require 'json'
require 'csv'
require 'rgeo'
require 'rgeo-geojson'

class Parser
	def initialize()
		@list_of_locations = {}
		@list_of_locations["type"] = "FeatureCollection"
		@list_of_locations["features"] = []
	end

	def fuse_two_entries(entry_1, entry_2) #Outputs a string that contains the value of the two entries, or only one if they repeat
		if entry_1 and entry_2
			if entry_1 != entry_2
				return entry_1 + " ou " + entry_2
			else
				return entry_1
			end
		elsif entry_1
			return entry_1
		elsif entry_2
			return entry_2
		else
			return nil
		end
	end
	
	def reverse_endianness(string) #Reverse endianness of the received string, by chunk of two hexadecimal characters
		res = ""
		while string.length > 0
			res += string[-2..-1]
			string = string[0..-3]
		end
		return res
	end
	
	def cut_from_wkb(string) #Removes data that stumped the Rgeo library
		res = string[0..6] + string[15..-1]
		return res
	end
	
	def reverse_polygon_endianness(string)
		res = ""
		endian = string[0..1] #Reverse the endianness of the metadata of the polygon
		string = string[2..-1]
		if endian == "01"
			res += "00"
			for i in 0..3
				res += reverse_endianness(string[0..7])
				string = string[8..-1]
			end
		end
		
		while string != nil and string.length > 0 #Reverse Endianness of the coordinates of each point
			res += reverse_endianness(string[0..15])
			string = string[16..-1]
		end
		res = res[0..9] + res[18..-1] #Removes data that stumped the RGeo library
		res[2] = "0"
		return res
	end
	
	def reverse_multipolygon_endianness(string)
		res = ""#Reverse the endianness of the metadata of the multipolygon
		res += "00"
		string = string[2..-1]
		for i in 0..2
			res += reverse_endianness(string[0..7])
			number_of_elements = string[0..1]
			string = string[8..-1]
		end
		res += "00"
		string = string[2..-1]
		res += reverse_endianness(string[0..7]) #Polygon type stored here
		string = string[8..-1]
		
		number_of_polygons = string[0..1].to_i(16)
		res += reverse_endianness(string[0..7]) #Number_of_polygons stored here
		string = string[8..-1]
		
		for i in 0..number_of_polygons-1 #Reverse Endianness of the coordinates of each point
			number_of_duo_of_values = string[0..1].to_i(16)
			res += reverse_endianness(string[0..7]) #Number_of_duo_of_values stored here
			string = string[8..-1]
			for j in 0..number_of_duo_of_values-1
				res += reverse_endianness(string[0..15])
				string = string[16..-1]
				res += reverse_endianness(string[0..15])
				string = string[16..-1]
			end
		end
		res = res[0..9] + res[18..-1] #Removes data that stumped the RGeo library
		res[2] = "0"
		return res
	end
	
	def reverse_wkb_endianness(string) #Check if an element is a polygon or a multipolygon (might need different shapes in the future, like a point or a line
		if string[3] == "6"
			res = reverse_multipolygon_endianness(string)
		elsif string[3] == "3"
			res = reverse_polygon_endianness(string)
		else
			puts "ALERT"
			res = cut_from_wkb(string)
		end
		return res
	end
		
	def parsePotagersFiles(data_file)
		data = CSV.parse(File.read(data_file), headers: true, :col_sep => ",")
		factory = RGeo::Cartesian.factory
		
		i = 0
		while i < data.length
			begin
				new_item = {}
				new_item["type"] = "Feature"
				#Coordinates
				string = reverse_wkb_endianness(data[i]["the_geom"])
				geom = factory.parse_wkb(string)
				geom = RGeo::GeoJSON.encode(geom)
				new_item["geometry"] = geom
				
				#IN COMMON data
				new_item["properties"] = {}
				new_item["properties"]["name"] = fuse_two_entries(data[i]["nom"], data[i]["name"])
				new_item["properties"]["description"] = data[i]["descriptio"]
				new_item["properties"]["entry_number"] = data[i]["cartodb_id"]
				new_item["properties"]["phone_number"] = "" #No equivalent in potagers database
				new_item["properties"]["website"] = "" #No equivalent in potagers database
				#There is two fields for emails, "email" and "email_2", so if both are filled, puts "or" between the two emails
				new_item["properties"]["mail"] = fuse_two_entries(data[i]["email"], data[i]["email_2"])
				#There is two fields for address, "rue_num" and "rue", sometimes a field is empty, so a string is constructed with nil as a parameter, to create "" and add to the address string
				new_item["properties"]["address"] = String(data[i]["rue"]) + " " + String(data[i]["rue_num"])
				new_item["properties"]["city"] = data[i]["n_commune"]
				new_item["properties"]["postal_code"] = "" #No equivalent in potagers database
				new_item["properties"]["categories"] = [43]
				new_item["properties"]["source"] = data[i]["source"]
				
				#Supplementary data
				new_item["meta"] = {}
				new_item["meta"]["commentaire"] = data[i]["comment_2"]
				new_item["meta"]["visibilite"] = data[i]["visibilite"]
				new_item["meta"]["acces"] = data[i]["acces"]
				new_item["meta"]["accessibilite"] = data[i]["accessibil"]
				new_item["meta"]["horaires"] = data[i]["horaires"]
				new_item["meta"]["utilisation"] = data[i]["utilisatio"]
				new_item["meta"]["type_de_lo"] = data[i]["type_de_lo"]
				new_item["meta"]["pollution"] = data[i]["pollution"]
				new_item["meta"]["pleine_t_1"] = data[i]["pleine_t_1"]
				new_item["meta"]["compost"] = data[i]["compost"]
				new_item["meta"]["g4_analyse"] = data[i]["g4_analyse"]
				new_item["meta"]["g3_autre_a"] = data[i]["g3_autre_a"]
				new_item["meta"]["g3_colla_1"] = data[i]["g3_colla_1"]
				new_item["meta"]["g3_finance"] = data[i]["g3_finance"]
				new_item["meta"]["g3_finance_2"] = data[i]["g3_finance"]
				new_item["meta"]["vandalisme"] = data[i]["vandalisme"]
				new_item["meta"]["g3_accord_2"] = data[i]["g3_accor_2"]
				new_item["meta"]["accord avec"] = data[i]["accord_ave"]
				new_item["meta"]["proprietaire"] = fuse_two_entries(data[i]["proprietai"], data[i]["propriet_1"])
				new_item["meta"]["forme_juridique"] = data[i]["forme_juri"]
				new_item["meta"]["g2_participants"] = data[i]["g2_partici"]
				new_item["meta"]["gestionnaire"] = data[i]["gestionnai"]
				new_item["meta"]["pleine_ter"] = data[i]["pleine_ter"]
				new_item["meta"]["license"] = data[i]["licence"]
				new_item["meta"]["icon"] = data[i]["icon"]
				new_item["meta"]["code_potager"] = data[i]["code_potag"]
				new_item["meta"]["type"] = data[i]["type"]
				new_item["meta"]["historique"] = data[i]["historique"]
				new_item["meta"]["annee_de_creation"] = data[i]["annee_de_c"]
				new_item["meta"]["adresse_co"] = data[i]["adresse_co"]
				new_item["meta"]["begin"] = data[i]["begin"]
				new_item["meta"]["end"] = data[i]["end"]
				new_item["meta"]["area_sqm"] = data[i]["area_sqm"]
				new_item["meta"]["area_acres"] = data[i]["area_acres"]
				
				new_item["properties"]["srid"] = "4326"
				@list_of_locations["features"].push(new_item)
			rescue RGeo::Error::InvalidGeometry => e
				puts "---"
				puts "Donnee numero " + i.to_s + " invalide. Erreur: " + e.to_s
				puts "valeur: " + data[i]["the_geom"]
			end

			i += 1
		end
	end
	def writeToFile(write_file)
		File.write(write_file, JSON.pretty_generate(@list_of_locations))
	end
end

BEGIN {
	puts "Starting parser"
}

parser = Parser.new()
parser.parsePotagersFiles("potagers_merged_spjoined_ar2_1.csv.diff")
parser.writeToFile("LocationsPotagers.geojson")

END {
	puts "Ending parser"
}