From f18527a25a45789fa154cf71e738a1a0ce6a017f Mon Sep 17 00:00:00 2001
From: Atharva Sawant <git@atharva.is>
Date: Sat, 2 Nov 2024 19:23:16 +0530
Subject: [PATCH] Implemented GPX file parsing with track statistics - Using
 gpx-parser-builder for parsing GPX files - Calculating some preliminary
 statistics - Some error handling

---
 .gitignore                   |   5 +-
 src/App.vue                  |  28 +++++-
 src/composables/useTracks.js |  71 ++++++++++++++
 src/utils/gpxParser.js       | 174 +++++++++++++++++++++++++++++++++++
 4 files changed, 273 insertions(+), 5 deletions(-)
 create mode 100644 src/composables/useTracks.js
 create mode 100644 src/utils/gpxParser.js

diff --git a/.gitignore b/.gitignore
index 54f07af..bdd538f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,4 +21,7 @@ dist-ssr
 *.ntvs*
 *.njsproj
 *.sln
-*.sw?
\ No newline at end of file
+*.sw?
+
+# Data used for testing
+test-files
diff --git a/src/App.vue b/src/App.vue
index 5dd2278..b63b4fb 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -19,8 +19,10 @@
 </template>
 
 <script>
+import { ref } from 'vue'
 import MapView from './components/MapView.vue'
 import FileUpload from './components/FileUpload.vue'
+import { useTracks } from './composables/useTracks.js'
 
 export default {
   name: 'App',
@@ -28,10 +30,28 @@ export default {
     MapView,
     FileUpload
   },
-  methods: {
-    handleFilesUploaded(files) {
-      console.log('Files uploaded:', files)
-      // TODO: Parse GPX files and display on map
+  setup() {
+    const { tracks, addTracks, totalStats } = useTracks()
+    const isLoading = ref(false)
+    
+    const handleFilesUploaded = async (files) => {
+      isLoading.value = true
+      try {
+        const newTracks = await addTracks(files)
+        console.log('Parsed tracks:', newTracks)
+        console.log('Total stats:', totalStats.value)
+      } catch (error) {
+        console.error('Error processing files:', error)
+      } finally {
+        isLoading.value = false
+      }
+    }
+    
+    return {
+      tracks,
+      totalStats,
+      isLoading,
+      handleFilesUploaded
     }
   }
 }
diff --git a/src/composables/useTracks.js b/src/composables/useTracks.js
new file mode 100644
index 0000000..17fb39e
--- /dev/null
+++ b/src/composables/useTracks.js
@@ -0,0 +1,71 @@
+import { ref, computed } from 'vue'
+import { parseGPXFile } from '../utils/gpxParser.js'
+
+const tracks = ref([])
+
+export const useTracks = () => {
+  const addTracks = async (files) => {
+    const newTracks = []
+    
+    for (const file of files) {
+      try {
+        const parsedTracks = await parseGPXFile(file)
+        newTracks.push(...parsedTracks)
+      } catch (error) {
+        console.error(`Error parsing ${file.name}:`, error)
+      }
+    }
+    
+    tracks.value.push(...newTracks)
+    return newTracks
+  }
+  
+  const removeTracks = (trackIndices) => {
+    trackIndices.sort((a, b) => b - a) // Sort descending to remove from end first
+    trackIndices.forEach(index => {
+      tracks.value.splice(index, 1)
+    })
+  }
+  
+  const clearAllTracks = () => {
+    tracks.value = []
+  }
+  
+  const totalStats = computed(() => {
+    if (tracks.value.length === 0) {
+      return {
+        totalTracks: 0,
+        totalDistance: 0,
+        totalDuration: 0,
+        totalElevationGain: 0,
+        avgSpeed: 0
+      }
+    }
+    
+    const totals = tracks.value.reduce((acc, track) => {
+      if (track.stats) {
+        acc.distance += track.stats.distance || 0
+        acc.duration += track.stats.duration || 0
+        acc.elevationGain += track.stats.elevationGain || 0
+      }
+      return acc
+    }, { distance: 0, duration: 0, elevationGain: 0 })
+    
+    return {
+      totalTracks: tracks.value.length,
+      totalDistance: Math.round(totals.distance / 1000 * 10) / 10, // km
+      totalDuration: Math.round(totals.duration / 3600 * 10) / 10, // hours
+      totalElevationGain: Math.round(totals.elevationGain), // meters
+      avgSpeed: totals.duration > 0 ? 
+        Math.round((totals.distance / totals.duration) * 3.6 * 10) / 10 : 0 // km/h
+    }
+  })
+  
+  return {
+    tracks: tracks.value,
+    addTracks,
+    removeTracks,
+    clearAllTracks,
+    totalStats
+  }
+}
\ No newline at end of file
diff --git a/src/utils/gpxParser.js b/src/utils/gpxParser.js
new file mode 100644
index 0000000..a452ef6
--- /dev/null
+++ b/src/utils/gpxParser.js
@@ -0,0 +1,174 @@
+import gpxParserBuilder from 'gpx-parser-builder'
+
+export const parseGPXFile = async (file) => {
+  return new Promise((resolve, reject) => {
+    const reader = new FileReader()
+    
+    reader.onload = (e) => {
+      try {
+        const gpxContent = e.target.result
+        const gpx = gpxParserBuilder.parse(gpxContent)
+        
+        console.log('Parsed GPX structure:', gpx)
+        
+        // Extract track data - handle both tracks and routes
+        let tracks = []
+        
+        // Handle tracks (trk property)
+        if (gpx.trk && Array.isArray(gpx.trk)) {
+          tracks = gpx.trk.map(track => {
+            const segments = track.trkseg?.map(segment => {
+              const points = segment.trkpt?.map(point => ({
+                lat: parseFloat(point.$.lat),
+                lng: parseFloat(point.$.lon),
+                elevation: point.ele ? parseFloat(point.ele[0]) : null,
+                time: point.time ? point.time[0] : null
+              })) || []
+              return { points }
+            }) || []
+            
+            return {
+              name: track.name?.[0] || file.name,
+              segments,
+              metadata: {
+                fileName: file.name,
+                fileSize: file.size,
+                uploadDate: new Date().toISOString()
+              }
+            }
+          })
+        }
+        
+        // Handle routes if no tracks (rte property)
+        if (tracks.length === 0 && gpx.rte && Array.isArray(gpx.rte)) {
+          tracks = gpx.rte.map(route => {
+            const points = route.rtept?.map(point => ({
+              lat: parseFloat(point.$.lat),
+              lng: parseFloat(point.$.lon),
+              elevation: point.ele ? parseFloat(point.ele[0]) : null,
+              time: point.time ? point.time[0] : null
+            })) || []
+            
+            return {
+              name: route.name?.[0] || file.name,
+              segments: [{ points }],
+              metadata: {
+                fileName: file.name,
+                fileSize: file.size,
+                uploadDate: new Date().toISOString()
+              }
+            }
+          })
+        }
+        
+        // Handle waypoints if no tracks or routes (wpt property)
+        if (tracks.length === 0 && gpx.wpt && Array.isArray(gpx.wpt)) {
+          const points = gpx.wpt.map(waypoint => ({
+            lat: parseFloat(waypoint.$.lat),
+            lng: parseFloat(waypoint.$.lon),
+            elevation: waypoint.ele ? parseFloat(waypoint.ele[0]) : null,
+            time: waypoint.time ? waypoint.time[0] : null
+          }))
+          
+          tracks = [{
+            name: gpx.metadata?.name?.[0] || file.name,
+            segments: [{ points }],
+            metadata: {
+              fileName: file.name,
+              fileSize: file.size,
+              uploadDate: new Date().toISOString()
+            }
+          }]
+        }
+        
+        // Calculate track statistics
+        const processedTracks = tracks.map(track => {
+          const stats = calculateTrackStats(track)
+          return { ...track, stats }
+        })
+        
+        resolve(processedTracks)
+      } catch (error) {
+        reject(new Error(`Failed to parse GPX file: ${error.message}`))
+      }
+    }
+    
+    reader.onerror = () => {
+      reject(new Error('Failed to read file'))
+    }
+    
+    reader.readAsText(file)
+  })
+}
+
+const calculateTrackStats = (track) => {
+  if (!track.segments || track.segments.length === 0) {
+    return {
+      distance: 0,
+      duration: 0,
+      avgSpeed: 0,
+      elevationGain: 0,
+      startTime: null,
+      endTime: null
+    }
+  }
+  
+  let totalDistance = 0
+  let totalElevationGain = 0
+  let startTime = null
+  let endTime = null
+  let prevPoint = null
+  
+  track.segments.forEach(segment => {
+    segment.points.forEach(point => {
+      // Track time bounds
+      if (point.time) {
+        const pointTime = new Date(point.time)
+        if (!startTime || pointTime < startTime) startTime = pointTime
+        if (!endTime || pointTime > endTime) endTime = pointTime
+      }
+      
+      // Calculate distance and elevation
+      if (prevPoint) {
+        totalDistance += calculateDistance(prevPoint, point)
+        
+        if (point.elevation && prevPoint.elevation) {
+          const elevDiff = point.elevation - prevPoint.elevation
+          if (elevDiff > 0) totalElevationGain += elevDiff
+        }
+      }
+      
+      prevPoint = point
+    })
+  })
+  
+  const duration = startTime && endTime ? 
+    (endTime.getTime() - startTime.getTime()) / 1000 : 0 // seconds
+  
+  const avgSpeed = duration > 0 ? (totalDistance / duration) * 3.6 : 0 // km/h
+  
+  return {
+    distance: Math.round(totalDistance), // meters
+    duration: Math.round(duration), // seconds
+    avgSpeed: Math.round(avgSpeed * 10) / 10, // km/h
+    elevationGain: Math.round(totalElevationGain), // meters
+    startTime: startTime ? startTime.toISOString() : null,
+    endTime: endTime ? endTime.toISOString() : null
+  }
+}
+
+// Haversine formula for distance between two points
+const calculateDistance = (point1, point2) => {
+  const R = 6371e3 // Earth's radius in meters
+  const φ1 = point1.lat * Math.PI / 180
+  const φ2 = point2.lat * Math.PI / 180
+  const Δφ = (point2.lat - point1.lat) * Math.PI / 180
+  const Δλ = (point2.lng - point1.lng) * Math.PI / 180
+
+  const a = Math.sin(Δφ/2) * Math.sin(Δφ/2) +
+          Math.cos(φ1) * Math.cos(φ2) *
+          Math.sin(Δλ/2) * Math.sin(Δλ/2)
+  const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a))
+
+  return R * c
+}
\ No newline at end of file