local forecast = {}

local HTTPS = require('ssl.https')
local URL = require('socket.url')
local JSON = require('dkjson')
local utilities = require('miku.utilities')
local bindings = require('miku.bindings')
local redis = (loadfile "./miku/redis.lua")()

function forecast:init(config)
	if not cred_data.forecastio_apikey then
		print('Missing config value: forecastio_apikey.')
		print('weather.lua will not be enabled.')
		return
	elseif not cred_data.google_apikey then
		print('Missing config value: google_apikey.')
		print('weather.lua will not be enabled.')
		return
	end

   forecast.triggers = {
    "^(/f)$",
	"^(/f) (.*)$",
	"^(/fh)$",
	"^(/fh) (.*)$",
	"^(/forecast)$",
	"^(/forecast) (.*)$",
	"^(/forecasth)$",
	"^(/forecasth) (.*)$"
	}
	forecast.doc = [[*
]]..config.cmd_pat..[[f*:  Wettervorhersage für deinen Wohnort _(/location set <Ort>)_
*]]..config.cmd_pat..[[f* _<Ort>_: Wettervorhersage für diesen Ort
*]]..config.cmd_pat..[[fh*: 24-Stunden-Wettervorhersage für deine Stadt _(/location set [Ort]_
*]]..config.cmd_pat..[[fh* _<Ort>_: 24-Stunden-Wettervorhersage für diesen Ort
]]
end

forecast.command = 'f [Ort]'

local BASE_URL = "https://api.forecast.io/forecast"
local apikey = cred_data.forecastio_apikey
local google_apikey = cred_data.google_apikey

function get_city_name(lat, lng)
  local city = redis:hget('telegram:cache:weather:pretty_names', lat..','..lng)
  if city then return city end
  local url = 'https://maps.googleapis.com/maps/api/geocode/json?latlng='..lat..','..lng..'&result_type=political&language=de&key='..google_apikey
  local res, code = HTTPS.request(url)
  if code ~= 200 then return 'Unbekannte Stadt' end
  local data = JSON.decode(res).results[1]
  local city = data.formatted_address
  print('Setting '..lat..','..lng..' in redis hash telegram:cache:weather:pretty_names to "'..city..'"')
  redis:hset('telegram:cache:weather:pretty_names', lat..','..lng, city)
  return city
end

function get_condition_symbol(weather, n)
  if weather.data[n].icon == 'clear-day' then
	return '☀️'
  elseif weather.data[n].icon == 'clear-night' then
    return '🌙'
  elseif weather.data[n].icon == 'rain' then
    return '☔️'
  elseif weather.data[n].icon == 'snow' then
	return '❄️'
  elseif weather.data[n].icon == 'sleet' then
    return '🌨'
  elseif weather.data[n].icon == 'wind' then
    return '💨'
  elseif weather.data[n].icon == 'fog' then
    return '🌫'
  elseif weather.data[n].icon == 'cloudy' then
    return '☁️☁️'
  elseif weather.data[n].icon == 'partly-cloudy-day' then
    return '🌤'
  elseif weather.data[n].icon == 'partly-cloudy-night' then
    return '🌙☁️'
  else
    return ''
  end
end

function get_temp(weather, n, hourly)
  if hourly then
    local temperature = string.gsub(round(weather.data[n].temperature, 1), "%.", ",")
	local condition = weather.data[n].summary
	return temperature..'°C | '..get_condition_symbol(weather, n)..' '..condition
  else
    local day = string.gsub(round(weather.data[n].temperatureMax, 1), "%.", ",")
    local night = string.gsub(round(weather.data[n].temperatureMin, 1), "%.", ",")
    local condition = weather.data[n].summary
    return '☀️ '..day..'°C | 🌙 '..night..'°C | '..get_condition_symbol(weather, n)..' '..condition
  end
end

function forecast:get_forecast(lat, lng)
  print('Finde Wetter in '..lat..', '..lng)
  local text = redis:get('telegram:cache:forecast:'..lat..','..lng)
  if text then print('...aus dem Cache..') return text end

  local url = BASE_URL..'/'..apikey..'/'..lat..','..lng..'?lang=de&units=si&exclude=currently,minutely,hourly,alerts,flags'
  
  local response_body = {}
  local request_constructor = {
      url = url,
      method = "GET",
      sink = ltn12.sink.table(response_body)
   }
  local ok, response_code, response_headers, response_status_line = HTTPS.request(request_constructor)
  if not ok then return nil end
  local data = JSON.decode(table.concat(response_body))
  local ttl = string.sub(response_headers["cache-control"], 9)

  
  local weather = data.daily
  local city = get_city_name(lat, lng)
  
  local header = '*Vorhersage für '..city..':*\n_'..weather.summary..'_\n'
  
  local text = '*Heute:* '..get_temp(weather, 1)
  local text = text..'\n*Morgen:* '..get_temp(weather, 2)
  
  for day in pairs(weather.data) do
	if day > 2 then 
	  text = text..'\n*'..convert_timestamp(weather.data[day].time, '%a, %d.%m')..'*: '..get_temp(weather, day)
    end
  end
  
  local text = string.gsub(text, "Mon", "Mo")
  local text = string.gsub(text, "Tue", "Di")
  local text = string.gsub(text, "Wed", "Mi")
  local text = string.gsub(text, "Thu", "Do")
  local text = string.gsub(text, "Fri", "Fr")
  local text = string.gsub(text, "Sat", "Sa")
  local text = string.gsub(text, "Sun", "So")
  
  cache_data('forecast', lat..','..lng, header..text, tonumber(ttl), 'key')
  
  return header..text
end

function forecast:get_forecast_hourly(lat, lng)
  print('Finde stündliches Wetter in '..lat..', '..lng)
  local text = redis:get('telegram:cache:forecast:'..lat..','..lng..':hourly')
  if text then print('...aus dem Cache..') return text end

  local url = BASE_URL..'/'..apikey..'/'..lat..','..lng..'?lang=de&units=si&exclude=currently,minutely,daily,alerts,flags'
  
  local response_body = {}
  local request_constructor = {
      url = url,
      method = "GET",
      sink = ltn12.sink.table(response_body)
   }
  local ok, response_code, response_headers, response_status_line = HTTPS.request(request_constructor)
  if not ok then return nil end
  local data = JSON.decode(table.concat(response_body))
  local ttl = string.sub(response_headers["cache-control"], 9)

  
  local weather = data.hourly
  local city = get_city_name(lat, lng)
  
  local header = '*24-Stunden-Vorhersage für '..city..':*\n_'..weather.summary..'_'
  local text = ""
  
  for hour in pairs(weather.data) do
	if hour < 26 then 
	  text = text..'\n*'..convert_timestamp(weather.data[hour].time, '%H:%M Uhr')..'* | '..get_temp(weather, hour, true)
	end
  end
  
  cache_data('forecast', lat..','..lng..':hourly', header..text, tonumber(ttl), 'key')
  
  return header..text
end

function forecast:action(msg, config, matches)
  local user_id = msg.from.id
  local city = get_location(user_id)
  
  if matches[2] then
    city = matches[2]
  else
    local set_location = get_location(user_id)
	if not set_location then
	  city = 'Berlin, Deutschland'
	else
	  city = set_location
	end
  end
  
  local lat = redis:hget('telegram:cache:weather:'..string.lower(city), 'lat')
  local lng = redis:hget('telegram:cache:weather:'..string.lower(city), 'lng')
  if not lat and not lng then
    print('Koordinaten nicht eingespeichert, frage Google...')
    coords = utilities.get_coords(city, config)
	lat = coords.lat
	lng = coords.lon
  end
  
  if not lat and not lng then
    utilities.send_reply(self, msg, '*Diesen Ort gibt es nicht!*', true)
    return
  end

  redis:hset('telegram:cache:weather:'..string.lower(city), 'lat', lat)
  redis:hset('telegram:cache:weather:'..string.lower(city), 'lng', lng)
  
  if matches[1] == '/forecasth' or matches[1] == '/fh' then
    text = forecast:get_forecast_hourly(lat, lng)
  else
    text = forecast:get_forecast(lat, lng)
  end
  if not text then
    text = '*Konnte die Wettervorhersage für diese Stadt nicht bekommen.*'
  end
  utilities.send_reply(self, msg, text, true)
end

return forecast