From 5845cd053b2af2b410d19fc93a683a4e525cf9e9 Mon Sep 17 00:00:00 2001
From: Benjamin Kreuscher <benni.kreuscher@gmail.com>
Date: Thu, 21 Apr 2022 00:16:11 +0200
Subject: [PATCH] read out content of generated .map files

- to check, if certain OSM tags / POIs are in the generated .map files
---
 tooling/map-info.py | 142 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)
 create mode 100644 tooling/map-info.py

diff --git a/tooling/map-info.py b/tooling/map-info.py
new file mode 100644
index 00000000..37003466
--- /dev/null
+++ b/tooling/map-info.py
@@ -0,0 +1,142 @@
+#!/usr/bin/python
+
+import argparse
+import sys
+import time
+
+
+class MapFileReader:
+    def __init__(self, filename) -> None:
+        self.mapFile = open(filename, "rb")
+
+    def close(self):
+        self.mapFile.close()
+
+    def readMagic(self):
+        return self.mapFile.read(20).decode('utf-8')
+
+    def readByte(self):
+        return self.mapFile.read(1)[0]
+
+    def readShort(self):
+        b = self.mapFile.read(2)
+        return b[0] << 8 | b[1]
+
+    def readInt(self):
+        b = self.mapFile.read(4)
+        return b[0] << 24 | b[1] << 16 | b[2] << 8 | b[3]
+
+    def readDegrees(self):
+        return float(self.readInt())/1000000
+
+    def readLong(self):
+        b = self.mapFile.read(8)
+        return b[0] << 56 | b[1] << 48 | b[2] << 40 | b[3] << 32 | b[4] << 24 | b[5] << 16 | b[6] << 8 | b[7]
+
+    def readVBEU(self):
+        res, shift, buf = 0, 0, 0
+        while True:
+            buf = int.from_bytes(self.mapFile.read(1), byteorder="big")
+            if (buf & 0x80) == 0:
+                break
+
+            res |= (buf & 0x7f) << shift
+            shift += 7
+
+        return res | (buf << shift)
+
+    def readString(self):
+        return self.mapFile.read(self.readVBEU()).decode('utf-8')
+
+    def readTags(self):
+        amount = self.readShort()
+        tags = []
+        for _ in range(amount):
+            tags.append(self.readString())
+
+        return tags
+
+    def readZoomIntervals(self):
+        amount = self.readByte()
+        intervals = []
+        for _ in range(amount):
+            values = (
+                self.readByte(),
+                self.readByte(),
+                self.readByte(),
+                self.readLong(),
+                self.readLong(),
+            )
+            intervals.append(values)
+        return intervals
+
+
+def main(args):
+    r = MapFileReader(args.mapfile)
+
+    magic = r.readMagic()
+    print("Magic:", magic)
+    if magic != "mapsforge binary OSM":
+        print("invalid magic bytes")
+        sys.exit(1)
+
+    print("Header size:", r.readInt())
+    print("File version:", r.readInt())
+    print("File size:", r.readLong())
+    print("Date of creation:", time.ctime(r.readLong()/1000))
+    print("Bounding box:")
+    print(
+        " - minLat: {:f} minLon: {:f}".format(r.readDegrees(), r.readDegrees()))
+    print(
+        " - maxLat: {:f} maxLon: {:f}".format(r.readDegrees(), r.readDegrees()))
+    print("Tile size:", r.readShort())
+    print("Projection:", r.readString())
+
+    flags = r.readByte()
+    print("Flags: {:08b}".format(flags))
+    if (flags & 0x80) != 0:
+        print(" - Debug file")
+    if (flags & 0x40) != 0:
+        print(
+            " - Map start position: lat: {:f} lon: {:f}", r.readDegrees(), r.readDegrees())
+    if (flags & 0x20) != 0:
+        print(" - Start zoom level", r.readByte())
+    if (flags & 0x10) != 0:
+        print(" - Languages", r.readString())
+    if (flags & 0x08) != 0:
+        print(" - Comment", r.readString())
+    if (flags & 0x04) != 0:
+        print(" - Created by", r.readString())
+
+    poiTags = r.readTags()
+    print("Poi tags:", len(poiTags))
+    if args.pois:
+        for tag in poiTags:
+            print(" -", tag)
+
+    wayTags = r.readTags()
+    print("Way tags:", len(wayTags))
+    if args.ways:
+        for tag in wayTags:
+            print(" -", tag)
+
+    zoomIntervals = r.readZoomIntervals()
+    print("Zoom intervals:", len(zoomIntervals))
+    if args.zoom_intervals:
+        for zi in zoomIntervals:
+            print(
+                " - Base: {} Min: {} Max: {} Pos: {} Size: {}".format(zi[0], zi[1], zi[2], zi[3], zi[4]))
+
+    r.close()
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        '-p', "--pois", help="show poi tags", action="store_true")
+    parser.add_argument(
+        '-w', "--ways", help="show way tags", action="store_true")
+    parser.add_argument('-z', "--zoom-intervals",
+                        help="show zoom intervals", action="store_true")
+    parser.add_argument('mapfile', help='map file')
+    main(parser.parse_args())