Extracts handling the Tag-file structure into an own class.

device/main/CMakeLists.txt

@@ -1,2 +1,2 @@
-idf_component_register(SRCS "Networking.cpp" "main.cpp" "WebInterface.cpp" "RFIDInterface.cpp" "audio_setup.c" "AudioPlayer.cpp" "TagPlayerControl.cpp"
+idf_component_register(SRCS "Networking.cpp" "main.cpp" "WebInterface.cpp" "RFIDInterface.cpp" "audio_setup.c" "AudioPlayer.cpp" "TagPlayerControl.cpp" "Tag.cpp"
     INCLUDE_DIRS ".")

device/main/Tag.cpp

@@ -0,0 +1,186 @@
+#include "Tag.hpp"
+
+#include <iostream>
+#include <fstream>
+#include <string>
+
+#include <cJSON.h>
+
+#define BASE_PATH "/sdcard/internal/";
+
+/**
+ * {
+ * 		tagId : "xa5_x1f_x13_xaa_x00",
+ * 		playlist : [
+ * 			"file://sdcard/music_intro.mp3",
+ * 			"file://sdcard/audiobook_chapter1.mp3",
+ * 			"file://sdcard/audiobook_chapter2.mp3"
+ * 		],
+ * 		currentIndex : 0,
+ * 		currentPosition : 1234 // the position as returned by the player. can be frames, can be ms or anything
+ * }
+ */
+
+Tag::Tag(char* tagId): Tag(std::string(tagId)) {
+
+}
+
+Tag::Tag(std::string tagId): tagId(tagId) {
+	this->playlist = std::vector<std::string>();
+}
+
+std::string Tag::getNextLink() {
+	return this->playlist.at(this->currentFileIndex);
+}
+
+bool Tag::isLinked() {
+	return ! this->playlist.empty();
+}
+
+void Tag::read() {
+	std::string contents;
+
+	try {
+		contents = readFileContents();
+	} catch (std::invalid_argument& e){
+		std::cout << "Execption while reading tag-file: " << e.what() << "\n";
+
+		write();
+		return;
+	}
+
+	cJSON* data = cJSON_Parse(contents.c_str());
+
+	char* tagId = cJSON_GetObjectItem(data, "tagId")->valuestring;
+
+	int currentIndex = cJSON_GetObjectItem(data, "currentIndex")->valueint;
+
+	if (currentIndex < 0) {
+		std::cout << "Bad file index, must be >= 0, was: " << currentIndex << "\n";
+		currentIndex = 0;
+	}
+
+	this->currentFileIndex = currentIndex;
+
+	int currentFilePosition = cJSON_GetObjectItem(data, "currentPosition")->valueint;
+
+	if (currentFilePosition < 0) {
+		std::cout << "Bad file position, must be >= 0, was: " << currentFilePosition << "\n";
+		currentFilePosition = 0;
+	}
+
+	this->currentFilePosition = 0;
+
+	cJSON* playlist = cJSON_GetObjectItem(data, "playlist");
+
+	if (playlist) {
+		int playlistLength = cJSON_GetArraySize(playlist);
+
+		for (int i = 0; i < playlistLength; i++) {
+			cJSON* item = cJSON_GetArrayItem(playlist, i);
+
+			// each item is just an URL
+			this->playlist.push_back(std::string(item->valuestring));
+		}
+	}
+
+	cJSON_Delete(data);
+}
+
+void Tag::write() {
+	std::string contents = createFileContents();
+
+	std::string filePath = getFilePath();
+
+	std::ofstream file(filePath);
+
+	if (! file.is_open()) {
+		std::cout << "Error opening file for tag " << tagId << " before writing";
+
+		char* errorName;
+
+		switch (errno) {
+			case EACCES:
+				errorName = "EACCESS";
+				break;
+			case ENOENT:
+				errorName = "ENOENT";
+				break;
+			default:
+				errorName = "not parsed";
+		}
+
+		std::cout << errorName << "\n";
+	}
+
+	file << contents << std::endl;
+	
+	file.close();
+}
+
+std::string Tag::createFileContents() {
+	cJSON* root = cJSON_CreateObject();
+	cJSON* playlist;
+
+	cJSON_AddStringToObject(root, "tagId", this->tagId.c_str());
+	cJSON_AddNumberToObject(root, "currentIndex", this->currentFileIndex);
+	cJSON_AddNumberToObject(root, "currentPosition", this->currentFilePosition);
+	playlist = cJSON_AddArrayToObject(root, "playlist");
+	
+	for (auto& link: this->playlist) {
+		cJSON_AddItemToArray(playlist, cJSON_CreateString(link.c_str()));
+	}
+
+	char* json = cJSON_Print(root);
+	cJSON_Delete(root); // playlist is also free'd
+
+	std::cout << json << std::endl;
+
+	return std::string(json);
+}
+
+std::string Tag::readFileContents() {
+	std::string filePath = getFilePath();
+
+	std::fstream file(filePath);
+
+	if (! file) {
+		std::cout << "Error opening file for tag " << tagId;
+
+		char* errorName;
+
+		switch (errno) {
+			case EACCES:
+				errorName = "EACCESS";
+				break;
+			case ENOENT:
+				errorName = "ENOENT";
+				break;
+			default:
+				errorName = "not parsed";
+		}
+
+		std::cout << errorName << "\n";
+
+		file.close();
+		throw std::invalid_argument(errorName);
+	}
+
+	std::string line;
+	std::string content;
+
+	while(getline(file, line)) {
+		content.append(line);
+	}
+
+	file.close();
+
+	return content;
+}
+
+std::string Tag::getFilePath() {
+	std::string filePath = BASE_PATH;
+	filePath.append(tagId);
+
+	return filePath;
+}

device/main/Tag.hpp

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+class Tag {
+	private:
+		std::string tagId{""};
+		std::vector<std::string> playlist;
+		uint32_t currentFileIndex{0};
+		uint32_t currentFilePosition{0};
+
+	public:
+		Tag(std::string tagId);
+		Tag(char* tagId);
+		void read();
+		void write();
+		bool isLinked();
+		std::string getNextLink();
+
+	private:
+		std::string createFileContents();
+		std::string readFileContents();
+		std::string getFilePath();
+};

device/main/TagPlayerControl.cpp

@@ -1,6 +1,7 @@
 #include "TagPlayerControl.hpp"
 
 #include "AudioPlayer.hpp"
+#include "Tag.hpp"
 
 #include <iostream>
 #include <fstream>
@@ -25,38 +26,10 @@ void TagPlayerControl::onTagChanged(char* tagId) {
 }
 
 void TagPlayerControl::playTag(char* tagId) {
-	std::string filePath = "/sdcard/internal/";
+	Tag tag(tagId);
-	filePath.append(tagId);
+	tag.read();
 
-	std::fstream file(filePath);
+	if (tag.isLinked()) {
-
+		audioPlayer->play(tag.getNextLink());
-	if (! file) {
-		ESP_LOGE(TAG, "Error opening file for tag %s", tagId);
-
-		char* error_name;
-
-		switch (errno)
-		{
-			case EACCES:
-				ESP_LOGE(TAG, "EACCESS");
-				break;
-			case ENOENT:
-				ESP_LOGE(TAG, "ENOENT");
-				break;
-			default:
-				ESP_LOGE(TAG, "not parsed");
-		}
-		return;
 	}
-
-	std::string line;
-	std::string content;
-
-	while(getline(file, line)) {
-		content.append(line);
-	}
-
-	audioPlayer->play(content);
-
-	file.close();
 }