using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Text.RegularExpressions;

namespace ST.Library.UI.STTextBox
{
 public partial class STTextBox
 {
 protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
 switch (keyData) {
 case Keys.Back:
 this.ProcessBackSpaceKey();
 return true;
 case Keys.Tab:
 this.ProcessTabKey();
 return true;
 case Keys.Enter:
 this.ProcessEnter();
 return true;
 //========================================================
 case Keys.Left:
 this.ProcessLeftKey(false);
 return true;
 case Keys.Right:
 this.ProcessRightKey(false);
 return true;
 case Keys.Up:
 this.ProcessUpKey(false);
 return true;
 case Keys.Down:
 this.ProcessDownKey(false);
 return true;
 case Keys.Home:
 this.ProcessHomeKey(false);
 return true;
 case Keys.End:
 this.ProcessEndKey(false);
 return true;
 case Keys.PageUp:
 this.ProcessPageUpKey(false);
 return true;
 case Keys.PageDown:
 this.ProcessPageDownKey(false);
 return true;
 //========================================================
 case Keys.Shift | Keys.Tab:
 this.ProcessShiftTabKey();
 return true;
 case Keys.Shift | Keys.Up:
 this.ProcessUpKey(true);
 return true;
 case Keys.Shift | Keys.Down:
 this.ProcessDownKey(true);
 return true;
 case Keys.Shift | Keys.Left:
 this.ProcessLeftKey(true);
 return true;
 case Keys.Shift | Keys.Right:
 this.ProcessRightKey(true);
 return true;
 case Keys.Shift | Keys.Home:
 this.ProcessHomeKey(true);
 return true;
 case Keys.Shift | Keys.End:
 this.ProcessEndKey(true);
 return true;
 case Keys.Shift | Keys.PageUp:
 this.ProcessPageUpKey(true);
 return true;
 case Keys.Shift | Keys.PageDown:
 this.ProcessPageDownKey(true);
 return true;
 //========================================================
 case Keys.Control | Keys.A:
 this.SelectAll();
 return true;
 case Keys.Control | Keys.C:
 this.Copy();
 return true;
 case Keys.Control | Keys.X:
 this.Cut();
 return true;
 case Keys.Control | Keys.V:
 this.Paste();
 return true;
 case Keys.Control | Keys.Z:
 this.Undo();
 return true;
 case Keys.Control | Keys.Y:
 this.Redo();
 return true;
 }
 return base.ProcessCmdKey(ref msg, keyData);
 }

 protected override void OnKeyPress(KeyPressEventArgs e) {
 base.OnKeyPress(e);
 if (e.KeyChar < 32/* || e.KeyChar > 126*/) {
 return;
 }
 this.EnterText(e.KeyChar.ToString());
 }
 //==================================================================================
 private void ProcessEnter() {
 var c = m_core;
 string strText = "\r\n";
 if (this._AutoIndent) {
 strText += Regex.Match(
 c.TextManager[c.TextManager.GetLineIndexFromCharIndex(c.Caret.IndexOfChar)].RawString,
 @"^[ \t]+" //Space,TAB
 ).Value;
 }
 this.EnterText(strText);
 }

 private void ProcessTabKey() {
 var c = m_core;
 int nIndexStartLine = 0, nIndexEndLine = 0;
 if (!c.Selection.IsEmptySelection) {
 nIndexStartLine = c.TextManager.GetLineIndexFromCharIndex(c.Selection.StartIndex);
 nIndexEndLine = c.TextManager.GetLineIndexFromCharIndex(c.Selection.EndIndex);
 }
 if (nIndexStartLine == nIndexEndLine) {
 if (!this._TabToSpace) {
 this.EnterText("\t");
 } else {
 float fSpaceCount = c.ITextBoxRender.GetTabSpaceCount(c.ITextView.GetCurrentCharOffset(), this._TabSize);
 this.EnterText("".PadLeft((int)Math.Ceiling(fSpaceCount)));
 }
 } else {
 string strInsert = this._TabToSpace ? "".PadLeft(this._TabSize) : "\t";
 var histories = c.TextManager.InsertAtStart(nIndexStartLine, nIndexEndLine - nIndexStartLine + 1, strInsert);
 c.ITextHistory.SetHistory(histories);
 var lineStart = c.TextManager[nIndexStartLine];
 var lineEnd = c.TextManager[nIndexEndLine];
 c.Selection.SetSelection(lineStart.IndexOfFirstChar, lineEnd.IndexOfFirstChar + lineEnd.GetLengthWithoutNewline());
 c.Caret.IndexOfChar = c.Selection.EndIndex;
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 }
 }

 private void ProcessShiftTabKey() {
 var c = m_core;
 int nIndexStartLine = 0, nIndexEndLine = 0;
 nIndexStartLine = c.TextManager.GetLineIndexFromCharIndex(c.Selection.StartIndex);
 nIndexEndLine = c.TextManager.GetLineIndexFromCharIndex(c.Selection.EndIndex);
 if (nIndexStartLine == nIndexEndLine) {
 var line = c.TextManager[nIndexStartLine];
 for (int i = 0; i < line.RawString.Length; i++) {
 switch (line.RawString[i]) {
 case ' ':
 case '\t':
 continue;
 default:
 break;
 }
 if (i == 0 || i + line.IndexOfFirstChar < c.Selection.StartIndex) {
 return;
 }
 }
 }
 var histories = c.TextManager.TrimStartTab(nIndexStartLine, nIndexEndLine - nIndexStartLine + 1, this._TabSize);
 c.ITextHistory.SetHistory(histories.ToArray());
 var lineStart = c.TextManager[nIndexStartLine];
 var lineEnd = c.TextManager[nIndexEndLine];
 c.Selection.SetSelection(lineStart.IndexOfFirstChar, lineEnd.IndexOfFirstChar + lineEnd.GetLengthWithoutNewline());
 c.Caret.IndexOfChar = c.Selection.EndIndex;
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 }

 private void ProcessBackSpaceKey() {
 var c = m_core;
 if (c.Caret.IndexOfChar == 0 && c.Selection.IsEmptySelection) {
 return;
 }
 if (c.Selection.IsEmptySelection) {
 //c.Selection.SetIndex(c.Caret.IndexOfChar);
 int nLineIndex = c.TextManager.GetLineIndexFromCharIndex(c.Caret.IndexOfChar);
 TextLine stLine = c.TextManager[nLineIndex];
 if (c.Caret.IndexOfChar == stLine.IndexOfFirstChar) {//if the index is the line start index
 stLine = c.TextManager[nLineIndex - 1];
 //c.Selection.StartIndex -= stLine.RawString.Length - stLine.GetLengthWithoutNewline();
 c.Selection.SetSelection(c.Caret.IndexOfChar, c.Caret.IndexOfChar - (stLine.RawString.Length - stLine.GetLengthWithoutNewline()));
 } else {
 int nIndex = stLine.IndexOfFirstChar;
 c.IGraphemeSplitter.Each(stLine.RawString, (str, nStart, nLen) => {
 if (nIndex + nLen >= c.Caret.IndexOfChar) {
 return false;
 }
 nIndex += nLen;
 return true;
 });
 //c.Selection.StartIndex = nIndex;
 c.Selection.SetSelection(nIndex, c.Caret.IndexOfChar);
 }
 }
 this.EnterText("");
 }

 private void ProcessUpKey(bool bShiftDown) {
 var c = m_core;
 if (c.Scroll.YValue == 0 && c.Caret.Y - m_core.ViewRectangle.Y < m_core.LineHeight) {
 return;
 }
 c.Caret.Y -= c.LineHeight;// c.ITextRender.GetFontHeight();
 var fi = c.ITextView.FindFromPoint(c.Caret.Location);
 if (!c.Caret.CopyFromFindInfo(fi)) {
 return;
 }
 bool bRedraw = false;
 if (bShiftDown) {
 c.Selection.SetSelection(c.Caret.IndexOfChar);
 bRedraw = true;
 } else {
 if (!c.Selection.IsEmptySelection) {
 bRedraw = true;
 c.Caret.IndexOfChar = c.Selection.StartIndex;
 }
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 }
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 if (c.ITextView.ScrollToCaret() || bRedraw) {
 this.Invalidate();
 }
 }

 private void ProcessDownKey(bool bShiftDown) {
 var c = m_core;
 if (c.Caret.IndexOfLine >= c.TextManager.LineCount - 1) {
 //return;
 }
 c.Caret.Y += c.LineHeight;// c.ITextRender.GetFontHeight();
 var fi = c.ITextView.FindFromPoint(c.Caret.Location);
 if (!c.Caret.CopyFromFindInfo(fi)) {
 return;
 }
 bool bRedraw = false;
 if (bShiftDown) {
 c.Selection.SetSelection(c.Caret.IndexOfChar);
 bRedraw = true;
 } else {
 if (!c.Selection.IsEmptySelection) {
 bRedraw = true;
 c.Caret.IndexOfChar = c.Selection.EndIndex;
 }
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 }
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 if (c.ITextView.ScrollToCaret() || bRedraw) {
 this.Invalidate();
 }
 }

 private void ProcessLeftKey(bool bShiftDown) {
 var c = m_core;
 bool bRedraw = false;
 if (bShiftDown) {
 var nIndex = c.TextBox.FindLeftIndex(c.Caret.IndexOfChar);
 if (nIndex == c.Caret.IndexOfChar) {
 return;
 }
 c.Caret.IndexOfChar = nIndex;
 c.Selection.SetSelection(c.Caret.IndexOfChar);
 bRedraw = true;
 } else {
 if (!c.Selection.IsEmptySelection) {
 bRedraw = true;
 c.Caret.IndexOfChar = c.Selection.StartIndex;
 } else {
 var nIndex = c.TextBox.FindLeftIndex(c.Caret.IndexOfChar);
 if (nIndex == c.Caret.IndexOfChar) {
 return;
 }
 c.Caret.IndexOfChar = nIndex;
 }
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 }
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 if (c.ITextView.ScrollToCaret() || bRedraw) {
 this.Invalidate();
 }
 }

 private void ProcessRightKey(bool bShiftDown) {
 var c = m_core;
 bool bRedraw = false;
 if (bShiftDown) {
 var nIndex = c.TextBox.FindRightIndex(c.Caret.IndexOfChar);
 if (nIndex == c.Caret.IndexOfChar) {
 return;
 }
 c.Caret.IndexOfChar = nIndex;
 c.Selection.SetSelection(nIndex);
 bRedraw = true;
 } else {
 if (!c.Selection.IsEmptySelection) {
 bRedraw = true;
 c.Caret.IndexOfChar = c.Selection.EndIndex;
 } else {
 var nIndex = c.TextBox.FindRightIndex(c.Caret.IndexOfChar);
 if (nIndex == c.Caret.IndexOfChar) {
 return;
 }
 c.Caret.IndexOfChar = nIndex;
 }
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 }
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 if (c.ITextView.ScrollToCaret() || bRedraw) {
 this.Invalidate();
 }
 }

 private void ProcessHomeKey(bool bShiftDown) {
 var c = m_core;
 bool bRedraw = false;
 var stLine = c.TextManager.GetLineFromCharIndex(c.Caret.IndexOfChar);
 c.Caret.IndexOfChar = stLine.IndexOfFirstChar;
 if (bShiftDown) {
 c.Selection.SetSelection(c.Caret.IndexOfChar);
 bRedraw = true;
 } else {
 if (!c.Selection.IsEmptySelection) {
 bRedraw = true;
 }
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 }
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 if (c.ITextView.ScrollToCaret() || bRedraw) {
 this.Invalidate();
 }
 }

 private void ProcessEndKey(bool bShiftDown) {
 var c = m_core;
 bool bRedraw = false;
 var stLine = c.TextManager.GetLineFromCharIndex(c.Caret.IndexOfChar);
 //c.Caret.IndexOfChar = stLine.IndexOfFirstChar + stLine.RawString.Length;
 c.Caret.IndexOfChar = stLine.IndexOfFirstChar + stLine.GetLengthWithoutNewline();
 if (bShiftDown) {
 c.Selection.SetSelection(c.Caret.IndexOfChar);
 bRedraw = true;
 } else {
 if (!c.Selection.IsEmptySelection) {
 bRedraw = true;
 }
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 }
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 if (c.ITextView.ScrollToCaret() || bRedraw) {
 this.Invalidate();
 }
 }

 private void ProcessPageUpKey(bool bShiftDown) {
 var c = m_core;
 if (c.Scroll.YValue == 0) {
 return;
 }
 int nCurrentLineCount = this.Height / c.LineHeight;
 c.Scroll.YValue -= nCurrentLineCount;
 if (c.Scroll.YValue < 0) {
 c.Scroll.YValue = 0;
 c.Caret.Y = 0;
 }
 var fi = c.ITextView.SetCaretPostion(c.Caret.Location);// c.ITextView.FindFromPoint(c.Caret.Location);
 if (!fi.Find) {
 return;
 }
 //c.Caret.CopyFromFindInfo(fi);
 if (bShiftDown) {
 c.Selection.SetSelection(c.Caret.IndexOfChar);
 } else {
 if (!c.Selection.IsEmptySelection) {
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 this.Invalidate();
 } else {
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 }
 }
 //c.ITextView.SetCaretPostion(c.Caret.X, c.Caret.Y);
 this.Invalidate();
 }

 private void ProcessPageDownKey(bool bShiftDown) {
 var c = m_core;
 if (c.Scroll.YValue == c.Scroll.MaxYValue) {
 return;
 }
 int nCurrentLineCount = this.Height / c.LineHeight;
 c.Scroll.YValue += nCurrentLineCount;
 if (c.Scroll.YValue > c.Scroll.MaxYValue) {
 c.Scroll.YValue = c.Scroll.MaxYValue;
 }
 var fi = c.ITextView.SetCaretPostion(c.Caret.Location);// c.ITextView.FindFromPoint(c.Caret.Location);
 if (!fi.Find) {
 return;
 }
 //c.Caret.CopyFromFindInfo(fi);
 if (bShiftDown) {
 c.Selection.SetSelection(c.Caret.IndexOfChar);
 } else {
 if (!c.Selection.IsEmptySelection) {
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 this.Invalidate();
 } else {
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 }
 }
 //c.ITextView.SetCaretPostion(c.Caret.X, c.Caret.Y);
 this.Invalidate();
 }

 private void EnterText(string strText) {
 var c = m_core;
 var history = c.TextManager.SetText(c.Selection.StartIndex, c.Selection.Length, strText);
 if (history != TextHistoryRecord.Empty) {
 c.ITextHistory.SetHistory(new TextHistoryRecord[] { history });
 }
 c.Caret.IndexOfChar = c.Selection.StartIndex + strText.Length;
 c.ITextView.SetCaretPostion(c.Caret.IndexOfChar);
 c.Selection.SetIndex(c.Caret.IndexOfChar);
 c.ITextView.ScrollToCaret();
 //this.Invalidate();
 }
 //==================================================
 private int FindRightIndex(int nIndex) {
 var c = m_core;
 if (nIndex >= c.TextManager.TextLength) {
 return c.TextManager.TextLength;
 }
 int nLineIndex = c.TextManager.GetLineIndexFromCharIndex(nIndex);
 var line = c.TextManager[nLineIndex];
 c.IGraphemeSplitter.Each(line.RawString, nIndex - line.IndexOfFirstChar, (str, nStart, nLen) => {
 nIndex += nLen;
 return false;
 });
 return nIndex;
 }
 //private FindInfo FindRightChar(int nIndex) {
 // //TODO: add location for return;
 // var c = m_core;
 // if (nIndex >= c.TextManager.TextLength) {
 // return FindInfo.Empty;
 // }
 // int nLineIndex = c.TextManager.GetLineIndexFromCharIndex(nIndex);
 // var line = c.TextManager[nLineIndex];
 // c.IGraphemeSplitter.Each(line.RawString, nIndex - line.IndexOfFirstChar, (str, nStart, nLen) => {
 // nIndex += nLen;
 // return false;
 // });
 // return new FindInfo() {
 // Find = true,
 // Line = line,
 // IndexOfCharInLine = nIndex - line.IndexOfFirstChar,
 // IndexOfLine = nLineIndex,
 // };
 //}

 public int FindLeftIndex(int nIndex) {
 var c = m_core;
 if (nIndex <= 1) return 0;
 int nLineIndex = c.TextManager.GetLineIndexFromCharIndex(nIndex);
 TextLine line = c.TextManager[nLineIndex];
 if (nIndex == line.IndexOfFirstChar) {
 line = c.TextManager[--nLineIndex];
 if (line.RawString.Length > 1 && line.RawString[line.RawString.Length - 2] == '\r') {
 nIndex -= 2;
 } else {
 nIndex -= 1;
 }
 } else {
 int nIndexRet = line.IndexOfFirstChar;
 c.IGraphemeSplitter.Each(line.RawString, (str, nStart, nLen) => {
 if (nIndexRet + nLen >= nIndex) {
 return false;
 }
 nIndexRet += nLen;
 return true;
 });
 nIndex = nIndexRet;
 }
 return nIndex;
 }

 //private FindInfo FindLeftChar(int nIndex) {
 // //TODO: add location for return;
 // var c = m_core;
 // if (nIndex <= 1) return new FindInfo() {
 // Find = true,
 // Line = c.TextManager[0]
 // };
 // int nLineIndex = c.TextManager.GetLineIndexFromCharIndex(nIndex);
 // TextLine line = c.TextManager[nLineIndex];
 // if (nIndex == line.IndexOfFirstChar) {
 // line = c.TextManager[--nLineIndex];
 // if (line.RawString.Length > 1 && line.RawString[line.RawString.Length - 2] == '\r') {
 // nIndex -= 2;
 // } else {
 // nIndex -= 1;
 // }
 // } else {
 // int nIndexRet = line.IndexOfFirstChar;
 // c.IGraphemeSplitter.Each(line.RawString, (str, nStart, nLen) => {
 // if (nIndexRet + nLen >= nIndex) {
 // return false;
 // }
 // nIndexRet += nLen;
 // return true;
 // });
 // nIndex = nIndexRet;
 // }
 // return new FindInfo() {
 // Find = true,
 // Line = line,
 // IndexOfCharInLine = nIndex - line.IndexOfFirstChar,
 // IndexOfLine = nLineIndex
 // };
 //}
 }
}