/* Copyright (C) 2010 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Implements the in-game console with scripting support.
 */

#include "precompiled.h"
#include <wctype.h>

#include "CConsole.h"

#include "lib/ogl.h"
#include "lib/res/graphics/unifont.h"
#include "lib/sysdep/clipboard.h"
#include "maths/MathUtil.h"
#include "network/NetClient.h"
#include "network/NetServer.h"
#include "ps/CLogger.h"
#include "ps/Filesystem.h"
#include "ps/Font.h"
#include "ps/Globals.h"
#include "ps/Hotkey.h"
#include "ps/Pyrogenesis.h"
#include "scripting/ScriptingHost.h"
#include "scriptinterface/ScriptInterface.h"

CConsole* g_Console = 0;

CConsole::CConsole()
{
	m_bToggle = false;
	m_bVisible = false;

	m_fVisibleFrac = 0.0f;

	m_szBuffer = new wchar_t[CONSOLE_BUFFER_SIZE];
	FlushBuffer();

	m_iMsgHistPos = 1;
	m_charsPerPage=0;
	
	InsertMessage(L"[ 0 A.D. Console v0.14 ]");
	InsertMessage(L"");
}

CConsole::~CConsole()
{
	m_deqMsgHistory.clear();
	m_deqBufHistory.clear();
	delete[] m_szBuffer;
}


void CConsole::SetSize(float X, float Y, float W, float H)
{
	m_fX = X;
	m_fY = Y;
	m_fWidth = W;
	m_fHeight = H;
}

void CConsole::UpdateScreenSize(int w, int h)
{
	float height = h * 0.6f;
	SetSize(0, h-height, (float)w, height);
}


void CConsole::ToggleVisible()
{
	m_bToggle = true;
	m_bVisible = !m_bVisible;
}

void CConsole::SetVisible( bool visible )
{
	if( visible != m_bVisible )
		m_bToggle = true;
	m_bVisible = visible;
}

void CConsole::FlushBuffer(void)
{
	// Clear the buffer and set the cursor and length to 0
	memset(m_szBuffer, '\0', sizeof(wchar_t) * CONSOLE_BUFFER_SIZE);
	m_iBufferPos = m_iBufferLength = 0;
}


void CConsole::ToLower(wchar_t* szMessage, size_t iSize)
{
	size_t L = (size_t)wcslen(szMessage);

	if (L <= 0) return;

	if (iSize && iSize < L) L = iSize;

	for(size_t i = 0; i < L; i++)
		szMessage[i] = towlower(szMessage[i]);
}


void CConsole::Trim(wchar_t* szMessage, const wchar_t cChar, size_t iSize)
{
	size_t L = wcslen(szMessage);
	if(!L)
		return;

	if (iSize && iSize < L) L = iSize;

	wchar_t szChar[2] = { cChar, 0 };

	// Find the first point at which szChar does not
	// exist in the message
	size_t ofs = wcsspn(szMessage, szChar);
	if(ofs == 0)	// no leading <cChar> chars - we're done
		return;

	// move everything <ofs> chars left, replacing leading cChar chars
	L -= ofs;
	memmove(szMessage, szMessage+ofs, L*sizeof(wchar_t));

	for(ssize_t i = (ssize_t)L; i >= 0; i--)
	{
		szMessage[i] = '\0';
		if (szMessage[i - 1] != cChar) break;
	}
}


void CConsole::Update(const float DeltaTime)
{
	if(m_bToggle)
	{
		const float AnimateTime = .30f;
		const float Delta = DeltaTime / AnimateTime;
		if(m_bVisible)
		{
			m_fVisibleFrac += Delta;
			if(m_fVisibleFrac > 1.0f)
			{
				m_fVisibleFrac = 1.0f;
				m_bToggle = false;
			}
		}
		else
		{
			m_fVisibleFrac -= Delta;
			if(m_fVisibleFrac < 0.0f)
			{
				m_fVisibleFrac = 0.0f;
				m_bToggle = false;
			}
		}
	}
}

//Render Manager.
void CConsole::Render()
{
	if (! (m_bVisible || m_bToggle) ) return;

	CFont font(CONSOLE_FONT);
	font.Bind();

	// animation: slide in from top of screen
	const float MaxY = m_fHeight;
	const float DeltaY = (1.0f - m_fVisibleFrac) * MaxY;

	glPushMatrix();

	glTranslatef(m_fX, m_fY + DeltaY, 0.0f); //Move to window position

	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

	DrawWindow();
	DrawHistory();
	DrawBuffer();

	glDisable(GL_BLEND);

	glPopMatrix();
}


void CConsole::DrawWindow()
{
	// TODO:  Add texturing
	glDisable(GL_TEXTURE_2D);

	// Draw Background
	// Set the color to a translucent blue
	glColor4f(0.0f, 0.0f, 0.5f, 0.6f);
	glBegin(GL_QUADS);
		glVertex2f(0.0f,		0.0f);
		glVertex2f(m_fWidth-1.0f,	0.0f);
		glVertex2f(m_fWidth-1.0f,	m_fHeight-1.0f);
		glVertex2f(0.0f,		m_fHeight-1.0f);
	glEnd();

	// Draw Border
	// Set the color to a translucent yellow
	glColor4f(0.5f, 0.5f, 0.0f, 0.6f);
	glBegin(GL_LINE_LOOP);
		glVertex2f(0.0f,		0.0f);
		glVertex2f(m_fWidth-1.0f,	0.0f);
		glVertex2f(m_fWidth-1.0f,	m_fHeight-1.0f);
		glVertex2f(0.0f,		m_fHeight-1.0f);
	glEnd();

	if (m_fHeight > m_iFontHeight + 4)
	{
		glBegin(GL_LINES);
			glVertex2f(0.0f,		(GLfloat)(m_iFontHeight + 4));
			glVertex2f(m_fWidth,	(GLfloat)(m_iFontHeight + 4));
		glEnd();
	}

	glEnable(GL_TEXTURE_2D);
}


void CConsole::DrawHistory()
{
	int i = 1;

	std::deque<std::wstring>::iterator Iter; //History iterator

	CScopeLock lock(m_Mutex); // needed for safe access to m_deqMsgHistory

	glPushMatrix();
		glColor3f(1.0f, 1.0f, 1.0f); //Set color of text
		glTranslatef(9.0f, (float)m_iFontOffset, 0.0f); //move away from the border

		// Draw the text upside-down, because it's aligned with
		// the GUI (which uses the top-left as (0,0))
		glScalef(1.0f, -1.0f, 1.0f);

		for (Iter = m_deqMsgHistory.begin();
			 Iter != m_deqMsgHistory.end()
				 && (((i - m_iMsgHistPos + 1) * m_iFontHeight) < m_fHeight);
			 Iter++)
		{
			if (i >= m_iMsgHistPos){
				glTranslatef(0.0f, -(float)m_iFontHeight, 0.0f);

				glPushMatrix();
					glwprintf(L"%ls", Iter->c_str());
				glPopMatrix();
			}

			i++;
		}
	glPopMatrix();
}

//Renders the buffer to the screen.
void CConsole::DrawBuffer(void)
{
	if (m_fHeight < m_iFontHeight) return;

	glPushMatrix();
		glColor3f(1.0f, 1.0f, 0.0f);
		glTranslatef(2.0f, (float)m_iFontOffset, 0);
		glScalef(1.0f, -1.0f, 1.0f);

		glwprintf(L"]");

		glColor3f(1.0f, 1.0f, 1.0f);
		if (m_iBufferPos==0) DrawCursor();

		for (int i = 0; i < m_iBufferLength; i++){
				glwprintf(L"%lc", m_szBuffer[i]);
				if (m_iBufferPos-1==i) DrawCursor();
		}
	glPopMatrix();
}


void CConsole::DrawCursor(void)
{
	// (glPushMatrix is necessary because glwprintf does glTranslatef)
	glPushMatrix();
		// Slightly translucent yellow
		glColor4f(1.0f, 1.0f, 0.0f, 0.8f);

		// Cursor character is chosen to be an underscore
		glwprintf(L"_");

		// Revert to the standard text colour
		glColor3f(1.0f, 1.0f, 1.0f);
	glPopMatrix();
}


//Inserts a character into the buffer.
void CConsole::InsertChar(const int szChar, const wchar_t cooked )
{
	static int iHistoryPos = -1;

	if (!m_bVisible) return;

	switch (szChar){
		case SDLK_RETURN:
			iHistoryPos = -1;
			m_iMsgHistPos = 1;
			ProcessBuffer(m_szBuffer);
			FlushBuffer();
			return;

		case SDLK_TAB:
			// Auto Complete
			return;

		case SDLK_BACKSPACE:
			if (IsEmpty() || IsBOB()) return;

			if (m_iBufferPos == m_iBufferLength)
				m_szBuffer[m_iBufferPos - 1] = '\0';
			else{
				for(int j=m_iBufferPos-1; j<m_iBufferLength-1; j++)
					m_szBuffer[j] = m_szBuffer[j+1]; // move chars to left
				m_szBuffer[m_iBufferLength-1] = '\0';
			}

			m_iBufferPos--;
			m_iBufferLength--;
			return;

		case SDLK_DELETE:
			if (IsEmpty() || IsEOB()) return;

			if (m_iBufferPos == m_iBufferLength-1)
			{
				m_szBuffer[m_iBufferPos] = '\0';
				m_iBufferLength--;
			}
			else
			{
				if (g_keys[SDLK_RCTRL] || g_keys[SDLK_LCTRL])
				{
					// Make Ctrl-Delete delete up to end of line
					m_szBuffer[m_iBufferPos] = '\0';
					m_iBufferLength = m_iBufferPos;
				}
				else 
				{
					// Delete just one char and move the others left
					for(int j=m_iBufferPos; j<m_iBufferLength-1; j++)
						m_szBuffer[j] = m_szBuffer[j+1];
					m_szBuffer[m_iBufferLength-1] = '\0';
					m_iBufferLength--;
				}
			}

			return;

		case SDLK_HOME:
			if (g_keys[SDLK_RCTRL] || g_keys[SDLK_LCTRL])
			{
				CScopeLock lock(m_Mutex); // needed for safe access to m_deqMsgHistory

				int linesShown = (int)m_fHeight/m_iFontHeight - 4;
				m_iMsgHistPos = clamp((int)m_deqMsgHistory.size() - linesShown, 1, (int)m_deqMsgHistory.size());
			}
			else
			{
				m_iBufferPos = 0;
			}
			return;

		case SDLK_END:
			if (g_keys[SDLK_RCTRL] || g_keys[SDLK_LCTRL])
			{
				m_iMsgHistPos = 1;
			}
			else
			{
				m_iBufferPos = m_iBufferLength;
			}
			return;

		case SDLK_LEFT:
			if (m_iBufferPos) m_iBufferPos--;
			return;

		case SDLK_RIGHT:
			if (m_iBufferPos != m_iBufferLength) m_iBufferPos++;
			return;

		// BEGIN: Buffer History Lookup
		case SDLK_UP:
			if ( m_deqBufHistory.size() )
			{
				int oldHistoryPos = iHistoryPos;
				while( iHistoryPos != (int)m_deqBufHistory.size() - 1)
				{
					iHistoryPos++;
					std::wstring& histString = m_deqBufHistory.at(iHistoryPos);
					if((int)histString.length() >= m_iBufferPos)
					{
						bool bad = false;
						for(int i=0; i<m_iBufferPos; i++)
						{
							if(histString[i] != m_szBuffer[i])
							{
								bad = true; break;
							}
						}
						if(!bad)
						{
							SetBuffer(m_deqBufHistory.at(iHistoryPos).c_str());
							return;
						}
					}
				}
				// if we got here, failed to find a string with the right prefix;
				// revert to the old position in case the user types more stuff
				iHistoryPos = oldHistoryPos;
			}
			return;

		case SDLK_DOWN:
			if ( m_deqBufHistory.size() && iHistoryPos > 0 )
			{
				int oldHistoryPos = iHistoryPos;
				while( iHistoryPos != 0)
				{
					iHistoryPos--;
					std::wstring& histString = m_deqBufHistory.at(iHistoryPos);
					if((int)histString.length() >= m_iBufferPos)
					{
						bool bad = false;
						for(int i=0; i<m_iBufferPos; i++)
						{
							if(histString[i] != m_szBuffer[i])
							{
								bad = true; break;
							}
						}
						if(!bad)
						{
							SetBuffer(m_deqBufHistory.at(iHistoryPos).c_str());
							return;
						}
					}
				}
				// if we got here, failed to find a string with the right prefix;
				// revert to the old position in case the user types more stuff,
				// and also clear any complietion we might've added going up
				iHistoryPos = oldHistoryPos;
				m_szBuffer[m_iBufferPos] = 0;
				m_iBufferLength = m_iBufferPos;
			}
			return;
		// END: Buffer History Lookup

		// BEGIN: Message History Lookup
		case SDLK_PAGEUP:
		{
			CScopeLock lock(m_Mutex); // needed for safe access to m_deqMsgHistory

			if (m_iMsgHistPos != (int)m_deqMsgHistory.size()) m_iMsgHistPos++;
			return;
		}

		case SDLK_PAGEDOWN:
			if (m_iMsgHistPos != 1) m_iMsgHistPos--;
			return;
		// END: Message History Lookup

		default: //Insert a character
			if (IsFull()) return;
			if (cooked == 0) return;

			if (IsEOB()) //are we at the end of the buffer?
				m_szBuffer[m_iBufferPos] = cooked; //cat char onto end
			else{ //we need to insert
				int i;
				for(i=m_iBufferLength; i>m_iBufferPos; i--)
					m_szBuffer[i] = m_szBuffer[i-1]; // move chars to right
				m_szBuffer[i] = cooked;
			}

			m_iBufferPos++;
			m_iBufferLength++;

			return;
	}
}


void CConsole::InsertMessage(const wchar_t* szMessage, ...)
{
	va_list args;
	wchar_t szBuffer[CONSOLE_MESSAGE_SIZE];

	va_start(args, szMessage);
	if (vswprintf(szBuffer, CONSOLE_MESSAGE_SIZE, szMessage, args) == -1)
	{
		debug_printf(L"Error printfing console message (buffer size exceeded?)\n");

		// Make it obvious that the text was trimmed (assuming it was)
		wcscpy(szBuffer+CONSOLE_MESSAGE_SIZE-4, L"...");
	}
	va_end(args);

	InsertMessageRaw(szBuffer);
}
	

void CConsole::InsertMessageRaw(const CStrW& message)
{
	// (TODO: this text-wrapping is rubbish since we now use variable-width fonts)

	//Insert newlines to wraparound text where needed
	CStrW wrapAround(message);
	CStrW newline(L"\n");
	size_t oldNewline=0;
	size_t distance;
	
	//make sure everything has been initialized
	if ( m_charsPerPage != 0 )
	{
		while ( oldNewline+m_charsPerPage < wrapAround.length() )
		{
			distance = wrapAround.find(newline, oldNewline) - oldNewline;
			if ( distance > m_charsPerPage )
			{
				oldNewline += m_charsPerPage;
				wrapAround.insert( oldNewline++, newline );
			}
			else
				oldNewline += distance+1;
		}
	}
	// Split into lines and add each one individually
	oldNewline = 0;

	{
		CScopeLock lock(m_Mutex); // needed for safe access to m_deqMsgHistory

		while ( (distance = wrapAround.find(newline, oldNewline)) != wrapAround.npos)
		{
			distance -= oldNewline;
			m_deqMsgHistory.push_front(wrapAround.substr(oldNewline, distance));
			oldNewline += distance+1;
		}
		m_deqMsgHistory.push_front(wrapAround.substr(oldNewline));
	}
}

const wchar_t* CConsole::GetBuffer()
{
	m_szBuffer[m_iBufferLength] = 0;
	return( m_szBuffer );
}

void CConsole::SetBuffer(const wchar_t* szMessage)
{
	int oldBufferPos = m_iBufferPos;	// remember since FlushBuffer will set it to 0

	FlushBuffer();

	wcsncpy(m_szBuffer, szMessage, CONSOLE_BUFFER_SIZE);
	m_iBufferLength = (int)wcslen(m_szBuffer);
	m_iBufferPos = std::min(oldBufferPos, m_iBufferLength);
}

void CConsole::UseHistoryFile(const VfsPath& filename, int max_history_lines)
{
	m_MaxHistoryLines = max_history_lines;

	m_sHistoryFile = filename;
	LoadHistory();
}

void CConsole::ProcessBuffer(const wchar_t* szLine)
{
	if (szLine == NULL) return;
	if (wcslen(szLine) <= 0) return;

	ENSURE(wcslen(szLine) < CONSOLE_BUFFER_SIZE);

	m_deqBufHistory.push_front(szLine);
	SaveHistory(); // Do this each line for the moment; if a script causes
	               // a crash it's a useful record.

	// Process it as JavaScript

	jsval rval = g_ScriptingHost.ExecuteScript(szLine, L"Console");
	if (!JSVAL_IS_VOID(rval))
		InsertMessage(L"%ls", g_ScriptingHost.GetScriptInterface().ToString(rval).c_str());
}

void CConsole::LoadHistory()
{
	// note: we don't care if this file doesn't exist or can't be read;
	// just don't load anything in that case.

	// do this before LoadFile to avoid an error message if file not found.
	if (!VfsFileExists(m_sHistoryFile))
		return;

	shared_ptr<u8> buf; size_t buflen;
	if (g_VFS->LoadFile(m_sHistoryFile, buf, buflen) < 0)
		return;

	CStr bytes ((char*)buf.get(), buflen);

	CStrW str (bytes.FromUTF8());
	size_t pos = 0;
	while (pos != CStrW::npos)
	{
		pos = str.find('\n');
		if (pos != CStrW::npos)
		{
			if (pos > 0)
				m_deqBufHistory.push_front(str.Left(str[pos-1] == '\r' ? pos - 1 : pos));
			str = str.substr(pos + 1);
		}
		else if (str.length() > 0)
			m_deqBufHistory.push_front(str);
	}
}

void CConsole::SaveHistory()
{
	WriteBuffer buffer;
	const int linesToSkip = (int)m_deqBufHistory.size() - m_MaxHistoryLines;
	std::deque<std::wstring>::reverse_iterator it = m_deqBufHistory.rbegin();
	if(linesToSkip > 0)
		std::advance(it, linesToSkip);
	for (; it != m_deqBufHistory.rend(); ++it)
	{
		CStr8 line = CStrW(*it).ToUTF8();
		buffer.Append(line.data(), line.length());
		static const char newline = '\n';
		buffer.Append(&newline, 1);
	}
	g_VFS->CreateFile(m_sHistoryFile, buffer.Data(), buffer.Size());
}

void CConsole::ReceivedChatMessage(const wchar_t *szSender, const wchar_t *szMessage)
{
	InsertMessage(L"%ls: %ls", szSender, szMessage);
}

static bool isUnprintableChar(SDL_keysym key)
{
	// U+0000 to U+001F are control characters
	if (key.unicode < 0x20)
	{
		switch (key.sym)
		{
			// We want to allow some, which are handled specially
		case SDLK_RETURN: case SDLK_TAB:
		case SDLK_BACKSPACE: case SDLK_DELETE:
		case SDLK_HOME: case SDLK_END:
		case SDLK_LEFT: case SDLK_RIGHT:
		case SDLK_UP: case SDLK_DOWN:
		case SDLK_PAGEUP: case SDLK_PAGEDOWN:
			return false;

			// Ignore the others
		default:
			return true;
		}
	}

	return false;
}

InReaction conInputHandler(const SDL_Event_* ev)
{
	if (ev->ev.type == SDL_HOTKEYDOWN)
	{
		std::string hotkey = static_cast<const char*>(ev->ev.user.data1);

		if (hotkey == "console.toggle")
		{
			g_Console->ToggleVisible();
			return IN_HANDLED;
		}
		else if (g_Console->IsActive() && hotkey == "console.copy")
		{
			sys_clipboard_set(g_Console->GetBuffer());
			return IN_HANDLED;
		}
		else if (g_Console->IsActive() && hotkey == "console.paste")
		{
			wchar_t* text = sys_clipboard_get();
			if (text)
			{
				for (wchar_t* c = text; *c; c++)
					g_Console->InsertChar(0, *c);

				sys_clipboard_free(text);
			}
			return IN_HANDLED;
		}
	}

	if (!g_Console->IsActive())
		return IN_PASS;

	if (ev->ev.type != SDL_KEYDOWN)
		return IN_PASS;

	SDLKey sym = ev->ev.key.keysym.sym;

	// Stop unprintable characters (ctrl+, alt+ and escape),
	// also prevent ` and/or ~ appearing in console every time it's toggled.
	if (!isUnprintableChar(ev->ev.key.keysym) &&
		!HotkeyIsPressed("console.toggle"))
	{
		g_Console->InsertChar(sym, (wchar_t)ev->ev.key.keysym.unicode);
		return IN_HANDLED;
	}

	return IN_PASS;
}