#! /bin/bash

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() {
    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: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 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] = 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_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() {
    dir_bin="$1"
    dir_data="$2"
    pipe="$dir_data/pipe"

    WEATHER_STATION_ID='KJFK'

    rm -f "$pipe"
    mkfifo "$pipe"

    spawn produce_datetime  "$pipe" 'in:DATE_TIME' 1
    spawn produce_weather   "$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_bar_req   "$pipe" 'out:BAR'      1
    consume "$pipe"
}

main $@