#!/usr/bin/env bash

# Copyright 2019 Mycroft AI Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

SOURCE="${BASH_SOURCE[0]}"
cd -P "$( dirname "$SOURCE" )"
DIR="$( pwd )"
script=${0}
script=${script##*/}

function help() {
    echo "${script}:  Mycroft configuration manager"
    echo "usage: ${script} [COMMAND] [params]"
    echo
    echo "COMMANDs:"
    echo "  edit (system|user)                  edit and validate config file"
    echo "  reload                              instruct services to reload config"
    echo "  show (default|remote|system|user)   display the specified setting file"
    echo "  set <var>                           set the variable (under USER)"
    echo "  get [var]                           display a particular variable"
    echo "                                      or all if no 'var' specified"
    echo "Note: Use jq format for specifying <var>"
    echo
    echo "Examples:"
    echo "  ${script} edit user"
    echo "  sudo ${script} edit system"
    echo "  ${script} show remote"
    echo "  ${script} get"
    echo "  ${script} get enclosure.platform"
    echo "  ${script} set test.subvalue \"foo\" "

    exit 1
}

################################################################
# Setup stuff based on the environment

VIEWER="nano --syntax=json --view"
if [ -z "$EDITOR" ] ; then
    if [ $( which sensible-editor ) ] ; then
        EDITOR="sensible-editor"
    else
        EDITOR="nano --syntax=json --tempfile"
    fi
fi

if [ -z "$TEMP" ] ; then
    TEMP="/tmp"
fi

function found_exe() {
    hash "$1" 2>/dev/null
}

if found_exe tput ; then
    GREEN="$(tput setaf 2)"
    BLUE="$(tput setaf 4)"
    CYAN="$(tput setaf 6)"
    YELLOW="$(tput setaf 3)"
    RESET="$(tput sgr0)"
    HIGHLIGHT=${YELLOW}
fi

################################################################
# Utilities

function validate_config_file() {
    if [ ! -f "$1" ] ; then
        # A missing config file is valid
        return 0
    fi

    echo -n ${BLUE}

    # Remove any comments (lines starting with # or //) found in the file and
    # Use jq to validate and output errors
    sed 's/^\s*[#\/].*$//g' "$1" | sed '/^$/d' | jq -e "." > /dev/null
    result=$?

    echo -n ${RESET}

    #xxx echo "RESULT=$result for $1"
    return $result
}

_conf_file="~/.mycroft/mycroft.conf"
function name_to_path() {
    case ${1} in
        "system")     _conf_file="/etc/mycroft/mycroft.conf" ;;
        "user")       _conf_file=$(readlink -f ~/.mycroft/mycroft.conf) ;;
        "default")    _conf_file="$DIR/../mycroft/configuration/mycroft.conf" ;;
        "remote")     _conf_file="/var/tmp/mycroft_web_cache.json" ;;

        *)
            echo "ERROR: Unknown name '${1}'."
            echo "       Must be one of: default, remote, system, or user"
            exit 1
    esac
}

################################################################

function edit_config() {
    name_to_path $1
    validate_config_file $_conf_file
    rc=$?
    if [ $rc -ne 0 ] ; then
        echo "${YELLOW}WARNING: ${RESET}Configuration file did not pass validation before edits."
        read -p "Review errors above and press ENTER to continue with editing."
    fi

    if [ -f "${_conf_file}" ] ; then
        cp "${_conf_file}" "${TEMP}/mycroft.json"
    else
        echo "{" > "${TEMP}/mycroft.json"
        echo "}" >> "${TEMP}/mycroft.json"
    fi

    while [ 1 ] ; do
        case $1 in
        system | user)
            # Allow user to edit
            $EDITOR $TEMP/mycroft.json
            ;;
        default | remote)
            # View-only
            echo "The default config shouldn't be changed, opening in View mode"
            sleep 2
            $VIEWER $TEMP/mycroft.json
            ;;
        esac

        cmp --quiet "${_conf_file}" "${TEMP}/mycroft.json"
        rc=$?
        if [ $rc -eq 0 ] ; then
            echo "Configuration unchanged."
            break
        fi

        # file was changed, validate changes
        validate_config_file $TEMP/mycroft.json
        if [ $? -ne 0 ] ; then
            echo "${YELLOW}WARNING: ${RESET}Configuration file does not pass validation, see errors above."
            echo "Press X to abandon changes, S to force save, any other key to edit again."
            read -N1 -s key
        else
            key="S"
        fi

        case $key in
        [Ss])
            echo "Saving..."
            mv $TEMP/mycroft.json $_conf_file
            signal_reload_config
            break
            ;;
        [Xx])
            # abandoning
            break
            ;;
        esac

    done
}

function signal_reload_config() {
    # Enter the Mycroft venv
    source "$DIR/../venv-activate.sh" -q

    # Post a messagebus notification to reload the config file
    output=$(python -m mycroft.messagebus.send "configuration.updated"  "{}")
}

function show_config() {
    name_to_path $1

    # Use jq to display formatted nicely (after stripping out comments)
    sed 's/^\s*[#\/].*$//g' "${_conf_file}" | sed '/^$/d' | jq "."
}

function get_config() {
    value=$1
    if [[ ! $value =~ ^\..* ]] ; then
        # Add the leading period if not included
        value=".${value}"
    fi

    # Load all the configuration(s)
    json_config=$( source "$DIR/../venv-activate.sh" -q && python -c "import json; from mycroft.configuration import Configuration; print(json.dumps(Configuration.get()))" )

    # Read the given variable from the mix
    echo ${json_config} | jq -r "${value}"
}

function set_config() {
    # Set all overrides under the user configuration
    value=$1
    if [[ ! $value =~ ^\..* ]] ; then
        # Add the leading period if not included
        value=".${value}"
    fi

    jq "${value} = \"$2\"" ~/.mycroft/mycroft.conf > "${TEMP}/~mycroft.conf"
    if [ $? -eq 0 ] ; then
        # Successful update, replace the config file
        mv "${TEMP}/~mycroft.conf" ~/.mycroft/mycroft.conf
        signal_reload_config
    fi
}

_opt=$1
case ${_opt} in
    "edit")
        edit_config $2
        ;;
    "reload")
        signal_reload_config
        ;;
    "show")
        show_config $2
        ;;
    "get")
        get_config $2
        ;;
    "set")
        set_config "$2" "$3"
        ;;

    *)
        help
        ;;
esac