#!/usr/bin/env bash
#
# Author: Pham
#
# This script accepts a single GPX file as parameter and
# output the processed GPX body to STDOUT, using Mapbox Map Matching API v4.
# read doc at: https://docs.mapbox.com/api/legacy/map-matching-v4/
#
# Example:
#
# match-road.sh raw.gpx > new.gpx
#
# Hint:
#
# Remember to put Mapbox Access Token at the top!

#set -x
set -e

# put yout Mapbox token here
ACCESS_TOKEN=$(cat ~/settings/tokens/mapbox)
# number of coordinates for each Mapbox Map Matching API request, Maximum value is 100
LIMIT=100
# define the lowest confidence of accepted matched points
THRESHOLD=0.0001

if [[ -z $1 ]]; then echo "You need to give a gpx file!"; exit 1; fi
ORIGIN_DATA=/tmp/$(basename $1).origin
RESPONSES=/tmp/$(basename $1).responses && true > $RESPONSES
MATCHED=/tmp/$(basename $1).matched

# extract data from the given gpx file
# only keep first point and remove the rest which in the same "second"
# input:  [gpx format]
# output: [121.0179739,14.5515336] 1984-01-01T08:00:46
get_data() {
    sed -nr '/<trkpt /, /<\/trkpt>/ {H; /<\/trkpt>/ {x; s/\n/ /g; p; s/.*//; x}}' $1 |
    sed -nr 'h; s/.*lon="([^"]+).*/\1/; H; g
                s/.*lat="([^"]+).*/\1/; H; g
                # If trkpt has no time, leave it blank
                /time/ {
                    s/.*<time>([^.]+).*<\/time>.*/\1/
                    H; g
                }
                s/^[^\n]+\n//; s/\n/ /g; p' |
    sed -r 's/^([^ ]+) ([^ ]+)/[\1,\2]/' |
    awk '!_[$2]++'
}

# Output GeoJSON object for Map Matching API
# input:  [121.0179739,14.5515336] 1984-01-01T08:00:46
# output: {type: "Feature", properties: {coordTimes: [...]}, geometry: {type: "LineString", coordinates: [...]}}
make_geojson() {
    # change input to format like: [[lon, lat], time]
    awk '{printf("[%s,\"%s\"]\n", $1, $2)}' |
    jq '[inputs] | {type: "Feature", geometry: {type: "LineString", coordinates: map(.[0])}, properties: {coordTimes: (map(.[1]))}}'
}

# Read GeoJSON body from STDIN, and return result from Mapbox Map Matching API
query_matched_points() {
    curl -X POST -s --data @- \
        --header "Content-Type:application/json" \
        https://api.mapbox.com/matching/v4/mapbox.driving.json?access_token=$ACCESS_TOKEN
}

# Get valid data from Map Matching API response
# output format is [coordinates] [index-of-original-data], like:
# [121.0179739,14.5515336] 35
# If the point is newly added, the index would be -1, like
# [121.0189339,14.5525931] -1
validate_matched_points() {
    VALID_DATA=$(jq ".features[] | if(.properties.confidence < $THRESHOLD) then .geometry.coordinates=(.properties.indices|map(.+1)) else . end")

    echo $VALID_DATA |
    jq -cr '.properties | [.matchedPoints, (.indices | map(.+1))] | transpose[] | "\(.[0]) \(.[1])"' > $MATCHED

    echo $VALID_DATA | jq -c '.geometry.coordinates[]' |
    while read point; do
        if [[ ${point:0:1} != '[' ]]; then
            echo $(sed -n "$point p" $ORIGIN_DATA) | while read coor time; do echo $coor $(date -d $time +%s); done
            sed -i 1d $MATCHED
        elif head -1 $MATCHED | grep -F $point > /dev/null; then
            index=$(head -1 $MATCHED | cut -d' ' -f2)
            echo $point $(sed -n "$index p" $ORIGIN_DATA | cut -d' ' -f2 | date -f - +%s)
            sed -i 1d $MATCHED
        else
            echo $point -1
        fi
    done
}

# Put existing timestamps to matched points, and interpolate new timestamps into new points
complete_data() {
    # interpolate timestamps to newly added points
    awk '{COOR[NR][0]=$1; N++; COOR[NR][1]=$2} END{for (i=1; i<=N; i++) {printf COOR[i][0]; if (COOR[i][1] != -1) {print " "COOR[i][1]; LAST=i} else {while(COOR[i+n][1] == -1) n++; print " "COOR[LAST][1]+(COOR[i+n][1]-COOR[LAST][1])*(i-LAST)/(i+n-LAST)}}}' |
    while read coor unix_time; do
        # Transform unix timestamp into human readable time format, like following:
        # Transform [121.018088,14.5516] 18.50
        # Into      [121.018088,14.5516] 1970-01-01T08:00:18.50Z
        echo $coor $(date -d @$unix_time +'%Y-%m-%dT%H:%M:%S.%2NZ')
    done
}

# Make GPX format for output
# Take input with format: [lon,lat] [time]
make_gpx() {
    sed -E 's/\[([^,]+),([^,]+)\] (.*)/      <trkpt lon="\1" lat="\2"><time>\3<\/time><\/trkpt>/' |
    sed "1i \
<gpx version=\"1.1\" creator=\"Garmin Connect\"\n\
  xsi:schemaLocation=\"http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd http://www.garmin.com/xmlschemas/GpxExtensions/v3 http://www.garmin.com/xmlschemas/GpxExtensionsv3.xsd http://www.garmin.com/xmlschemas/TrackPointExtension/v1 http://www.garmin.com/xmlschemas/TrackPointExtensionv1.xsd\"\n\
  xmlns=\"http://www.topografix.com/GPX/1/1\"\n\
  xmlns:gpxtpx=\"http://www.garmin.com/xmlschemas/TrackPointExtension/v1\"\n\
  xmlns:gpxx=\"http://www.garmin.com/xmlschemas/GpxExtensions/v3\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\">\n\
  <trk>\n    <trkseg>" |
    sed "\$a \ \ \ \ <\/trkseg>\n  <\/trk>\n<\/gpx>"
}

get_data $1 > $ORIGIN_DATA

#RAW_REQUEST=$(basename $1 | tr '.' '_')_request.geojson
#cat $ORIGIN_DATA | make_geojson | jq '.properties.stroke="#ff0000"' > $RAW_REQUEST

# Consume raw data with serveral request
while [ -s $ORIGIN_DATA ]; do
    # Take original data by limited points for each time: [121.0179739,14.5515336] 1984-01-01T08:00:46
    # Make geojson body: {type: "Feature", properties: {coordTimes: [...]}, geometry: {type: "LineString", coordinates: [...]}}
    # Call Mapbox Map Matching API: {geometry: {coordinates: [...]}, properties: {confidence: 0.9, matching: [...], indices: [...]}}
    # Get valid point and index by confidence value: [121.0179739,14.5515336] 5
    # complete_data
    head -$LIMIT $ORIGIN_DATA |
    make_geojson |
    query_matched_points |
    tee -a $RESPONSES |
    validate_matched_points |
    complete_data

    # Remove processed raw data
    sed -i "1,$LIMIT d" $ORIGIN_DATA
done | make_gpx
#make_geojson > test.geojson

#RAW_RESPONSE=$(basename $1 | tr '.' '_')_response.geojson
#MATCHED_POINTS=$(basename $1 | tr '.' '_')_matched.geojson
#jq . $RESPONSES | jq -s '.[0].features=[.[]|.features[]] | .[0] | del(.code) | .features=(.features|map(.properties.stroke="#00ff00"))' > $RAW_RESPONSE
#jq ".features=(.features|map(select(.properties.confidence>=$THRESHOLD).geometry.coordinates=.properties.matchedPoints)|map(.properties.stroke=\"#0000ff\"))" $RAW_RESPONSE > $MATCHED_POINTS
#
#DEBUG=$(basename $1 | tr '.' '_')_total.geojson
#cat $RAW_REQUEST $RAW_RESPONSE $MATCHED_POINTS | jq -s '{type: "FeatureCollection", features: ([.[0]] + .[1].features + .[2].features)}' > $DEBUG