#!/bin/bash
set -e

echo '=== FULL HYPSO GENERATION ==='
echo "Start: $(date)"

SRTM_DIR='/home/slin/enduro-trails/data/srtm'
TERRAIN_DIR='/home/slin/enduro-trails/data/terrain'
HYPSO_DIR="${TERRAIN_DIR}/hypso"
TMP='/tmp/hypso_full_gen'

rm -rf $TMP
mkdir -p $TMP

echo ''
echo '=== Step 1: Remove old empty hypso tiles ==='
rm -rf ${HYPSO_DIR}
mkdir -p ${HYPSO_DIR}
echo 'Old tiles removed'

echo ''
echo '=== Step 2: Build VRT from all HGT files ==='
find $SRTM_DIR -name '*.hgt' > $TMP/file_list.txt
gdalbuildvrt -vrtnodata -32768 -overwrite -input_file_list $TMP/file_list.txt $TMP/srtm_all.vrt 2>&1
echo 'VRT built'
gdalinfo -stats $TMP/srtm_all.vrt 2>&1 | grep STATISTICS
echo "HGT files: $(wc -l < $TMP/file_list.txt)"

echo ''
echo '=== Step 3: Generate color-relief GeoTIFF ==='
cat > $TMP/color_ramp.txt << 'EOF'
nv    0    0    0    0
-100  0    0    0    0
0     0    0    0    0
1     57   151  105  255
50    80   165  110  255
100   120  180  100  255
150   160  190  95   255
200   139  176  96   255
300   170  185  105  255
500   189  188  115  255
700   210  200  130  255
1000  220  206  148  255
1500  235  220  175  255
2000  210  185  140  255
2500  185  152  110  255
3000  160  120  80   255
4000  120  80   40   255
5000  200  200  200  255
EOF

gdaldem color-relief \
  $TMP/srtm_all.vrt \
  $TMP/color_ramp.txt \
  $TMP/hypso_full.tif \
  -alpha \
  -of GTiff \
  -co COMPRESS=LZW \
  -co BIGTIFF=YES 2>&1

echo 'Hypso GeoTIFF done:'
gdalinfo -stats $TMP/hypso_full.tif 2>&1 | grep STATISTICS_MAX
du -sh $TMP/hypso_full.tif

echo ''
echo '=== Step 4: Generate tiles (zoom 5-12, 4 processes) ==='
gdal2tiles.py \
  --zoom=5-12 \
  --processes=4 \
  --tilesize=256 \
  --webviewer=none \
  $TMP/hypso_full.tif \
  ${HYPSO_DIR}/ 2>&1

echo ''
echo '=== Step 5: Stats ==='
for z in 5 6 7 8 9 10 11 12; do
  total=$(find ${HYPSO_DIR}/$z/ -name '*.png' 2>/dev/null | wc -l)
  nonempty=$(find ${HYPSO_DIR}/$z/ -name '*.png' -size +400c 2>/dev/null | wc -l)
  echo "  zoom $z: $total total, $nonempty non-empty"
done

echo ''
echo 'Total tiles:'
find ${HYPSO_DIR} -name '*.png' | wc -l
du -sh ${HYPSO_DIR}

echo ''
echo '=== DONE ==='
echo "End: $(date)"