#!/bin/bash
set -e

echo '=== TRI MAX-AGGREGATION REGEN (GDAL 3.4 compatible) ==='
echo "Start: $(date)"

TMP='/tmp/tri_gen'
TERRAIN_DIR='/home/slin/enduro-trails/data/terrain'
TRI_DIR="${TERRAIN_DIR}/tri"

mkdir -p $TMP

echo ''
echo '=== Step 1: Verify tri_raw_full.tif ==='
if [ ! -f "$TMP/tri_raw_full.tif" ]; then
  echo "FATAL: tri_raw_full.tif not found"
  exit 1
fi
echo "OK: $(gdalinfo $TMP/tri_raw_full.tif 2>&1 | grep 'Size is')"

echo ''
echo '=== Step 2: Color relief (v5 ramp, threshold 15) ==='
cat > $TMP/tri_color_max.txt << 'RAMP'
nv    0    0    0    0
0     0    0    0    0
14    0    0    0    0
15    255  255  100  60
20    255  230  50   100
25    255  200  0    140
30    255  150  0    180
40    255  100  0    200
50    230  50   0    220
65    200  0    0    235
80    180  0   50    245
100   150  0   100   255
RAMP

gdaldem color-relief \
  $TMP/tri_raw_full.tif \
  $TMP/tri_color_max.txt \
  $TMP/tri_colored_max.tif \
  -alpha \
  -of GTiff \
  -co COMPRESS=LZW \
  -co BIGTIFF=YES
echo "Colored TRI: $(du -sh $TMP/tri_colored_max.tif | cut -f1)"

echo ''
echo '=== Step 3: Create low-res version with MAX resampling ==='
# Target resolution ~0.005 deg (~500m) for zooms 5-9
# gdalwarp -r max works on GDAL 3.4 (unlike gdaladdo -r max)
gdalwarp -r max \
  -tr 0.005 0.005 \
  -srcnodata "0 0 0 0" \
  $TMP/tri_colored_max.tif \
  $TMP/tri_colored_lowres.tif \
  -co COMPRESS=LZW \
  -co BIGTIFF=YES \
  -overwrite
echo "Low-res colored TRI: $(du -sh $TMP/tri_colored_lowres.tif | cut -f1)"
echo "Size: $(gdalinfo $TMP/tri_colored_lowres.tif 2>&1 | grep 'Size is')"

echo ''
echo '=== Step 4: Clean output directory ==='
rm -rf ${TRI_DIR}
mkdir -p ${TRI_DIR}

echo ''
echo '=== Step 5: Generate tiles z5-9 from LOW-RES (max-aggregated) ==='
gdal2tiles.py \
  --zoom=5-9 \
  --processes=4 \
  --tilesize=256 \
  --resampling=average \
  --webviewer=none \
  $TMP/tri_colored_lowres.tif \
  ${TRI_DIR}/
echo "Low zoom tiles done"

echo ''
echo '=== Step 6: Generate tiles z10-12 from FULL-RES ==='
gdal2tiles.py \
  --zoom=10-12 \
  --processes=4 \
  --tilesize=256 \
  --resampling=average \
  --webviewer=none \
  $TMP/tri_colored_max.tif \
  ${TRI_DIR}/
echo "High zoom tiles done"

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

echo ''
echo '=== Step 8: Sample tile check (zoom 7) ==='
TILE=$(find ${TRI_DIR}/7/ -name '*.png' -size +1000c 2>/dev/null | head -1)
if [ -n "$TILE" ]; then
  echo "Sample: $TILE"
  python3 -c "from PIL import Image; im=Image.open('$TILE'); print('Size:', im.size, 'Mode:', im.mode); bands=im.split(); print('R range:', bands[0].getextrema(), 'A range:', bands[3].getextrema())" 2>/dev/null || file "$TILE"
else
  echo "No large tiles at zoom 7"
fi

echo ''
echo '=== Step 9: Avg tile size at zoom 7 ==='
find ${TRI_DIR}/7/ -name '*.png' -size +400c -exec ls -la {} \; 2>/dev/null | awk '{sum+=$5; n++} END {if(n>0) print "avg:", sum/n, "bytes, count:", n; else print "no tiles"}'

echo ''
du -sh ${TRI_DIR}
echo '=== DONE ==='
echo "End: $(date)"