# Prog-09: Weather Report
# 6?3??????21 Name ?

import math
import matplotlib.pyplot as plt
import json

# ----------------------------------------------
def read_weather_data():        
    def read_province_region_data():
        region_of = {}   
        f = open('provinces.txt', encoding='utf-8')   
        for line in f:         
            province, region = line.split()   
            region_of[province] = region
        return region_of   

    def get_value(attr):      
        if attr == None:     
            return None
        else:
            return float(attr['Value'])

    filename = "weather.json"
    f = open(filename, encoding='utf-8')
    json_data = json.load(f)
    f.close()
    region_of = read_province_region_data()

    stations = {}
    names_in_region = {'N':[], 'E':[], 'W':[], 'S':[], 'C':[], 'NE':[]}
    for station in json_data['Stations']:
        name = station["StationNameEng"].upper()
        lat  = get_value(station["Latitude"])
        long = get_value(station["Longitude"])
        temp = get_value(station["Observe"]["Temperature"])
        region = region_of[station["Province"]]
        if lat != None and long != None and temp != None:
            stations[name] = {'lat': lat, 'long': long, 'temp': temp}
            names_in_region[region].append(name)
    date_time = json_data['Header']['LastBuiltDate']
    return date_time, names_in_region, stations

def distance(lat1, long1, lat2, long2):
    # Haversine’ formula
    lat1 = math.radians(lat1)
    long1 = math.radians(long1)
    lat2 = math.radians(lat2)
    long2 = math.radians(long2)
    dlat, dlong = lat1 - lat2, long1 - long2
    x = math.sin(dlat/2)**2 + math.cos(lat1)*math.cos(lat2)*math.sin(dlong/2)**2
    return 2*math.asin(x**0.5) * 6371 # Radius of the earth in Km.

def show_all_station_names(stations):
    names = []
    for name in stations:
        names.append(name.title())
    names.sort()
    for i in range(0, len(names), 5): # five names per line
        print(', '.join(names[i: i+4]))

def plot_map_info(stations, names, date_time):
    lats  = [stations[name]['lat' ] for name in names]
    longs = [stations[name]['long'] for name in names]
    temps = [str(stations[name]['temp'])+'°c' for name in names]
    ruh_m = plt.imread('th_map.jpg')
    fig, ax = plt.subplots(figsize = (8,7))
    bbox = [95.5, 107.0, 5.5, 20.7]
    ax.set(xlim=bbox[:2], ylim=bbox[2:], title='Thailand '+ date_time)
    sc = ax.scatter(longs, lats, zorder=1, c='r', s=40)
    for i in range(len(temps)):
        ax.annotate(temps[i], (longs[i], lats[i]), c='k', fontsize=14)
        print(names[i].title(), temps[i])
    ax.imshow(ruh_m, zorder=0, extent=bbox, aspect='equal')

    # https://stackoverflow.com/questions/7908636
    annot = ax.annotate("", xy=(0,0), xytext=(20,20),
                    textcoords="offset points", fontsize=16,
                    bbox=dict(boxstyle="round", fc="orange"),
                    arrowprops=dict(arrowstyle="->"))
    annot.set_visible(False)

    def update_annot(ind):
        k = ind["ind"][0]
        annot.xy = sc.get_offsets()[k]
        annot.set_text(names[k].title() + ': ' + temps[k])

    def hover(event):
        vis = annot.get_visible()
        if event.inaxes == ax:
            cont, ind = sc.contains(event)
            if cont:
                update_annot(ind)
                annot.set_visible(True)
                fig.canvas.draw_idle()
            else:
                if vis:
                    annot.set_visible(False)
                    fig.canvas.draw_idle()
    fig.canvas.mpl_connect("motion_notify_event", hover)
    fig.tight_layout()
    plt.show()

def main():
    while True:
        print("Weather Report:\n" +
              " (0) List all stations\n" +
              " (1) Temperatures at selected stations\n" +
              " (2) Top K max & min temperature stations\n" +
              " (3) Temperatures at the peak stations\n" +
              " (4) Temperatures at the nearby stations\n" +
              " (5) Average temperatures in the region")
        choice = input('Select 0,1,2,3,4,5: ')
        if '0' <= choice <= '5': break
        print('Try again.')

    date_time, names_in_region, stations = read_weather_data()
    names = []
    if choice == '0':
        show_all_station_names(stations)
    elif choice == '1':
        name = input("Station name: ")
        names = approx_match(stations, name)
        if len(names) == 0:
            print('No', name, 'in database.')
    elif choice == '2':
        k = int(input("K: "))
        names = top_k_min_temp_stations(stations, k)
        names.extend(top_k_max_temp_stations(stations, k))
    elif choice == '3':
        names = peak_stations(stations)
    elif choice == '4':
        main_station = input("Main station: ").strip().upper()
        if main_station not in stations:
            print('No ' + main_station + ' in database')
        else:
            k = int(input("How many nearby stations? "))
            names = [main_station] + k_nearby_stations(stations, main_station, k)
    elif choice == '5':
        region = input("Region (N,E,W,S,C,NE): ").strip().upper()
        if region not in names_in_region:
            print('Invalid region')
        else:
            names = names_in_region[region]
            avg_temp = average_temp(stations, names)
            print('Average temperature =', str(round(avg_temp,1)) + '°c')

    if len(names) > 0: plot_map_info(stations, names, date_time)
# --------------------------------------------------
#
def approx_match(stations, name):



def top_k_min_temp_stations(stations, K):



def top_k_max_temp_stations(stations, K):



def peak_stations(stations):



def k_nearby_stations(stations, main_station, K):



def average_temp(stations, names):



# --------------------------------------------------
main()