flyover

#!/usr/bin/env bash

# Author: Pooya Moradi
# Date: 2022-03-10
# License: MIT
# Description: A simple client for flightradar24.com. Shows info of aircrafts
#              flying overhead in a [latitude ± δ, longitude ± δ] vicinity
# Dependencies: jq, bc, curl, notify-send
# Note: depends on 'nominatim.openstreetmap.org' for geolocation service

version=0.25
log_level=3
use_notify=0
brief_mode=0
latitude=""
longitude=""
delta_deg=""
lat1=""
lon1=""
lat2=""
lon2=""
bounds=""
custom_bounds=""
flight_ids=""
mode=""
excl_grnd=0
details_file_tmp=""
curl_opts=()
script_tmp_dir=$(mktemp -d "flyover-tmp-XXX" -p "")
# clean up temporary variables and directories
trap 'cleanup' EXIT

print_help() {
    cat << 'END_HEREDOC'
DESCRIPTION
    A simple client for flightradar24.com. Shows info of aircrafts flying
    overhead in a [latitude ± δ, longitude ± δ] vicinity

USAGE: flyover [OPTIONS]
OPTIONS
      [-s search_str]
        Search for city/region/place
        Use quotes for multi-word queries
      [-y latitude]
        Negative for south of equator and positive for north of equator
        Range: -90 <= latitude[float] <= +90
      [-x longitude]
        Negative for west of Prime Meridian and positive for east of Prime Meridian
        Range: -180 <= longitude[float] <= +180
      [-b bounds]
        Geographic bounds of the region of interest
        Format (comma-separated): "lat1,lon1,lat2,lon2"
      [-i flight_ids]
        flightradar24 flight_ids as a comma-separated list
        In this mode, only the corresponding flight details are queried
        Note: id is flightradar24's internal id (not ICAO or other standards)
        Format example: "id1,id2,id3"
      [-r delta_deg]
        δ in degrees in scan square : [latitude ± δ, longitude ± δ]
        Note: 1° of latitude ≈ 111 km
        Range: r[float] > 0
      [-o /path/to/detailed_flights]
        Set output path for detailed info of flights (json array)
        (implies 'detailed' mode)
      [-n]
        Use notification (implies 'detailed' mode)
      [-f]
        Set mode to 'brief', only print an augmented json
      [-g]
        Exclude GRND-type vehicles from presentation
        (only applies to STDOUT and notifications of 'detailed' mode)
      [-v log_level]
        v = 0 : No logs. Equivalent to -q
        v = 1 : Set level to error
        v = 2 : Set level to warn
        v = 3 : Set level to info (default)
        v = 4 : Set level to debug
      [-q]
        Set log level to v = 0
      [-V]
        Print version
      [-h]
        Print help message

NOTES
    - latitude/longitude should be input in decimal degrees (not DMS)
    - Either use -s (geolocation service) OR (-y,-x) but NOT both
    - Default mode of operation is 'detailed'

EXAMPLES
    flyover -s "deylaman" -r 2
    flyover -s "قلعه گبری" -r 0.5 -n -v4
    flyover -y "-27.115" -x "-109.395" -r 24.15 -o /tmp/detailed.json
    flyover -s "深圳" -qf
    flyover -i "2b1abd2f,2b1cae23"
    flyover -b "43.58,58.72,46.58,61.72"
    flyover -s "oslo" -g
END_HEREDOC
}

cleanup() {
    rm -rf "$script_tmp_dir"
}

log() {
    local mode
    case "$1" in
        "debug")
            mode="debug"
            ((log_level < 4)) && return
            ;;
        "info")
            mode="info"
            ((log_level < 3)) && return
            ;;
        "warn")
            mode="warn"
            ((log_level < 2)) && return
            ;;
        "error")
            mode="error"
            ((log_level < 1)) && return
            ;;
    esac
    printf >&2 "[%-5s] %s\n" "$mode" "$2"
}

fetch() {
    local url="$1"
    if ! curl --silent --fail --retry-connrefused --retry 3 \
        "${curl_opts[@]}" \
        --get "$url"; then
        return 1
    fi
}

sanitize_latlon() {
    local latitude="$1"
    local longitude="$2"
    if jq -e -n "$latitude < -90 or $latitude > 90 or \
        $longitude < -180 or $longitude > 180" > /dev/null; then
        log error "Bad usage! latitude/longitude out of range"
        return 2
    fi
    #remove +- signs from numbers
    if ! printf "%f %f\n" "$latitude" "$longitude"; then
        log error "Bad usage! latitude/longitude are invalid numbers"
        return 2
    fi
}

sanitize() {
    local result

    if ((use_notify)) || [[ -n $details_file ]]; then
        brief_mode=0
    fi

    if ((brief_mode)); then
        log debug "Mode is set to 'brief'"
    else
        log debug "Mode is set to 'detailed'"
    fi

    if [[ -n "$flight_ids" ]]; then
        if [[ -n "$latitude" || -n "$longitude" || -n "$query_str" ||
            -n "$delta_deg" ]]; then
            log warn "Ignoring search_city/latitude/longitude/delta_deg/bounds"
        fi
        mode="direct-ids"
        return 0
    fi

    if [[ -n "$bounds" ]]; then
        if [[ -n "$latitude" || -n "$longitude" || -n "$query_str" ||
            -n "$delta_deg" ]]; then
            log warn "Ignoring search_city/latitude/longitude/delta_deg."
        fi
        mode="scan_bounds"
        # remove all whilespaces from the list
        bounds="${bounds//[[:space:]]/}"
        IFS="," read -r lat1 lon1 lat2 lon2 <<< "$bounds"
        if [[ -z "$lat1" || -z "$lon1" || -z "$lat2" || -z "$lon2" ]]; then
            log error "Bad usage! lat1/lon1/lat2/lon2 are not given"
            return 2
        fi
        if ! result="$(sanitize_latlon "$lat1" "$lon1")"; then
            return 2
        fi
        read -r lat1 lon1 <<< "$result"
        if ! result="$(sanitize_latlon "$lat2" "$lon2")"; then
            return 2
        fi
        read -r lat2 lon2 <<< "$result"

        return 0
    fi
    if [[ -n "$query_str" ]]; then
        if [[ -n "$latitude" || -n "$longitude" ]]; then
            log warn "Ignoring latitude/longitude"
        fi
        if ! result="$(geolocate "$query_str")"; then
            return 2
        fi
        read -r latitude longitude <<< "$result"
    else
        if [[ -z "$latitude" || -z "$longitude" ]]; then
            log error "latitude/longitude is not provided"
            return 2
        fi
        if ! result="$(sanitize_latlon "$latitude" "$longitude")"; then
            return 2
        fi
        read -r latitude longitude <<< "$result"
    fi

    if [[ -z "$delta_deg" ]]; then
        log info "Using default r: δ = 1°"
        delta_deg=1
    else
        if ! jq -e -n "$delta_deg > 0" > /dev/null; then
            log error "Bad usage! delta_deg invalid or out of range"
            return 2
        fi
    fi
    mode="scan_bounds"
    return 0
}

geolocate() {
    local query="$1"
    local latitude longitude
    local response
    local endpoint="https://nominatim.openstreetmap.org"
    curl_opts=()
    curl_opts+=(--data-urlencode "q=$query")
    curl_opts+=(--data-urlencode "format=json")
    if ! response=$(fetch \
        "$endpoint/search"); then
        log error "Problem in connecting to $endpoint"
        return 1
    fi
    log info "Match found: $(jq '.[0].display_name' <<< "$response")"
    read -r latitude longitude < \
        <(jq -r '.[0] | .lat + " " + .lon' <<< "$response")
    if [[ -z "$latitude" || -z "$longitude" ]]; then
        log error "No match was found for : $query"
        return 1
    fi
    log info "'$query' WGS84 coordinates at latitude=$latitude, longitude=$longitude"
    printf "%s %s\n" "$latitude" "$longitude"
}

get_flights() {
    local bounds="$1"
    local endpoint="https://data-cloud.flightradar24.com"
    local config="faa=1&satellite=1&mlat=1&flarm=1&adsb=1&gnd=1&air=1&\
vehicles=1&estimated=1&maxage=14400&gliders=1&stats=1"
    curl_opts=()
    local response
    if ! response=$(fetch \
        "$endpoint/zones/fcgi/feed.js?$config&bounds=$bounds"); then
        log error "Problem in connecting to $endpoint"
        return 1
    fi
    printf "%s\n" "$response"
}

generate_bounds() {
    local delta="$1"
    local latitude="$2"
    local longitude="$3"
    local y1 y2 x1 x2
    if ! { read -r y1 && read -r x1 && read -r y2 && read -r x2; } < \
        <(
            bc --quiet --standard --warn <<< \
                "scale=10;
            $latitude-$delta;
            $longitude-$delta;
            $latitude+$delta;
            $longitude+$delta;
            "
        ); then
        return 1
    fi
    # note the bound order required for flightradar24
    printf "%f,%f,%f,%f\n" "$y2" "$y1" "$x1" "$x2"
}

get_flight_details() {
    local id="$1"
    local endpoint="https://data-live.flightradar24.com"
    local response
    curl_opts=()
    if ! response=$(fetch \
        "$endpoint/clickhandler/?version=1.5&flight=$id"); then
        log error "Problem in connecting to $endpoint"
        return 1
    fi
    printf "%s\n" "$response"
}

filter_flights() {
    local flights="$1"
    local latitude="$2"
    local longitude="$3"
    local delta_deg="$4"
    local filter="
        del(.[] | arrays | select(
            pow(.[1] - \$lat ; 2) > pow(\$delta; 2) or
            pow(.[2] - \$lon ; 2) > pow(\$delta; 2)))
    "
    jq --argjson lat "$latitude" --argjson lon "$longitude" \
        --argjson delta "$delta_deg" \
        "$filter" \
        <<< "$flights"
}

# Augments the output of get_flights (brief json) with explanatory keys
# The correspondence of array elements assignment is based on:
# https://github.com/JeanExtreme002/FlightRadarAPI/blob/main/python/FlightRadar24/entities/flight.py
gen_brief() {
    local brief="$1"
    jq '
. as $x 
| (del (.stats, .version, .full_count)) as $y 
| [($y | keys[] as $id
| {
    "id"             : $id,
    "icao_hex"       : $y.[$id][0],
    "lat"            : $y.[$id][1],
    "lng"            : $y.[$id][2],
    "hd"             : $y.[$id][3],
    "alt"            : $y.[$id][4],
    "spd"            : $y.[$id][5],
    "squawk"         : $y.[$id][6],
    "feeder_id"      : $y.[$id][7],
    "aircraft_model" : $y.[$id][8],
    "aircraft_reg"   : $y.[$id][9],
    "timestamp"      : $y.[$id][10],
    "airport_orig"   : $y.[$id][11],
    "airport_dest"   : $y.[$id][12],
    "flight_num"     : $y.[$id][13],
    "on_ground"      : $y.[$id][14],
    "vertical_speed" : $y.[$id][15],
    "callsign"       : $y.[$id][16],
    "airline_icao"   : $y.[$id][18]
   })] as $flights
|
{
"full_count": $x.full_count,
"version": $x.version,
$flights,
"stats" : $x.stats,
}
' <<< "$brief"
}

show() {
    local detail="$1"
    local msg
    local flightradar_link
    local link_handle
    local filter='
    .aircraft.images.thumbnails[0].src + "\n" +
    .airline.name + ", " +
    .identification.number.default + "/" + .identification.callsign + "\n" +
    "✈️ " + .aircraft.model.text + "\n" +
    "↗️ " + .airport.origin.position.country.name + ", " +
    .airport.origin.position.region.city + "\n" +
    "↘️ " + .airport.destination.position.country.name + ", " +
    .airport.destination.position.region.city + "\n" +
    "📅 " + .status.text + "\n" +
    "📏 " +
    try ((.trail[0].alt * 0.0003048) | floor | tostring) catch ("?") + "km" +
    ", " +
    try ((.trail[0].spd * 1.8520000) | floor | tostring) catch ("?") + "km/h"
    '

    # apply presentation filter
    if ((excl_grnd)); then
        if jq -e '.aircraft.model.code | test("grnd"; "i")' \
            > /dev/null <<< "$detail"; then
            log debug "Skipping GRND-type vehicle"
            return
        fi
    fi

    msg=$(jq -r "$filter" <<< "$detail")
    # img_link of airplane body
    local airplane_img_link
    # title = airline_name + flight_number/flight_callsign
    local title
    { read -r airplane_img_link && read -r title; } <<< "$msg"
    msg=$(tail -n+3 <<< "$msg")

    link_handle=$(jq -r '.identification as $id
                        | ($id.callsign + "/" + $id.id)' <<< "$detail")
    flightradar_link="https://www.flightradar24.com/$link_handle"

    printf "———————\n%s\n%s\n%s\n" "$title" "$msg" "$flightradar_link"

    if [[ "$use_notify" == 1 ]]; then
        local img_path
        local ua="User-Agent: Mozilla/5.0 \
(X11; Ubuntu; Linux x86_64; rv:84.0) Gecko/20100101 Firefox/84.0"
        if [[ -n "$airplane_img_link" ]]; then
            img_path=$(mktemp "$script_tmp_dir/img-XXX")
            curl_opts=()
            curl_opts+=(--header "$ua" --output "$img_path")
            fetch "$airplane_img_link"
        fi
        [[ -z "$title" ]] && title=" "
        notify-send "$title" "$msg\n$flightradar_link" \
            --icon "$img_path" --expire-time 10000
    fi
}

while getopts s:r:y:x:b:i:v:o:gfnqVh name; do
    case $name in
        s)
            query_str="$OPTARG"
            ;;
        r)
            delta_deg="$OPTARG"
            ;;
        y)
            latitude="$OPTARG"
            ;;
        x)
            longitude="$OPTARG"
            ;;
        b)
            bounds="$OPTARG"
            custom_bounds=1
            ;;
        i)
            flight_ids="$OPTARG"
            ;;
        v)
            log_level="$OPTARG"
            ;;
        o)
            details_file="$OPTARG"
            brief_mode=0
            ;;
        f)
            brief_mode=1
            ;;
        g)
            excl_grnd=1
            ;;
        n)
            use_notify=1
            brief_mode=0
            ;;
        q)
            log_level=0
            ;;
        V)
            printf "%s\n" "$version"
            exit 0
            ;;
        h)
            print_help
            exit 0
            ;;
        ?)
            log error "Bad usage! Check -h"
            exit 2
            ;;
    esac
done

# sanitization
if ! sanitize; then
    exit 2
fi

case $mode in
    "scan_bounds")
        if [[ -z "$custom_bounds" ]]; then
            # creating bounds based on inputted city/(lat/lon) and delta_deg
            if ! bounds=$(generate_bounds \
                "$delta_deg" "$latitude" "$longitude"); then
                log error "Problem in generating bounds. Check -h"
                exit 2
            fi
            log info "Scan region for δ=$delta_deg°: $bounds"
        else
            # reforming the directly inputed bounds
            bounds=$(printf "%s,%s,%s,%s\n" "$lat2" "$lat1" "$lon1" "$lon2")
            log info "Scan region: $bounds"
        fi

        # get all flights in region defined by bounds
        if ! flights=$(get_flights "$bounds"); then
            exit 1
        fi

        # get only flights that are within the desired geographical region
        # if [[ -z "$custom_bounds" ]]; then
        #     filtered_flights=$(filter_flights "$flights" \
        #         "$latitude" "$longitude" "$delta_deg")
        # else
        #     filtered_flights="$flights"
        # fi
        filtered_flights="$flights"

        log debug "Flights brief info: $(jq -c . <<< "$filtered_flights")"

        ;;
    "direct-ids")
        flight_ids="${flight_ids//[[:space:]]/}"
        filtered_flights="{}"
        old_ifs="$IFS"
        IFS=","
        for id in $flight_ids; do
            flights_tmp=$(jq \
                ". + {\"$id\" : []}" <<< "$filtered_flights")
            filtered_flights="$flights_tmp"
        done
        IFS="$old_ifs"
        ;;

esac

if [[ -n "$details_file" ]]; then
    details_file_tmp=$(mktemp "$script_tmp_dir/details-XXX.json")
    printf "" > "$details_file"
fi

# handle brief mode
if ((brief_mode)); then
    gen_brief "$filtered_flights"
    exit
fi

# handle detailed mode
# loop over `flight_id`s and print their info
while read -r id; do
    if ! detail=$(get_flight_details "$id"); then
        log error "Problem getting details of flight_id: $id"
        exit 1
    fi

    if [[ -n "$details_file" ]]; then
        # append details json (one line) to details_file
        jq --compact-output '.' <<< "$detail" >> "$details_file_tmp"
    fi

    # present the details of matched flight
    show "$detail"

done < <(jq -r 'del (.stats, .version, .full_count) | keys[]' \
    <<< "$filtered_flights")

# slurp the details_file as a single json array
if [[ -n "$details_file" ]]; then
    swap_tmp=$(mktemp "$script_tmp_dir/details_tmp-XXX")
    cp "$details_file_tmp" "$swap_tmp"
    jq --slurp '.' "$swap_tmp" > "$details_file_tmp"
    cp "$details_file_tmp" "$details_file"
fi