Naughty or Nice Santa hat

hat.lua

-- setup spi
spi.setup(1, spi.MASTER, spi.CPOL_HIGH, spi.CPHA_HIGH, spi.DATABITS_8, 0);
-- number of LEDS connected to the SPI device
NUM_LEDS = 42;

-- connect to iphone tether
wifi.setmode(wifi.STATION)
wifi.sta.config("SSID", "PASSWORD")

-- our server
THE_CLOWN = 'IP ADDRESS RUNNING hat.py'
THE_CLOWN_PORT = 8080

-- handle button presses
gpio.mode(3, gpio.INPUT)

-- globals
FRAME = {}
MODE = 'dunno'

-- flatten our frame table so it's suitable for spi.send
-- {{1, 2, 3, 4}. {5, 6, 7, 8}} becomes {1, 2, 3, 4, 5, 6, 7, 8}
-- is there a better way to do this in LUA"
function lframe(frame)
    result = {};
    z = 0;
    for k, v in pairs(frame) do
        for kk, vv in pairs(v) do
            result[z] = vv;
            z = z + 1;
        end 
    end 

    return result;
end


-- all our pattern functions are iterators, each are expected to write _one_ frame
-- to the SPI device each time they are called

-- generate a green "barber pole" / "chase" pattern"
function nice()
    local start = 0;

    return function ()
        
        for k = 0, NUM_LEDS, 1 do
            if start == 0 then
                FRAME[k] = {255, 0, 0, 0};
                start = 1
            else
                FRAME[k] = {255, 255, 0, 0};
                start = 0
            end 
        end

        spi.send(1, {0, 0, 0, 0});
        spi.send(1, lframe(FRAME));

        return start
    end
end

-- generate a red "barber pole" / "chase" pattern"
function naughty()
    local start = 0;

    return function ()
        
        for k = 0, NUM_LEDS, 1 do
            if start == 0 then
                FRAME[k] = {255, 0, 0, 0};
                start = 1
            else
                FRAME[k] = {255, 0, 0, 255};
                start = 0
            end 
        end

        spi.send(1, {0, 0, 0, 0});
        spi.send(1, lframe(FRAME));

        return start
    end
end

-- immediately set entire strip red
-- then fill pixel by pixel with white
function white()
    local i = 0;

    -- fill white
    for k = 0, NUM_LEDS, 1 do
        FRAME[k] = {255, 255, 0, 0};
    end

    -- fill one pixel red each iteration until we reach the end of the strip
    return function ()
        i = i + 1;

        if i == NUM_LEDS then
            return nil
        end

        FRAME[i] = {255, 255, 255, 255}

        spi.send(1, {0, 0, 0, 0});
        spi.send(1, lframe(FRAME));

        return i
    end
end

-- immediately set entire strip white
-- then fill pixel by pixel with green
function green()
    local i = 0;

    for k= 0, NUM_LEDS, 1 do
        FRAME[k] = {255, 255, 255, 255};
    end

    return function ()
        i = i + 1;

        if i == NUM_LEDS then
            return nil
        end

        FRAME[i] = {255, 0, 0, 255}

        spi.send(1, {0, 0, 0, 0});
        spi.send(1, lframe(FRAME));

        return i
    end
end

-- immediately set entire strip green
-- then fill pixel by pixel with red
function red()
    local i = 0;

    for k = 0, NUM_LEDS, 1 do
        FRAME[k] = {255, 0, 0, 255};
    end

    return function ()
        i = i + 1;

        if i == NUM_LEDS then
            return nil
        end

        FRAME[i] = {255, 255, 0, 0}

        spi.send(1, {0, 0, 0, 0});
        spi.send(1, lframe(FRAME));

        return i
    end
end

-- exepcted to be called like: wifi.sta.getap(geoloc)
-- packs all discovered APs into a string and sends to the clown
-- the clown does geolocation based on observed APs,
-- then looks up last week's crime stats and returns a naughty/nice/dunno ranking
function geoloc(aps)
    -- if we aren't connected to wifi, just return 'don't know'
    if wifi.sta.status() ~= 5 then
        print("Not connected to WIFI, unable to load crime stats")
        MODE = 'dunno'
        return
    end

    -- pack our table of aps into a string
    -- we'll need this below to make our request
    local t = {}
    for k, v in pairs(aps) do
        table.insert(t, v)
    end

    -- setup the request
    conn = net.createConnection(net.TCP, 0)
    good = false;

    -- we received data
    conn:on("receive", function(conn, payload) 
        local s = 0;
        local e = 0;

        -- extact the first line
        s, e = string.find(payload, "\r")
        local line = string.sub(payload, 0, s)

        -- it should be the status line, if not, bounce
        s, e = string.find(line, 'HTTP/1.')
        if s ~= 1 then
            return
        end

        -- ok, we have the status line, chop out the response code
        s, e = string.find(line, " ", e+2)
        code = tonumber(string.sub(line, s+1, s+4))

        -- set our disply mode based on the result
        if code == 200 then
            MODE = 'nice'
        elseif code == 210 then
            MODE = 'naughty'
        else
            MODE = 'dunno'
        end

        print(MODE)
        good = true

    end)
    
    conn:on("connection", function(c)
        -- send our request to the clown
        conn:send("GET /?aps="..table.concat(t, "|").." HTTP/1.0\r\nHost: santa-hat.appspot.com\r\n\r\n") 
    end)

    conn:on("disconnection",function(c)
        -- if this flag isn't set to true
        -- then on("receive") was never called so we should go to 'dunno' state
        if good == false then
            MODE = 'dunno'
            print("closed bad")
        else
            -- if the flag is set, we are good, bounce
            print("closed good")
        end
    end)

    -- hardcoded ip for cnelson.org so we are more likely to get a response
    -- if we don't have to deal with possible DNS failures
    print("Getting crime info...")
    conn:connect(THE_CLOWN_PORT, THE_CLOWN)
end


-- variables to manage state between calls to draw()
iter = nil
iname = ''

last_status = nil
last_btn = nil


-- this function is called every 5ms, it should update the LED strip
function draw()

    -- trigger a check / mode change if the WIFI connection status has changed
    local status = wifi.sta.status()
    if status == 5 and status ~= last_status then
        print("Conneced to AP. Triggering Crime Check")
        wifi.sta.getap(geoloc)
    end

    if status ~= 5 and status ~= last_status then
        print("WIFI Disconnected Switching to dunno")
        MODE = 'dunno'
    end

    last_status = status        

    -- manually switch display modes if the button is pressed
    local btn = gpio.read(3)

    if btn == 0 and btn ~= last_btn then
        if MODE == 'nice' then
            print("Manually switching to naughty")
            MODE = 'naughty'
        elseif MODE =='naughty' then
            print("Manually switching to dunno")
            MODE = 'dunno'
        else
            print("Manually switching to nice")
            MODE = 'nice'
        end
    end

    last_btn = btn

    -- if we are nice or naughty, then stay there until something changes our mode
    -- this could be a button press, or new crime data
    if MODE == 'nice' then
        if iname ~= 'nice' then
            iter = nice()
            iname = 'nice'
        end

        iter()
    elseif MODE == 'naughty' then
        if iname ~= 'naughty' then
            iter = naughty()
            iname = 'naughty'
        end

        iter()
    else
        -- we are 'dunno' if we got here

        -- if we were in a different mode, switch to red
        if iname ~= 'r' and iname ~= 'g' and iname ~= 'w' then
            iter = white()
            iname = 'w'
        end

        -- rotate through our color fill
        if iter() == nil then
            if iname == 'w' then
                iter = green()
                iname ='g'
            elseif iname == 'g' then
                iter = red()
                iname = 'r'
            else 
                iter = white()
                iname = 'w'
            end
        end
    end

    -- kick off another frame in 5 ms
    tmr.alarm(0, 5, 0, draw)
end

-- check for new crime data every 5 minutes
tmr.alarm(6, 1000*60*5, 1, function() wifi.sta.getap(geoloc) end)

-- update the led every 5 miliseconds
tmr.alarm(0, 5, 0, draw)

hat.py

#!/usr/bin/env python
"""Accept a list of APs, then:
     * Do geolocation with google's API,
     * Lookup crime in that area with spotcrime's API
"""

# DO NOT USE ANY OF THIS CODE IN A PRODUCTION SYSTEM, IT'S JOKE CODE FOR A JOKE HAT

import datetime
import json
import urllib2

from flask import Flask, request
app = Flask(__name__)

# our API keys
GEO_API_KEY = 'GOOGLE-API-KEY'
CRIME_API_KEY = 'SPOTCRIME-API-KEY'

# stash the last request in memory for debugging
last_geo = None
last_check = None
last_crimes = None

# our results
NICE = ('nice', 200)
NAUGHTY = ('naughty', 210)
DUNNO = ('dunno', 211)

@app.route('/')
def index():
    """Given a list of APs, do geolocatoin to find lat/lng,
    then use lat/lng to lookup crime statistics for the area in question
    """

    global last_geo, last_check, last_crimes

    # this is a string like: authmode,rssi,bssid,channel|authmode,rssi,bssid,channel|...
    # this isn't JSON or some other structed formated as the callers of the API are
    # likely to be very small / dumb devices
    # so lets not assume they have a JSON library available,
    # and let them send a simple delimited string instead
    aps = request.args.get('aps', '')

    wifiaps = []

    # get the list of APs
    for ap in aps.split('|'):
        # and the values for each one
        try:
            authmode, rssi, bssid, channel = ap.split(',')
        except ValueError:
            continue

        # back into the data structure the API expects
        wifiaps.append({
            "macAddress": bssid.upper(),
            "signalStrength": int(rssi),
            "age": 0,
            "channel": int(channel),
        })

    #can't geo locate with no APs
    if len(wifiaps) == 0:
        return DUNNO

    # make the api call
    url = 'https://www.googleapis.com/geolocation/v1/geolocate?key={0}'.format(GEO_API_KEY)
    req = urllib2.Request(
        url,
        json.dumps({"wifiAccessPoints": wifiaps}),
        {'Content-Type': 'application/json'}
    )
    geo = json.loads(urllib2.urlopen(req).read())

    # some test coordinates:
    #
    # coalinga
    # geo = {
    #     'location': {
    #         'lat': 34.137726,
    #         'lng': -118.358772
    #     }
    # }
    # east oakland
    # geo = {
    #     'location': {
    #         'lat': 37.779691,
    #         'lng': -122.218603
    #     }
    # }

    # now that we have the lat/lng, lookup nearby crime
    crime_url = 'http://api.spotcrime.com/crimes.json?key={0}&lat={1}&lon={2}&radius={3}'.format(
        CRIME_API_KEY,
        geo['location']['lat'],
        geo['location']['lng'],
        0.01
    )
    resp = urllib2.urlopen(crime_url)
    crimes = json.loads(resp.read())

    last_geo = geo
    last_check = datetime.datetime.now()
    last_crimes = None

    # if there are no crimes, then say 'dunno' not 'nice'
    # as no place as _no crimes... it's likely a hole in the API's data sources
    if len(crimes['crimes']) == 0:
        # no data
        return DUNNO

    # figure out if naughty or nice
    # yeah, yeah all crimes are bad, but try to distinguish between
    # 'violent crimes' and 'property crimes'
    naughty_crimes = ['Assault', 'Shooting', 'Robbery', 'Arson']
    nice_crimes = ['Burglary', 'Vandalism', 'Arrest', 'Theft']

    naughty = 0
    nice = 0

    # get a list of all the types of crime we have
    types = [c['type'] for c in crimes['crimes']]

    # build a dict where k = type, and v = the number of crimes of that type
    summary = dict((i, types.count(i)) for i in types)

    # remove the outlier, and then count our crimes
    if len(summary) > 1:
        del summary[sorted(summary.items(), key=lambda x: x[1], reverse=True)[0][0]]

    last_crimes = summary

    print summary

    # add up our naughty crimes
    for c in naughty_crimes:
        naughty += summary.get(c, 0)

    # and our nice crimes
    for c in nice_crimes:
        nice += summary.get(c, 0)

    # return our status
    if naughty >= nice:
        return NAUGHTY
    else:
        return NICE

@app.route('/info')
def info():
    """Show debugging info for the last request
    yes this leaks your lat/lng. Enjoy being stalked :  )
    """

    if last_geo is not None:
        lg = '<a href="https://www.google.com/maps/@{0},{1},15z">{0}, {1}</a>'.format(
            last_geo['location']['lat'],
            last_geo['location']['lng']
        )
    else:
        lg = 'None'

    if last_crimes is not None:
        lc = ', '.join([kk+': '+str(vv) for kk, vv in last_crimes.items()])
    else:
        lc = 'None'

    return """
    <p><strong>Last Geo: </strong> {0}</p>
    <p><strong>Last Crimes: </strong> {1}</p>    
    <p><strong>Last Check: </strong> {2}</p>    
    """.format(lg, lc, last_check)

if __name__ == "__main__":
    app.run(host='0.0.0.0', port=8080, debug=False)