#! /usr/bin/awk -f

/^OK/ { debug("OK line", $0) }

/^ERROR/ {
	debug("ERROR line", $0)
	shift()
	msg_head = $1
	shift()
	msg_body = $0
	alert_trigger_hi(msg_head, "KhatusSensorError", msg_body)
}

/^OK in:ENERGY battery/\
{
    debug("ENERGY battery", $0)
    sub("%$", "", $5)
    db["energy_state_prev"] = db["energy_state_curr"]
    db["energy_state_curr"] = $4
    db["energy_percentage"] = ensure_numeric($5)
    alert_check_energy_battery()
}

/^OK in:ENERGY line_power/\
{
    debug("ENERGY line_power", $0)
    db["energy_line_power_prev"] = db["energy_line_power_curr"]
    db["energy_line_power_curr"] = $4
    alert_check_energy_line_power()
}

/^OK in:MEMORY/\
{
    shift()
    shift()
    db["memory_total"] = $1
    db["memory_used"]  = $2
}

/^OK in:FAN +status:/\
{
    shift()
    shift()
    db["fan_status"] = $2
}

/^OK in:FAN +speed:/\
{
    shift()
    shift()
    db["fan_speed"] = $2
}

/^OK in:FAN +level:/\
{
    shift()
    shift()
    db["fan_level"] = $2
}

/^OK in:TEMPERATURE/\
{
    shift()
    shift()
    db["temperature"] = $1
}

/^OK in:LOAD_AVG/\
{
    shift()
    shift()
    set_load_avg()
}

/^OK in:DISK_IO/\
{
    shift()
    shift()
    set_disk_io()
}

/^OK in:DISK_SPACE/\
{
    shift()
    shift()
    db["disk_space_used"] = $0
}

/^OK in:NET_ADDR_IO/\
{
    shift()
    shift()
    set_net_addr_io()
}

/^OK in:NET_WIFI_STATUS/\
{
    shift()
    shift()
    set_net_wifi_status()
}

/^OK in:BLUETOOTH_POWER/\
{
    shift()
    shift()
    db["bluetooth_power"] = $0
}

/^OK in:SCREEN_BRIGHTNESS/\
{
    shift()
    shift()
    set_screen_brightness()
}

/^OK in:VOLUME/\
{
    shift()
    set_volume()
}

/^OK in:MPD_SONG OK +MPD/ { delete db_mpd_song; next }
/^OK in:MPD_SONG OK$/     { set_mpd_playing() ; next }
/^OK in:MPD_SONG /        { set_mpd_song()    ; next }

/^OK in:MPD_STATE /\
{
    shift()
    shift()
    db["mpd_status_state"]   = $1
    db["mpd_status_time"]    = $2
    db["mpd_status_percent"] = $3
}

/^OK in:WEATHER/\
{
    shift()
    shift()
    db["weather_temperature"] = $0
}

/^OK in:DATE_TIME/\
{
    shift()
    shift()
    db["datetime"] = $0
    output_msg_status_bar(make_status_bar())
}

function set_volume(    mute, left, right) {
    # 0 RUNNING no 75% 75%
    #msg_head = $1
    #sink     = $2
    #state    = $3
    mute      = $4
    left      = $5
    right     = $6

    if (mute == "no") {
        db["volume"] = sprintf("%s %s", left, right)
    } else if (mute == "yes") {
        db["volume"] = "X"
    } else {
        error("set_volume", "Unexpected value for 'mute' field: " mute)
    }
}

function set_mpd_song(    key, val) {
    shift()
    key = $2
    shift()
    shift()
    val = $0
    db_mpd_song[key] = val
    debug("set_mpd_song", "", db_mpd_song)
}

function set_mpd_playing(    \
    currently_playing, name, title, file, last, parts\
) {
    debug("set_mpd_playing", "", db_mpd_song)
    name  = db_mpd_song["Name:"]
    title = db_mpd_song["Title:"]
    file  = db_mpd_song["file:"]

    if (name) {
        currently_playing = name
    } else if (title) {
        currently_playing = title
    } else if (file) {
        last = split(file, parts, "/")
        currently_playing = parts[last]
    } else {
        currently_playing = ""
    }
    db["mpd_playing_prev"] = db["mpd_playing_curr"]
    db["mpd_playing_curr"] = currently_playing

    alert_check_mpd()
}

function alert_check_mpd(    curr, prev, name, body) {
    prev = db["mpd_playing_prev"]
    curr = db["mpd_playing_curr"]
    if (curr && curr != prev) {
        name = db_mpd_song["Name:"]
        if (name) {
            body = name
        } else {
            body = \
                      db_mpd_song["Artist:"] \
                " - " db_mpd_song["Album:"] \
                " - " db_mpd_song["Title:"]
        }
        alert_trigger_low("alert_check_mpd", "MpdNowPlaying", body)
    }
}

# TODO: Generalize alert spec lang
#       - trigger threshold
#       - above/bellow/equal to threshold value
#       - priority
#       - snooze time (if already alerted, when to re-alert?)
#       - text: subject/body
function alert_check_energy_battery(    \
    from, dbg, state_curr, state_prev, remaining, subj, body\
) {
    from = "alert_check_energy_battery"

    state_curr = db["energy_state_curr"]
    state_prev = db["energy_state_prev"]
    remaining  = db["energy_percentage"]

    dbg["state_curr"] = state_curr
    dbg["remaining"] = remaining
    debug(from, "", dbg)

    if (state_curr == "discharging") {
        if (remaining < 5) {
            subj = "Energy_CRITICALLY_Low"
            body = sprintf("%d%% CHARGE NOW!!! GO GO GO!!!", remaining)
            alert_trigger_hi(from, subj, body)
        } else if (remaining < 10) {
            subj = "Energy_Very_Low"
            body = sprintf("%d%% Plug it in ASAP.", remaining)
            alert_trigger_hi(from, subj, body)
        } else if (remaining < 15) {
            subj = "Energy_Low"
            body = sprintf("%d%% Get the charger.", remaining)
            alert_trigger_hi(from, subj, body)
        } else if (remaining < 20) {
            subj = "Energy_Low"
            body = sprintf("%d%% Get the charger.", remaining)
            alert_trigger_med(from, subj, body)
        } else if (remaining < 50) {
            if (!state__alerts__energy__notified_bellow_half) {
                state__alerts__energy__notified_bellow_half = 1
                subj = "Energy_Bellow_Half"
                body = sprintf("%d%% Where is the charger?", remaining)
                alert_trigger_med(from, subj, body)
            }
        }
    } else {
        # TODO: Reconsider the competing global-state organizing-conventions
        state__alerts__energy__notified_bellow_half = 0
    }
}

function alert_check_energy_line_power(    \
    from, dbg, line_power_curr, line_power_prev, subj, body \
) {
    from = "alert_check_energy_line_power"

    dbg["energy_line_power_prev"] = db["energy_line_power_prev"]
    dbg["energy_line_power_curr"] = db["energy_line_power_curr"]
    debug(from, "", dbg)

    line_power_curr = db["energy_line_power_curr"]
    line_power_prev = db["energy_line_power_prev"]

    if (line_power_curr == "no" && line_power_prev != "no") {
        alert_trigger_low(from, "PowerUnplugged", "")
    }
}

function alert_trigger_low(from, subject, body) {
    alert_trigger("low", from, subject, body)
}

function alert_trigger_med(from, subject, body) {
    alert_trigger("med", from, subject, body)
}

function alert_trigger_hi(from, subject, body) {
    alert_trigger("hi", from, subject, body)
}

function alert_trigger(priority, from, subject, body,    msg) {
    # priority : "low" | "med" | "hi"
    # subject  : no spaces
    # body     : anything
    msg = sprintf("khatus_%s %s %s %s", from, priority, subject, body)
    output_msg_alert(msg)
}

function output_msg_alert(msg) {
    # TODO: Should alerts go into a dedicated channel?
    output_msg("ALERT", msg, "/dev/stdout")
}

function output_msg_status_bar(msg) {
    output_msg("STATUS_BAR", msg, "/dev/stdout")
}

function output_msg(type, content, channel) {
    print(type, content) > channel
}

function set_load_avg(    sched) {
    split($4, sched, "/")
    db["load_avg_1min"]             = $1
    db["load_avg_5min"]             = $2
    db["load_avg_15min"]            = $3
    db["kern_sched_queue_runnable"] = sched[1]
    db["kern_sched_queue_total"]    = sched[2]
    db["kern_sched_latest_pid"]     = $5
}

function set_disk_io(    curr_w, curr_r, prev_w, prev_r) {
    curr_w = $1
    curr_r = $2
    prev_w = db["disk_io_curr_w"]
    prev_r = db["disk_io_curr_r"]
    db["disk_io_curr_w"] = curr_w
    db["disk_io_curr_r"] = curr_r
    db["disk_io_diff_w"] = curr_w - prev_w
    db["disk_io_diff_r"] = curr_r - prev_r
}

function set_net_wifi_status(    interface) {
    interface = $1
    shift()
    db["net_wifi_status", interface] = $0
}

function set_net_addr_io(    \
    interface, address, io_curr_w, io_curr_r, io_prev_w, io_prev_r\
) {
    interface = $1
    address   = $2
    io_curr_w = $3
    io_curr_r = $4
    if (interface) {
        if (address && io_curr_w && io_curr_r) {
            # recalculate
            io_prev_w = net_io_curr_w[interface]
            io_prev_r = net_io_curr_r[interface]

            net_addr[interface]      = address
            net_io_curr_w[interface] = io_curr_w
            net_io_curr_r[interface] = io_curr_r
            net_io_diff_w[interface] = io_curr_w - io_prev_w
            net_io_diff_r[interface] = io_curr_r - io_prev_r
        } else {
            # clear
            net_addr[interface]      = ""
            net_io_curr_w[interface] = 0
            net_io_curr_r[interface] = 0
            net_io_diff_w[interface] = 0
            net_io_diff_r[interface] = 0
        }
    }
}

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

# TODO: Revise overuse of shift() where it is not really needed
function shift() {
    sub("^" $1 " +", "")
}

function make_status_bar(    position, bar, sep, i, j) {
    position[++i] = make_status_energy()
    position[++i] = make_status_mem()
    position[++i] = make_status_cpu()
    position[++i] = make_status_disk()
    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_energy(    state, direction_of_change) {
    state = db["energy_state_curr"]
    if (state == "discharging") {
        direction_of_change = "<"
    } else if (state == "charging") {
        direction_of_change = ">"
    } else {
        direction_of_change = "="
    };
    return sprintf("E%s%d%%", direction_of_change, db["energy_percentage"])
}

function make_status_mem(    total, used, percent, status) {
    total = db["memory_total"]
    used  = db["memory_used"]
    # To avoid division by zero when data is missing
    if (total && used) {
        percent = round((used / total) * 100)
        status = sprintf("%d%%", percent)
    } else {
        status = "__"
    }
    return sprintf("M=%s", status)
}

function make_status_cpu(    load, temp, fan) {
    load = db["load_avg_1min"]
    temp = db["temperature"] / 1000
    fan  = db["fan_speed"]
    return sprintf("C=[%4.2f %d°C %4drpm]", load, temp, fan)
}

function make_status_disk(    bytes_per_sector, bytes_per_mb, w, r) {
    bytes_per_sector = 512
    bytes_per_mb     = 1024 * 1024
    w = (db["disk_io_diff_w"] * bytes_per_sector) / bytes_per_mb
    r = (db["disk_io_diff_r"] * bytes_per_sector) / bytes_per_mb
    return \
        sprintf("D=[%s %0.3f▲ %0.3f▼]", db["disk_space_used"], w, r)
}

function make_status_net(    \
    out,
    number_of_interfaces_to_show,
    n,
    array_of_prefixes_of_interfaces_to_show,
    prefix,
    interface,
    label,
    count_printed,
    sep,
    io_stat,
    dw, dr,
    bytes_per_unit\
) {
    out = ""
    number_of_interfaces_to_show = \
        split(\
            opt_prefixes_of_net_interfaces_to_show,\
            array_of_prefixes_of_interfaces_to_show,\
            ","\
        )
    for (n = 1; n <= number_of_interfaces_to_show; n++) {
        prefix = array_of_prefixes_of_interfaces_to_show[n]
        for (interface in net_addr) {
            if (interface ~ ("^" prefix)) {
                label = substr(interface, 1, 1)
                if (net_addr[interface]) {
                    bytes_per_mb = 1024 * 1024  # TODO: option
                    dw = net_io_diff_w[interface] / bytes_per_mb
                    dr = net_io_diff_r[interface] / bytes_per_mb
                    io_stat = sprintf("%0.3f▲ %0.3f▼", dw, dr)
                } else {
                    io_stat = "--"
                }
                if (interface ~ "^w") {
                    label = label ":" db["net_wifi_status", interface]
                }
                if (++count_printed > 1) {
                    sep = "  "
                } else {
                    sep = ""
                }
                out = out sep label ":" io_stat
            }
        }
    }
    return sprintf("N[%s]", out)
}

function make_status_mpd(    state, status) {
    state = db["mpd_status_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_status_time"],
        db["mpd_status_percent"],
        substr(db["mpd_playing_curr"], 1, opt_mpd_song_max_chars)\
    )
}

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

function round(n) {
    return int(n + 0.5)
}

function debug(location, msg, values,    sep, vals, key, payload) {
    if (opt_debug) {
        sep = ""
        vals = ""
        for (key in values) {
            vals = sprintf("%s%s%s: %s", vals, sep, key, values[key])
            sep = ", "
        }
        payload = \
            sprintf("LOCATION[%s] MSG[%s] DATA[%s]", location, msg, vals)
        output_msg("DEBUG", payload, "/dev/stderr")
    }
}

function error(location, msg) {
    # TODO: Reconsider classifying internal errors as alerts
    #       Maybe better to keep the error class distinct and provide a
    #       an optional transformation from error to alert
    alert_trigger_hi(location, "KhatusControllerError", msg)
}

function ensure_numeric(n) {
    return n + 0
}
#-------------------------------
# Why do we need ensure_numeric?
#-------------------------------
# awk appears to be guessing the type of an inputted scalar based on usage, so
# if we read-in a number, but did not use it in any numeric operations, but did
# use as a string (even in just a format string!) - it will be treated as a
# string and can lead to REALLY SURPRISING behavior in conditional statements,
# where smaller number may compare as greater than the bigger ones, such as.
#
# Demo:
#
# $ awk 'BEGIN {x = "75"; y = "100"; sprintf("x: %d, y: %d\n", x, y); if (x > y) {print "75 > 100"} else if (x < y) {print "75 < 100"}}'
# 75 < 100
# $ awk 'BEGIN {x = "75"; y = "100"; sprintf("x: %s, y: %d\n", x, y); if (x > y) {print "75 > 100"} else if (x < y) {print "75 < 100"}}'
# 75 > 100

# However, once used as a number, seems to stay that way even after being
# used as string:
#
# $ awk 'BEGIN {x = "75"; y = "100"; x + y; sprintf("x: %s, y: %d\n", x, y); if (x > y) {print "75 > 100"} else if (x < y) {print "75 < 100"}}'
# 75 < 100
# 
# $ awk 'BEGIN {x = "75"; y = "100"; x + y; sprintf("x: %s, y: %d\n", x, y); z = x y; if (x > y) {print "75 > 100"} else if (x < y) {print "75 < 100"}}'
# 75 < 100
# 
# $ awk 'BEGIN {x = "75"; y = "100"; x + y; z = x y; if (x > y) {print "75 > 100"} else if (x < y) {print "75 < 100"}}'
# 75 < 100
# $ awk 'BEGIN {x = "75"; y = "100"; z = x y; if (x > y) {print "75 > 100"} else if (x < y) {print "75 < 100"}}'
# 75 > 100