adding csv import to channels

app/controllers/channels_controller.rb

@@ -2,6 +2,7 @@ class ChannelsController < ApplicationController
 	before_filter :require_user, :except => [ :show, :post_data ]
 	before_filter :set_channels_menu
 	protect_from_forgery :except => :post_data
+	require 'csv'
 
 	def index
 		@channels = current_user.channels
@@ -72,6 +73,10 @@ class ChannelsController < ApplicationController
 			f.delete
 		end
 
+		# set the channel's last_entry_id to nil
+		channel.last_entry_id = nil
+		channel.save
+
 		redirect_to channels_path
 	end
 
@@ -146,4 +151,144 @@ class ChannelsController < ApplicationController
 		render :text => status
 	end
 
+
+	# import view
+	def import
+		get_channel_data
+	end
+
+	# upload csv file to channel
+	def upload
+		# if no data
+		render :text => t(:select_file) and return if params[:upload].blank? or params[:upload][:csv].blank?
+
+		channel = Channel.find(params[:channel_id])
+		channel_id = channel.id
+		# make sure channel belongs to current user
+		check_permissions(channel)
+		
+		# set time zone
+		Time.zone = params[:feed][:time_zone]
+
+		# read data from uploaded file
+		csv_array = CSV.parse(params[:upload][:csv].read)
+
+		# does the column have headers
+		headers = has_headers?(csv_array)
+
+		# remember the column positions
+		entry_id_column = -1
+		latitude_column = -1
+		longitude_column = -1
+		elevation_column = -1
+		status_column = -1
+		if headers
+			csv_array[0].each_with_index do |column, index|
+				entry_id_column = index if column.downcase == 'entry_id'
+				latitude_column = index if column.downcase == 'latitude'
+				longitude_column = index if column.downcase == 'longitude'
+				elevation_column = index if column.downcase == 'elevation'
+				status_column = index if column.downcase == 'status'
+			end
+		end
+
+		# delete the first row if it contains headers
+		csv_array.delete_at(0) if headers
+
+		# determine if the date can be parsed
+		parse_date = date_parsable?(csv_array[0][0])
+
+		# if 2 or more rows
+		if !csv_array[1].blank?
+			date1 = parse_date ? Time.parse(csv_array[0][0]) : Time.at(csv_array[0][0])
+			date2 = parse_date ? Time.parse(csv_array[1][0]) : Time.at(csv_array[1][0])
+
+			# reverse the array if 1st date is larger than 2nd date
+			csv_array = csv_array.reverse if date1 > date2
+		end
+
+		# loop through each row
+		csv_array.each do |row|
+			# if row isn't blank
+			if !row.blank?
+				feed = Feed.new
+	
+				# set location and status then delete the rows
+				# these 4 deletes must be performed in the proper (reverse) order
+				feed.status = row.delete_at(status_column) if status_column > 0
+				feed.elevation = row.delete_at(elevation_column) if elevation_column > 0
+				feed.longitude = row.delete_at(longitude_column) if longitude_column > 0
+				feed.latitude = row.delete_at(latitude_column) if latitude_column > 0
+
+				# remove entry_id column if necessary
+				row.delete_at(entry_id_column) if entry_id_column > 0
+
+				# update entry_id for channel and feed
+				entry_id = channel.last_entry_id.nil? ? 1 : channel.last_entry_id + 1
+				channel.last_entry_id = entry_id
+				feed.entry_id = entry_id
+	
+				# set feed data
+				feed.channel_id = channel_id
+				feed.created_at = parse_date ? Time.zone.parse(row[0]) : Time.zone.at(row[0].to_f)
+				feed.raw_data = row.to_s
+				feed.field1 = row[1]
+				feed.field2 = row[2]
+				feed.field3 = row[3]
+				feed.field4 = row[4]
+				feed.field5 = row[5]
+				feed.field6 = row[6]
+				feed.field7 = row[7]
+				feed.field8 = row[8]
+
+				# save channel and feed
+				feed.save
+				channel.save
+
+			end
+		end
+
+		# set the user's time zone back
+		set_time_zone(params)
+
+		# redirect 
+		redirect_to channel_path(channel.id)
+	end
+
+	# determine if the date can be parsed
+	def date_parsable?(date)
+		return !is_a_number?(date)
+	end
+
+	# determine if the csv file has headers
+	def has_headers?(csv_array)
+		headers = false
+
+		# if there are at least 2 rows
+		if (csv_array[0] and csv_array[1])
+			row0_integers = 0
+			row1_integers = 0	
+	
+			# if first row, first value contains 'create' or 'date', assume it has headers
+			if (csv_array[0][0].downcase.include?('create') or csv_array[0][0].downcase.include?('date'))
+				headers = true
+			else
+				# count integers in row0
+				csv_array[0].each_with_index do |value, i|
+					row0_integers += 1 if is_a_number?(value)
+				end
+	
+				# count integers in row1
+				csv_array[1].each_with_index do |value, i|
+					row1_integers += 1 if is_a_number?(value)
+				end
+	
+				# if row1 has more integers, assume row0 is headers
+				headers = true if row1_integers > row0_integers
+			end
+		end
+
+		return headers
+	end
+
 end