(** Main GPX document type *)

(** Main GPX document type *)
type t = {
  version : string;                    (* GPX version: "1.0" or "1.1" *)
  creator : string;                    (* Creating application *)
  metadata : Metadata.t option;       (* Document metadata *)
  waypoints : Waypoint.t list;        (* Waypoints *)
  routes : Route.t list;               (* Routes *)
  tracks : Track.t list;               (* Tracks *)
  extensions : Extension.t list;       (* Document-level extensions *)
}

(** {2 Document Constructors} *)

(** Create empty GPX document *)
let empty ~creator = {
  version = "1.1";
  creator;
  metadata = None;
  waypoints = [];
  routes = [];
  tracks = [];
  extensions = [];
}

(** Create GPX document with metadata *)
let make ~creator ~metadata = 
  { (empty ~creator) with metadata = Some metadata }

(** {2 Document Properties} *)

(** Get version *)
let version t = t.version

(** Get creator *)
let creator t = t.creator

(** Get metadata *)
let metadata t = t.metadata

(** Get waypoints *)
let waypoints t = t.waypoints

(** Get routes *)
let routes t = t.routes

(** Get tracks *)
let tracks t = t.tracks

(** Get extensions *)
let extensions t = t.extensions

(** {2 Document Modification} *)

(** Update metadata *)
let with_metadata t metadata = { t with metadata = Some metadata }

(** Add waypoint *)
let add_waypoint t waypoint = { t with waypoints = t.waypoints @ [waypoint] }

(** Add waypoints *)
let add_waypoints t waypoints = { t with waypoints = t.waypoints @ waypoints }

(** Add route *)
let add_route t route = { t with routes = t.routes @ [route] }

(** Add routes *)
let add_routes t routes = { t with routes = t.routes @ routes }

(** Add track *)
let add_track t track = { t with tracks = t.tracks @ [track] }

(** Add tracks *)
let add_tracks t tracks = { t with tracks = t.tracks @ tracks }

(** Add extensions *)
let add_extensions t extensions = { t with extensions = t.extensions @ extensions }

(** Clear waypoints *)
let clear_waypoints t = { t with waypoints = [] }

(** Clear routes *)
let clear_routes t = { t with routes = [] }

(** Clear tracks *)
let clear_tracks t = { t with tracks = [] }

(** {2 Document Analysis} *)

(** Count waypoints *)
let waypoint_count t = List.length t.waypoints

(** Count routes *)
let route_count t = List.length t.routes

(** Count tracks *)
let track_count t = List.length t.tracks

(** Count total points *)
let total_points t =
  let waypoint_points = List.length t.waypoints in
  let route_points = List.fold_left (fun acc route -> 
    acc + Route.point_count route) 0 t.routes in
  let track_points = List.fold_left (fun acc track -> 
    acc + Track.point_count track) 0 t.tracks in
  waypoint_points + route_points + track_points

(** Check if document has elevation data *)
let has_elevation t =
  List.exists (fun wpt -> Waypoint.elevation wpt <> None) t.waypoints ||
  List.exists (fun route ->
    List.exists (fun pt -> Waypoint.elevation pt <> None) (Route.points route)
  ) t.routes ||
  List.exists (fun track ->
    List.exists (fun pt -> Waypoint.elevation pt <> None) (Track.all_points track)
  ) t.tracks

(** Check if document has time data *)
let has_time t =
  List.exists (fun wpt -> Waypoint.time wpt <> None) t.waypoints ||
  List.exists (fun route ->
    List.exists (fun pt -> Waypoint.time pt <> None) (Route.points route)
  ) t.routes ||
  List.exists (fun track ->
    List.exists (fun pt -> Waypoint.time pt <> None) (Track.all_points track)
  ) t.tracks

(** Check if document is empty *)
let is_empty t = 
  waypoint_count t = 0 && route_count t = 0 && track_count t = 0

(** Get statistics *)
type stats = {
  waypoint_count : int;
  route_count : int;
  track_count : int;
  total_points : int;
  has_elevation : bool;
  has_time : bool;
}

let stats t = {
  waypoint_count = waypoint_count t;
  route_count = route_count t;
  track_count = track_count t;
  total_points = total_points t;
  has_elevation = has_elevation t;
  has_time = has_time t;
}

(** Pretty print statistics *)
let pp_stats ppf t =
  let s = stats t in
  Format.fprintf ppf "@[<v>GPX Statistics:@,  Waypoints: %d@,  Routes: %d@,  Tracks: %d@,  Total points: %d@,  Has elevation data: %s@,  Has time data: %s@]"
    s.waypoint_count s.route_count s.track_count s.total_points
    (if s.has_elevation then "yes" else "no")
    (if s.has_time then "yes" else "no")

(** {2 Comparison and Utilities} *)

(** Compare documents *)
let compare t1 t2 =
  let version_cmp = String.compare t1.version t2.version in
  if version_cmp <> 0 then version_cmp
  else
    let creator_cmp = String.compare t1.creator t2.creator in
    if creator_cmp <> 0 then creator_cmp
    else
      let waypoints_cmp = List.compare Waypoint.compare t1.waypoints t2.waypoints in
      if waypoints_cmp <> 0 then waypoints_cmp
      else
        let routes_cmp = List.compare Route.compare t1.routes t2.routes in
        if routes_cmp <> 0 then routes_cmp
        else List.compare Track.compare t1.tracks t2.tracks

(** Test document equality *)
let equal t1 t2 = compare t1 t2 = 0

(** Pretty print document *)
let pp ppf t =
  let stats = stats t in
  Format.fprintf ppf "GPX v%s by %s (%d wpt, %d routes, %d tracks, %d total points)"
    t.version t.creator 
    stats.waypoint_count stats.route_count stats.track_count stats.total_points