#! /bin/bash

set -e

consume() {
    pipe="$1"
    debug="$2"
    dir_bin="$3"
    prefixes_of_net_interfaces_to_show="$4"
    tail -f "$pipe" \
    | stdbuf -o L "$dir_bin"/khatus_controller \
        -v opt_debug="$debug" \
        -v opt_mpd_song_max_chars=10 \
        -v opt_prefixes_of_net_interfaces_to_show="$prefixes_of_net_interfaces_to_show"
}

run_producer() {
    pipe="$1"
    dir_bin="$2"
    log="$3"
    cmd="$4"
    msg_head="$5"
    "$dir_bin"/$cmd | while read line; do
        echo "${msg_head} $line" > "$pipe"
    done \
    2> "$log"
    # TODO: Perhaps direct log to pipe, so that controller can monitor sensors?
}

fork_reactor() {
    run_producer "$@" &
}

fork_poller() {
    interval="$1"
    shift
    while true
    do
        run_producer "$@"
        sleep "$interval"
    done &
}

main() {
    # Defaults
    debug=0
    dir_bin="$HOME/bin"
    dir_logs=$(mktemp -d)
    file_pipe=$(mktemp)
    weather_station_id='KJFK'
    screen_brightness_device_name='acpi_video0'
    prefixes_of_net_interfaces_to_show='w'  # comma-separated
    disk_space_device='/'
    disk_io_device='sda'
    thermal_zone=0
    fan_path='/proc/acpi/ibm/fan'

    interval_inp_datetime=1
    interval_inp_brightness=1
    interval_inp_weather=$(( 30 * 60))  # 30 minutes
    interval_inp_mpd_state=1
    interval_inp_mpd_song=1
    interval_inp_volume=1
    interval_inp_bluetooth=5
    interval_inp_net_wifi=5
    interval_inp_net_io=1
    interval_inp_disk_space=5
    interval_inp_disk_io=1
    interval_inp_loadavg=1
    interval_inp_temp=1
    interval_inp_fan=1
    interval_inp_mem=1

    # User-overrides
    # ---------------------------------------------------------------------
    # IMPORTANT:
    # In order for automatic value reporting, at startup, to work - ensure that
    # long option names match corresponding variable names!
    # ---------------------------------------------------------------------
    long_options=''
    long_options+='debug'
    long_options+=',dir_bin:'
    long_options+=',dir_logs:'
    long_options+=',file_pipe:'
    long_options+=',weather_station_id:'
    long_options+=',screen_brightness_device_name:'
    long_options+=',prefixes_of_net_interfaces_to_show:'
    long_options+=',disk_space_device:'
    long_options+=',disk_io_device:'
    long_options+=',thermal_zone:'
    long_options+=',fan_path:'
    long_options+=',interval_inp_datetime:'
    long_options+=',interval_inp_brightness:'
    long_options+=',interval_inp_weather:'
    long_options+=',interval_inp_mpd_state:'
    long_options+=',interval_inp_mpd_song:'
    long_options+=',interval_inp_volume:'
    long_options+=',interval_inp_bluetooth:'
    long_options+=',interval_inp_net_wifi:'
    long_options+=',interval_inp_net_io:'
    long_options+=',interval_inp_disk_space:'
    long_options+=',interval_inp_disk_io:'
    long_options+=',interval_inp_loadavg:'
    long_options+=',interval_inp_temp:'
    long_options+=',interval_inp_fan:'
    long_options+=',interval_inp_mem:'
    OPTS=$(
        getopt \
            -o 'd' \
            -l $long_options \
            -- "$@"
    )
    eval set -- "$OPTS"
    while true
    do
        case "$1" in
            -d|--debug)
                debug=1
                shift
                ;;
            --dir_bin)
                dir_bin="$2"
                shift 2
                ;;
            --dir_logs)
                dir_logs="$2"
                shift 2
                ;;
            --file_pipe)
                file_pipe="$2"
                shift 2
                ;;
            --weather_station_id)
                weather_station_id="$2"
                shift 2
                ;;
            --screen_brightness_device_name)
                screen_brightness_device_name="$2"
                shift 2
                ;;
            --prefixes_of_net_interfaces_to_show)
                prefixes_of_net_interfaces_to_show="$2"
                shift 2
                ;;
            --disk_space_device)
                disk_space_device="$2"
                shift 2
                ;;
            --disk_io_device)
                disk_io_device="$2"
                shift 2
                ;;
            --thermal_zone)
                thermal_zone="$2"
                shift 2
                ;;
            --fan_path)
                fan_path="$2"
                shift 2
                ;;
            --interval_inp_datetime)
                interval_inp_datetime="$2"
                shift 2
                ;;
            --interval_inp_brightness)
                interval_inp_brightness="$2"
                shift 2
                ;;
            --interval_inp_weather)
                interval_inp_weather="$2"
                shift 2
                ;;
            --interval_inp_mpd_state)
                interval_inp_mpd_state="$2"
                shift 2
                ;;
            --interval_inp_mpd_song)
                interval_inp_mpd_song="$2"
                shift 2
                ;;
            --interval_inp_volume)
                interval_inp_volume="$2"
                shift 2
                ;;
            --interval_inp_bluetooth)
                interval_inp_bluetooth="$2"
                shift 2
                ;;
            --interval_inp_net_wifi)
                interval_inp_net_wifi="$2"
                shift 2
                ;;
            --interval_inp_net_io)
                interval_inp_net_io="$2"
                shift 2
                ;;
            --interval_inp_disk_space)
                interval_inp_disk_space="$2"
                shift 2
                ;;
            --interval_inp_disk_io)
                interval_inp_disk_io="$2"
                shift 2
                ;;
            --interval_inp_loadavg)
                interval_inp_loadavg="$2"
                shift 2
                ;;
            --interval_inp_temp)
                interval_inp_temp="$2"
                shift 2
                ;;
            --interval_inp_fan)
                interval_inp_fan="$2"
                shift 2
                ;;
            --interval_inp_mem)
                interval_inp_mem="$2"
                shift 2
                ;;
            --)
                shift
                break
                ;;
        esac
    done

    screen_brightness_device_path='/sys/class/backlight'
    screen_brightness_device_path+="/$screen_brightness_device_name"

    (
        echo '=============================================='
        echo "Khatus starting with the following parameters:"
        echo '=============================================='
        for param in \
            $(echo -n "$long_options" \
            | awk -v RS=, '{sub(":$", ""); print $0}'
            )
        do
            echo "$param := ${!param}"
        done \
        | column -ts:
        echo '----------------------------------------------'
    ) >&2

    rm -f "$file_pipe"
    mkfifo "$file_pipe"

    cmd_sens_screen_brightness='khatus_sensor_screen_brightness'
    cmd_sens_screen_brightness+=" $screen_brightness_device_path"

    cmd_sens_weather="khatus_sensor_weather $weather_station_id"
    cmd_sens_disk_space="khatus_sensor_disk_space $disk_space_device"
    cmd_sens_disk_io="khatus_sensor_disk_io $disk_io_device"
    cmd_sens_temperature="khatus_sensor_temperature $thermal_zone"
    cmd_sens_fan="khatus_sensor_fan $fan_path"
    cmd_sens_bluetooth="khatus_sensor_bluetooth_power $dir_bin"
    cmd_sens_mpd_state="khatus_sensor_mpd_state $dir_bin"
    cmd_sens_net_addr_io="khatus_sensor_net_addr_io $dir_bin"

    # TODO: Redirect each worker's stderr to a dedicated log file
    pipe="$file_pipe"
    log="$dir_logs"/khatus_sensors.log

    fork_reactor                         "$pipe" "$dir_bin" "$log" "khatus_sensor_energy $dir_bin" 'in:ENERGY'

    fork_poller $interval_inp_datetime   "$pipe" "$dir_bin" "$log" khatus_sensor_datetime          'in:DATE_TIME'
    fork_poller $interval_inp_brightness "$pipe" "$dir_bin" "$log" "$cmd_sens_screen_brightness"   'in:SCREEN_BRIGHTNESS'
    fork_poller $interval_inp_weather    "$pipe" "$dir_bin" "$log" "$cmd_sens_weather"             'in:WEATHER'
    fork_poller $interval_inp_mpd_state  "$pipe" "$dir_bin" "$log" "$cmd_sens_mpd_state"           'in:MPD_STATE'
    fork_poller $interval_inp_mpd_song   "$pipe" "$dir_bin" "$log" khatus_sensor_mpd_song          'in:MPD_SONG'
    fork_poller $interval_inp_volume     "$pipe" "$dir_bin" "$log" khatus_sensor_volume            'in:VOLUME'
    fork_poller $interval_inp_bluetooth  "$pipe" "$dir_bin" "$log" "$cmd_sens_bluetooth"           'in:BLUETOOTH_POWER'
    fork_poller $interval_inp_net_wifi   "$pipe" "$dir_bin" "$log" khatus_sensor_net_wifi_status   'in:NET_WIFI_STATUS'
    fork_poller $interval_inp_net_io     "$pipe" "$dir_bin" "$log" "$cmd_sens_net_addr_io"         'in:NET_ADDR_IO'
    fork_poller $interval_inp_disk_space "$pipe" "$dir_bin" "$log" "$cmd_sens_disk_space"          'in:DISK_SPACE'
    fork_poller $interval_inp_disk_io    "$pipe" "$dir_bin" "$log" "$cmd_sens_disk_io"             'in:DISK_IO'
    fork_poller $interval_inp_loadavg    "$pipe" "$dir_bin" "$log" khatus_sensor_loadavg           'in:LOAD_AVG'
    fork_poller $interval_inp_temp       "$pipe" "$dir_bin" "$log" "$cmd_sens_temperature"         'in:TEMPERATURE'
    fork_poller $interval_inp_fan        "$pipe" "$dir_bin" "$log" "$cmd_sens_fan"                 'in:FAN'
    fork_poller $interval_inp_mem        "$pipe" "$dir_bin" "$log" khatus_sensor_memory            'in:MEMORY'

    consume \
      "$pipe" \
      "$debug" \
      "$dir_bin" \
      "$prefixes_of_net_interfaces_to_show"
}

main $@