#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Functions for selecting which apps to install or remove
#
# License
# =======
#
# Copyright (C) 2015-2016 Bob Mottram <bob@robotics.uk.to>
#
# 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/>.

# Array containing names of available apps
APPS_AVAILABLE=()

# Array containing 1 or 0 indicating installed apps
APPS_INSTALLED=()

# Apps selected with checklist
APPS_CHOSEN=()

# A list of the names of installed apps
APPS_INSTALLED_NAMES=()

# file containing a list of removed apps
REMOVED_APPS_FILE=/root/removed

# gets the variants list from an app script
function app_variants {
    filename=$1
    variants_line=$(cat ${filename} | grep "VARIANTS=")
    if [[ "$variants_line" == *"'"* ]]; then
        variants_list=$(echo "$variants_line" | awk -F '=' '{print $2}' | awk -F "'" '{print $2}')
    else
        variants_list=$(echo "$variants_line" | awk -F '=' '{print $2}' | awk -F '"' '{print $2}')
    fi
    echo "$variants_list"
}

# whether a given item is in an array
function item_in_array {
    local e
    for e in "${@:2}"; do [[ "$e" == "$1" ]] && return 0; done
    return 1
}

# mark a given app as having been removed so that it doesn't get reinstalled on updates
function remove_app {
    app_name=$1
    if [ ! -f $REMOVED_APPS_FILE ]; then
        touch $REMOVED_APPS_FILE
    fi
    if ! grep -Fxq "_${app_name}_" $REMOVED_APPS_FILE; then
        echo "_${app_name}_" >> $REMOVED_APPS_FILE
    fi
}

# returns 1 if an app has been marked as removed
function app_is_removed {
    app_name="$1"
    if [ ! -f $REMOVED_APPS_FILE ]; then
        echo "0"
        return
    fi

    if ! grep -Fxq "_${app_name}_" $REMOVED_APPS_FILE; then
        echo "0"
    else
        echo "1"
    fi
}

# Allows an app to be reinstalled even if it was previously marked as being removed
function reinstall_app {
    app_name=$1
    if [ ! -f $REMOVED_APPS_FILE ]; then
        return
    fi
    if [[ $(app_is_removed $app_name) == "1" ]]; then
        sed -i "/_${app_name}_/d" $REMOVED_APPS_FILE
    fi
}

# returns 1 if an app is installed
function app_is_installed {
    app_name="$1"

    # Why does this secondary file exist, apart from COMPLETION_FILE ?
    # It's so that it is visible to unprivileged users from the user control panel
    INSTALLED_APPS_LIST=/usr/share/${PROJECT_NAME}/installed.txt
    if [ -f $INSTALLED_APPS_LIST ]; then
        if ! grep -Fxq "install_${app_name}" $INSTALLED_APPS_LIST; then
            echo "0"
        else
            echo "1"
        fi
        return
    fi

    # check the completion file to see if it was installed
    if [ ! -f $COMPLETION_FILE ]; then
        echo "0"
        return
    fi

    if ! grep -Fxq "install_${app_name}" $COMPLETION_FILE; then
        echo "0"
    else
        echo "1"
    fi
}

# called at the end of the install section of an app script
function install_completed {
    if [ ! ${1} ]; then
        exit 673935
    fi
    echo "install_${1}" >> $COMPLETION_FILE
}

# populates an array of "0" or "1" for whether apps are installed
function get_apps_installed {
    for a in "${APPS_AVAILABLE[@]}"
    do
        APPS_INSTALLED+=("$(app_is_installed $a)")
    done
}

# populates an array of installed app names
function get_apps_installed_names {
    APPS_INSTALLED_NAMES=()
    for a in "${APPS_AVAILABLE[@]}"
    do
        if [[ $(app_is_installed $a) == "1" ]]; then
            APPS_INSTALLED_NAMES+=("$a")
        fi
    done
}

# detects what apps are available
function detect_apps {
    FILES=/usr/share/${PROJECT_NAME}/apps/${PROJECT_NAME}-app-*

    APPS_AVAILABLE=()
    APPS_CHOSEN=()

    # for all the app scripts
    for filename in $FILES
    do
        app_name=$(echo "${filename}" | awk -F '-app-' '{print $2}')
        if [[ $(item_in_array ${app_name} ${APPS_AVAILABLE[@]}) != 0 ]]; then
            APPS_AVAILABLE+=("${app_name}")
            APPS_CHOSEN+=("0")
        fi
    done

    function_check get_apps_installed
    get_apps_installed
    get_apps_installed_names
}

# detects what apps are available and can be installed
# If the variants list within an app script is an empty string then
# it is considered to be too experimental to be installable
function detect_installable_apps {
    FILES=/usr/share/${PROJECT_NAME}/apps/${PROJECT_NAME}-app-*

    APPS_AVAILABLE=()
    APPS_CHOSEN=()
    APPS_INSTALLED=()
    APPS_INSTALLED_NAMES=()

    function_check app_is_installed

    # for all the app scripts
    for filename in $FILES
    do
        app_name=$(echo "${filename}" | awk -F '-app-' '{print $2}')
        if [[ $(item_in_array ${app_name} ${APPS_AVAILABLE[@]}) != 0 ]]; then
            variants_list=$(app_variants $filename)
            # check for empty string
            if [ ${#variants_list} -gt 0 ]; then
                APPS_AVAILABLE+=("${app_name}")
                APPS_CHOSEN+=("0")
                APPS_INSTALLED+=("$(app_is_installed $app_name)")
                if [[ $(app_is_installed $app_name) == "1" ]]; then
                    APPS_INSTALLED_NAMES+=("$app_name")
                fi
            fi
        fi
    done
}

# creates the APPS_AVAILABLE and APPS_CHOSEN arrays based on
# the given variant name
function choose_apps_for_variant {
    variant_name="$1"

    FILES=/usr/share/${PROJECT_NAME}/apps/${PROJECT_NAME}-app-*

    APPS_AVAILABLE=()
    APPS_CHOSEN=()

    # for all the app scripts
    for filename in $FILES
    do
        app_name=$(echo "${filename}" | awk -F '-app-' '{print $2}')
        if [[ $(item_in_array ${app_name} ${APPS_AVAILABLE[@]}) != 0 ]]; then
            APPS_AVAILABLE+=("${app_name}")

            if grep -q "VARIANTS=" ${filename}; then
                variants_list=$(app_variants $filename)
                if [[ "${variants_list}" == 'all'* || \
                      "${variants_list}" == "$variant_name "* || \
                      "${variants_list}" == *" $variant_name "* || \
                      "${variants_list}" == *" $variant_name" ]]; then
                    if [[ $(app_is_removed ${a}) == "0" ]]; then
                        APPS_CHOSEN+=("1")
                    else
                        APPS_CHOSEN+=("0")
                    fi
                else
                    APPS_CHOSEN+=("0")
                fi
            else
                APPS_CHOSEN+=("0")
            fi

        fi
    done

    function_check get_apps_installed
    get_apps_installed
}

# show a list of apps which have been chosen
function list_chosen_apps {
    app_index=0
    for a in "${APPS_AVAILABLE[@]}"
    do
        if [[ ${APPS_CHOSEN[$app_index]} == "1" ]]; then
            echo $"${a}"
        fi
        app_index=$[app_index+1]
    done
}

function remove_apps {
    app_index=0
    for a in "${APPS_AVAILABLE[@]}"
    do
        if [[ ${APPS_INSTALLED[$app_index]} == "1" ]]; then
            if [[ ${APPS_CHOSEN[$app_index]} == "0" ]]; then
                echo $"Removing application: ${a}"
                remove_app ${a}
                remove_${a}
                echo $"${a} was removed"
            fi
        fi
        app_index=$[app_index+1]
    done
    update_installed_apps_list
}

function install_apps {
    is_interactive=$1

    # interactive install configuration for each app
    if [ ${is_interactive} ]; then
        app_index=0
        for a in "${APPS_AVAILABLE[@]}"
        do
            if [[ ${APPS_INSTALLED[$app_index]} == "0" ]]; then
                if [[ ${APPS_CHOSEN[$app_index]} == "1" ]]; then
                    # interactively obtain settings for this app
                    if [[ $(function_exists install_interactive_${a}) == "1" ]]; then
                        install_interactive_${a}
                    fi
                fi
            fi
            app_index=$[app_index+1]
        done
    fi

    # now install the apps
    app_index=0
    for a in "${APPS_AVAILABLE[@]}"
    do
        if [[ ${APPS_INSTALLED[$app_index]} == "0" ]]; then
            if [[ ${APPS_CHOSEN[$app_index]} == "1" ]]; then
                if [ ${is_interactive} ]; then
                    # clears any removal indicator
                    reinstall_app ${a}

                    echo $"Installing application from interactive: ${a}"
                    install_${a}
                    echo $"${a} was installed from interactive"
                else
                    # check if the app was removed
                    if [[ $(app_is_removed ${a}) == "0" ]]; then
                        echo $"Installing application: ${a}"
                        install_${a}
                        echo $"${a} was installed"
                    else
                        echo $"${a} has been removed and so will not be reinstalled"
                    fi
                fi
            fi
        fi
        app_index=$[app_index+1]
    done

    update_installed_apps_list
}

# NOTE: deliberately no exit 0