using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace SmartStore.Data.Setup
{
	internal class LocaleResourceEntry
	{
		public string Key { get; set; }
		public string Value { get; set; }
		public string Lang { get; set; }

		public bool UpdateOnly { get; set; }
		public bool Important { get; set; }
	}

	public interface IResourceAddBuilder : IHideObjectMembers
	{
		IResourceAddBuilder Value(string value);
		IResourceAddBuilder Value(string lang, string value);
		IResourceAddBuilder Hint(string value);
		IResourceAddBuilder Hint(string lang, string value);
	}
	
	public class LocaleResourcesBuilder : IHideObjectMembers
	{
		private readonly List<LocaleResourceEntry> _entries = new List<LocaleResourceEntry>();

		/// <summary>
		/// Deletes one or many locale resources in any language from the database
		/// </summary>
		/// <param name="keys">The key(s) of the resources to delete</param>
		public void Delete(params string[] keys)
		{
			keys.Each(x => _entries.Add(new LocaleResourceEntry { Key = x, Important = true }));
		}

		/// <summary>
		/// Deletes one or many locale resources in the specified language from the database
		/// </summary>
		/// <param name="lang">The language identifier</param>
		/// <param name="keys">The key(s) of the resources to delete</param>
		public void DeleteFor(string lang, params string[] keys)
		{
			Guard.NotEmpty(lang, nameof(lang));
			lang = lang.NullEmpty();

			keys.Each(x => _entries.Add(new LocaleResourceEntry { Key = x, Lang = lang, Important = true }));
		}

		/// <summary>
		/// Updates existing locale resources
		/// </summary>
		/// <param name="key">The key of the resource</param>
		/// <returns>IResourceAddBuilder</returns>
		public IResourceAddBuilder Update(string key)
		{
			Guard.NotEmpty(key, nameof(key));

			Action<string, string, bool> fn = (string v, string l, bool isHint) =>
			{
				string k = key;
				if (isHint)
				{
					k += ".Hint";
				}

				_entries.Add(new LocaleResourceEntry { Key = k, Value = v, Lang = l, UpdateOnly = true });
			};

			return new ResourceAddBuilder(key, fn);
		}

		/// <summary>
		/// Adds or updates locale resources
		/// </summary>
		/// <param name="key">The key of the resource</param>
		/// <returns>IResourceAddBuilder</returns>
		public IResourceAddBuilder AddOrUpdate(string key)
		{
			Guard.NotEmpty(key, nameof(key));

			Action<string, string, bool> fn = (string v, string l, bool isHint) => 
			{
				string k = key;
				if (isHint)
				{
					k += ".Hint";
				}

				_entries.Add(new LocaleResourceEntry { Key = k, Value = v, Lang = l });
			};

			return new ResourceAddBuilder(key, fn);
		}

		/// <summary>
		/// Adds or updates locale resources
		/// </summary>
		/// <param name="key">The key of the resource</param>
		/// <param name="value">Primary English (untranslated) value of the resource</param>
		/// <param name="deValue">German value of the resource</param>
		public void AddOrUpdate(string key, string value, string deValue)
		{
			Guard.NotEmpty(key, nameof(key));

			_entries.Add(new LocaleResourceEntry { Key = key, Value = value });
			_entries.Add(new LocaleResourceEntry { Key = key, Value = deValue, Lang = "de" });
		}

		/// <summary>
		/// Adds or updates locale resources
		/// </summary>
		/// <param name="key">The key of the resource</param>
		/// <param name="value">Primary English (untranslated) value of the resource</param>
		/// <param name="deValue">German value of the resource</param>
		/// <param name="hint">Primary English (untranslated) hint resource</param>
		/// <param name="deHint">German hint resource</param>
		public void AddOrUpdate(string key, string value, string deValue, string hint, string deHint)
		{
			Guard.NotEmpty(key, nameof(key));

			AddOrUpdate(key, value, deValue);
			AddOrUpdate(key + ".Hint", hint, deHint);
		}

		internal void Reset()
		{
			_entries.Clear();
		}

		internal IEnumerable<LocaleResourceEntry> Build()
		{
			return _entries.OrderByDescending(x => x.Important).ThenBy(x => x.Lang).ToList();
		}

		#region Nested builder for AddOrUpdate

		internal class ResourceAddBuilder : IResourceAddBuilder
		{
			private readonly Action<string, string, bool> _fn;

			public ResourceAddBuilder(string key, Action<string, string, bool> fn)
			{
				_fn = fn;
			}
			
			public IResourceAddBuilder Value(string value)
			{
				return Value(null, value);
			}

			public IResourceAddBuilder Value(string lang, string value)
			{
				Guard.NotEmpty(value, nameof(value));
				_fn(value, lang.NullEmpty(), false);
				return this;
			}


			public IResourceAddBuilder Hint(string value)
			{
				return Hint(null, value);
			}

			public IResourceAddBuilder Hint(string lang, string value)
			{
				Guard.NotEmpty(value, nameof(value));
				_fn(value, lang.NullEmpty(), true);
				return this;
			}
		}

		#endregion

	}
}
