(** Neovere Live - Interactive Urbit runtime with Eio *)

open Eio.Std
open Nock_lib

let version = "0.1.0"

let project_root =
  match Sys.getenv_opt "NEOVERE_ROOT" with
  | Some root -> root
  | None ->
      let exe_dir = Filename.dirname Sys.executable_name in
      let rec find_root dir =
        let pills_dir = Filename.concat dir "pills" in
        if Sys.file_exists pills_dir && Sys.is_directory pills_dir then dir
        else
          let parent = Filename.dirname dir in
          if String.equal parent dir then
            failwith "unable to locate project root containing pills/"
          else find_root parent
      in
      find_root exe_dir

(** Boot the ship *)
let boot_ship pier_name =
  traceln "Booting ship: %s" pier_name;

  let pier_path = Filename.concat project_root pier_name in
  if Sys.file_exists pier_path then begin
    traceln "Error: Pier %s already exists" pier_path;
    exit 1
  end;

  Unix.mkdir pier_path 0o755;

  let state = State.create ~pier_path () in

  (* Boot ivory *)
  let ivory_path = Filename.concat project_root "pills/ivory.pill" in
  begin match Boot.boot_ivory state ivory_path with
  | Error _ -> traceln "Ivory boot failed"; exit 1
  | Ok () -> traceln "✓ Ivory kernel loaded"
  end;

  (* Boot solid *)
  let solid_path = Filename.concat project_root "pills/solid.pill" in
  begin match Boot.boot_solid_lifecycle state solid_path with
  | Error _ -> traceln "Solid boot failed"; exit 1
  | Ok () ->
      traceln "✓ Solid boot complete (events: %Ld)" (State.event_number state)
  end;

  state

(** Main event loop using Eio's structured concurrency *)
let run_event_loop env state =
  let stdin = Eio.Stdenv.stdin env in
  let stdout = Eio.Stdenv.stdout env in
  let clock = Eio.Stdenv.clock env in

  traceln "\n~zod:dojo> ";
  Eio.Flow.copy_string "~zod:dojo> " stdout;

  (* Create Dill wire for terminal 1 *)
  let dill_wire = Noun.cell
    (Noun.atom (Z.of_int (Char.code 'd')))
    (Noun.cell
      (Noun.atom_of_string "term")
      (Noun.cell (Noun.atom (Z.of_int 1)) (Noun.atom Z.zero)))
  in

  (* Process effects helper *)
  let process_effects result =
    match result with
    | Noun.Cell (effects, _new_core) ->
        Nock_lib.Dill.render_effects ~stdout effects
    | _ ->
        traceln "Warning: poke returned unexpected structure"
  in

  (* Run concurrent fibers *)
  Switch.run @@ fun _sw ->
    Fiber.all [
      (* Terminal input fiber *)
      (fun () ->
        traceln "[Input fiber started]";
        Nock_lib.Dill.input_loop ~stdin ~state ~wire:dill_wire process_effects
      );

      (* Timer fiber (placeholder) *)
      (fun () ->
        traceln "[Timer fiber started]";
        while true do
          Eio.Time.sleep clock 10.0;
          traceln "[Timer tick]"
        done
      );

      (* Status fiber (placeholder) *)
      (fun () ->
        traceln "[Status fiber started]";
        Eio.Time.sleep clock 5.0;
        let eve = State.event_number state in
        traceln "[Status] Events: %Ld" eve;
      );
    ]

(** Main entry point *)
let main env =
  let pier_name =
    if Array.length Sys.argv > 1 then Sys.argv.(1)
    else "zod-live"
  in

  traceln "╔═══════════════════════════════════════════════════════╗";
  traceln "║  Neovere Live v%s                                   ║" version;
  traceln "╚═══════════════════════════════════════════════════════╝";
  traceln "";

  (* Boot ship *)
  let state = boot_ship pier_name in

  traceln "";
  traceln "Ship booted successfully!";
  traceln "Starting event loop with Eio structured concurrency...";
  traceln "";

  (* Run event loop *)
  run_event_loop env state;

  (* Cleanup *)
  State.close_eventlog state;
  traceln "Shutdown complete"

let () =
  Eio_main.run @@ fun env ->
    try
      main env
    with
    | Sys_error msg ->
        traceln "System error: %s" msg;
        exit 1
    | e ->
        traceln "Fatal error: %s" (Printexc.to_string e);
        Printexc.print_backtrace stderr;
        exit 1