using System;
using System.Linq;
using System.Collections.Generic;
using SwissAcademic.Citavi;
using SwissAcademic.Citavi.Metadata;
using SwissAcademic.Collections;
using SwissAcademic.Drawing;
using System.Reflection;

namespace SwissAcademic.Citavi.Citations
{
	public class ComponentPartFilter
		:
		IComponentPartFilter
	{
		//CPS012 Add first or middle names for ambiguous last names v5.0
		//Version 5.0   Completely re-written for Citavi 6.4 (> Citavi 6.3.16)
		//Berücksichtigt die 3 neuen Werte: NameIdentity.LastNamePrefix, NameIdentity.LastNameFirstNameInitialMiddleNameInitial & NameIdentity.LastNameFirstNameInitialMiddleNameFull
		//Version 4.2   Added first name font style parameter
		//Version 4.1   Built-in option to insert non-breaking spaces and hyphens
		//Version 4.0   Completely re-written for Citavi 6 (6.2 or higher)
		//Disambiguation of identical person names by successively adding first name initials, full first names, middle name initals and full middle names (if available)
		public IEnumerable<ITextUnit> GetTextUnits(ComponentPart componentPart, Template template, Citation citation, out bool handled)
		{
			//Should only the primary authors be considered in checking last names for ambiguity?
			bool checkAmbiguityForPrimaryAuthorsOnly = false;
			
			//When a first and/or middle name is added for disambiguation, should that be before or after the last name?
			PersonNameOrder nameOrderForAmbiguityResolution = PersonNameOrder.FirstNameLastName;
			
			//Formatting of the first name; combine several styles with a pipe character
			//FontStyle firstNameFontStyle = FontStyle.Bold | FontStyle.Italic;
			FontStyle firstNameFontStyle = FontStyle.Neutral;
			
			//In case of ambiguous last names, should the first attempt to disambigutate be the addition of full first names or just the initials?
			NameFormat firstNameFormatForAmbiguityResolution = NameFormat.Abbreviated; 
			//NameFormat.Full					John Mike
			//NameFormat.Abbreviated			J. M.
			//NameFormat.AbbreviatedNoPeriod	J M
			//NameFormat.AbbreviatedCompact		J.M.
			//NameFormat.Compact				JM
			
			//Insert non-breaking spaces and hyphens - geschütztes Leerzeichen und geschützten Bindestrich einfügen
			var useNonBreakingSpacesInAndBetweenFirstAndMiddleNames = true;		//if true, then e.g. Meyers, J.°R.
			var useNonBreakingSpaceBetweenLastAndFirstName = true;				//if true, then e.g. Meyers,°John Richard
			var useNonBreakingSpaceBetweenPrefixAndName = true;					//if true, then e.g. von°Bülow, V.
			var useNonBreakingHyphenInFirstAndMiddleName = true;				//if true, then e.g. Ewing, J.-R.
			
			handled = false;

			if (citation == null || citation.Reference == null) return null;
			if (componentPart == null || componentPart.Elements == null || !componentPart.Elements.Any()) return null;
			
			CitationManager citationManager = citation.CitationManager;
			if (citationManager == null) return null;

			PersonFieldElement personFieldElement = componentPart.Elements.OfType<PersonFieldElement>().FirstOrDefault();
			if (personFieldElement == null) return null;
			if (personFieldElement.SuppressOutput) return null;
			
			#region Insert non-breaking spaces and hyphens
			
			IEnumerable<PersonFieldElement> personFieldElements = componentPart.Elements.OfType<PersonFieldElement>();
			if (personFieldElements == null || personFieldElements.Count() == 0) return null;
			
			
			foreach(PersonFieldElement element in personFieldElements)
			{
				if (useNonBreakingSpacesInAndBetweenFirstAndMiddleNames)
				{
					element.FirstGroupUseNonBreakingSpaceInAndBetweenFirstAndMiddleNames = true;
					element.SecondGroupUseNonBreakingSpaceInAndBetweenFirstAndMiddleNames = true;
					element.LastPersonUseNonBreakingSpaceInAndBetweenFirstAndMiddleNames = true;				
				}

				if (useNonBreakingSpaceBetweenLastAndFirstName)
				{
					element.FirstGroupUseNonBreakingSpaceBetweenLastAndFirstName = true;
					element.SecondGroupUseNonBreakingSpaceBetweenLastAndFirstName = true;
					element.LastPersonUseNonBreakingSpaceBetweenLastAndFirstName = true;				
				}

				if (useNonBreakingSpaceBetweenPrefixAndName)
				{
					element.FirstGroupUseNonBreakingSpaceBetweenPrefixAndName = true;
					element.SecondGroupUseNonBreakingSpaceBetweenPrefixAndName = true;
					element.LastPersonUseNonBreakingSpaceBetweenPrefixAndName = true;
				}

				if (useNonBreakingHyphenInFirstAndMiddleName)
				{
					element.FirstGroupUseNonBreakingHyphenInFirstAndMiddleNames = true;
					element.SecondGroupUseNonBreakingHyphenInFirstAndMiddleNames = true;
					element.LastPersonUseNonBreakingHyphenInFirstAndMiddleNames = true;
				}
			}
			
			#endregion
			
			#region BeforeFormatPerson: Resolve last name ambiguity

			BeforeFormatPersonEventArgs bfp;
			personFieldElement.PersonFormatter.BeforeFormatPerson +=
			(sender, e) =>
			{
				bfp = (BeforeFormatPersonEventArgs)e;
				if (bfp.Person == null) return;
				if (checkAmbiguityForPrimaryAuthorsOnly && bfp.Index > 1) return;

				bool isLastNameAmbiguous = checkAmbiguityForPrimaryAuthorsOnly ? 
					citationManager.IsFirstCitedPersonLastnameAmbiguous(bfp.Person.LastName) :
					citationManager.IsCitedPersonLastNameAmbiguous(bfp.Person.LastName);
				
				if (!isLastNameAmbiguous) return;
				
				NameIdentity nameIdentity = checkAmbiguityForPrimaryAuthorsOnly ? 
					citationManager.GetFirstPersonNameIdentity(bfp.Person) :
					citationManager.GetPersonNameIdentity(bfp.Person);
				
				/*														PERSON A				PERSON B
				NameIdentity.None										Müller, Gerd Jakob		Meier, Konrad Martin
				NameIdentity.LastName									Müller, Gerd Jakob		Müller, Konrad Martin
				NameIdentity.LastNamePrefix								Müller, Gerd Jakob von	Müller, Konrad Martin von
				NameIdentity.LastNameFirstNameInitial					Müller, Gerd Jakob		Müller, Gustav Martin
				NameIdentity.LastNameFirstNameFull						Müller, Gerd Jakob		Müller, Gerd Martin
				NameIdentity.LastNameFirstNameFullMiddleNameInitial		Müller, Gerd Jakob		Müller, Gerd Johann
				NameIdentity.LastNameFirstNameFullMiddleNameFull		Müller, Gerd Jakob		Müller, Gerd Jakob [der Ältere]
				*/
				switch (nameIdentity)
				{
					case NameIdentity.LastName:
						{
							if (!string.IsNullOrEmpty(bfp.Person.Prefix))
							{
								bfp.FirstNameFormat = firstNameFormatForAmbiguityResolution;
								bfp.MiddleNameUsage = MiddleNameUsage.None;
								break;
							}
							else
							{
								bfp.FirstNameFormat = firstNameFormatForAmbiguityResolution;
								bfp.MiddleNameFormat = firstNameFormatForAmbiguityResolution;
								bfp.MiddleNameUsage = MiddleNameUsage.All;
								break;
							}
						}
					case NameIdentity.LastNamePrefix:
						{
							bfp.FirstNameFormat = firstNameFormatForAmbiguityResolution;
							bfp.MiddleNameFormat = firstNameFormatForAmbiguityResolution;
							bfp.MiddleNameUsage = MiddleNameUsage.All;
							bfp.NamePrefixFontStyle = firstNameFontStyle;
							break;
						}
					case NameIdentity.LastNameFirstNameInitial:
						{
							if (!string.IsNullOrEmpty(bfp.Person.MiddleName))
							{
								bfp.FirstNameFormat = firstNameFormatForAmbiguityResolution;
								bfp.MiddleNameFormat = firstNameFormatForAmbiguityResolution;
								bfp.MiddleNameUsage = MiddleNameUsage.All;
								break;
							}
							else
							{
								bfp.FirstNameFormat = NameFormat.Full;
								bfp.MiddleNameFormat = NameFormat.Full;
								bfp.MiddleNameUsage = MiddleNameUsage.All;
								break;
							}
						}
					case NameIdentity.LastNameFirstNameInitialMiddleNameInitial:
						{
							bfp.FirstNameFormat = NameFormat.Full;
							bfp.MiddleNameFormat = NameFormat.Full;
							bfp.MiddleNameUsage = MiddleNameUsage.All;
							break;
						}
					case NameIdentity.LastNameFirstNameInitialMiddleNameFull:
						{
							bfp.FirstNameFormat = NameFormat.Full;
							bfp.MiddleNameFormat = NameFormat.Full;
							bfp.MiddleNameUsage = MiddleNameUsage.All;
							break;
						}
					case NameIdentity.LastNameFirstNameFull:
						{
							bfp.FirstNameFormat = firstNameFormatForAmbiguityResolution;
							bfp.MiddleNameFormat = firstNameFormatForAmbiguityResolution;
							bfp.MiddleNameUsage = MiddleNameUsage.All;
							break;
						}
					case NameIdentity.LastNameFirstNameFullMiddleNameInitial:
						{
							bfp.FirstNameFormat = NameFormat.Full;
							bfp.MiddleNameFormat = NameFormat.Full;
							bfp.MiddleNameUsage = MiddleNameUsage.All;
							break;
						}
					case NameIdentity.LastNameFirstNameFullMiddleNameFull:
						{
							//we can safely assume, that they have a different title or name addendum, like Jr. Sr. etc.
							bfp.SuppressNameSuffix = false;
							bfp.MiddleNameUsage = MiddleNameUsage.None;
							break;
						}
					case NameIdentity.None:
					default:
					{
						return;
					}
				}
				
				bfp.NameOrder = nameOrderForAmbiguityResolution;
			};

			#endregion

			return null;
		}
	}
}