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

namespace Demos.Warden.TagTextEditing
{
    public class FlowDocumentWalker
    {
        public delegate void ElementAction(TagBaseElement element, Inline inlineOwner);

        public Exception[] PerformActionOnTagElements(FlowDocument document, ElementAction actionOnTagElement)
        {
            List<Exception> encounteredCatchedExceptions = new List<Exception>();

            Block[] blocks = document.Blocks.ToArray<Block>();
            foreach (Block block in blocks)
            {
                encounteredCatchedExceptions.AddRange(this.performActionOnTEBlocks(block, actionOnTagElement));
            }
            
            return encounteredCatchedExceptions.ToArray();
        }

        private Exception[] performActionOnTEBlocks(Block block, ElementAction action)
        {
            List<Exception> encounteredCatchedExceptions = new List<Exception>();

            try
            {

                if (block is Paragraph)
                {
                    encounteredCatchedExceptions.AddRange(this.performActionOnTEInParagraph((Paragraph)block, action));
                }
                else if (block is Table)
                {
                    encounteredCatchedExceptions.AddRange(this.performActionOnTEInTable((Table)block, action));
                }
                else
                {
                    encounteredCatchedExceptions.Add(new NotImplementedException(String.Format("Conversion method for block of type {0} is missing.", block.GetType())));
                }
            }
            catch (Exception exception) { encounteredCatchedExceptions.Add(exception); }

            return encounteredCatchedExceptions.ToArray();
        }

        private Exception[] performActionOnTEInParagraph(Paragraph paragraph, ElementAction action)
        {
            List<Exception> encounteredCatchedExceptions = new List<Exception>();

            Inline[] inlines = paragraph.Inlines.ToArray<Inline>();
            foreach (Inline curInline in inlines)
            {
                if (!(curInline is TagBaseElement))
                {
                    continue;
                }

                TagBaseElement myElement = (TagBaseElement)curInline;

                action(myElement, curInline);
            }

            return encounteredCatchedExceptions.ToArray();
        }

        private Exception[] performActionOnTEInTable(Table table, ElementAction action)
        {
            List<Exception> encounteredCatchedExceptions = new List<Exception>();

            try
            {

                foreach (TableRowGroup trg in table.RowGroups)
                {
                    foreach (TableRow tr in trg.Rows)
                    {
                        foreach (TableCell tc in tr.Cells)
                        {
                            foreach (Block block in tc.Blocks.ToArray<Block>())
                            {
                                encounteredCatchedExceptions.AddRange(this.performActionOnTEBlocks(block, action));
                            }
                        }
                    }
                }
            }
            catch (Exception ex) { encounteredCatchedExceptions.Add(ex); }

            return encounteredCatchedExceptions.ToArray();
        }
    }
}