/*
 * Planetarium — XZBT Exhibit Contract 5.2 adapter.
 *
 * Declares the catalog, binds targets to real exhibit services, and routes
 * the native UI through the canonical mutation path. No state of its own.
 */
(function () {
  'use strict';

  var Core = window.XZBTContractCore;

  var IDENTITY = {
    product: 'Planetarium',
    version: '1.0.0',
    build: 'reference-exhibit'
  };

  var DESCRIPTORS = [
    {
      id: 'sky.constellation',
      kind: 'selection',
      label: 'Constellation',
      description: 'Constellation currently tracked and drawn.',
      options: [
        { value: 'orion', label: 'Orion' },
        { value: 'cygnus', label: 'Cygnus' },
        { value: 'scorpius', label: 'Scorpius' },
        { value: 'ursa-major', label: 'Ursa Major' },
        { value: 'cassiopeia', label: 'Cassiopeia' },
        { value: 'lyra', label: 'Lyra' }
      ],
      readable: true, writable: true, restorable: true,
      category: 'sky', requires: []
    },
    {
      id: 'sky.magnitude-limit',
      kind: 'range',
      label: 'Magnitude limit',
      description: 'Faintest stellar magnitude rendered. Higher values show more stars.',
      min: 1, max: 6, step: 0.1, unit: 'mag',
      readable: true, writable: true, restorable: true,
      category: 'sky', requires: []
    },
    {
      id: 'sky.azimuth',
      kind: 'range',
      label: 'Azimuth',
      description: 'Compass bearing of the view, 0 to 1 of a full turn.',
      min: 0, max: 1, step: 0.01,
      readable: true, writable: true, restorable: true,
      category: 'sky', requires: []
    },
    {
      id: 'sky.altitude',
      kind: 'range',
      label: 'Altitude',
      description: 'Elevation of the view above the horizon, 0 to 1.',
      min: 0, max: 1, step: 0.01,
      readable: true, writable: true, restorable: true,
      category: 'sky', requires: []
    },
    {
      id: 'sky.time-scale',
      kind: 'range',
      label: 'Time scale',
      description: 'Rate at which sky time advances.',
      min: 0, max: 4, step: 0.05, unit: 'x',
      readable: true, writable: true, restorable: true,
      category: 'sky', requires: []
    },
    {
      id: 'sky.filter',
      kind: 'selection',
      label: 'Filter',
      description: 'Optical filter applied to the view.',
      options: [
        { value: 'none', label: 'None' },
        { value: 'light-pollution', label: 'Light pollution' },
        { value: 'h-alpha', label: 'H-alpha' },
        { value: 'oxygen-iii', label: 'Oxygen III' }
      ],
      readable: true, writable: true, restorable: true,
      category: 'sky', requires: []
    },
    {
      id: 'sky.tracking',
      kind: 'state',
      valueType: 'boolean',
      label: 'Tracking',
      description: 'Whether the mount is tracking the selected constellation.',
      readable: true, writable: true, restorable: true,
      category: 'sky', requires: []
    },
    {
      id: 'sky.paused',
      kind: 'state',
      valueType: 'boolean',
      label: 'Sky frozen',
      description: 'Whether sky time is frozen.',
      readable: true, writable: true, restorable: true,
      category: 'sky', requires: []
    },
    {
      id: 'action.advance-time',
      kind: 'impulse',
      label: 'Advance time',
      description: 'Advance sky time. Optional argument: minutes (1 to 240).',
      arguments: [
        { name: 'minutes', type: 'number', required: false, min: 1, max: 240, default: 10 }
      ],
      readable: false, writable: false, restorable: false,
      category: 'action', requires: []
    },
    {
      id: 'action.reset-sky',
      kind: 'impulse',
      label: 'Reset sky',
      description: 'Return sky time to epoch.',
      readable: false, writable: false, restorable: false,
      category: 'action', requires: []
    },
    {
      id: 'action.toggle-tracking',
      kind: 'impulse',
      label: 'Toggle tracking',
      description: 'Engage or disengage the mount.',
      readable: false, writable: false, restorable: false,
      category: 'action', requires: []
    },
    {
      id: 'telemetry.visible-stars',
      kind: 'state',
      valueType: 'number',
      label: 'Visible stars',
      description: 'Stars currently above the magnitude limit.',
      readable: true, writable: false, restorable: false,
      category: 'telemetry', requires: []
    },
    {
      id: 'telemetry.sky-time',
      kind: 'state',
      valueType: 'number',
      unit: 'h',
      label: 'Sky time',
      description: 'Elapsed sky time in hours.',
      readable: true, writable: false, restorable: false,
      category: 'telemetry', requires: []
    },
    {
      id: 'telemetry.moon-phase',
      kind: 'state',
      valueType: 'number',
      label: 'Moon phase',
      description: 'Lunar phase as a fraction of the cycle.',
      readable: true, writable: false, restorable: false,
      category: 'telemetry', requires: []
    }
  ];

  function createPlanetariumContract(exhibit, ui) {
    var catalog = new Core.Catalog(DESCRIPTORS);

    var capabilities = new Core.CapabilityRegistry();
    capabilities.declare('render', 'ready');

    var setters = {
      'sky.constellation': function (v) { return exhibit.setConstellation(v); },
      'sky.magnitude-limit': function (v) { return exhibit.setMagnitudeLimit(v); },
      'sky.azimuth': function (v) { return exhibit.setAzimuth(v); },
      'sky.altitude': function (v) { return exhibit.setAltitude(v); },
      'sky.time-scale': function (v) { return exhibit.setTimeScale(v); },
      'sky.filter': function (v) { return exhibit.setFilter(v); },
      'sky.tracking': function (v) { return exhibit.setTracking(v); },
      'sky.paused': function (v) { return exhibit.setPaused(v); }
    };

    var readers = {};
    var ids = catalog.ids();
    for (var i = 0; i < ids.length; i++) {
      (function (id) {
        readers[id] = function () { return exhibit.read(id); };
      })(ids[i]);
    }

    var actions = {
      'action.advance-time': function (args) { return exhibit.advanceTime(args); },
      'action.reset-sky': function () { return exhibit.resetSky(); },
      'action.toggle-tracking': function () { return exhibit.toggleTracking(); }
    };

    var core = new Core.ContractCore({
      identity: IDENTITY,
      catalog: catalog,
      capabilities: capabilities,
      setters: setters,
      readers: readers,
      actions: actions
    });

    ui.dispatchOverride = function (targetId, value) {
      core.applyMutation(targetId, value, 'ui');
      ui.sync();
    };
    ui.invokeOverride = function (targetId, args) {
      core.invokeAction(targetId, args || {}, 'ui');
      ui.sync();
    };

    exhibit.onChange = function () { ui.sync(); };

    return core;
  }

  window.PlanetariumContract = { create: createPlanetariumContract, IDENTITY: IDENTITY };
})();