View.cs

using Meep.Tech.Collections.Generic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

namespace Simple.Ux.Data {

  /// <summary>
  /// A simple ux view, with controls, and potentially with multiple pannels that contain content.
  /// </summary>
  public class View : IEnumerable<KeyValuePair<Pannel.Tab, Pannel>> {
    internal OrderedDictionary<string, Pannel> _pannels
      = new();
    internal OrderedDictionary<string, Pannel.Tab> _tabs
      = new();
    internal IReadOnlyDictionary<string, DataField> _fields;

    /// <summary>
    /// The unique id of this view
    /// </summary>
    public string Id {
      get;
    } = Guid.NewGuid().ToString();

    /// <summary>
    /// Extra context you can provide to the component.
    /// </summary>
    public IReadOnlyDictionary<string, object> Context {
      get;
      private set;
    }

    /// <summary>
    /// The main title of this view.
    /// </summary>
    public Title MainTitle {
      get;
      private set;
    }

    /// <summary>
    /// If this view has more than one pannel.
    /// </summary>
    public bool HasMultiplePannels
      => _pannels.Count > 1;

    /// <summary>
    /// The number of tabs/pannels
    /// </summary>
    public int NumberOfTabs
      => _pannels.Count;

    internal View(Title mainTitle) {
      MainTitle = mainTitle;
    }

    /// <summary>
    /// Get the pannel at the given tab
    /// </summary>
    public Pannel GetPannel(Pannel.Tab tab)
      => _pannels[tab.Key];

    /// <summary>
    /// Get the pannel at the given tab
    /// </summary>
    public Pannel GetPannel(string tabKey, out Pannel.Tab tab) {
      tab = GetTab(tabKey);
      return GetPannel(tab);
    }

    /// <summary>
    /// Get the pannel at the given tab
    /// </summary>
    public Pannel GetPannel(int tabIndex, out Pannel.Tab tab) {
      tab = GetTab(tabIndex);
      return GetPannel(tab);
    }

    /// <summary>
    /// Get the pannel at the given tab
    /// </summary>
    public Pannel GetPannel(int tabIndex)
      => _pannels[tabIndex];

    /// <summary>
    /// Get the pannel at the given tab
    /// </summary>
    public Pannel.Tab GetTab(int tabIndex)
      => _tabs[tabIndex];

    /// <summary>
    /// Get the pannel at the given tab
    /// </summary>
    public Pannel.Tab GetTab(string key)
      => _tabs[key.ToLower()];

    /// <summary>
    /// Get a field by key
    /// </summary>
    public DataField GetField(string key)
      => _fields[key.ToLower()];

    /// <summary>
    /// try to get a field by key
    /// </summary>
    public DataField TryToGetField(string key)
      => key is null ? null : _fields.TryGetValue(key.ToLower(), out var value)
       ? value
       : null;

    /// <summary>
    /// try to get a field by key
    /// </summary>
    public bool TryToGetField(string key, out DataField field)
      => _fields.TryGetValue(key?.ToLower() ?? "__noKey_", out field);

    /// <summary>
    /// Get a field by key
    /// </summary>
    public TDataField GetField<TDataField>(string key)
      where TDataField : DataField
        => (TDataField)_fields[key.ToLower()];

    /// <summary>
    /// try to get a field by key
    /// </summary>
    public TDataField TryToGetField<TDataField>(string key)
      where TDataField : DataField
        => _fields.TryGetValue(key.ToLower(), out var value)
         ? (TDataField)value
         : null;

    /// <summary>
    /// try to get a field by key
    /// </summary>
    public bool TryToGetField<TDataField>(string key, out TDataField field)
      where TDataField : DataField
        => _fields.TryGetValue(key.ToLower(), out var found)
          ? (field = (TDataField)found) != null
          : (field = null) != null;

    /// <summary>
    /// Get a field value by key
    /// </summary>
    public object GetFieldValue(string key)
      => _fields[key.ToLower()].Value;

    /// <summary>
    /// Get a field value by key
    /// </summary>
    public TValue GetFieldValue<TValue>(string key)
      => (TValue)_fields[key.ToLower()].Value;

    /// <summary>
    /// Try to Get a field value by key
    /// </summary>
    public TValue TryToGetValueFromKeyValueFieldSet<TValue>(string fieldKey, string valueKey) {
      object found = null;
      bool success = (TryToGetField(fieldKey) as DataFieldKeyValueSet)?.TryGetValue(valueKey, out found) ?? false;
      return  success ? (TValue)found : default;
    }

    /// <summary>
    /// Try to Get a field value by key
    /// </summary>
    public bool TryToGetValueFromKeyValueFieldSet<TValue>(string fieldKey, string valueKey, out TValue value) {
      object found = null;
      bool success = (TryToGetField(fieldKey) as DataFieldKeyValueSet)?.TryGetValue(valueKey, out found) ?? false;
      value = (TValue)(found ?? default(TValue));

      return success;
    }

    /// <summary>
    /// Get a field value by key
    /// </summary>
    public TValue GetValueFromKeyValueFieldSet<TValue>(string fieldKey, string valueKey)
      => (TValue)((DataFieldKeyValueSet)GetField(fieldKey)).Value[valueKey];

    /// <summary>
    /// Copy this view layout and current values to a brand new view with a new id.
    /// </summary>
    public View Copy() {
      OrderedDictionary<string, Pannel> newPannelDic = new();
      OrderedDictionary<string, Pannel.Tab> newTabDic = new();
      View newView = new(MainTitle) {
        _pannels = newPannelDic,
        _tabs = newTabDic
      };

      // copy the layout.
      _pannels.ForEach(pannel => newPannelDic.Add(pannel.Key, pannel.Value.Copy(newView)));
      _tabs.ForEach(tab => newTabDic.Add(tab.Key, tab.Value.Copy(newView)));
      // find the new fields.
      Dictionary<string, DataField> copiedFields = new();
      _fields = newPannelDic.Values
        .SelectMany(pannel => pannel.Elements._getExpandedFieldsByKey())
        .ToDictionary(
          e => e.Key,
          e => e.Value
        );

      // set up and return the copy
      newView.Context = Context;
      newView._pannels = newPannelDic;
      return newView;
    }

    /// <summary>
    /// <inheritdoc/>
    /// </summary>
    public IEnumerator<KeyValuePair<Pannel.Tab, Pannel>> GetEnumerator()
      => _pannels.Select(_pannelData => new KeyValuePair<Pannel.Tab, Pannel>(_tabs[_pannelData.Key.ToLower()], _pannelData.Value)).GetEnumerator();

    IEnumerator IEnumerable.GetEnumerator()
      => GetEnumerator();
  }
}