#!/usr/bin/python3
# coding=utf-8

# CodeQ: an online programming tutor.
# Copyright (C) 2015 UL FRI
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option) any
# later version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.

"""This tool processes all problem files, and outputs JSON files to describe
problems, to be used as static web resources. It also adds missing problem
identifiers in the database.
Before running the script define the following environment variables, if defaults are not okay:
CODEQ_WEB_OUTPUT - directory where to write the output, defaults to /var/www/html/data
CODEQ_PROBLEMS - directory where you have codeq-problems checked out, defaults to /var/local/codeq-problems
CODEQ_DB_HOST - hostname or IP of the database server, defaults to localhost
CODEQ_DB_PORT - TCP port number of the database server, defaults to 5432
CODEQ_DB_DATABASE - name of the database, defaults to codeq
CODEQ_DB_USER - database username, defaults to codeq
CODEQ_DB_PASS - database password, defaults to c0d3q
"""

import os
import traceback
import sys
import json
import shutil

# insert the parent directory, so the problem scripts find their modules
sys.path.insert(0, os.sep.join(os.path.dirname(__file__).split(os.sep)[:-1]))

import server.problems
import db

problems_path = os.environ.get('CODEQ_PROBLEMS') or '/var/local/codeq-problems'  # where to find problems, the same as server.problems._path_prefix
output_path = os.environ.get('CODEQ_WEB_OUTPUT') or '/var/www/html/data'  # the base directory where to create subdirectories and output the files for web

toplevel = {'style.css'}  # files to copy from the toplevel directory (CODEQ_PROBLEMS)
translations = {'sl', 'en'}  # translations to seek (sl.py, en.py, ...)

# default values (properties) for various types of items, also the list of properties to copy from modules
language_props = {  # for translation files inside the language subdirectory
    'name': 'Name not set',
    'description': 'Description not set',
    'hint': {}
}
language_common_props = {  # for common.py inside the language subdirectory
    'id': None,  # database ID of the language
    'hint_type': {}  # type definitions of common hints
}
group_props = {  # for translation files inside the problem group subdirectory
    'name': 'Name not set',
    'description': 'Description not set'
}
group_common_props = {  # for common.py inside the problem group subdirectory
    'id': None,  # database ID of the problem group
    'number': 1  # display index of the problem group
}
problem_props = {  # for translation files inside the problem subdirectory
    'name': 'Name not set',
    'slug': 'Slug not set',
    'description': 'Description not set',
    'plan': [],
    'hint': {}
}
problem_common_props = {  # for common.py inside the problem subdirectory
    'id': None,  # database ID of the problem
    'number': 1,  # display index of problems inside their groups
    'visible': True,  # whether the problem is enabled (disabled problems are excluded from the application)
    'initial': None,  # code to put in the editor when the user first opens this problem
    'hint_type': {},  # type definitions of problem hints
}

if not os.path.exists(output_path):
    os.mkdir(output_path)

def load_translation_data(package, defaults):
    result = {}
    path = os.sep.join(package.split('.'))
    for lang in translations:
        mod_path = os.path.join(problems_path, path, lang + '.py')
        if os.path.exists(mod_path) and os.path.isfile(mod_path):
            mod = None
            try:
                mod = server.problems.load_module(package + '.' + lang)
            except:
                traceback.print_exc(limit=0)
            lang_data = {}
            result[lang] = lang_data
            if mod is None:
                print('Could not load translation module {}'.format(package + '.' + lang))
                for prop, default in defaults.items():
                    lang_data[prop] = default
            else:
                for prop, default in defaults.items():
                    lang_data[prop] = getattr(mod, prop, default)
    return result

def load_common_data(package, defaults):
    mod = None
    path = os.sep.join(package.split('.'))
    mod_path = os.path.join(problems_path, path, 'common.py')
    if os.path.exists(mod_path) and os.path.isfile(mod_path):
        try:
            mod = server.problems.load_module(package + '.common')
        except:
            print('Error loading module {}:'.format(mod_path))
            traceback.print_exc(limit=0)
    if mod is None:
        return None

    result = {}
    for prop, default in defaults.items():
        result[prop] = getattr(mod, prop, default)
    return result

def process_hint_type(hint_type):
    result = {}
    for identifier, hint in hint_type.items():
        result[identifier] = hint.hint_type
    return result

resource_tree = {}  # a directory tree where branches are paths and leaves are filenames, it is rooted at the web data directory
def copy_web_resources(package, dst_dir_fragments, filter=None):
    src_path = os.path.join(problems_path, os.sep.join(package.split('.')))
    dst_path = output_path
    node = resource_tree
    for fragment in dst_dir_fragments:
        dst_path = os.path.join(dst_path, fragment)
        subnode = node.get(fragment)
        if subnode is None:
            subnode = {}
            node[fragment] = subnode
        node = subnode
    for filename in os.listdir(src_path):
        if filter and filename not in filter:
            continue
        if filename.startswith('.') or filename.endswith('.py'):
            continue
        full_filename = os.path.join(src_path, filename)
        if os.path.isfile(full_filename):
            shutil.copy(full_filename, dst_path)
            node[filename] = True

def dump_language_defs(data, output_path):
    # sort groups and problems
    groups = data['groups']
    for group in groups:
        group['problems'].sort(key=lambda p: p.get('number', 0))
    groups.sort(key=lambda p: p.get('number', 0))
    # write out the JSON file
    with open(os.path.join(output_path, 'language.json'), 'w') as f:
        json.dump(data, f, indent=2)

conn = db.get_connection()
cur = conn.cursor()

def db_add(table, id, data):
    data = sorted(data.items())
    cols = tuple([d[0] for d in data])
    vals = tuple([d[1] for d in data])

    cur.execute('select ' + ','.join(cols) + ' from ' + table + ' where id = %s', (id,))
    row = cur.fetchone()
    if row is None:
        print('Inserting new {} in database: cols={} vals={}'.format(table, cols, vals))
        args = ','.join(['%s'] * len(cols))
        sql = 'insert into ' + table + ' (' + ','.join(cols) + ') values (' + args + ')'
        cur.execute(sql, vals)
    elif row != vals:
        print('Updating {} {} in database: cols={} vals={}'.format(table, id, cols, vals))
        args = ','.join([col + ' = %s' for col in cols])
        sql = 'update ' + table + ' set ' + args + ' where id = %s'
        cur.execute(sql, vals + (id,))

try:
    # copy top-level files (style etc.)
    copy_web_resources('', [], filter=toplevel)

    # get problem descriptors
    for lang_identifier in os.listdir(problems_path):
        lang_data = load_common_data(lang_identifier, language_common_props)
        if lang_data is None:
            continue

        # create language output directory
        lang_output_path = os.path.join(output_path, lang_identifier)
        if not os.path.exists(lang_output_path):
            os.mkdir(lang_output_path)

        lang_data['hint_type'] = process_hint_type(lang_data.get('hint_type', {}))
        lang_data['identifier'] = lang_identifier
        lang_data['groups'] = []
        lang_data['translations'] = load_translation_data(lang_identifier, language_props)
        copy_web_resources(lang_identifier, [lang_identifier])
        db_add('language', lang_data['id'],
                {'id': lang_data['id'], 'identifier': lang_identifier})

        groups_path = os.path.join(problems_path, lang_identifier, 'problems')
        for group_identifier in os.listdir(groups_path):
            group_package = lang_identifier + '.problems.' + group_identifier
            group_data = load_common_data(group_package, group_common_props)
            if group_data is None:
                continue

            # create group directory
            group_output_path = os.path.join(lang_output_path, group_identifier)
            if not os.path.exists(group_output_path):
                os.mkdir(group_output_path)

            group_data['identifier'] = group_identifier
            group_data['problems'] = []
            group_data['translations'] = load_translation_data(group_package, group_props)
            db_add('problem_group', group_data['id'],
                    {'id': group_data['id'], 'identifier': group_identifier})

            group_path = os.path.join(groups_path, group_identifier)
            for problem_identifier in os.listdir(group_path):
                problem_package = group_package + '.' + problem_identifier
                common_data = load_common_data(problem_package, problem_common_props)
                if common_data is None:
                    continue

                common_data['identifier'] = problem_identifier
                if not common_data['visible']:
                    continue  # problem is not visible, do not generate anything
                del common_data['visible']  # we don't need this field in the GUI

                # save for later, to be used in problem_data below
                hint_type = process_hint_type(common_data['hint_type'])
                del common_data['hint_type']  # we don't need this field in the language index

                group_data['problems'].append(common_data)

                # load translations, and copy only problem names to the common data
                problem_translations = load_translation_data(problem_package, problem_props)
                name_translations = {}
                for key, value in problem_translations.items():
                    name_translations[key] = {'name': value.get('name')}
                common_data['translations'] = name_translations

                problem_data = {
                    'id': common_data['id'],
                    'identifier': problem_identifier,
                    'translations': problem_translations,
                    'initial': common_data['initial'],
                    'hint_type': hint_type,
                }

                problem_output_path = os.path.join(group_output_path, problem_identifier)
                if not os.path.exists(problem_output_path):
                    os.mkdir(problem_output_path)
                with open(os.path.join(problem_output_path, 'problem.json'), 'w') as f:
                    json.dump(problem_data, f, indent=2)
                copy_web_resources(problem_package, [lang_identifier, group_identifier, problem_identifier])
                db_add('problem', problem_data['id'], {
                            'id': problem_data['id'],
                            'language_id': lang_data['id'],
                            'problem_group_id': group_data['id'],
                            'identifier': problem_identifier
                        })

            # add only non-empty problem groups
            if group_data['problems']:
                copy_web_resources(group_package, [lang_identifier, group_identifier])
                lang_data['groups'].append(group_data)

        dump_language_defs(lang_data, lang_output_path)
    cur.close()
    conn.commit()
except:
    conn.rollback()
    raise
finally:
    db.return_connection(conn)

# dump the tree of resources
with open(os.path.join(output_path, 'resources.json'), 'w') as f:
    json.dump(resource_tree, f, indent=2)