#!/bin/bash

#=================================================
# GENERIC STARTING
#=================================================
# IMPORT GENERIC HELPERS
#=================================================

source _common.sh
source /usr/share/yunohost/helpers

#=================================================
# MANAGE SCRIPT FAILURE
#=================================================

# Exit if an error occurs during the execution of the script
ynh_abort_if_errors

#=================================================
# RETRIEVE ARGUMENTS
#=================================================

set_permissions() {
    local file="$1"
    if [ -f $file ]
    then
        chown $app:$app $file
        chmod go=--- $file
    fi
}

#=================================================
# SPECIFIC GETTERS FOR TOML SHORT KEY
#=================================================

BACKTICK='`'
TRIPLEBACKTICKS='```'

get__status() {
    local service_enabled=$(ynh_app_setting_get $app service_enabled)

    ipv4=$(ping -w3 -c1 ip.yunohost.org  >/dev/null 2>&1 && curl --max-time 5 https://ip.yunohost.org --silent)
    ipv6=$(ping -w3 -c1 ip6.yunohost.org >/dev/null 2>&1 && curl --max-time 5 https://ip6.yunohost.org --silent)

    if ip route get 1.2.3.4 | grep -q tun0 && [[ -n "$ipv4" ]]
    then
        if [ $service_enabled -eq 1 ]
        then
            cat << EOF
style: success
ask:
  en: |-
    The VPN is enabled and running ! :)

    **IPv4:** $BACKTICK$ipv4$BACKTICK

    **IPv6:** $BACKTICK$ipv6$BACKTICK
EOF

        else
            cat << EOF
style: warning
ask:
  en: The VPN is running, but it shouldn't !?
EOF
        fi
    elif [ $service_enabled -eq 1 ]
    then
        cat << EOF
style: danger
ask:
  en: |-
    The VPN is down ! Here are errors logged in the last few minutes
    $TRIPLEBACKTICKS
$(journalctl -u ynh-vpnclient -o cat | sed 's/^/    /g' | tail -n 15)
    $TRIPLEBACKTICKS
EOF
    else
        cat << EOF
style: info
ask:
  en: The VPN is not enabled
EOF

    fi
}

get__login_user() {
    if [ -s /etc/openvpn/keys/credentials ]
    then
        echo "$(sed -n 1p /etc/openvpn/keys/credentials)"
    else
        echo ""
    fi
}

get__login_passphrase() {
    if [ -s /etc/openvpn/keys/credentials ]
    then
        echo "$(sed -n 2p /etc/openvpn/keys/credentials)"
    else
        echo ""
    fi
}


#=================================================
# SPECIFIC VALIDATORS FOR TOML SHORT KEYS
#=================================================
validate__login_user() {

    if grep -q '^\s*auth-user-pass' ${config_file}
    then
        if [[ -z "${login_user}" ]]
        then
            echo 'A Username is needed with this configuration file'
        fi
    fi
}

validate__login_passphrase() {
    if grep -q '^\s*auth-user-pass' ${config_file}
    then
        if [[ -z "${login_passphrase}" ]]
        then
            echo 'A Password is needed with this configuration file'
        fi
    fi
}

validate__crt_server_ca() {
    if grep -q '^\s*ca\s' ${config_file}
    then
        if [[ ! -e "${crt_server_ca}" ]]
        then
            echo "A server CA certificate is needed"
        fi
    fi
}

validate__crt_client() {
    if grep -q '^\s*cert\s' ${config_file}
    then
        if [[ ! -e "${crt_client}" ]]
        then
            echo "A Client certificate is needed with this configuration file"
        fi
    fi
}

validate__crt_client_key() {
    if grep -q '^\s*key\s' ${config_file}
    then
        if [[ ! -e "${crt_client_key}" ]]
        then
            echo "A client private key is needed with this configuration file"
        fi
    fi
}

validate__crt_client_ta() {
    if grep -q '^\s*tls-auth\s' ${config_file}
    then
        if [[ ! -e "${crt_client_ta}" ]]
        then
            echo "A TLS auth shared secret is needed with this configuration file"
        fi
    fi
}

validate__nameservers() {
    if [[ "$dns_method" == "custom" ]] && [[ -z "$nameservers" ]]
    then
        echo "You need to choose DNS resolvers or select an other method to provide DNS resolvers"
    fi
}
#=================================================
# SPECIFIC SETTERS FOR TOML SHORT KEYS
#=================================================
set__login_user() {
    if [ -n "${login_user}" ]
    then
        echo "${login_user}" > /etc/openvpn/keys/credentials
        echo "${login_passphrase}" >> /etc/openvpn/keys/credentials
        set_permissions /etc/openvpn/keys/credentials
    else
        echo "" > /etc/openvpn/keys/credentials
    fi
}

set__login_passphrase() {
    :
}

#=================================================
# OVERWRITING VALIDATE STEP
#=================================================
read_cube() {
    tmp_dir=$(dirname "$1")
    setting_value="$(jq --raw-output ".$2" "$1")"
    if [[ "$setting_value" == "null" ]]
    then
        setting_value=''
    # Save file in tmp dir
    elif [[ "$2" == "crt_"* ]]
    then
        if [ -n "${setting_value}" ]
        then
            echo "${setting_value}" | sed 's/|/\n/g' > $tmp_dir/$2
            setting_value="$tmp_dir/$2"
        fi
    fi
    echo $setting_value
}
ynh_app_config_validate() {
    # At this moment this var is not already set with the old value
    if [ -z ${config_file+x} ]
    then
        config_file="${old[config_file]}"

    # Overwrite form response with cube files data before validation process

    # We don't have the extension, so we use this ugly hack to check that this is a json-like
    # (i.e. it starts with { ..)
    elif [ -f "${config_file}" ] && [[ "$(cat ${config_file} | tr -d ' ' | grep -v "^$" | head -c1)" == "{" ]]
    then
        ynh_print_info --message="Transforming .cube into OVPN file"
        server_name="$(read_cube $config_file server_name)"
        server_port="$(read_cube $config_file server_port)"
        server_proto="$(read_cube $config_file server_proto)"
        ip6_net="$(read_cube $config_file ip6_net)"
        ip6_addr="$(read_cube $config_file ip6_addr)"
        login_user="$(read_cube $config_file login_user)"
        login_passphrase="$(read_cube $config_file login_passphrase)"
        dns0="$(read_cube $config_file dns0)"
        dns1="$(read_cube $config_file dns1)"
        crt_server_ca="$(read_cube $config_file crt_server_ca)"
        crt_client="$(read_cube $config_file crt_client)"
        crt_client_key="$(read_cube $config_file crt_client_key)"
        crt_client_ta="$(read_cube $config_file crt_client_ta)"
        dns_method="custom"
        nameservers="$dns0,$dns1"

        # Build specific OVPN template
        tmp_dir=$(dirname "${config_file}")
        cp -f /etc/yunohost/apps/vpnclient/conf/openvpn_client.conf.tpl $tmp_dir/client.conf.tpl
        # Remove some lines
        jq --raw-output '.openvpn_rm[]' "${config_file}" | while read -r rm_regex
        do
            if [ ! -z "${rm_regex}" ] ; then
                sed -i "/$rm_regex/d" $tmp_dir/client.conf.tpl
            fi
        done

        # Add some other lines
        echo "# Custom additions from .cube" >> $tmp_dir/client.conf.tpl
        jq --raw-output ".openvpn_add[]" "${config_file}" >> $tmp_dir/client.conf.tpl

        # Temporarily tweak sever_proto for template hydratation
        [ "$server_proto" == tcp ] && server_proto=tcp-client

        # Define other needed vars for template hydratation
        [ -e "$crt_client_key" ] && cert_comment="" || cert_comment="#"
        [ -e "$crt_client_ta" ] && ta_comment="" || ta_comment="#"
        [[ "$server_proto" =~ udp ]] && udp_comment="" || udp_comment="#"
        [ -n "$login_user" ] && login_comment="" || login_comment="#"

        # Actually generate/hydrate the final configuration
        ynh_add_config --template="$tmp_dir/client.conf.tpl" --destination="${config_file}"

        [ "$server_proto" == tcp-client ] && server_proto=tcp


    # Othewise, assume that it's a .ovpn / .conf
    elif [ -f "${config_file}" ]
    then
        tmp_dir=$(dirname "${config_file}")
        ynh_print_info --message="Extracting TLS keys from .ovpn file"
        if grep -q '^\s*<ca>' ${config_file}
        then
            grep -Poz '(?<=<ca>)(.*\n)*.*(?=</ca>)' ${config_file} | sed '/^$/d'  > $tmp_dir/crt_server_ca
            crt_server_ca=$tmp_dir/crt_server_ca
            sed -i '/^\s*<ca>/,/\s*<\/ca>/d' ${config_file}
            sed -i '/^\s*ca\s/d' ${config_file}
            echo "ca /etc/openvpn/keys/ca-server.crt" >> ${config_file}
        fi
        if grep -q '^\s*<cert>' ${config_file}
        then
            grep -Poz '(?<=<cert>)(.*\n)*.*(?=</cert>)' ${config_file} | sed '/^$/d'  > $tmp_dir/crt_client
            crt_client=$tmp_dir/crt_client
            sed -i '/^\s*<cert>/,/\s*<\/cert>/d' ${config_file}
            sed -i '/^\s*cert\s/d' ${config_file}
            echo "cert /etc/openvpn/keys/user.crt" >> ${config_file}
        elif ! grep -q '^\s*cert\s' ${config_file}
        then
            crt_client=""
        fi
        if grep -q '^\s*<key>' ${config_file}
        then
            grep -Poz '(?<=<key>)(.*\n)*.*(?=</key>)' ${config_file} | sed '/^$/d' > $tmp_dir/crt_client_key
            crt_client_key=$tmp_dir/crt_client_key
            sed -i '/^\s*<key>/,/\s*<\/key>/d' ${config_file}
            sed -i '/^\s*key\s/d' ${config_file}
            echo "key /etc/openvpn/keys/user.key" >> ${config_file}
        elif ! grep -q '^\s*key\s' ${config_file}
        then
            crt_client_key=""
        fi
        if grep -q '^\s*<tls-auth>' ${config_file}
        then
            grep -Poz '(?<=<tls-auth>)(.*\n)*.*(?=</tls-auth>)' ${config_file} | sed '/^$/d' > $tmp_dir/crt_client_ta
            crt_client_ta=$tmp_dir/crt_client_ta
            sed -i '/^\s*<tls-auth>/,/\s*<\/tls-auth>/d' ${config_file}
            sed -i '/^\s*tls-auth\s/d' ${config_file}
            echo "tls-auth /etc/openvpn/keys/user_ta.key 1" >> ${config_file}
        elif ! grep -q '^\s*tls-auth\s' ${config_file}
        then
            crt_client_ta=""
        fi
        sed -i 's@^\s*ca\s.*$@ca /etc/openvpn/keys/ca-server.crt@g' ${config_file}
        sed -i 's@^\s*cert\s.*$@cert /etc/openvpn/keys/user.crt@g' ${config_file}
        sed -i 's@^\s*key\s.*$@key /etc/openvpn/keys/user.key@g' ${config_file}
        sed -i 's@^\s*tls-auth\s.*$@tls-auth /etc/openvpn/keys/user-ta.key@g' ${config_file}
    fi

    # Currently we need root priviledge to create tun0
    if [ -f "${config_file}" ]
    then
        sed -i '/^\s*user\s/d' ${config_file}
        sed -i '/^\s*group\s/d' ${config_file}
    fi

    _ynh_app_config_validate
}

#=================================================
# OVERWRITING APPLY STEP
#=================================================
ynh_app_config_apply() {

    # Stop vpn client
    ynh_print_info --message="Stopping vpnclient in order to edit files"
    touch /tmp/.ynh-vpnclient-stopped
    /usr/local/bin/ynh-vpnclient stop

    chown $app:$app /etc/openvpn/keys
    chmod go=--- /etc/openvpn/keys

    _ynh_app_config_apply

    set_permissions /etc/openvpn/client.conf
    set_permissions /etc/openvpn/keys/ca-server.crt
    set_permissions /etc/openvpn/keys/user.crt
    set_permissions /etc/openvpn/keys/user.key
    set_permissions /etc/openvpn/keys/user_ta.key

    # Start vpn client
    ynh_print_info --message="Starting vpnclient service if needed"
    /usr/local/bin/ynh-vpnclient start
    rm -f /tmp/.ynh-vpnclient-stopped

}

ynh_app_config_run $1