esmp3/src/playlist_manager.cpp

#include "playlist_manager.h"
#include "spi_master.h"
#include <SD.h>

PlaylistManager::PlaylistManager() {
	SPIMaster::enable_sd();
	current_rfid_tag_id = String("");

	if (!SD.exists("/_mapping.txt")) {
		Serial.println("WARNING: /_mapping.txt not found!");
	} else {
		map.clear();
		File f = SD.open("/_mapping.txt");
		Serial.println("  Reading /_mapping.txt...");
		while (f.available()) {
			char buffer[512];
			size_t pos = f.readBytesUntil('\n', buffer, 511);
			buffer[pos] = '\0';

			String data = buffer;
			uint8_t eq = data.indexOf('=');
			if (eq>0 && eq<data.length()-1) {
				String rfid_id = data.substring(0, eq);
				String folder = data.substring(eq + 1);
				Serial.printf("  Adding mapping: %s=>%s\n", rfid_id.c_str(), folder.c_str());
				map[rfid_id] = folder;
			}
		}
		f.close();
	}
}

Playlist PlaylistManager::get_playlist(String rfid_id) {
	if (rfid_id.equals(current_rfid_tag_id)) {
		return current_playlist;
	} else {
		if (map.count(rfid_id)==0) {
			Serial.printf("No known playlist for id %s.\n", rfid_id);
			return current_playlist;
		} else {
			current_playlist = Playlist(rfid_id);
			String path = map[rfid_id];
			if (path.startsWith("/")) {
				File dir = SD.open(path);
				while(File entry = dir.openNextFile()) {
					String filename = entry.name();
					String ext = filename.substring(filename.length()-4);
					if (!entry.isDirectory() &&
						!filename.startsWith(".") &&
						ext.equals(".mp3")) {
						Serial.printf("Adding %s to the list of files\n", (path + "/" + filename).c_str());
						current_playlist.add_file(path + "/" + filename);
					}
					entry.close();
				}
				dir.close();
			}
			current_playlist.sort();
			current_rfid_tag_id = rfid_id;
			return current_playlist;
		}
	}
}

void PlaylistManager::set_audio_current_time(uint32_t time) {
	audio_current_time = time;
}

bool PlaylistManager::has_playlist(String rfid_id) {
	return map.count(rfid_id) == 1;
}