Generate a information thumbnail from a GPX file.

visutrack.py

"""Generate a information thumbnail from a GPX file.
"""

import io
import re
import os
import math
import time
import uuid
import base64
import codecs
import logging
import argparse
import urllib.parse
import xml.etree.ElementTree
import PIL.Image
import matplotlib.pyplot
import selenium.webdriver.support.expected_conditions
import selenium.webdriver.firefox.options
import selenium.webdriver.support.wait
import selenium.webdriver.common.by
import selenium.webdriver
import seaborn
import slugify
import folium


seaborn.set(style="darkgrid")


GPX_NS = "{http://www.topografix.com/GPX/1/1}"
GECKODRIVER = r"C:\Scripts\geckodriver.exe"


def load_gpx(filename):
    """Load a GPX file. Return a list of (latitude, longitude, elevation).
    """
    tree = xml.etree.ElementTree.parse(filename)
    root = tree.getroot()
    trkseg = list()
    for trkpt in root.find(GPX_NS + "trk").find(GPX_NS + "trkseg"):
        lat = float(trkpt.attrib["lat"])
        lon = float(trkpt.attrib["lon"])
        ele_el = trkpt.find(GPX_NS + "ele")
        ele = (float(ele_el.text) if ele_el is not None else None)
        trkseg.append((lat, lon, ele))
    return trkseg


def create_map(trkseg):
    """Create a folium map with the track segment displayed on it.
    """
    lats = list(map(lambda x: x[0], trkseg))
    lons = list(map(lambda x: x[1], trkseg))
    mean_lat = sum(lats) / len(trkseg)
    mean_lon = sum(lons) / len(trkseg)
    map_ = folium.Map(location=[mean_lat, mean_lon], control_scale=True)
    folium.features.ColorLine(
        positions=[trkpt[:2] for trkpt in trkseg],
        colors=[1 for _ in trkseg],
        colormap=["r", "r"],
        weight=5,
        opacity=.6
    ).add_to(map_)
    southwest = [min(lats), min(lons)]
    northeast = [max(lats), max(lons)]
    map_.fit_bounds([southwest, northeast])
    filename = os.path.realpath("_tmp" + uuid.uuid4().hex + ".html")
    map_.save(filename)
    with open(filename) as file:
        html = file.read()
    with open(filename, "w") as file:
        file.write(re.sub("openstreetmap", "opentopomap", html))
    return filename


def create_browser():
    """Create selenium driver handle.
    """
    options = selenium.webdriver.firefox.options.Options()
    options.headless = True
    driver = selenium.webdriver.Firefox(
        options=options,
        executable_path=GECKODRIVER,
        service_log_path=os.path.devnull
    )
    driver.set_window_size(1080, 1080 + 74)
    return driver


def export_map_to_png(driver, filename, delay=1):
    # pylint: disable=C0301
    """Create a PNG out of a folium map.
    """
    driver.get("file://{}".format(filename))
    driver.execute_script("document.body.style.width = '100%';")
    driver.execute_script("document.querySelector('.leaflet-control-container .leaflet-top.leaflet-left').style.display = 'none';")
    driver.execute_script("document.querySelector('.leaflet-control-container .leaflet-bottom.leaflet-right').style.display = 'none';")
    driver.execute_script("document.querySelector('.leaflet-tile-container').style.opacity = 0.8;")
    time.sleep(delay)
    png = driver.get_screenshot_as_png()
    filename = os.path.realpath("_tmp" + uuid.uuid4().hex + ".png")
    PIL.Image.open(io.BytesIO(png)).save(filename)
    return filename


def distance(lat1, lon1, lat2, lon2):
    # pylint: disable=C0103
    """Compute the distance in meters between two points.
    """
    r = 6371000
    phi1 = lat1 * math.pi / 180.
    phi2 = lat2 * math.pi / 180.
    delta_phi = (lat2 - lat1) * math.pi / 180.
    delta_lambda = (lon2 - lon1) * math.pi / 180.
    a = math.sin(.5 * delta_phi) * math.sin(.5 * delta_phi)\
        + math.cos(phi1)\
        * math.cos(phi2)\
        * math.sin(.5 * delta_lambda)\
        * math.sin(.5 * delta_lambda)
    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
    d = r * c
    return d


def add_gpx_elevation(driver, filename):
    """Create a new GPX file with elevation data.
    """
    driver.get("https://www.gpsvisualizer.com/elevation")
    file_upload = driver.find_element(
        selenium.webdriver.common.by.By.XPATH,
        "/html/body/table/tbody/tr/td[2]/form/div/div[1]/input[1]"
    )
    file_upload.send_keys(filename)
    submit_button = driver.find_element(
        selenium.webdriver.common.by.By.XPATH,
        "/html/body/table/tbody/tr/td[2]/form/div/div[2]/div[1]/input"
    )
    submit_button.click()
    selenium.webdriver.support.wait.WebDriverWait(driver, 10).until(
        selenium.webdriver.support.expected_conditions.presence_of_element_located((
            selenium.webdriver.common.by.By.XPATH,
            "/html/body/table/tbody/tr/td[2]/table[2]/tbody/tr/td[1]/iframe"
        ))
    )
    frame = driver.find_element(
        selenium.webdriver.common.by.By.XPATH,
        "/html/body/table/tbody/tr/td[2]/table[2]/tbody/tr/td[1]/iframe"
    )
    driver.switch_to.frame(frame)
    output_pre = driver.find_element(
        selenium.webdriver.common.by.By.XPATH,
        "/html/body/pre"
    )
    filename = os.path.realpath("_tmp" + uuid.uuid4().hex + ".gpx")
    with codecs.open(filename, "w", "utf8") as file:
        file.write(output_pre.text)
    return filename


def parse_trkseg(trkseg):
    """Parse a track segment.
    """
    prev_pos = trkseg[0][:2]
    prev_ele = trkseg[0][2]
    tot_ele_up, tot_ele_down = 0, 0
    tot_dist = 0
    distances, elevations = [], []
    for lat, lon, ele in trkseg:
        tot_dist += distance(*prev_pos, lat, lon)
        distances.append(tot_dist)
        ele_diff = ele - prev_ele
        if ele_diff > 0:
            tot_ele_up += ele_diff
        else:
            tot_ele_down -= ele_diff
        prev_pos = (lat, lon)
        prev_ele = ele
        elevations.append(ele)
    return tot_dist, tot_ele_up, tot_ele_down, (distances, elevations)


def plot_elevation_profile(distances, elevations):
    """Plot the elevation profile.
    """
    dpi = 100
    figure, axis = matplotlib.pyplot.subplots(figsize=(1080./dpi, 360./dpi))
    axis.plot(distances, elevations, "r")
    xticks = [1000 * i for i in range(math.ceil(.001 * distances[-1]))][1::2]
    xlabels = ["%dkm" % (.001 * tick) for tick in xticks]
    axis.set_xlim(distances[0], distances[-1])
    axis.set_ylim(bottom=min(elevations))
    axis.set_xticks(xticks)
    axis.set_xticklabels(xlabels, ha="right")
    seaborn.despine(left=True, bottom=True, right=True, top=True)
    axis.tick_params(direction="in")
    for tick in [*axis.xaxis.get_major_ticks(), *axis.xaxis.get_minor_ticks()]:
        tick.set_pad(-12)
    for tick in [*axis.yaxis.get_major_ticks(), *axis.yaxis.get_minor_ticks()]:
        tick.set_pad(-30)
    axis.fill_between(
        distances, elevations, [min(elevations) for _ in elevations],
        color="r", alpha=.1)
    matplotlib.pyplot.tight_layout(pad=0)
    filename = os.path.realpath("_tmp" + uuid.uuid4().hex + ".png")
    figure.savefig(filename, dpi=dpi)
    return filename


def format_sexagesimal(degree):
    """Convert a degree into the sexagesimal format.
    """
    if degree < 0:
        degree = -degree
    minutes = 1 / 60
    seconds = 1 / 3600
    string = ""
    remainder = int(degree)
    string += "%s°" % str(int(remainder))
    degree -= remainder
    remainder = degree // minutes
    string += "%s'" % str(int(remainder)).zfill(2)
    degree -= minutes * remainder
    remainder = degree / seconds
    string += ("%.1f" % remainder).zfill(4) + '"'
    return string


def format_latlon(lat, lon):
    """Format latitude and longitude into sexagesimal format.
    """
    return format_sexagesimal(lat) + ("N" if lat >= 0 else "S")\
        + " " + format_sexagesimal(lon) + ("E" if lon >= 0 else "W")


HTML_TEMPLATE = """
<!DOCTYPE html>
<html lang="fr">
    <head>
        <meta charset="utf-8">
        <title>{title}</title>
        <link href="https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;700&display=swap" rel="stylesheet">
        <style media="screen">
            html {{
                padding: 16px;
                display: flex;
                flex-diretion: row;
                justify-content: center;
            }}
            body {{
                text-align: center;
            }}
            @media all and (max-width:1200px) {{
                body {{
                    width: 100%;
                }}
            }}
            * {{
                font-family: 'Open Sans', sans-serif;
            }}
            h1 {{
                font-size: 64px;
                max-width: 1080px;
                margin: auto;
            }}
            .separator {{
                display: inline-block;
                width: 64px;
            }}
            .img_wrapper {{
                margin: auto;
                max-width: 1080px;
                height: auto;
                border-radius: 8px;
                overflow: hidden;
                margin-bottom: 16px;
                box-shadow: 0 2px 2px rgba(0, 0, 0, .1);
            }}
            .img_wrapper img {{
                width: inherit;
            }}
            h2 {{
                font-size: 32px;
                font-weight: normal;
                display: flex;
                flex-direction: row;
                justify-content: space-between;
                max-width: 1080px;
                margin: auto;
                margin-top: 24px;
                margin-bottom: 24px;
            }}
            a {{
                color: black;
            }}
        </style>
    </head>
    <body>
        <h1>{title}</h1>
        <h2>
            <span>{tot_dist:.1f}km</span>
            <span>&nearr; {tot_ele_up:.0f}m</span>
            <span>&searr; {tot_ele_down:.0f}m</span>
            <span>&#9872; <a href="https://www.google.com/maps/place/{start_url}">{start_surface}</a></span>
        </h2>
        <div class="img_wrapper" style="height: 1080px;">
            <a href="{track}"><img src="data:image/png;base64,{img_map}" alt=""></a>
        </div>
        <div class="img_wrapper" style="height: 360px;">
            <img src="data:image/png;base64,{img_ele}" alt="">
        </div>
    </body>
</html>
"""


def _main(args):  # pylint: disable=R0914
    """Set of operations.
    """
    logging.info("Using file '%s' as input", os.path.realpath(args.gpx))
    driver = create_browser()
    logging.info("Created selenium handle")
    gpxfn = add_gpx_elevation(driver, os.path.realpath(args.gpx))
    logging.info("Fetched elevation data and saved it to '%s'", gpxfn)
    trkseg = load_gpx(gpxfn)
    logging.info("Loaded GPX and found a track with %d points", len(trkseg))
    mapfn = create_map(trkseg)
    logging.info("Exported folium map to '%s'", mapfn)
    pngfn = export_map_to_png(driver, mapfn)
    logging.info("Exported map image to '%s'", pngfn)
    driver.quit()
    logging.info("Closed selenium handle")
    tot_dist, tot_ele_up, tot_ele_down, elevation_profile = parse_trkseg(trkseg)
    logging.info("Parsed track (total distance: %dm)", tot_dist)
    elefn = plot_elevation_profile(*elevation_profile)
    start = format_latlon(*trkseg[0][:2])
    with open(pngfn, "rb") as image_file:
        img_map = base64.b64encode(image_file.read()).decode()
    with open(elefn, "rb") as image_file:
        img_ele = base64.b64encode(image_file.read()).decode()
    html = HTML_TEMPLATE.format(
        title=args.title,
        tot_dist=.001 * tot_dist,
        tot_ele_up=tot_ele_up,
        tot_ele_down=tot_ele_down,
        start_surface=start,
        start_url=urllib.parse.quote(start),
        img_map=img_map,
        img_ele=img_ele,
        track=os.path.basename(args.gpx),
    )
    with codecs.open(slugify.slugify(args.title) + ".html", "w", "utf8") as file:
        file.write(html)
    logging.info("Plotted elevation profile at '%s'", elefn)
    os.remove(mapfn)
    os.remove(pngfn)
    os.remove(gpxfn)
    os.remove(elefn)
    logging.info("Cleaned temp files")


def main():
    """Parse arguments.
    """
    parser = argparse.ArgumentParser()
    parser.add_argument("gpx", type=str, help="GPX input file")
    parser.add_argument("title", type=str)
    _main(parser.parse_args())


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    main()