feature: add conversion for tank level and capacity (#11)

conversions/tanks.js

@@ -0,0 +1,85 @@
+const _ = require('lodash')
+
+module.exports = (app, plugin) => {
+
+  const typeMapping = {
+    'fuel': 'Fuel',
+    'blackWater': 'Black water',
+    'freshWater': 'Water',
+    'wasteWater': 'Gray water',
+    'liveWell': 'Live well',
+    'lubrication': 'Oil',
+    'gas': 'Fuel'
+  }
+
+  return {
+    title: 'Tank Levels (127505)',
+    optionKey: 'TANKS',
+    context: 'vessels.self',
+    properties: () => {
+      var tanks = _.get(app.signalk.self, 'tanks')
+      var tankPaths = []
+      if ( !_.isUndefined(tanks) ) {
+        _.keys(tanks).forEach(type => {
+          _.keys(tanks[type]).forEach(instance => {
+            tankPaths.push(`tanks.${type}.${instance}`)
+          })
+        })
+      }
+
+      return {
+        tanks: {
+          title: 'Tank Mapping',
+          type: 'array',
+          items: {
+            type: 'object',
+            properties: {
+              signalkPath: {
+                title: 'Tank Path',
+                type: 'string',
+                enum: tankPaths
+              },
+              instanceId: {
+                title: 'NMEA2000 Tanks Instance Id',
+                type: 'number'
+              }
+            }
+          }
+        }
+      }
+    },
+
+    conversions: (options) => {
+      if ( !_.get(options, 'TANKS.tanks') ) {
+        return null
+      }
+      return options.TANKS.tanks.map(tank => {
+        var split = tank.signalkPath.split('.')
+        var type = typeMapping[split[1]]
+        if ( !_.isUndefined(type) ) {
+          return {
+            keys: [`${tank.signalkPath}.currentLevel`, `${tank.signalkPath}.capacity`],
+            timeouts: [60000, 60000],
+            callback: (currentLevel, capacity) => {
+              var res = []
+              if ( currentLevel != null || capacity != null ) {
+
+                res.push({
+                  pgn: 127505,
+                  "Instance": tank.instanceId,
+                  Type: type,
+                  Level: currentLevel * 100,
+                  Capacity: capacity
+                })
+              }
+
+              return res
+            }
+          }
+        }
+      })
+    }
+  }
+}
+
+