(json_writer, v);
  return output.GetString();
}

struct CommonCodeLensParams {
  std::vector<lsCodeLens> *result;
  DB *db;
  WorkingFile *wfile;
};
} // namespace

void MessageHandler::textDocument_codeLens(TextDocumentParam &param,
                                           ReplyOnce &reply) {
  std::vector<lsCodeLens> result;
  std::string path = param.textDocument.uri.GetPath();

  QueryFile *file = FindFile(reply, path);
  WorkingFile *wfile =
      file ? working_files->GetFileByFilename(file->def->path) : nullptr;
  if (!wfile) {
    return;
  }

  auto Add = [&](const char *singular, Cmd_xref show, Range range, int num,
                 bool force_display = false) {
    if (!num && !force_display)
      return;
    std::optional<lsRange> ls_range = GetLsRange(wfile, range);
    if (!ls_range)
      return;
    lsCodeLens &code_lens = result.emplace_back();
    code_lens.range = *ls_range;
    code_lens.command = lsCommand();
    code_lens.command->command = std::string(ccls_xref);
    bool plural = num > 1 && singular[strlen(singular) - 1] != 'd';
    code_lens.command->title =
        llvm::formatv("{0} {1}{2}", num, singular, plural ? "s" : "").str();
    code_lens.command->arguments.push_back(ToString(show));
  };

  std::unordered_set<Range> seen;
  for (auto [sym, refcnt] : file->symbol2refcnt) {
    if (refcnt <= 0 || !sym.extent.Valid() || !seen.insert(sym.range).second)
      continue;
    switch (sym.kind) {
    case SymbolKind::Func: {
      QueryFunc &func = db->GetFunc(sym);
      const QueryFunc::Def *def = func.AnyDef();
      if (!def)
        continue;
      std::vector<Use> base_uses = GetUsesForAllBases(db, func);
      std::vector<Use> derived_uses = GetUsesForAllDerived(db, func);
      Add("ref", {sym.usr, SymbolKind::Func, "uses"}, sym.range,
          func.uses.size(), base_uses.empty());
      if (base_uses.size())
        Add("b.ref", {sym.usr, SymbolKind::Func, "bases uses"}, sym.range,
            base_uses.size());
      if (derived_uses.size())
        Add("d.ref", {sym.usr, SymbolKind::Func, "derived uses"}, sym.range,
            derived_uses.size());
      if (base_uses.empty())
        Add("base", {sym.usr, SymbolKind::Func, "bases"}, sym.range,
            def->bases.size());
      Add("derived", {sym.usr, SymbolKind::Func, "derived"}, sym.range,
          func.derived.size());
      break;
    }
    case SymbolKind::Type: {
      QueryType &type = db->GetType(sym);
      Add("ref", {sym.usr, SymbolKind::Type, "uses"}, sym.range,
          type.uses.size(), true);
      Add("derived", {sym.usr, SymbolKind::Type, "derived"}, sym.range,
          type.derived.size());
      Add("var", {sym.usr, SymbolKind::Type, "instances"}, sym.range,
          type.instances.size());
      break;
    }
    case SymbolKind::Var: {
      QueryVar &var = db->GetVar(sym);
      const QueryVar::Def *def = var.AnyDef();
      if (!def || (def->is_local() && !g_config->codeLens.localVariables))
        continue;
      Add("ref", {sym.usr, SymbolKind::Var, "uses"}, sym.range, var.uses.size(),
          def->kind != lsSymbolKind::Macro);
      break;
    }
    case SymbolKind::File:
    case SymbolKind::Invalid:
      llvm_unreachable("");
    };
  }

  reply(result);
}

void MessageHandler::workspace_executeCommand(Reader &reader,
                                              ReplyOnce &reply) {
  lsCommand param;
  Reflect(reader, param);
  if (param.arguments.empty()) {
    return;
  }
  rapidjson::Document reader1;
  reader1.Parse(param.arguments[0].c_str());
  JsonReader json_reader{&reader1};
  if (param.command == ccls_xref) {
    Cmd_xref cmd;
    Reflect(json_reader, cmd);
    std::vector<lsLocation> result;
    auto Map = [&](auto &&uses) {
      for (auto &use : uses)
        if (auto loc = GetLsLocation(db, working_files, use))
          result.push_back(std::move(*loc));
    };
    switch (cmd.kind) {
    case SymbolKind::Func: {
      QueryFunc &func = db->Func(cmd.usr);
      if (cmd.field == "bases") {
        if (auto *def = func.AnyDef())
          Map(GetFuncDeclarations(db, def->bases));
      } else if (cmd.field == "bases uses") {
        Map(GetUsesForAllBases(db, func));
      } else if (cmd.field == "derived") {
        Map(GetFuncDeclarations(db, func.derived));
      } else if (cmd.field == "derived uses") {
        Map(GetUsesForAllDerived(db, func));
      } else if (cmd.field == "uses") {
        Map(func.uses);
      }
      break;
    }
    case SymbolKind::Type: {
      QueryType &type = db->Type(cmd.usr);
      if (cmd.field == "derived") {
        Map(GetTypeDeclarations(db, type.derived));
      } else if (cmd.field == "instances") {
        Map(GetVarDeclarations(db, type.instances, 7));
      } else if (cmd.field == "uses") {
        Map(type.uses);
      }
      break;
    }
    case SymbolKind::Var: {
      QueryVar &var = db->Var(cmd.usr);
      if (cmd.field == "uses")
        Map(var.uses);
      break;
    }
    default:
      break;
    }
    reply(result);
  }
}
} // namespace ccls