New: Download GPS cache data from Garmin server and store it on device

2 files changed, 153 insertions, 22 deletions

diff --git a/lib/postrunner/EPO_Downloader.rb b/lib/postrunner/EPO_Downloader.rb
new file mode 100644
index 0000000..6121d20
--- /dev/null
+++ b/lib/postrunner/EPO_Downloader.rb
@@ -0,0 +1,95 @@
+#!/usr/bin/env ruby -w
+# encoding: UTF-8
+#
+# = EPO_Downloader.rb -- PostRunner - Manage the data from your Garmin sport devices.
+#
+# Copyright (c) 2015 by Chris Schlaeger <cs@taskjuggler.org>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of version 2 of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+
+require 'uri'
+require 'net/http'
+
+module PostRunner
+
+  # This class can download the current set of ephemeris data for GPS
+  # satellites and store them in the EPO.BIN file format. Some Garmin devices
+  # pick up this file under GARMIN/GARMIN/REMOTESW/EPO.BIN.
+  class EPO_Downloader
+
+    @@URI = URI('http://omt.garmin.com/Rce/ProtobufApi/EphemerisService/GetEphemerisData')
+    # This is the payload of the POST request. It was taken from
+    # http://www.kluenter.de/garmin-ephemeris-files-and-linux/. It may contain
+    # a product ID or serial number.
+    @@POST_DATA = "\n-\n\aexpress\u0012\u0005de_DE\u001A\aWindows\"\u0012601 Service Pack 1\u0012\n\b\x8C\xB4\x93\xB8\u000E\u0012\u0000\u0018\u0000\u0018\u001C\"\u0000"
+    @@HEADER = {
+      'Garmin-Client-Name' => 'CoreService',
+      'Content-Type' => 'application/octet-stream',
+      'Content-Length' => '63'
+    }
+
+    # Create an EPO_Downloader object.
+    def initialize
+      @http = Net::HTTP.new(@@URI.host, @@URI.port)
+      @request = Net::HTTP::Post.new(@@URI.path, initheader = @@HEADER)
+      @request.body = @@POST_DATA
+    end
+
+    # Download the current ephemeris data from the Garmin server and write it
+    # into the specified output file.
+    # @param output_file [String] The name of the output file. Usually this is
+    #        'EPO.BIN'.
+    def download(output_file)
+      return false unless (epo = get_epo_from_server)
+      return false unless (epo = fix(epo))
+      write_file(output_file, epo)
+      Log.info "GPS caching data has been downloaded from Garmin site."
+
+      true
+    end
+
+    private
+
+    def get_epo_from_server
+      res = @http.request(@request)
+      if res.code.to_i != 200
+        Log.error "GPS data download failed: #{res}"
+        return nil
+      end
+      res.body
+    end
+
+    # The downloaded data contains ephemeris data for 6 hour windows for 7
+    # days. Each window set is 2307 bytes long, but the first 3 bytes must
+    # be removed for the FR620 to understand it.
+    # https://forums.garmin.com/showthread.php?79555-when-will-garmin-express-mac-be-able-to-sync-GPS-EPO-bin-file-on-fenix-2&p=277398#post277398
+    def fix(epo)
+      unless epo.length == 28 * 2307
+        Log.error "GPS data has unexpected length of #{epo.length} bytes"
+        return nil
+      end
+
+      epo_fixed = ''
+      0.upto(27) do |i|
+        offset = i * 2307
+        epo_fixed += epo[offset + 3, 2304]
+      end
+
+      epo_fixed
+    end
+
+    def write_file(output_file, data)
+      begin
+        File.write(output_file, data)
+      rescue IOError
+        Log.fatal "Cannot write EPO file '#{output_file}': #{$!}"
+      end
+    end
+
+  end
+
+end
+
diff --git a/lib/postrunner/Main.rb b/lib/postrunner/Main.rb
index 0dffde2..ddec18e 100644
--- a/lib/postrunner/Main.rb
+++ b/lib/postrunner/Main.rb
@@ -17,6 +17,7 @@ require 'fit4ruby'
 require 'postrunner/version'
 require 'postrunner/RuntimeConfig'
 require 'postrunner/ActivitiesDB'
+require 'postrunner/EPO_Downloader'
 
 module PostRunner
 
@@ -115,51 +116,54 @@ EOT
 Commands:
 
 check [ <fit file> | <ref> ... ]
-          Check the provided FIT file(s) for structural errors. If no file or
-          reference is provided, the complete archive is checked.
+           Check the provided FIT file(s) for structural errors. If no file or
+           reference is provided, the complete archive is checked.
 
 dump <fit file> | <ref>
-          Dump the content of the FIT file.
+           Dump the content of the FIT file.
 
 import [ <fit file> | <directory> ]
-          Import the provided FIT file(s) into the postrunner database. If no
-          file or directory is provided, the directory that was used for the
-          previous import is being used.
+           Import the provided FIT file(s) into the postrunner database. If no
+           file or directory is provided, the directory that was used for the
+           previous import is being used.
 
 delete <ref>
-          Delete the activity from the archive.
+           Delete the activity from the archive.
 
 list
-          List all FIT files stored in the data base.
+           List all FIT files stored in the data base.
 
 records
-          List all personal records.
+           List all personal records.
 
 rename <new name> <ref>
-          For the specified activities replace current activity name with a
-          new name that describes the activity. By default the activity name
-          matches the FIT file name.
+           For the specified activities replace current activity name with a
+           new name that describes the activity. By default the activity name
+           matches the FIT file name.
 
 set <attribute> <value> <ref>
-          For the specified activies set the attribute to the given value. The
-          following attributes are supported:
+           For the specified activies set the attribute to the given value. The
+           following attributes are supported:
 
-          name: The activity name (defaults to FIT file name)
-          type: The type of the activity
-          subtype: The subtype of the activity
+           name: The activity name (defaults to FIT file name)
+           type: The type of the activity
+           subtype: The subtype of the activity
 
 show [ <ref> ]
-          Show the referenced FIT activity in a web browser. If no reference
-          is provided show the list of activities in the database.
+           Show the referenced FIT activity in a web browser. If no reference
+           is provided show the list of activities in the database.
 
 summary <ref>
-          Display the summary information for the FIT file.
+           Display the summary information for the FIT file.
 
 units <metric | statute>
-          Change the unit system.
+           Change the unit system.
 
 htmldir <directory>
-          Change the output directory for the generated HTML files
+           Change the output directory for the generated HTML files
+
+update-gps Download the current set of GPS ephemeris data and store them
+           on the device.
 
 
 <fit file> An absolute or relative name of a .FIT file.
@@ -239,6 +243,8 @@ EOT
         change_unit_system(args)
       when 'htmldir'
         change_html_dir(args)
+      when 'update-gps'
+        update_gps_data
       when nil
         Log.fatal("No command provided. " +
                   "See 'postrunner -h' for more information.")
@@ -352,6 +358,36 @@ EOT
       end
     end
 
+    def update_gps_data
+      epo_dir = File.join(@db_dir, 'epo')
+      @cfg.create_directory(epo_dir, 'GPS Data Cache')
+      epo_file = File.join(epo_dir, 'EPO.BIN')
+
+      if !File.exists?(epo_file) ||
+         (File.mtime(epo_file) < Time.now - (24 * 60 * 60))
+        if EPO_Downloader.new.download(epo_file)
+          unless (remotesw_dir = @cfg[:import_dir])
+            Log.error "No device directory set. Please import an activity " +
+                      "from your device first."
+            return
+          end
+          remotesw_dir = File.join(remotesw_dir, '..', 'REMOTESW')
+          unless Dir.exists?(remotesw_dir)
+            Log.error "Cannot find '#{remotesw_dir}'. Please connect and " +
+                      "mount your Garmin device."
+            return
+          end
+          begin
+            FileUtils.cp(epo_file, remotesw_dir)
+          rescue
+            Log.error "Cannot copy EPO.BIN file to your device at " +
+                      "'#{remotesw_dir}'."
+            return
+          end
+        end
+      end
+    end
+
     def handle_version_update
       if @cfg.get_option(:version) != VERSION
         Log.warn "PostRunner version upgrade detected."