* COMMENT -*- mode: org -*-
#+Date: 2019-09-28
Time-stamp: <2020-01-14>

* zero-pinyin-service

zero-pinyin-service is a dbus service to provide pinyin input method service
for zero-el pinyin input method. This allows doing arbitrarily complex things
in C, while the elisp side code can be simple and efficient.

You can see the dbus service interface in
./com.emacsos.zero.ZeroPinyinService1.ZeroPinyinServiceInterface.xml

You can check zero-el document at https://blog.emacsos.com/zero-el.html

zero-pinyin-service requires a character/word table to get candidates for
pinyin preedit string. It uses libpyzy's openphrase db for
this. zero-pinyin-service should know how to break pinyin and how to convert
pinyin preedit string to Chinese character candidates, currently it also use
libpyzy for this. So you can think of the current implementation as an adapter
that makes libpyzy work with zero-el pinyin input method. This implementation
is to get zero-el pinyin working with minimum effort. There are lots of
improvements that can be done here.

* how to build zero-pinyin-service

- Get [[https://mesonbuild.com][meson build tool]] and install the ninja backend.

  Usually this should do:
  #+BEGIN_SRC sh
    sudo apt install meson ninja
  #+END_SRC

  You may prefer installing a newer version of meson via PyPI:
  #+BEGIN_SRC sh
    sudo apt install python3-pip
    python3 -m pip install --user meson ninja
    # add ~/.local/bin to PATH
  #+END_SRC

- Install zero-pinyin-service dependencies

  #+BEGIN_SRC sh
    sudo apt install libglib2.0-dev libsqlite3-dev uuid-dev
  #+END_SRC

- Build zero-pinyin-service

  #+BEGIN_SRC sh
    git clone https://gitlab.emacsos.com/sylecn/libpyzy.git
    cd libpyzy/src/
    # Side note: zero-pinyin-service must be in libpyzy src dir to build, because
    # it uses the source code directly. I didn't use libpyzy as a dependency
    # because I have done code review and patched the libpyzy code and those
    # changes are not sent to upstream. libpyzy is pretty inactive these days.
    git clone https://gitlab.emacsos.com/sylecn/zero-pinyin-service.git
    cd zero-pinyin-service/
    meson setup release/
    cd release && ninja
  #+END_SRC

  You can install it on local system via
  #+BEGIN_SRC sh
    cd release
    sudo ninja install
  #+END_SRC

  Or you can build a deb and install the deb instead.

- Create deb for zero-pinyin-service

  Create deb requires [[https://github.com/jordansissel/fpm][fpm]] tool.

  #+BEGIN_SRC sh
    fpm --version
  #+END_SRC

  At project root dir,
  #+BEGIN_SRC sh
    ./create-deb.sh
  #+END_SRC

** how to install fpm tool
Read official doc for how to install it. The key commands are

#+BEGIN_SRC sh
  apt install ruby ruby-dev
  gem install --user fpm
  # add ruby gem bin dir to PATH
#+END_SRC

* 2019-08-31 ibus-pinyin user db inference notice.
zero-pinyin-service reuses ibus-pinyin's userdb at
~/.cache/ibus/pinyin/user-1.0.db

This is generally not a problem. But if ibus-pinyin (libpyzy) changes their
table schema in the future, zero-pinyin-service may require update.

zero-pinyin-service also stores user phrase in this db. So user phrases are
shared between zero-pinyin and ibus-pinyin.

If you don't use ibus-pinyin, this is not a problem for
you. zero-pinyin-service works fine when ibus-pinyin is not installed.