main.cpp

00001 #include "mbed.h"
00002 #include "MSCFileSystem.h"
00003 #include "EthernetInterface.h"
00004 #include "HTTPClient.h"
00005 #include "HTTPFile.h"
00006 #include "BlinkLed.h"
00007 #include "tinyxml2.h"
00008 
00009 using namespace tinyxml2;
00010 
00011 int GetFile(const char *path, const char *url);
00012 
00013 EthernetInterface eth;
00014 HTTPClient http;
00015 MSCFileSystem usb("usb");
00016 BlinkLed led3(LED3, 0.02);
00017 BlinkLed led4(LED4, 0.2);
00018 BlinkLed ethGreen(p26, 0.02);
00019 BlinkLed ethYellow(p25, 0.2);
00020 DigitalOut fsusb30s(p9);
00021 
00022 const char* rssUrl = "http://www3.nhk.or.jp/rj/podcast/rss/english.xml";
00023 const char* rssPath = "/usb/english.xml";
00024 const char* mp3Path = "/usb/english.mp3";
00025 
00026 int main()
00027 {
00028     printf("\n\n================================\n");
00029     printf("mpod NHK English news Downloader\n");
00030     printf("================================\n\n");
00031     
00032     // Indicate downloading
00033     led4.startBlink();
00034     ethYellow.startBlink();
00035     
00036     // FSUSB30 switches to HSD1 (mbed)
00037     printf("USB host was switched to HSD1(mbed).\n\n");
00038     fsusb30s = 0; // HSD1
00039     
00040     // Network setup
00041     printf("Setup EtherNet with DHCP.\n");
00042     eth.init(); //Use DHCP
00043     eth.connect();
00044     
00045     // Obtain original lastBuildDate
00046     char lastBuildDateOriginal[128] = {0};
00047     {
00048         XMLDocument docOriginal;
00049         if(XML_SUCCESS != docOriginal.LoadFile(rssPath))
00050         {
00051             strcpy(lastBuildDateOriginal, "No original english.xml in USB memory");
00052         }
00053         else
00054         {
00055             XMLElement* lastBuildDateOriginalElement = docOriginal.FirstChildElement("rss")->FirstChildElement("channel")->FirstChildElement("lastBuildDate");
00056             if(NULL == lastBuildDateOriginalElement)
00057             {
00058                 strcpy(lastBuildDateOriginal, "No \"lastBuildDate\" element in original RSS");
00059             }
00060             else
00061             {
00062                 strcpy(lastBuildDateOriginal, lastBuildDateOriginalElement->GetText());
00063             }
00064         }
00065     }
00066     printf("\nlastBuildDate (original): %s\n", lastBuildDateOriginal);
00067     
00068     // Download RSS
00069     GetFile(rssPath, rssUrl);
00070     
00071     // Obtain current lastBuildDate 
00072     char lastBuildDateCurrent[128] = {0};
00073     char mp3Url[256] = {0};
00074     char mp3Length[32] = {0};
00075     {
00076         XMLDocument docCurrent;
00077         if(XML_SUCCESS != docCurrent.LoadFile(rssPath))
00078         {
00079             fsusb30s = 1; // HSD2
00080             error("No current english.xml in USB memory.\n");
00081         }
00082         
00083         XMLElement* lastBuildDateCurrentElement = docCurrent.FirstChildElement("rss")->FirstChildElement("channel")->FirstChildElement("lastBuildDate");
00084         if(NULL == lastBuildDateCurrentElement)
00085         {
00086             fsusb30s = 1; // HSD2
00087             error("No \"lastBuildDate\" element in current RSS.\n");
00088         }
00089         strcpy(lastBuildDateCurrent, lastBuildDateCurrentElement->GetText());
00090         
00091         XMLElement* enclosureElement = docCurrent.FirstChildElement("rss")->FirstChildElement("channel")->FirstChildElement("item")->FirstChildElement("enclosure");
00092         if(NULL == enclosureElement)
00093         {
00094             fsusb30s = 1; // HSD2
00095             error("No \"enclosure\" element in current RSS.\n");
00096         }
00097         strcpy(mp3Url, enclosureElement->Attribute("url"));
00098         strcpy(mp3Length, enclosureElement->Attribute("length"));
00099     }
00100     printf("\nlastBuildDate (current) : %s\n", lastBuildDateCurrent);
00101     
00102     // Determine the necessity of downloading new MP3.
00103     bool flgDownloadMp3 = false;
00104     if ( strcmp(lastBuildDateOriginal, lastBuildDateCurrent) == 0 )
00105     {
00106         printf("lastBuildDate (original) == lastBuildDate (current)\n");
00107         FILE* mp3fp = fopen(mp3Path, "r"); // check an existance of english.mp3
00108         if (mp3fp != NULL)
00109         {
00110             fseek(mp3fp, 0, SEEK_END); // seek to end of file
00111             if (ftell(mp3fp) != atol(mp3Length))
00112             {
00113                 printf("MP3 file size is invalid.\n");
00114                 flgDownloadMp3 = true;
00115             }
00116             fclose(mp3fp);
00117         }
00118         else
00119         {
00120             printf("However, no enlish.mp3 in USB memory\n");
00121             flgDownloadMp3 = true;
00122         }
00123     }
00124     else
00125     {
00126         printf("lastBuildDate (original) != lastBuildDate (current)\n");
00127         flgDownloadMp3 = true;
00128     }
00129     
00130     // Download new MP3
00131     if(flgDownloadMp3 == true)
00132     {
00133         GetFile(mp3Path, mp3Url);
00134     }
00135     
00136     // Wait for the completion of writing to USB Mass Storage Device.
00137     wait(1);
00138     
00139     // FSUSB30 switches to HSD2 (External Device)
00140     printf("\nUSB host was switched to HSD2(External Device).\n");
00141     fsusb30s = 1; // HSD2
00142 
00143     // Indicate finish downloading
00144     led4.finishBlink();
00145     ethYellow.finishBlink();
00146     led3.startBlink();
00147     ethGreen.startBlink();
00148     
00149     while(true){}
00150 }
00151 
00152 int GetFile(const char *path, const char *url)
00153 {
00154     printf("Getting %s -> %s\n", url, path);
00155     
00156     HTTPFile file(path);
00157     HTTPResult retGet = http.get(url, &file);
00158     if (retGet != HTTP_OK)
00159     {
00160         fsusb30s = 1; // HSD2
00161         error("Error in http.get in GetFile(): %d\n", retGet);
00162     }
00163     file.clear();
00164     
00165     return (0);
00166 }