import boto3
import math

def lambda_handler(event,context):
    dynamodb = boto3.resource('dynamodb')
    table = dynamodb.Table('tableforhotspot')
    data = table.scan()['Items']

    loc_x = []
    loc_y = []
    location_info = []


    #print(data[0])


    for i in range(len(data)):
        #string_out = string_out +str(data[i]['record']) + "<br><br>"
        location_info.append(str(data[i]['record']))
        array = str(data[i]['record']).split(',')
        loc_x.append(float(array[2]))
        loc_y.append(float(array[3]))

    #record_from_data = data[0]['record']

    #grupowanie
    group_x = []
    group_y = []

    group_x.append(loc_x[0])
    group_y.append(loc_y[0])

    asigned_to_groups = [ [] ]



    for i in range(len(loc_x)):

        assigned = False

        for j in range(len(group_x)):

            distance =  math.sqrt(math.pow(loc_x[i]-group_x[j],2) + math.pow(math.cos((loc_x[i]*3.14)/180)*(loc_y[i]-group_y[j]),2)) * 40075.704/360

            if distance < 3:

                asigned_to_groups[j].append(i)
                assigned = True

        if assigned == False:
            group_x.append(loc_x[i])
            group_y.append(loc_y[i])
            asigned_to_groups.append([])
            asigned_to_groups[len(asigned_to_groups)-1].append(i)

    #tworzenie stringa wyjsciowego

    string_out = "<b> LISTA HOTSPOTOW W GDANSKU </b> <br><br>"
    string_out = string_out+"liczba grup:"+ str(len(group_x))+"<br><br>"
    print(len(string_out))

    for i in range(len(asigned_to_groups)):
        string_out = string_out+','+"Grupa"+ str(i)+ ",<br><br><br><br> "
        for j in range(len(asigned_to_groups[i])):
            string_out = string_out + ','+location_info[asigned_to_groups[i][j]]+"<br><br> "

    #print(loc_x)
    #print(len(loc_x))
    #print(len(asigned_to_groups))
    #print(len(group_x))

    return string_out