Implement SmartSource header parser

lib/www/server/lib/headers/smartsource.js

@@ -1,10 +1,234 @@
 
+const NavHeaderError = require('./error');
+
 function detect (buffer) {
-	return false;
+	const s = buffer.indexOf("*SMSRC");
+	return s != -1 ? s : false;
 }
 
 function parse (buffer) {
-	return; // undefined
+	let offset = buffer.indexOf("*SMSRC");
+
+	if (offset == -1) {
+		return; // undefined
+	}
+
+	function ascii (length, start = offset) {
+// 		const start = offset;
+		const end = start+length;
+		offset = end;
+// 		const v = buffer.subarray(start, end).toString('ascii');
+// 		console.log("s, e", start, end, offset);
+// 		console.log("v = ", v);
+// 		return v;
+		return buffer.subarray(start, end).toString('ascii');
+	}
+
+	const header = {
+		header: (buf, ctx) => {
+			const header = ascii(6);
+			if (header != "*SMSRC") {
+				throw new NavHeaderError("Expected SmartSource marker not found at position " + s, buf);
+			}
+		},
+		
+		blk_siz: (buf, ctx) => {
+			return Number(ascii(4));
+		},
+		
+		line: (buf, ctx) => {
+			return ascii(30).trim();
+		},
+		
+		shot: (buf, ctx) => {
+			return Number(ascii(10));
+		},
+		
+		mask: (buf, ctx) => {
+			return Number(ascii(2));
+		},
+		
+		trg_mode: (buf, ctx) => {
+			const trg_mode = ascii(1);
+			switch (trg_mode) {
+				case "I":
+					return "internal";
+				case "E":
+					return "external";
+				default:
+					throw new NavHeaderError("Unknown SmartSource trigger mode: " + trg_mode, buf);
+			}
+		},
+		
+		time: (buf, ctx) => {
+			const time = ascii(17);
+			'20/08/30:05:45:58'
+			return new Date(time.replace(/(\d{2})\/(\d{2})\/(\d{2}):(\d{2}):(\d{2}):(\d{2})/, "20$1-$2-$3T$4:$5:$6Z"));
+		},
+		
+		src_number: (buf, ctx) => {
+			return Number(ascii(1));
+		},
+		
+		num_subarray: (buf, ctx) => {
+			return Number(ascii(1));
+		},
+		
+		num_guns: (buf, ctx) => {
+			return Number(ascii(2));
+		},
+		
+		num_active: (buf, ctx) => {
+			return Number(ascii(2));
+		},
+		
+		num_delta: (buf, ctx) => {
+			return Number(ascii(2));
+		},
+		
+		num_auto: (buf, ctx) => {
+			return Number(ascii(2));
+		},
+		
+		num_nofire: (buf, ctx) => {
+			return Number(ascii(2));
+		},
+		
+		spread: (buf, ctx) => {
+			// Convert to ms
+			return Number(ascii(4))/10;
+		},
+		
+		volume: (buf, ctx) => {
+			return Number(ascii(6));
+		},
+		
+		avg_delta: (buf, ctx) => {
+			return Number(ascii(5));
+		},
+		
+		std_delta: (buf, ctx) => {
+			return Number(ascii(5));
+		},
+		
+		baroPress: (buf, ctx) => {
+			// Converted to millibars
+			return Number(ascii(6))/100;
+		},
+		
+		manifold: (buf, ctx) => {
+			return Number(ascii(4)); // PSI
+		},
+		
+		spare: (buf, ctx) => {
+			return ascii(88).trim();
+		},
+	};
+	
+	const gun = {
+		string: (buf, ctx) => {
+			return Number(ascii(1));
+		},
+		
+		gun: (buf, ctx) => {
+			return Number(ascii(2));
+		},
+		
+		source: (buf, ctx) => {
+			return Number(ascii(1));
+		},
+
+		mode: (buf, ctx) => {
+			const v = ascii(1);
+			switch (v) {
+				case "A":
+				case "M":
+				case "O":
+				case "D":
+					return v;
+				default:
+					throw new NavHeaderError("Unrecognised SmartSource gun mode value: "+v, buf);
+			}
+		},
+
+		detect: (buf, ctx) => {
+			const v = ascii(1);
+			switch (v) {
+				case "P":
+				case "Z":
+				case "L":
+					return v;
+				default:
+					throw new NavHeaderError("Unrecognised SmartSource detect value: "+v, buf);
+			}
+		},
+
+		autofire: (buf, ctx) => {
+			const v = ascii(1);
+			switch (v) {
+				case "N": return false;
+				case "Y": return true;
+				default:
+					throw new NavHeaderError("Unrecognised SmartSource autofire value: "+v, buf);
+			}
+		},
+
+		spare: (buf, ctx) => {
+			return ascii(1).trim();
+		},
+
+		aimport: (buf, ctx) => {
+			// Convert to ms
+			return Number(ascii(6))/10;
+		},
+
+		firetime: (buf, ctx) => {
+			// Convert to ms
+			return Number(ascii(6))/10;
+		},
+
+		delay: (buf, ctx) => {
+			// Convert to ms
+			return Number(ascii(4))/10;
+		},
+
+		depth: (buf, ctx) => {
+			// Convert to metres
+			return Number(ascii(4))/10;
+		},
+
+		pressure: (buf, ctx) => {
+			return Number(ascii(4));
+		},
+
+		volume: (buf, ctx) => {
+			return Number(ascii(4));
+		},
+
+		filltime: (buf, ctx) => {
+			return Number(ascii(4));
+		}
+	};
+
+
+	const smartsource = {};
+	smartsource._type = "smartsource";
+	smartsource._received = new Date();
+	for (const key of Object.keys(header)) {
+		smartsource[key] = header[key](buffer, smartsource);
+	}
+	
+	smartsource.guns = [];
+	for (let n=0; n<smartsource.num_guns; n++) {
+		const gunItem = {};
+		for (const key of Object.keys(gun)) {
+			gunItem[key] = gun[key](buffer, gunItem);
+		}
+		smartsource.guns.push(gunItem);
+	}
+
+	return smartsource;
+
 }
  
 module.exports = {