#!/bin/bash

function help() { cat; }<<EOF
Backup Script Version $script_version
    usage: SERVER:LABEL [...]
           [--file|-f CSV_FILE] [--limit-y|-l Y_MAX] [--time-zone|-t UTC_HOURS]
           [--start-date|-S DATE] [--end-date|-E DATE] [--show-hours|-H HOURS]
    
    args:  SERVER:LABEL [...]
               Space sperated list of servers to plot. Needs to be before any other args.
               SERVER matches column 2 of the csv file and LABEL is the text displayed in the plot's legend.
               NOTE: This can be ommited if a servers.env file is present in the parent[1] or scripts[2] directory.
               The args always take precedence over the file.
    
           --file|-f CSV_FILE
               CSV_FILE gives the path to csv file to parse. If this option is ommitted the csv file defaults to:
               $default_csv

           --limit-y|-l Y_MAX
               Y_MAX defaults to $default_ymax and limits the Y Axis.

           --time-zone|-t UTC_HOURS
               The current timezone ($(date +%-:::z)) is always passed to gnuplot.
               Disable this by passing no argument.

           --start-date|-S DATE
               DATE defaults to 1 week ago and sets the X Axis starting point.
               Will be overwritten by -H if declared later.
           
           --end-date|-E DATE
               DATE defaults to the current date and time and sets the X Axis end point.
               Can be used in conjunction with -S but not -H.

           --show-hours|-H HOURS
               HOURSE defaults to $default_hours and sets the Y Axis starting point HOURS before the end point.
               Will be overwritten by -s if declared later.

    example: ${BASH_SOURCE[0]} example.com:example 0.0.0.0:localhost --limit-y 100 --show-hours 5 --end-date "$(date +"%Y-%m-%d %H:%M")" --time-zone $(date +%-:::z)
             ${BASH_SOURCE[0]} example.com:example 0.0.0.0:localhost -S "$(date --date='yesterday' +"%Y-%m-%d")" -E "$(date +"%Y-%m-%d")" -f data.csv

Author: pascal@pdev.dev
EOF

##############################
# configuration

script_path=$(cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd)

plot_file="$script_path/pinger.gp"
log_file="" # leave empty for stdout

# defaults
default_csv="$script_path/../data/ping.csv"
default_ymax=250
default_start_date=$(date --date="1 week ago" -Is)
default_end_date=$(date -Is)
default_hours=24
default_tz=$(date +%-:::z)

# end configuration
##############################

# variables
declare -A plot_env

#functions
function log()
{
    local time=$(date +%F_%T)
    local prefix="LOG"
    case $1 in
        ERR | ERROR)
            prefix="ERR"
            shift
            ;;
        WAR | WARNING)
            prefix="WAR"
            shift
            ;;
    esac
    local func=$1; shift
    # remove any \n 
    #local text=$(echo "$@"| tr '\n' '#' | sed 's|#|\\n |g')
    case "$log_file" in
        "")
            echo "[$time]:[$prefix]:[$0][$func]: $@" 2>&1
            ;;
        *)
            echo "[$time]:[$prefix]:[$0][$func]: $@" >> $log_file
            ;;
    esac
}

function date_to_epoch()
{
    echo $(date --date="$1" +"%s")
}

function load_server_env()
{
    if [ -f "$script_path/../servers.env" ]; then
        echo $(cat "$script_path/../servers.env" 2>/dev/null) | sed 's|\s|;|g'
    elif [ -f "$script_path/servers.env" ]; then
        echo $(cat "$script_path/servers.env" 2>/dev/null) | sed 's|\s|;|g'
    else
        echo ''
    fi    
}

# set X_MIN relative to X_MAX is set
function set_relative_X_MIN()
{
    local hours=$1
    if [[ -z "${plot_env[X_MAX]}" ]]; then
        plot_env[X_MIN]=$(date_to_epoch $(date --date="$hours hours ago" -Is))
    else
        plot_env[X_MIN]=$(( ${plot_env[X_MAX]} - $hours * 3600 ))
    fi
}

function create_env()
{
    local env=""
    for env_var in "${!plot_env[@]}"; do
        env+=" -e $env_var=${plot_env[$env_var]}"
    done
    echo "$env"
}

main()
{
    local unknown_args=()
    local servers=$(load_server_env)
    local csv_file="$default_csv" limit time_zone="$default_tz" start_date end_date hours
    
    # if servers passed as args reset list and parse
    [[ $# -gt 0 ]] && [[ $1 != -* ]] && servers=""
    while [[ $# -gt 0 ]] && [[ $1 != -* ]]; do
        servers="$servers;$1"
        shift
    done
    
    # parse args
    while [[ $# -gt 0 ]]; do
        key="$1"

        case $key in
            --file|-f)
                if [[ $2 == -* ]] || [[ -z "$2" ]]; then
                    echo "log WAR main Invalid csv file, using default: $csv_file"
                    shift # past argument, no value
                else 
                    csv_file=$2
                    shift # past argument
                    shift # past value
                fi
                ;;
            --limit-y|-l)
                if [[ $2 == -* ]] || [[ -z "$2" ]]; then
                    limit=$default_ymax
                    shift # past argument, no value
                else 
                    limit=$2
                    shift # past argument
                    shift # past value
                fi
                ;;
            --time-zone|-t)
                if [[ $2 == -* ]] || [[ -z "$2" ]]; then
                    time_zone=''
                    shift # past argument, no value
                else 
                    time_zone=$2
                    shift # past argument
                    shift # past value
                fi
                ;;
            --start-date|-S)
                if [[ $2 == -* ]] || [[ -z "$2" ]]; then
                    start_date=$(date_to_epoch $default_start_date)
                    shift # past argument, no value
                else 
                    start_date=$(date_to_epoch "$2")
                    shift # past argument
                    shift # past value
                fi
                ;;
            --end-date|-E)
                if [[ $2 == -* ]] || [[ -z "$2" ]]; then
                    end_date=$(date_to_epoch $default_end_date)
                    shift # past argument, no value
                else 
                    end_date=$(date_to_epoch "$2")
                    shift # past argument
                    shift # past value
                fi
                ;;
            --show-hours|-H)
                if [[ $2 == -* ]] || [[ -z "$2" ]]; then
                    hours=$default_hours
                    shift # past argument, no value
                else 
                    hours=$2
                    shift # past argument
                    shift # past value
                fi
                ;;
            --help|-h)
                help
                exit
                ;;
            *)    # unknown option
                unknown_args+=("$1") # save it in an array for later
                shift # past argument
                ;;
        esac
    done

    # exit with error if no servers to plot
    if [[ -z "$servers" ]]; then
        log ERR main no servers to plot
        exit 1
    fi

    # assign env in order to set relative X_MIN
    [[ ! -z "$servers" ]] && plot_env[SERVERS]=\"$servers\"
    [[ ! -z "$csv_file" ]] && plot_env[CSV_FILE]=\"$csv_file\"
    [[ ! -z "$limit" ]] && plot_env[Y_MAX]=$limit
    [[ ! -z "$time_zone" ]] && plot_env[TZ]=$time_zone
    [[ ! -z "$start_date" ]] && plot_env[X_MIN]=$start_date
    [[ ! -z "$end_date" ]] && plot_env[X_MAX]=$end_date
    [[ ! -z "$hours" ]] && set_relative_X_MIN $hours
    
    [[ ${#unknown_args[@]} -ne 0 ]] && log main WARNING "ignored unknown args: ${unknown_args[@]}"
    
    log main "plot ARGS: $(create_env)"
    gnuplot $(create_env) -p $plot_file
    
}

main "$@"