syntax = "proto3";

package pb;

option go_package = "github.com/ringsaturn/tzf/pb;pb";

// Basic Point data define.
message Point {
  float lng = 1;
  float lat = 2;
}

// Define a polygon, mostly based on GeoJSON's Polygon define.
//
// Excerpt from RFC-9476 section 'Polygon'
//
//   -  A linear ring is a closed LineString with four or more positions.
//   -  The first and last positions are equivalent, and they MUST contain
//     identical values; their representation SHOULD also be identical.
//   -  A linear ring is the boundary of a surface or the boundary of a
//     hole in a surface.
//   -  A linear ring MUST follow the right-hand rule with respect to the
//     area it bounds, i.e., exterior rings are counterclockwise, and
//     holes are clockwise.
//
//   Note: the [GJ2008] specification did not discuss linear ring winding
//   order.  For backwards compatibility, parsers SHOULD NOT reject
//   Polygons that do not follow the right-hand rule.
//
//   Though a linear ring is not explicitly represented as a GeoJSON
//   geometry type, it leads to a canonical formulation of the Polygon
//   geometry type definition as follows:
//
//   -  For type "Polygon", the "coordinates" member MUST be an array of
//     linear ring coordinate arrays.
//   -  For Polygons with more than one of these rings, the first MUST be
//     the exterior ring, and any others MUST be interior rings.  The
//     exterior ring bounds the surface, and the interior rings (if
//     present) bound holes within the surface.
//
// [GJ2008]: https://geojson.org/geojson-spec
//
message Polygon {
  repeated Point points = 1;   // define the "exterior ring"
  repeated Polygon holes = 2;  // define the "interior rings" as holes
}

// Timezone is a timezone's all data.
message Timezone {
  repeated Polygon polygons = 1;
  string name = 2;
}

message Timezones {
  repeated Timezone timezones = 1;
  bool reduced = 2;  // Reduced data will toggle neighbor search as plan b
  string version = 3;
}

enum CompressMethod {
  Unknown = 0;
  Polyline =
      1;  // https://developers.google.com/maps/documentation/utilities/polylinealgorithm
}

message CompressedPolygon {
  bytes points = 1;
  repeated CompressedPolygon holes = 2;
}

// CompressedTimezonesItem designed for binary file as small as possible.
message CompressedTimezone {
  repeated CompressedPolygon data = 1;
  string name = 2;
}

message CompressedTimezones {
  CompressMethod method = 1;
  repeated CompressedTimezone timezones = 2;
  string version = 3;
}

// PreindexTimezone tile item.
//
// The X/Y/Z are OSM style like map tile index values.
message PreindexTimezone {
  string name = 1;
  int32 x = 2;
  int32 y = 3;
  int32 z = 4;
}

// PreindexTimezones is all preindex timezone's dumps.
message PreindexTimezones {
  int32 idxZoom = 1;  // which zoom value the tiles generated
  int32 aggZoom = 2;  // which zoom value the tiles merge up with.
  repeated PreindexTimezone keys = 3;
  string version = 4;
}