#! /bin/bash

set -e

produce_net_wifi_status() {
    nmcli \
        -f ACTIVE,SSID,SIGNAL \
        -t \
        d wifi \
    | awk \
        -F ':' \
        '
        BEGIN       {wifi_status = "--"}
        $1 == "yes" {wifi_status =  $2 ":" $3 "%"}
        END         {print wifi_status}
        '
}

produce_bluetooth_power() {
    echo -e 'show \n quit' \
    | bluetoothctl \
    | awk '
        /^Controller / {
            controller = $2;
            controllers[++ctrl_count] = controller;
        }
        /^\t[A-Z][A-Za-z]+:/ {
            key = $1;
            sub(":$", "", key);
            val = $2;
            for (i=3; i<=NF; i++) {
                val = val " " $i};
                data[controller, key] = val;
        }
        END {
            # Using the 1st seen controller. Should we select specific instead?
            power_status = data[controllers[1], "Powered"];
            if (ctrl_count > 0) {
                if (power_status == "no") {
                    power_status = "off"
                } else if (power_status == "yes") {
                    power_status = "on"
                } else {
                    printf("Unexpected bluetooth power status: %s\n", power_status)\
                        > "/dev/stderr";
                    power_status = "ERROR"
                }
            } else {
                power_status = "off"  # TODO: Perhaps use differentiated marker?
            }
            printf("%s", power_status);
        }'
}

produce_screen_brightness() {
    screen_brightness_device_path="$1"
    echo "\
        $(cat $screen_brightness_device_path/max_brightness) \
        $(cat $screen_brightness_device_path/brightness)\
    "
}

produce_volume() {
    pactl list sinks \
    | awk '
        /^\tMute:/ {
            printf("%s,", $0);
        }
        /^\tVolume:/ {
            for (i=2; i<=NF; i++) printf(" %s", $i);
        }' \
    | awk -v RS=',' '
        /^[ \t]*Mute:/        {mute  = $2}
        /^[ \t]*front-left:/  {left  = $4}
        /^[ \t]*front-right:/ {right = $4}
        END {
            if (mute == "yes") {
                printf("x")
            } else {
                printf("%s %s", left, right)
            }
        }
        '
}

produce_mpd_state() {
    echo 'status' \
    | nc 127.0.0.1 6600 \
    | awk '
        {
            status[$1] = $2
        }

        /^time: +[0-9]+:[0-9]+$/ {
            split($2, time, ":")
            seconds_current = time[1]
            seconds_total   = time[2]

            hours = int(seconds_current / 60 / 60);
            secs_beyond_hours = seconds_current - (hours * 60 * 60);
            mins = int(secs_beyond_hours / 60);
            secs = secs_beyond_hours - (mins * 60);
            if (hours > 0) {
                current_time = sprintf("%d:%.2d:%.2d", hours, mins, secs)
            } else {
                current_time = sprintf("%.2d:%.2d", mins, secs)
            }

            if (seconds_total > 0) {
                time_percentage = (seconds_current / seconds_total) * 100
                current_percentage = sprintf("%d%%", time_percentage)
            } else {
                current_percentage = "~"
            }
        }

        END {
            state = status["state:"]

            if (state == "play") {
                symbol = "▶"
            } else if (state == "pause") {
                symbol = "❚❚"
            } else if (state == "stop") {
                symbol = "⬛"
            } else {
                symbol = "--"
            }

            printf(\
                "%s %s %s",
                status["state:"], current_time, current_percentage\
            )
        }
        '
}

produce_mpd_song() {
    echo 'currentsong' \
    | nc 127.0.0.1 6600 \
    | awk '
        /^OK/ {
            next
        }

        {
            key = $1
            sub("^" key " +", "")
            val = $0
            data[key] = val
        }

        END {
            name  = data["Name:"]
            title = data["Title:"]
            file  = data["file:"]

            if (name) {
                out = name
            } else if (title) {
                out = title
            } else if (file) {
                last = split(file, parts, "/")
                out = parts[last]
            } else {
                out = ""
            }
            print out
        }
        '
}

produce_weather() {
    weather_station_id="$1"
    metar -d "$weather_station_id" 2>&1 \
    | awk '
        /METAR pattern not found in NOAA data/ {
            failures++
        }

        /^Temperature/ {
            celsius = $3;
            fahrenheit = (celsius * (9 / 5)) + 32;
            temperature = fahrenheit
        }

        END {
            if (failures > 0) {
                temperature = "--"
            }
            print temperature "°F"
        }'
}

produce_datetime() {
    date +'%a %b %d %H:%M:%S'
}

consume() {
    pipe="$1"
    tail -f "$pipe" \
    | stdbuf -o L awk \
        -v opt_debug=0 \
        -v opt_mpd_song_max_chars=10 \
        '
            /^in:NET_WIFI_STATUS/\
            {
                split_msg_parts()
                db["net_wifi_status"] = msg_body
            }

            /^in:BLUETOOTH_POWER/\
            {
                split_msg_parts()
                db["bluetooth_power"] = msg_body
            }

            /^in:SCREEN_BRIGHTNESS/\
            {
                split_msg_parts()
                set_screen_brightness()
            }

            /^in:VOLUME/\
            {
                split_msg_parts()
                db["volume"] = msg_body
            }

            /^in:MPD_STATE/\
            {
                split_msg_parts()
                db["mpd_state"]             = $1
                db["mpd_curr_song_time"]    = $2
                db["mpd_curr_song_percent"] = $3
            }

            /^in:MPD_SONG/\
            {
                split_msg_parts()
                db["mpd_curr_song_name"] = msg_body
            }

            /^in:WEATHER/\
            {
                split_msg_parts()
                db["weather_temperature"] = msg_body
            }

            /^in:DATE_TIME/\
            {
                split_msg_parts()
                db["datetime"] = msg_body
            }

            /^out:BAR/\
            {
                split_msg_parts()
                print make_bar()
            }


            function set_screen_brightness(    max, cur) {
                max = $1
                cur = $2
                db["screen_brightness"] = (cur / max) * 100
            }

            function split_msg_parts() {
                msg_head = $1
                sub("^" msg_head " +", "")
                msg_body = $0
                debug(msg_head, msg_body)
            }

            function make_bar(    position, bar, sep, i, j) {
                position[++i] = make_status_net()
                position[++i] = sprintf("B=%s", db["bluetooth_power"])
                position[++i] = sprintf("*%d%%", db["screen_brightness"])
                position[++i] = sprintf("(%s)", db["volume"])
                position[++i] = make_status_mpd()
                position[++i] = db["weather_temperature"]
                position[++i] = db["datetime"]
                bar = ""
                sep = ""
                for (j = 1; j <= i; j++) {
                    bar = bar sep position[j]
                    sep = " "
                }
                return bar
            }

            function make_status_net() {
                return sprintf("N[w:%s]", db["net_wifi_status"])
            }

            function make_status_mpd(    state, status) {
                state = db["mpd_state"]

                if (state == "play") {
                    status = make_status_mpd_state_known("▶")
                } else if (state == "pause") {
                    status = make_status_mpd_state_known("❚❚")
                } else if (state == "stop") {
                    status = make_status_mpd_state_known("⬛")
                } else {
                    status = make_status_mpd_state_unknown("--")
                }

                return sprintf("[%s]", status)
            }

            function make_status_mpd_state_known(symbol) {
                return sprintf(\
                    "%s %s %s %s",
                    symbol,
                    db["mpd_curr_song_time"],
                    db["mpd_curr_song_percent"],
                    substr(db["mpd_curr_song_name"], 1, opt_mpd_song_max_chars)\
                )
            }

            function make_status_mpd_state_unknown(symbol) {
                return sprintf("%s", symbol)
            }

            function debug(location, msg) {
                if (opt_debug) {
                    print_error(location, msg)
                }
            }

            function print_error(location, msg) {
                print(location " ==> " msg) > "/dev/stderr"
            }
        '
}

produce_bar_req() {
    echo ''
}

spawn() {
    cmd="$1"
    pipe="$2"
    msg_head="$3"
    interval="$4"
    while true; do
        echo "${msg_head} $($cmd)" > "$pipe"
        sleep  "$interval"
    done &
}

main() {
    # Defaults
    dir_data="$HOME/.khatus"
    weather_station_id='KJFK'
    screen_brightness_device_name='acpi_video0'

    # User-overrides
    OPTS=$(
        getopt \
            -o '' \
            -l data-dir:,weather-station:screen-device: \
            -- "$@"
    )
    eval set -- "$OPTS"
    while true
    do
        case "$1" in
            --data-dir)
                dir_data="$2"
                shift 2
                ;;
            --weather-station)
                weather_station_id="$2"
                shift 2
                ;;
            --screen-device)
                screen_brightness_device_name="$2"
                shift 2
                ;;
            --)
                shift
                break
                ;;
        esac
    done

    pipe="$dir_data/khatus_data_pipe"
    screen_brightness_device_path='/sys/class/backlight'
    screen_brightness_device_path+="/$screen_brightness_device_name"

    ( echo "Khatus starting with the following parameters:"
      ( echo "    dir_data|= $dir_data"
        echo "    pipe|= $pipe"
        echo "    screen_brightness_device_name|=$screen_brightness_device_name"
        echo "    screen_brightness_device_path|=$screen_brightness_device_path"
        echo "    weather_station_id|= $weather_station_id"
      ) | column -ts\|
      echo ''
    ) >&2

    mkdir -p "$dir_data"
    rm -f "$pipe"
    mkfifo "$pipe"

    cmd_produce_screen_brightness='produce_screen_brightness'
    cmd_produce_screen_brightness+=" $screen_brightness_device_path"
    cmd_produce_weather="produce_weather $weather_station_id"

    # TODO: Redirect each worker's stderr to a dedicated log file
    spawn produce_datetime                 "$pipe" 'in:DATE_TIME' 1
    spawn "$cmd_produce_screen_brightness" "$pipe" 'in:SCREEN_BRIGHTNESS' 1
    spawn "$cmd_produce_weather"           "$pipe" 'in:WEATHER'   $(( 30 * 60 ))
    spawn produce_mpd_state                "$pipe" 'in:MPD_STATE' 1
    spawn produce_mpd_song                 "$pipe" 'in:MPD_SONG'  1
    spawn produce_volume                   "$pipe" 'in:VOLUME'    1
    spawn produce_bluetooth_power          "$pipe" 'in:BLUETOOTH_POWER' 5
    spawn produce_net_wifi_status          "$pipe" 'in:NET_WIFI_STATUS' 5
    spawn produce_bar_req                  "$pipe" 'out:BAR'      1
          consume                          "$pipe"
}

main $@