#include <ESPAsyncWebServer.h>
#include <FS.h>

#define FLASH_TEXT(name)   const char *name

namespace webdav_constants {
    FLASH_TEXT(MULTISTATUS_START) = "<?xml version=\"1.0\" ?><D:multistatus xmlns:D=\"DAV:\">";
    FLASH_TEXT(MULTISTATUS_END) = "</D:multistatus>";
    FLASH_TEXT(RESPONSE_START) = "<D:response>";
    FLASH_TEXT(RESPONSE_END) = "</D:response>";
    FLASH_TEXT(HREF_START) = "<D:href>";
    FLASH_TEXT(HREF_END) = "</D:href>";
    FLASH_TEXT(PROPSTAT_START) = "<D:propstat>";
    FLASH_TEXT(PROPSTAT_END) = "</D:propstat>";
    FLASH_TEXT(PROP_START) = "<D:prop>";
    FLASH_TEXT(PROP_END) = "</D:prop>";
    FLASH_TEXT(RESOURCETYPE_START) = "<D:resourcetype>";
    FLASH_TEXT(RESOURCETYPE_END) = "</D:resourcetype>";
    FLASH_TEXT(RESOURCE_COLLECTION) = "<D:collection/>";
    FLASH_TEXT(HTTP_204_NO_CONTENT) = "HTTP/1.1 204 No Content";

    FLASH_TEXT(CONTENTLEN_START) = "<D:getcontentlength>";
    FLASH_TEXT(CONTENTLEN_END) = "</D:getcontentlength>";
    FLASH_TEXT(CREATEDATE_START) = "<D:creationdate>";
    FLASH_TEXT(CREATEDATE_END) = "</D:creationdate>";
    FLASH_TEXT(MODDATE_START) = "<D:getlastmodified>";
    FLASH_TEXT(MODDATE_END) = "</D:getlastmodified>";
    FLASH_TEXT(STATUS_OK) = "<D:status>HTTP/1.1 200 OK</D:status>";
}

void listFiles(AsyncResponseStream * response, const char *folderPath, Dir * dir)
{
    using namespace webdav_constants;
    response->println(MULTISTATUS_START);
    Serial.println("Before rewind");
    dir->rewind();
    Serial.println("After rewind");
    while (dir->next()) {
        Serial.println("Inside dir loop");
        Serial.println(folderPath);
        Serial.println(dir->fileName());

        response->print(RESPONSE_START);
        response->print(HREF_START);
        response->print(folderPath);
        response->print(dir->fileName());
        response->print(HREF_END);
        response->print(PROPSTAT_START);
        response->print(PROP_START);
        if (dir->isDirectory()) {
            response->print(RESOURCETYPE_START);
            response->print(RESOURCE_COLLECTION);
            response->print(RESOURCETYPE_END);
        } else {
            response->print(CONTENTLEN_START);
            response->print(dir->fileSize(), DEC);
            response->print(CONTENTLEN_END);
        }

        response->print(PROP_END);
        response->print(STATUS_OK);
        response->print(PROPSTAT_END);
        response->println(webdav_constants::RESPONSE_END);
    }
    response->println(MULTISTATUS_END);
}


class SpiffsWebDavHandler : public AsyncWebHandler
{
public:
    SpiffsWebDavHandler(const String & prefix, const String & folder)
        : prefix_(prefix), folder_(folder)
    {}

    virtual bool canHandle(AsyncWebServerRequest *request) override final
    {
        Serial.print("Can handle for url : ");
        Serial.println(request->url());
        return request->url().startsWith(prefix_);
    }

    virtual void handleRequest(AsyncWebServerRequest *request) override final
    {
        if (request->url() == prefix_ + "/" && request->method() == HTTP_PROPFIND) {
            Serial.println("Propfind start");
            AsyncResponseStream * response = request->beginResponseStream("application/xml");
            Dir dir = SPIFFS.openDir(folder_);
            listFiles(response, "/", &dir);
            request->send(response);
        } else if(request->url() == prefix_ + "/" && request->method() == HTTP_GET) {
            AsyncResponseStream * response = request->beginResponseStream("text/plain", 1460*10);
            Dir dir = SPIFFS.openDir(folder_);
            Serial.print("Opening folder ");
            Serial.println(folder_);
            while (dir.next()) {
                Serial.print("  File: ");
                Serial.println(dir.fileName());
                response->println(dir.fileName());
            }
            request->send(response);
        }
        else if (request->method() == HTTP_GET) {
            auto path = folder_ + request->url().substring(prefix_.length());
            if (SPIFFS.exists(path)) {
                request->send(SPIFFS, path, "application/x-msgpack");
            } else {
                request->send(404, "text/plain", "Webdav: File not found");
            }
        } else if (request->method() == HTTP_DELETE) {
            auto path = folder_ + request->url().substring(prefix_.length());
            if (SPIFFS.exists(path)) {
                if(SPIFFS.remove(path))
                    request->send(204, "text/plain", "Success");
                else
                    request->send(404, "text/plain", "Webdav: Invalid delete request");
            } else {
                request->send(404, "text/plain", "Webdav: File to delete not found");
            }
        } else {
            request->send(404, "text/plain", "Webdav: Invalid request");
        }
    }
    virtual bool isRequestHandlerTrivial() override final {return false;}

private:
    String prefix_;
    String folder_;
};