From dc508c30f93d7271955274d97157f5713e95ac0f Mon Sep 17 00:00:00 2001
From: Jef Driesen <jef@libdivecomputer.org>
Date: Thu, 22 Aug 2019 21:18:48 +0200
Subject: [PATCH] Add support for multiple tank transmitters

The Ratio dive computers support up to 10 tank pressure sensors. The ID
of the active tank sensor is stored in the sample data, and gets mapped
to the corresponding tank index.
---
 src/divesystem_idive_parser.c | 42 +++++++++++++++++++++++++++++------
 1 file changed, 35 insertions(+), 7 deletions(-)

diff --git a/src/divesystem_idive_parser.c b/src/divesystem_idive_parser.c
index ec3399a..bba5d51 100644
--- a/src/divesystem_idive_parser.c
+++ b/src/divesystem_idive_parser.c
@@ -39,7 +39,7 @@
 #define SZ_SAMPLE_IX3M_APOS4 0x40
 
 #define NGASMIXES 8
-#define NTANKS    1
+#define NTANKS    10
 
 #define EPOCH 1199145600 /* 2008-01-01 00:00:00 */
 
@@ -58,6 +58,7 @@ typedef struct divesystem_idive_gasmix_t {
 } divesystem_idive_gasmix_t;
 
 typedef struct divesystem_idive_tank_t {
+	unsigned int id;
 	unsigned int beginpressure;
 	unsigned int endpressure;
 } divesystem_idive_tank_t;
@@ -126,6 +127,7 @@ divesystem_idive_parser_create (dc_parser_t **out, dc_context_t *context, unsign
 		parser->gasmix[i].helium = 0;
 	}
 	for (unsigned int i = 0; i < NTANKS; ++i) {
+		parser->tank[i].id = 0;
 		parser->tank[i].beginpressure = 0;
 		parser->tank[i].endpressure = 0;
 	}
@@ -153,6 +155,7 @@ divesystem_idive_parser_set_data (dc_parser_t *abstract, const unsigned char *da
 		parser->gasmix[i].helium = 0;
 	}
 	for (unsigned int i = 0; i < NTANKS; ++i) {
+		parser->tank[i].id = 0;
 		parser->tank[i].beginpressure = 0;
 		parser->tank[i].endpressure = 0;
 	}
@@ -368,6 +371,8 @@ divesystem_idive_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callba
 	unsigned int he_previous = 0xFFFFFFFF;
 	unsigned int mode_previous = INVALID;
 	unsigned int divemode = INVALID;
+	unsigned int tank_previous = INVALID;
+	unsigned int tank_idx = INVALID;
 
 	unsigned int firmware = 0;
 	unsigned int apos4 = 0;
@@ -502,16 +507,39 @@ divesystem_idive_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callba
 
 		// Tank Pressure
 		if (samplesize == SZ_SAMPLE_IX3M_APOS4) {
+			unsigned int id = data[offset + 47] & 0x0F;
 			unsigned int pressure = data[offset + 49];
-			if (tank[0].beginpressure == 0 && pressure != 0) {
-				tank[0].beginpressure = pressure;
-				ntanks = 1;
+
+			// Get the index of the tank.
+			if (id != tank_previous) {
+				unsigned int i = 0;
+				while (i < ntanks) {
+					if (id == tank[i].id)
+						break;
+					i++;
+				}
+
+				tank_previous = id;
+				tank_idx = i;
 			}
-			if (tank[0].beginpressure) {
-				sample.pressure.tank = 0;
+
+			// Add a new tank if necessary.
+			if (tank_idx >= ntanks && pressure != 0) {
+				if (tank_idx >= NTANKS) {
+					ERROR (abstract->context, "Maximum number of tanks reached.");
+					return DC_STATUS_DATAFORMAT;
+				}
+				tank[tank_idx].id = id;
+				tank[tank_idx].beginpressure = pressure;
+				tank[tank_idx].endpressure = pressure;
+				ntanks = tank_idx + 1;
+			}
+
+			if (tank_idx < ntanks) {
+				sample.pressure.tank = tank_idx;
 				sample.pressure.value = pressure;
 				if (callback) callback (DC_SAMPLE_PRESSURE, sample, userdata);
-				tank[0].endpressure = pressure;
+				tank[tank_idx].endpressure = pressure;
 			}
 		}