feat(metadata): implement MetadataRequest and supporting classes for file metadata extraction and response formatting

scripts/API/actions/metadata.js

@@ -0,0 +1,24 @@
+const CustomErrors = require(`../../utilities/errors`);
+const Messaging = require(`../../utilities/messaging`);
+
+const MetadataExtractor = require(`../../file-management/analyze`);
+const Cleaner = require(`../response/simple-data`);
+
+const MetadataRequest = class Request {
+	static analyze (REQUEST, RESPONSE) {
+		// Check if the file is valid.
+		if (REQUEST.file) {
+			// Get the file information.
+			const fileInfo = new MetadataExtractor(REQUEST.file).extract([ `originalname`, `mimetype`, `size`]);
+			
+			const cleanedData = (new Cleaner(fileInfo)).format();
+			RESPONSE.status(200).json(cleanedData);
+		} else {
+			// If the file is not valid, return an error.
+			const ERROR = new CustomErrors.Data.Missing(REQUEST.file);
+			Messaging.exception(RESPONSE, ERROR);
+		};
+	};
+}
+
+module.exports = MetadataRequest;

scripts/API/response/parser.js

@@ -0,0 +1,49 @@
+/* 
+	Modify data returned by "middle-man" scripts. 
+*/
+const Parser = class {
+	constructor(DATA = {}, MAPPINGS = {}) {
+		this.data = DATA;
+		this.mappings = MAPPINGS;
+	}
+
+	/*
+		Modify the data for output. 
+
+		@return {Object} cleaned data
+	*/
+	format () {
+		let ENTRIES;
+		/* 
+			Map certain new keys to their original counterparts. 
+		*/
+		function mapKeys (ORIGINAL = {}, MAPPINGS) {
+			let RESULT = {};
+			
+			Object.entries(MAPPINGS).forEach(([NEW, OLD]) => {
+				RESULT[NEW] = (ORIGINAL[OLD] != null ? (typeof ORIGINAL[OLD]).includes(`str`) : false) ? ORIGINAL[OLD].trim() : ORIGINAL[OLD];
+			});
+			
+			return RESULT;
+		}
+		
+		if (this.data instanceof Array) {
+			ENTRIES = [];
+	
+			(this.data.length) ? this.data.forEach((SELECTED) => {
+				if (SELECTED) {
+					let CLEANED = mapKeys(SELECTED, this.mappings);
+					(Object.keys(CLEANED).length) ? ENTRIES.push(CLEANED) : false;
+				};
+			}) : false;
+		} else if (this.data && this.data instanceof Object) {
+			ENTRIES = mapKeys(this.data, this.mappings);
+		};
+
+		this.cleaned = ENTRIES;
+		return (this.cleaned);
+	}
+
+}
+
+module.exports = Parser;

scripts/API/response/simple-data.js

@@ -0,0 +1,18 @@
+const Parser = require(`./parser`);
+
+class SimpleMetadata extends Parser {
+	/*
+		Clean the log information. 
+	
+		@param {Object} ENTRY the selected entry, or the entries
+	*/
+	constructor(ENTRY) {
+		super(ENTRY, {
+			"name": "originalname",
+			"type": "mimetype",
+			"size": "size"
+		});
+	};
+}
+
+module.exports = SimpleMetadata;

scripts/file-management/analyze.js

@@ -0,0 +1,35 @@
+const MetadataExtractor = class {
+	/* 
+	 * MetadataExtractor class
+	 * This class is used to extract metadata from a BLOB object.
+	*/
+	constructor(BLOB) {
+		this.blob = BLOB;
+
+		this.extract([`fieldname`, `encoding`, `originalname`, `mimetype`, `size`]);
+	}
+
+	/* 
+	 * Extract data from the blob. 
+	*/
+	extract(FIELDS) {
+		// Verify the validity of the blob.
+		if (!this.blob) {
+			throw new Error("Invalid BLOB object");
+		};
+
+		// Extract the relevant fields. 
+		let RESPONSE = {};
+		FIELDS.forEach((FIELD) => {
+			if (!(this.blob[FIELD] === undefined)) {
+				this[FIELD] = this.blob[FIELD];
+				RESPONSE[FIELD] = this.blob[FIELD];
+			}
+		});
+
+		// Return the response.
+		return (RESPONSE);
+	}
+}
+
+module.exports = MetadataExtractor;