Installation
============

Minimum versions of required packages:

  - python3-psycopg2 ≥ 2.5.4
  - swi-prolog ≥ 7.3

These instructions assume you are running Debian Jessie. Install dependencies:

    apt install apache2 nodejs npm python3 python3-ply python3-psycopg2 python3-termcolor

SWI prolog
----------

To use the correct SWI prolog package (>= 7.3) on Debian, add a custom
repository by creating the file /etc/apt/sources.list.d/prolog.list
containing the following 2 lines:

deb http://ppa.launchpad.net/swi-prolog/devel/ubuntu trusty main
deb-src http://ppa.launchpad.net/swi-prolog/devel/ubuntu trusty main

After that run the following sequence of shell statements to update
the package cache, register the new repository's key, and again refresh
the package cache using the additional key:

apt-get update
apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EF8406856DBFCA18
apt-get update

libseccomp
----------

A new version of libseccomp (≥ 2.2) with Python bindings is needed to sandbox
Python interpreters. This is not available yet in most distributions. You can
download custom-built packages for Debian Jessie at

    http://codeq.si/libseccomp2_2.2.3-2_amd64.deb
    http://codeq.si/seccomp_2.2.3-2_amd64.deb

and install them using

    dpkg --install libseccomp2_2.2.3-2_amd64.deb seccomp_2.2.3-2_amd64.deb

Alternatively, fetch the latest sources with

    git clone https://github.com/seccomp/libseccomp

and configure with --enable-python.

nodejs
------

Run "npm install" inside the codeq-server/web directory to install all
dependencies (they will be installed inside the web directory)

sandbox
-------

Go to directory codeq-server/python/runner and run the following commands to
build the sandbox and set appropriate permissions:

    make sandbox
    sudo setcap cap_setuid,cap_setgid+ep sandbox

Settings
========

Replace $webroot in this section with the path to codeq-web repo. Remember to
grant read access to $webroot to the apache user.

Set environment variables:

    CODEQ_PROBLEMS=<path to codeq-problems repo>
    CODEQ_WEB_OUTPUT=$webroot/data
    CODEQ_DB_HOST=<address of database server>
    CODEQ_DB_DATABASE=<database name, default is 'codeq'>
    CODEQ_DB_USER=<database user, default is 'codeq'>
    CODEQ_DB_PASS=<database password, default is 'c0d3q'>

Set up apache:

    a2enmod proxy proxy_http proxy_wstunnel rewrite

Add the following directives to the VirtualHost configuration:

    DocumentRoot "$webroot"
    <Directory "$webroot">
        Require all granted
    </Directory>

    RewriteEngine on
    RewriteCond %{REQUEST_URI} ^/ws/ [NC]
    RewriteCond %{QUERY_STRING} transport=websocket [NC]
    RewriteRule /(.*) ws://localhost:8083/$1 [P,L]
    ProxyPass /ws/ http://localhost:8083/ws/
    ProxyPassReverse /ws/ http://localhost:8083/ws/

Running
=======

  - first build static JSON data with scripts/build_web_resources.py, read its heading comment for details
  - run the prolog interpreter server: swipl prolog/runner/main.pl
  - run the session daemon: python3 daemon.py
  - run the web server for client communication: node web/main.js

Testing
=======

You can test stuff in a python interpreter:

    >>> import server
    >>> session = server.user_session.authenticate_and_create_session(<user>, <pass>)
    >>> session.get_problem_data('python', 'introduction', 'fahrenheit_to_celsius')

    >>> python = session.get_python()
    >>> python.test(231, 180, '''print('-17.7')''')
    >>> python.hint(231, 180, '''print('-17.7')''')

    >>> prolog = session.get_prolog()
    >>> prolog.test(231, 96, 'sister(X,Y):- parent(P,X), parent(P,Y), female(X).')
    >>> prolog.hint(231, 96, 'sister(X,Y):- parent(P,X), parent(P,Y), female(X).')

To check for errors in hint definitions you can use the problem_html script:

    python3 -m scripts.problem_html python introduction ballistics sl > out.html

Traces
======

Actions and corresponding additional attributes are specified here.

Generic:
  - open(time)     # when opening the problem page, time = Date.now() on client
  - close()        # when closing the problem page
  - ins(off, txt)  # offset, text
  - rm(off, txt)   # offset, text, was rm(off, len)
  - plan()
  - hint(feedback)  # feedback = list of returned hint objects
  - test(feedback)  # feedback = list of returned hint objects

Prolog:
  - prolog_solve(query)  # was slv(qry)
  - prolog_next()        # was nxt
  - prolog_end()         # was stp

Python:
  - python_run(program)
  - python_stop()
  - python_input(txt)

Robot:
  - robot_run(program)
  - robot_stop()

Obsolete actions:
  - slva(qry)      # "solve all" from tuProlog
  - hnt            # hint button press
  - tst(tot, pas)  # test results (total / passed)