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#include "win32/tip/tip_linguistic_alternates.h"

#include <Windows.h>
#define _ATL_NO_AUTOMATIC_NAMESPACE
#define _WTL_NO_AUTOMATIC_NAMESPACE
#include <Ctffunc.h>
#include <atlbase.h>
#include <atlcom.h>

#include <memory>
#include <vector>

#include "base/util.h"
#include "win32/tip/tip_candidate_list.h"
#include "win32/tip/tip_edit_session.h"
#include "win32/tip/tip_query_provider.h"
#include "win32/tip/tip_ref_count.h"
#include "win32/tip/tip_text_service.h"

using ::ATL::CComPtr;
using ::std::unique_ptr;

namespace mozc {
namespace win32 {
namespace tsf {

namespace {

#ifdef GOOGLE_JAPANESE_INPUT_BUILD
const wchar_t kSearchCandidateProviderName[] = L"Google Japanese Input";
#else
const wchar_t kSearchCandidateProviderName[] = L"Mozc";
#endif

class GetLinguisticAlternatesImpl : public ITfFnGetLinguisticAlternates {
 public:
  GetLinguisticAlternatesImpl(TipTextService *text_service,
                              TipQueryProvider *provider)
      : text_service_(text_service), provider_(provider) {}

 private:
  // The IUnknown interface methods.
  virtual HRESULT STDMETHODCALLTYPE QueryInterface(const IID &interface_id,
                                                   void **object) {
    if (!object) {
      return E_INVALIDARG;
    }

    // Find a matching interface from the ones implemented by this object.
    // This object implements IUnknown and ITfEditSession.
    if (::IsEqualIID(interface_id, IID_IUnknown)) {
      *object = static_cast<IUnknown *>(this);
    } else if (IsEqualIID(interface_id, IID_ITfFunction)) {
      *object = static_cast<ITfFunction *>(this);
    } else if (IsEqualIID(interface_id, IID_ITfFnGetLinguisticAlternates)) {
      *object = static_cast<ITfFnGetLinguisticAlternates *>(this);
    } else {
      *object = nullptr;
      return E_NOINTERFACE;
    }

    AddRef();
    return S_OK;
  }

  virtual ULONG STDMETHODCALLTYPE AddRef() { return ref_count_.AddRefImpl(); }

  virtual ULONG STDMETHODCALLTYPE Release() {
    const ULONG count = ref_count_.ReleaseImpl();
    if (count == 0) {
      delete this;
    }
    return count;
  }

  // The ITfFunction interface method.
  virtual HRESULT STDMETHODCALLTYPE GetDisplayName(BSTR *name) {
    if (name == nullptr) {
      return E_INVALIDARG;
    }
    *name = ::SysAllocString(kSearchCandidateProviderName);
    return S_OK;
  }

  // The ITfFnGetLinguisticAlternates interface method.
  virtual HRESULT STDMETHODCALLTYPE
  GetAlternates(ITfRange *range, ITfCandidateList **candidate_list) {
    if (range == nullptr) {
      return E_INVALIDARG;
    }
    if (candidate_list == nullptr) {
      return E_INVALIDARG;
    }
    *candidate_list = nullptr;
    std::wstring query;
    if (!TipEditSession::GetTextSync(text_service_, range, &query)) {
      return E_FAIL;
    }
    std::vector<std::wstring> candidates;
    if (!provider_->Query(query, TipQueryProvider::kDefault, &candidates)) {
      return E_FAIL;
    }
    *candidate_list = TipCandidateList::New(candidates, nullptr);
    (*candidate_list)->AddRef();
    return S_OK;
  }

  TipRefCount ref_count_;
  CComPtr<TipTextService> text_service_;
  unique_ptr<TipQueryProvider> provider_;

  DISALLOW_COPY_AND_ASSIGN(GetLinguisticAlternatesImpl);
};

}  // namespace

// static
IUnknown *TipLinguisticAlternates::New(TipTextService *text_service) {
  auto *provider = TipQueryProvider::Create();
  if (provider == nullptr) {
    return nullptr;
  }
  return new GetLinguisticAlternatesImpl(text_service, provider);
}

// static
const IID &TipLinguisticAlternates::GetIID() {
  return IID_ITfFnGetLinguisticAlternates;
}

}  // namespace tsf
}  // namespace win32
}  // namespace mozc
