/*
** c_commandbuffer.cpp
**
**---------------------------------------------------------------------------
** Copyright 1998-2006 Randy Heit
** Copyright 2010-2020 Christoph Oelckers
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/
#include "c_commandbuffer.h"
#include "v_draw.h"
#include "v_2ddrawer.h"
#include "v_font.h"
#include "utf8.h"

FCommandBuffer CmdLine;

FCommandBuffer::FCommandBuffer(const FCommandBuffer &o)
{
	Text = o.Text;
	CursorPos = o.CursorPos;
	StartPos = o.StartPos;
}

FString FCommandBuffer::GetText() const
{
	FString build;
	for (auto chr : Text) build.AppendCharacter(chr);
	return build;
}

void FCommandBuffer::Draw(int x, int y, int scale, bool cursor)
{
	if (scale == 1)
	{
		DrawChar(twod, CurrentConsoleFont, CR_ORANGE, x, y, '\x1c', TAG_DONE);
		DrawText(twod, CurrentConsoleFont, CR_ORANGE, x + CurrentConsoleFont->GetCharWidth(0x1c), y,
			&Text[StartPos], TAG_DONE);

		if (cursor)
		{
			DrawChar(twod, CurrentConsoleFont, CR_YELLOW,
				x + CurrentConsoleFont->GetCharWidth(0x1c) + (CursorPosCells - StartPosCells) * CurrentConsoleFont->GetCharWidth(0xb),
				y, '\xb', TAG_DONE);
		}
	}
	else
	{
		DrawChar(twod, CurrentConsoleFont, CR_ORANGE, x, y, '\x1c',
			DTA_VirtualWidth, twod->GetWidth() / scale,
			DTA_VirtualHeight, twod->GetHeight() / scale,
			DTA_KeepRatio, true, TAG_DONE);

		DrawText(twod, CurrentConsoleFont, CR_ORANGE, x + CurrentConsoleFont->GetCharWidth(0x1c), y,
			&Text[StartPos],
			DTA_VirtualWidth, twod->GetWidth() / scale,
			DTA_VirtualHeight, twod->GetHeight() / scale,
			DTA_KeepRatio, true, TAG_DONE);

		if (cursor)
		{
			DrawChar(twod, CurrentConsoleFont, CR_YELLOW,
				x + CurrentConsoleFont->GetCharWidth(0x1c) + (CursorPosCells - StartPosCells) * CurrentConsoleFont->GetCharWidth(0xb),
				y, '\xb',
				DTA_VirtualWidth, twod->GetWidth() / scale,
				DTA_VirtualHeight, twod->GetHeight() / scale,
				DTA_KeepRatio, true, TAG_DONE);
		}
	}
}

unsigned FCommandBuffer::CalcCellSize(unsigned length)
{
	unsigned cellcount = 0;
	for (unsigned i = 0; i < length; i++)
	{
		int w = NewConsoleFont->GetCharWidth(Text[i]);
		cellcount += w / 9;
	}
	return cellcount;

}

unsigned FCommandBuffer::CharsForCells(unsigned cellin, bool *overflow)
{
	unsigned chars = 0;
	int cells = cellin;
	while (cells > 0)
	{
		int w = NewConsoleFont->GetCharWidth(Text[chars++]);
		cells -= w / 9;
	}
	*overflow = (cells < 0);
	return chars;
}


void FCommandBuffer::MakeStartPosGood()
{
	// Make sure both values point to something valid.
	if (CursorPos > Text.length()) CursorPos = (unsigned)Text.length();
	if (StartPos > Text.length()) StartPos = (unsigned)Text.length();

	CursorPosCells = CalcCellSize(CursorPos);
	StartPosCells = CalcCellSize(StartPos);
	unsigned LengthCells = CalcCellSize((unsigned)Text.length());

	int n = StartPosCells;
	unsigned cols = ConCols / active_con_scale(twod);

	if (StartPosCells >= LengthCells)
	{ // Start of visible line is beyond end of line
		n = CursorPosCells - cols + 2;
	}
	if ((CursorPosCells - StartPosCells) >= cols - 2)
	{ // The cursor is beyond the visible part of the line
		n = CursorPosCells - cols + 2;
	}
	if (StartPosCells > CursorPosCells)
	{ // The cursor is in front of the visible part of the line
		n = CursorPosCells;
	}
	StartPosCells = std::max(0, n);
	bool overflow;
	StartPos = CharsForCells(StartPosCells, &overflow);
	if (overflow)
	{
		// We ended up in the middle of a double cell character, so set the start to the following character.
		StartPosCells++;
		StartPos = CharsForCells(StartPosCells, &overflow);
	}
}

void FCommandBuffer::CursorStart()
{
	CursorPos = 0;
	StartPos = 0;
	CursorPosCells = 0;
	StartPosCells = 0;
}

void FCommandBuffer::CursorEnd()
{
	CursorPos = (unsigned)Text.length();
	MakeStartPosGood();
}

void FCommandBuffer::CursorLeft()
{
	if (CursorPos > 0)
	{
		MoveCursorLeft();
		MakeStartPosGood();
	}
}

void FCommandBuffer::CursorRight()
{
	if (CursorPos < Text.length())
	{
		MoveCursorRight();
		MakeStartPosGood();
	}
}

void FCommandBuffer::CursorWordLeft()
{
	if (CursorPos > 0)
	{
		do MoveCursorLeft();
		while (CursorPos > 0 && Text[CursorPos - 1] != ' ');
		MakeStartPosGood();
	}
}

void FCommandBuffer::CursorWordRight()
{
	if (CursorPos < Text.length())
	{
		do MoveCursorRight();
		while (CursorPos < Text.length() && Text[CursorPos] != ' ');
		MakeStartPosGood();
	}
}

void FCommandBuffer::DeleteLeft()
{
	if (CursorPos > 0)
	{
		MoveCursorLeft();
		Text.erase(CursorPos, 1);
		MakeStartPosGood();
	}
}

void FCommandBuffer::DeleteRight()
{
	if (CursorPos < Text.length())
	{
		Text.erase(CursorPos, 1);
		MakeStartPosGood();
	}
}

void FCommandBuffer::DeleteWordLeft()
{
	if (CursorPos > 0)
	{
		auto now = CursorPos;

		CursorWordLeft();

		if (AppendToYankBuffer) {
			YankBuffer = Text.substr(CursorPos, now - CursorPos) + YankBuffer;
		} else {
			YankBuffer = Text.substr(CursorPos, now - CursorPos);
		}
		Text.erase(CursorPos, now - CursorPos);
		MakeStartPosGood();
	}
}

void FCommandBuffer::DeleteLineLeft()
{
	if (CursorPos > 0)
	{
		if (AppendToYankBuffer) {
			YankBuffer = Text.substr(0, CursorPos) + YankBuffer;
		} else {
			YankBuffer = Text.substr(0, CursorPos);
		}
		Text.erase(0, CursorPos);
		CursorStart();
	}
}

void FCommandBuffer::DeleteLineRight()
{
	if (CursorPos < Text.length())
	{
		if (AppendToYankBuffer) {
			YankBuffer += Text.substr(CursorPos, Text.length() - CursorPos);
		} else {
			YankBuffer = Text.substr(CursorPos, Text.length() - CursorPos);
		}
		Text.resize(CursorPos);
		CursorEnd();
	}
}

void FCommandBuffer::AddChar(int character)
{
	if (Text.length() == 0)
	{
		Text += character;
	}
	else
	{
		Text.insert(CursorPos, 1, character);
	}
	CursorPos++;
	MakeStartPosGood();
}

void FCommandBuffer::AddString(FString clip)
{
	if (clip.IsNotEmpty())
	{
		// Only paste the first line.
		long brk = clip.IndexOfAny("\r\n\b");
		std::u32string build;
		if (brk >= 0)
		{
			clip.Truncate(brk);
		}
		auto strp = (const uint8_t*)clip.GetChars();
		while (auto chr = GetCharFromString(strp)) build += chr;
		
		if (Text.length() == 0)
		{
			Text = build;
		}
		else
		{
			Text.insert(CursorPos, build);
		}
		CursorPos += (unsigned)build.length();
		MakeStartPosGood();
	}
}

void FCommandBuffer::SetString(const FString &str)
{
	Text.clear();
	auto strp = (const uint8_t*)str.GetChars();
	while (auto chr = GetCharFromString(strp)) Text += chr;

	CursorEnd();
	MakeStartPosGood();
}

void FCommandBuffer::AddYankBuffer()
{
	if (YankBuffer.length() > 0)
	{
		if (Text.length() == 0)
		{
			Text = YankBuffer;
		}
		else
		{
			Text.insert(CursorPos, YankBuffer);
		}
		CursorPos += (unsigned)YankBuffer.length();
		MakeStartPosGood();
	}
}