From 77bf14bfb0e289b6f4dea8ea2f4bbf1625f09492 Mon Sep 17 00:00:00 2001
From: Eric Fischer <enf@pobox.com>
Date: Mon, 17 Jul 2017 13:28:46 -0700
Subject: [PATCH] Track sample values for each attribute in each layer

---
 geojson.cpp | 37 +++++++++++++++++++++++++++++++------
 mbtiles.cpp |  4 ++--
 mbtiles.hpp |  1 +
 3 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/geojson.cpp b/geojson.cpp
index 129aaf5..0697e9c 100644
--- a/geojson.cpp
+++ b/geojson.cpp
@@ -429,17 +429,42 @@ int serialize_geometry(json_object *geometry, json_object *properties, json_obje
 				}
 			}
 
+			// XXX tilestats: tas.type shouldn't be used since, type is also tracked as variant inside it
+
 			if (tas.type >= 0) {
 				auto fk = layermap->find(layername);
 				fk->second.file_keys.insert(std::pair<type_and_string, type_and_string_stats>(tas, type_and_string_stats()));
-			}
 
-			if (track) {
-				type_and_string attrib;
-				attrib.type = metatype[m - 1];
-				attrib.string = metaval[m - 1];
+				if (track) {
+					auto fka = fk->second.file_keys.find(tas);
+					if (fka == fk->second.file_keys.end()) {
+						fprintf(stderr, "Can't happen (tilestats)\n");
+						exit(EXIT_FAILURE);
+					}
 
-				// XXX increment in type_and_string_stats.sample_values
+					type_and_string attrib;
+					attrib.type = metatype[m - 1];
+					attrib.string = metaval[m - 1];
+
+					if (attrib.type == mvt_double) {
+						double d = atof(attrib.string.c_str());
+
+						if (d < fka->second.min) {
+							fka->second.min = d;
+						}
+						if (d > fka->second.max) {
+							fka->second.max = d;
+						}
+					}
+
+					if (!fka->second.sample_values.count(attrib)) {
+						if (fka->second.sample_values.size() < 1000) {
+							fka->second.sample_values.insert(attrib);
+						}
+					}
+
+					fka->second.type |= (1 << attrib.type);
+				}
 			}
 		}
 	}
diff --git a/mbtiles.cpp b/mbtiles.cpp
index 4095f64..535b613 100644
--- a/mbtiles.cpp
+++ b/mbtiles.cpp
@@ -367,6 +367,8 @@ std::map<std::string, layermap_entry> merge_layermaps(std::vector<std::map<std::
 				exit(EXIT_FAILURE);
 			}
 
+			// XXX tilestats: merge file-keys
+
 			for (auto fk = map->second.file_keys.begin(); fk != map->second.file_keys.end(); ++fk) {
 				out_entry->second.file_keys.insert(*fk);
 			}
@@ -381,8 +383,6 @@ std::map<std::string, layermap_entry> merge_layermaps(std::vector<std::map<std::
 			out_entry->second.points += map->second.points;
 			out_entry->second.lines += map->second.lines;
 			out_entry->second.polygons += map->second.polygons;
-
-			printf("%zu %zu %zu\n", out_entry->second.points, out_entry->second.lines, out_entry->second.polygons);
 		}
 	}
 
diff --git a/mbtiles.hpp b/mbtiles.hpp
index bcdbb77..67e85e5 100644
--- a/mbtiles.hpp
+++ b/mbtiles.hpp
@@ -16,6 +16,7 @@ struct type_and_string_stats {
 	std::set<type_and_string> sample_values;
 	double min = INFINITY;
 	double max = -INFINITY;
+	int type = 0;
 };
 
 struct layermap_entry {