package PBF;

/* OSM Binary file format 

This is the master schema file of the OSM binary file format. This
file is designed to support limited random-access and future
extendability.

A binary OSM file consists of a sequence of FileBlocks (please see
fileformat.proto). The first fileblock contains a serialized instance
of HeaderBlock, followed by a sequence of PrimitiveBlock blocks that
contain the primitives.

Each primitiveblock is designed to be independently parsable. It
contains a string table storing all strings in that block (keys and
values in tags, roles in relations, usernames, etc.) as well as
metadata containing the precision of coordinates or timestamps in that
block.

A primitiveblock contains a sequence of primitive groups, each
containing primitives of the same type (nodes, densenodes, ways,
relations). Coordinates are stored in signed 64-bit integers. Lat&lon
are measured in units <granularity> nanodegrees. The default of
granularity of 100 nanodegrees corresponds to about 1cm on the ground,
and a full lat or lon fits into 32 bits.

Converting an integer to a lattitude or longitude uses the formula:
$OUT = IN * granularity / 10**9$. Many encoding schemes use delta
coding when representing nodes and relations.

*/

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/* Contains the file header. */

message HeaderBlock {
  optional HeaderBBox bbox = 1;
  /* Additional tags to aid in parsing this dataset */
  repeated string required_features = 4;
  repeated string optional_features = 5;

  optional string writingprogram = 16; 
  optional string source = 17; // From the bbox field.
}


/** The bounding box field in the OSM header. BBOX, as used in the OSM
header. Units are always in nanodegrees -- they do not obey
granularity rules. */

message HeaderBBox {
   required sint64 left = 1;
   required sint64 right = 2;
   required sint64 top = 3;
   required sint64 bottom = 4;
}


///////////////////////////////////////////////////////////////////////
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message PrimitiveBlock {
  required StringTable stringtable = 1;
  repeated PrimitiveGroup primitivegroup = 2;

  // Granularity, units of nanodegrees, used to store coordinates in this block
  optional int32 granularity = 17 [default=100]; 
  // Offset value between the output coordinates coordinates and the granularity grid in unites of nanodegrees.
  optional int64 lat_offset = 19 [default=0];
  optional int64 lon_offset = 20 [default=0]; 

// Granularity of dates, normally represented in units of milliseconds since the 1970 epoch.
  optional int32 date_granularity = 18 [default=1000]; 


  // Proposed extension:
  //optional BBox bbox = 19;
}

// Group of OSMPrimitives. All primitives in a group must be the same type.
message PrimitiveGroup {
  repeated Node     nodes = 1;
  optional DenseNodes dense = 2;
  repeated Way      ways = 3;
  repeated Relation relations = 4;
  repeated ChangeSet changesets = 5;
}


/** String table, contains the common strings in each block.

 Note that we reserve index '0' as a delimiter, so the entry at that
 index in the table is ALWAYS blank and unused.

 */
message StringTable {
   repeated bytes s = 1;
}

/* Optional metadata that may be included into each primitive. */
message Info {
   optional int32 version = 1 [default = -1];
   optional int64 timestamp = 2;
   optional int64 changeset = 3;
   optional int32 uid = 4;
   optional int32 user_sid = 5; // String IDs
}

/** Optional metadata that may be included into each primitive. Special dense format used in DenseNodes. */
message DenseInfo {
   repeated int32 version = 1 [packed = true]; 
   repeated sint64 timestamp = 2 [packed = true]; // DELTA coded
   repeated sint64 changeset = 3 [packed = true]; // DELTA coded
   repeated sint32 uid = 4 [packed = true]; // DELTA coded
   repeated sint32 user_sid = 5 [packed = true]; // String IDs for usernames. DELTA coded
}


// THIS IS STUB DESIGN FOR CHANGESETS. NOT USED RIGHT NOW.
// TODO:    REMOVE THIS?
message ChangeSet {
   required int64 id = 1;
//   
//   // Parallel arrays.
//   repeated uint32 keys = 2 [packed = true]; // String IDs.
//   repeated uint32 vals = 3 [packed = true]; // String IDs.
//
//   optional Info info = 4;

//   optional int64 created_at = 8;
//   optional int64 closetime_delta = 9;
//   optional bool open = 10;
//   optional HeaderBBox bbox = 11;
}


message Node {
   required sint64 id = 1;
   // Parallel arrays.
   repeated uint32 keys = 2 [packed = true]; // String IDs.
   repeated uint32 vals = 3 [packed = true]; // String IDs.

   optional Info info = 4; // May be omitted in omitmeta

   required sint64 lat = 8;
   required sint64 lon = 9;
}

/* Used to densly represent a sequence of nodes that do not have any tags.

We represent these nodes columnwise as five columns: ID's, lats, and
lons, all delta coded. When metadata is not omitted, 

We encode keys & vals for all nodes as a single array of integers
containing key-stringid and val-stringid, using a stringid of 0 as a
delimiter between nodes.

   ( (<keyid> <valid>)* '0' )*
 */

message DenseNodes {
   repeated sint64 id = 1 [packed = true]; // DELTA coded

   //repeated Info info = 4;
   optional DenseInfo denseinfo = 5;

   repeated sint64 lat = 8 [packed = true]; // DELTA coded
   repeated sint64 lon = 9 [packed = true]; // DELTA coded

   // Special packing of keys and vals into one array. May be empty if all nodes in this block are tagless.
   repeated int32 keys_vals = 10 [packed = true]; 
}


message Way {
   required int64 id = 1;
   // Parallel arrays.
   repeated uint32 keys = 2 [packed = true];
   repeated uint32 vals = 3 [packed = true];

   optional Info info = 4;

   repeated sint64 refs = 8 [packed = true];  // DELTA coded
}

message Relation {
  enum MemberType {
    NODE = 0;
    WAY = 1;
    RELATION = 2;
  } 
   required int64 id = 1;

   // Parallel arrays.
   repeated uint32 keys = 2 [packed = true];
   repeated uint32 vals = 3 [packed = true];

   optional Info info = 4;

   // Parallel arrays
   repeated int32 roles_sid = 8 [packed = true];
   repeated sint64 memids = 9 [packed = true]; // DELTA encoded
   repeated MemberType types = 10 [packed = true];
}

