/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "chat.h"

#include <algorithm>
#include <cctype>
#include <sstream>

#include "config.h"
#include "debug.h"
#include "util/strfnd.h"
#include "util/string.h"
#include "util/numeric.h"

ChatBuffer::ChatBuffer(u32 scrollback):
	m_scrollback(scrollback)
{
	if (m_scrollback == 0)
		m_scrollback = 1;
	m_empty_formatted_line.first = true;

	m_cache_clickable_chat_weblinks = false;
	// Curses mode cannot access g_settings here
	if (g_settings != nullptr) {
		m_cache_clickable_chat_weblinks = g_settings->getBool("clickable_chat_weblinks");
		if (m_cache_clickable_chat_weblinks) {
			std::string colorval = g_settings->get("chat_weblink_color");
			parseColorString(colorval, m_cache_chat_weblink_color, false, 255);
			m_cache_chat_weblink_color.setAlpha(255);
		}
	}
}

void ChatBuffer::addLine(const std::wstring &name, const std::wstring &text)
{
	m_lines_modified = true;

	ChatLine line(name, text);
	m_unformatted.push_back(line);

	if (m_rows > 0) {
		// m_formatted is valid and must be kept valid
		bool scrolled_at_bottom = (m_scroll == getBottomScrollPos());
		u32 num_added = formatChatLine(line, m_cols, m_formatted);
		if (scrolled_at_bottom)
			m_scroll += num_added;
	}

	// Limit number of lines by m_scrollback
	if (m_unformatted.size() > m_scrollback) {
		deleteOldest(m_unformatted.size() - m_scrollback);
	}
}

void ChatBuffer::clear()
{
	m_unformatted.clear();
	m_formatted.clear();
	m_scroll = 0;
	m_lines_modified = true;
}

u32 ChatBuffer::getLineCount() const
{
	return m_unformatted.size();
}

const ChatLine& ChatBuffer::getLine(u32 index) const
{
	assert(index < getLineCount());	// pre-condition
	return m_unformatted[index];
}

void ChatBuffer::step(f32 dtime)
{
	for (ChatLine &line : m_unformatted) {
		line.age += dtime;
	}
}

void ChatBuffer::deleteOldest(u32 count)
{
	bool at_bottom = (m_scroll == getBottomScrollPos());

	u32 del_unformatted = 0;
	u32 del_formatted = 0;

	while (count > 0 && del_unformatted < m_unformatted.size()) {
		++del_unformatted;

		// keep m_formatted in sync
		if (del_formatted < m_formatted.size()) {
			sanity_check(m_formatted[del_formatted].first);
			++del_formatted;
			while (del_formatted < m_formatted.size() &&
					!m_formatted[del_formatted].first)
				++del_formatted;
		}

		--count;
	}

	m_unformatted.erase(m_unformatted.begin(), m_unformatted.begin() + del_unformatted);
	m_formatted.erase(m_formatted.begin(), m_formatted.begin() + del_formatted);

	if (del_unformatted > 0)
		m_lines_modified = true;

	if (at_bottom)
		m_scroll = getBottomScrollPos();
	else
		scrollAbsolute(m_scroll - del_formatted);
}

void ChatBuffer::deleteByAge(f32 maxAge)
{
	u32 count = 0;
	while (count < m_unformatted.size() && m_unformatted[count].age > maxAge)
		++count;
	deleteOldest(count);
}

u32 ChatBuffer::getRows() const
{
	return m_rows;
}

void ChatBuffer::reformat(u32 cols, u32 rows)
{
	if (cols == 0 || rows == 0)
	{
		// Clear formatted buffer
		m_cols = 0;
		m_rows = 0;
		m_scroll = 0;
		m_formatted.clear();
	}
	else if (cols != m_cols || rows != m_rows)
	{
		// TODO: Avoid reformatting ALL lines (even invisible ones)
		// each time the console size changes.

		// Find out the scroll position in *unformatted* lines
		u32 restore_scroll_unformatted = 0;
		u32 restore_scroll_formatted = 0;
		bool at_bottom = (m_scroll == getBottomScrollPos());
		if (!at_bottom)
		{
			for (s32 i = 0; i < m_scroll; ++i)
			{
				if (m_formatted[i].first)
					++restore_scroll_unformatted;
			}
		}

		// If number of columns change, reformat everything
		if (cols != m_cols)
		{
			m_formatted.clear();
			for (u32 i = 0; i < m_unformatted.size(); ++i)
			{
				if (i == restore_scroll_unformatted)
					restore_scroll_formatted = m_formatted.size();
				formatChatLine(m_unformatted[i], cols, m_formatted);
			}
		}

		// Update the console size
		m_cols = cols;
		m_rows = rows;

		// Restore the scroll position
		if (at_bottom)
		{
			scrollBottom();
		}
		else
		{
			scrollAbsolute(restore_scroll_formatted);
		}
	}
}

const ChatFormattedLine& ChatBuffer::getFormattedLine(u32 row) const
{
	s32 index = m_scroll + (s32) row;
	if (index >= 0 && index < (s32) m_formatted.size())
		return m_formatted[index];

	return m_empty_formatted_line;
}

void ChatBuffer::scroll(s32 rows)
{
	scrollAbsolute(m_scroll + rows);
}

void ChatBuffer::scrollAbsolute(s32 scroll)
{
	s32 top = getTopScrollPos();
	s32 bottom = getBottomScrollPos();

	m_scroll = scroll;
	if (m_scroll < top)
		m_scroll = top;
	if (m_scroll > bottom)
		m_scroll = bottom;
}

void ChatBuffer::scrollBottom()
{
	m_scroll = getBottomScrollPos();
}

u32 ChatBuffer::formatChatLine(const ChatLine& line, u32 cols,
		std::vector<ChatFormattedLine>& destination) const
{
	u32 num_added = 0;
	std::vector<ChatFormattedFragment> next_frags;
	ChatFormattedLine next_line;
	ChatFormattedFragment temp_frag;
	u32 out_column = 0;
	u32 in_pos = 0;
	u32 hanging_indentation = 0;

	// Format the sender name and produce fragments
	if (!line.name.empty()) {
		temp_frag.text = L"<";
		temp_frag.column = 0;
		//temp_frag.bold = 0;
		next_frags.push_back(temp_frag);
		temp_frag.text = line.name;
		temp_frag.column = 0;
		//temp_frag.bold = 1;
		next_frags.push_back(temp_frag);
		temp_frag.text = L"> ";
		temp_frag.column = 0;
		//temp_frag.bold = 0;
		next_frags.push_back(temp_frag);
	}

	std::wstring name_sanitized = line.name.c_str();

	// Choose an indentation level
	if (line.name.empty()) {
		// Server messages
		hanging_indentation = 0;
	} else if (name_sanitized.size() + 3 <= cols/2) {
		// Names shorter than about half the console width
		hanging_indentation = line.name.size() + 3;
	} else {
		// Very long names
		hanging_indentation = 2;
	}
	//EnrichedString line_text(line.text);

	next_line.first = true;
	// Set/use forced newline after the last frag in each line
	bool mark_newline = false;

	// Produce fragments and layout them into lines
	while (!next_frags.empty() || in_pos < line.text.size()) {
		mark_newline = false; // now using this to USE line-end frag

		// Layout fragments into lines
		while (!next_frags.empty()) {
			ChatFormattedFragment& frag = next_frags[0];

			// Force newline after this frag, if marked
			if (frag.column == INT_MAX)
				mark_newline = true;

			if (frag.text.size() <= cols - out_column) {
				// Fragment fits into current line
				frag.column = out_column;
				next_line.fragments.push_back(frag);
				out_column += frag.text.size();
				next_frags.erase(next_frags.begin());
			} else {
				// Fragment does not fit into current line
				// So split it up
				temp_frag.text = frag.text.substr(0, cols - out_column);
				temp_frag.column = out_column;
				temp_frag.weblink = frag.weblink;

				next_line.fragments.push_back(temp_frag);
				frag.text = frag.text.substr(cols - out_column);
				frag.column = 0;
				out_column = cols;
			}

			if (out_column == cols || mark_newline) {
				// End the current line
				destination.push_back(next_line);
				num_added++;
				next_line.fragments.clear();
				next_line.first = false;

				out_column = hanging_indentation;
				mark_newline = false;
			}
		}

		// Produce fragment(s) for next formatted line
		if (!(in_pos < line.text.size()))
			continue;

		const std::wstring &linestring = line.text.getString();
		u32 remaining_in_output = cols - out_column;
		size_t http_pos = std::wstring::npos;
		mark_newline = false;  // now using this to SET line-end frag

		// Construct all frags for next output line
		while (!mark_newline) {
			// Determine a fragment length <= the minimum of
			// remaining_in_{in,out}put. Try to end the fragment
			// on a word boundary.
			u32 frag_length = 0, space_pos = 0;
			u32 remaining_in_input = line.text.size() - in_pos;

			if (m_cache_clickable_chat_weblinks) {
				// Note: unsigned(-1) on fail
				http_pos = linestring.find(L"https://", in_pos);
				if (http_pos == std::wstring::npos)
					http_pos = linestring.find(L"http://", in_pos);
				if (http_pos != std::wstring::npos)
					http_pos -= in_pos;
			}

			while (frag_length < remaining_in_input &&
					frag_length < remaining_in_output) {
				if (iswspace(linestring[in_pos + frag_length]))
					space_pos = frag_length;
				++frag_length;
			}

			if (http_pos >= remaining_in_output) {
				// Http not in range, grab until space or EOL, halt as normal.
				// Note this works because (http_pos = npos) is unsigned(-1)

				mark_newline = true;
			} else if (http_pos == 0) {
				// At http, grab ALL until FIRST whitespace or end marker. loop.
				// If at end of string, next loop will be empty string to mark end of weblink.

				frag_length = 6;  // Frag is at least "http://"

				// Chars to mark end of weblink
				// TODO? replace this with a safer (slower) regex whitelist?
				static const std::wstring delim_chars = L"\'\";,";
				wchar_t tempchar = linestring[in_pos+frag_length];
				while (frag_length < remaining_in_input &&
						!iswspace(tempchar) &&
						delim_chars.find(tempchar) == std::wstring::npos) {
					++frag_length;
					tempchar = linestring[in_pos+frag_length];
				}

				space_pos = frag_length - 1;
				// This frag may need to be force-split. That's ok, urls aren't "words"
				if (frag_length >= remaining_in_output) {
					mark_newline = true;
				}
			} else {
				// Http in range, grab until http, loop

				space_pos = http_pos - 1;
				frag_length = http_pos;
			}

			// Include trailing space in current frag
			if (space_pos != 0 && frag_length < remaining_in_input)
				frag_length = space_pos + 1;

			temp_frag.text = line.text.substr(in_pos, frag_length);
			// A hack so this frag remembers mark_newline for the layout phase
			temp_frag.column = mark_newline ? INT_MAX : 0;

			if (http_pos == 0) {
				// Discard color stuff from the source frag
				temp_frag.text = EnrichedString(temp_frag.text.getString());
				temp_frag.text.setDefaultColor(m_cache_chat_weblink_color);
				// Set weblink in the frag meta
				temp_frag.weblink = wide_to_utf8(temp_frag.text.getString());
			} else {
				temp_frag.weblink.clear();
			}
			next_frags.push_back(temp_frag);
			in_pos += frag_length;
			remaining_in_output -= std::min(frag_length, remaining_in_output);
		}
	}

	// End the last line
	if (num_added == 0 || !next_line.fragments.empty()) {
		destination.push_back(next_line);
		num_added++;
	}

	return num_added;
}

s32 ChatBuffer::getTopScrollPos() const
{
	s32 formatted_count = (s32) m_formatted.size();
	s32 rows = (s32) m_rows;
	if (rows == 0)
		return 0;

	if (formatted_count <= rows)
		return formatted_count - rows;

	return 0;
}

s32 ChatBuffer::getBottomScrollPos() const
{
	s32 formatted_count = (s32) m_formatted.s<span class="hl com">/* mini-gmp, a minimalistic implementation of a GNU GMP subset.</span>
<span class="hl com"></span>
<span class="hl com">Copyright 2011, 2012, 2013 Free Software Foundation, Inc.</span>
<span class="hl com"></span>
<span class="hl com">This file is part of the GNU MP Library.</span>
<span class="hl com"></span>
<span class="hl com">The GNU MP Library is free software; you can redistribute it and/or modify</span>
<span class="hl com">it under the terms of the GNU Lesser General Public License as published by</span>
<span class="hl com">the Free Software Foundation; either version 3 of the License, or (at your</span>
<span class="hl com">option) any later version.</span>
<span class="hl com"></span>
<span class="hl com">The GNU MP Library is distributed in the hope that it will be useful, but</span>
<span class="hl com">WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY</span>
<span class="hl com">or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public</span>
<span class="hl com">License for more details.</span>
<span class="hl com"></span>
<span class="hl com">You should have received a copy of the GNU Lesser General Public License</span>
<span class="hl com">along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */</span>

<span class="hl com">/* About mini-gmp: This is a minimal implementation of a subset of the</span>
<span class="hl com">   GMP interface. It is intended for inclusion into applications which</span>
<span class="hl com">   have modest bignums needs, as a fallback when the real GMP library</span>
<span class="hl com">   is not installed.</span>
<span class="hl com"></span>
<span class="hl com">   This file defines the public interface. */</span>

<span class="hl ppc">#ifndef __MINI_GMP_H__</span>
<span class="hl ppc">#define __MINI_GMP_H__</span>

<span class="hl com">/* For size_t */</span>
<span class="hl ppc">#include &lt;stddef.h&gt;</span>

<span class="hl ppc">#if defined (__cplusplus)</span>
<span class="hl kwc">extern</span> <span class="hl str">&quot;C&quot;</span> <span class="hl opt">{</span>
<span class="hl ppc">#endif</span>

<span class="hl kwb">void</span> <span class="hl kwd">mp_set_memory_functions</span> <span class="hl opt">(</span><span class="hl kwb">void</span> <span class="hl opt">*(*) (</span><span class="hl kwb">size_t</span><span class="hl opt">),</span>
			      <span class="hl kwb">void</span> <span class="hl opt">*(*) (</span><span class="hl kwb">void</span> <span class="hl opt">*,</span> <span class="hl kwb">size_t</span><span class="hl opt">,</span> <span class="hl kwb">size_t</span><span class="hl opt">),</span>
			      <span class="hl kwb">void</span> <span class="hl opt">(*) (</span><span class="hl kwb">void</span> <span class="hl opt">*,</span> <span class="hl kwb">size_t</span><span class="hl opt">));</span>

<span class="hl kwb">void</span> <span class="hl kwd">mp_get_memory_functions</span> <span class="hl opt">(</span><span class="hl kwb">void</span> <span class="hl opt">*(**) (</span><span class="hl kwb">size_t</span><span class="hl opt">),</span>
			      <span class="hl kwb">void</span> <span class="hl opt">*(**) (</span><span class="hl kwb">void</span> <span class="hl opt">*,</span> <span class="hl kwb">size_t</span><span class="hl opt">,</span> <span class="hl kwb">size_t</span><span class="hl opt">),</span>
			      <span class="hl kwb">void</span> <span class="hl opt">(**) (</span><span class="hl kwb">void</span> <span class="hl opt">*,</span> <span class="hl kwb">size_t</span><span class="hl opt">));</span>

<span class="hl kwc">typedef</span> <span class="hl kwb">unsigned long</span> mp_limb_t<span class="hl opt">;</span>
<span class="hl kwc">typedef</span> <span class="hl kwb">long</span> mp_size_t<span class="hl opt">;</span>
<span class="hl kwc">typedef</span> <span class="hl kwb">unsigned long</span> mp_bitcnt_t<span class="hl opt">;</span>

<span class="hl kwc">typedef</span> mp_limb_t <span class="hl opt">*</span>mp_ptr<span class="hl opt">;</span>
<span class="hl kwc">typedef</span> <span class="hl kwb">const</span> mp_limb_t <span class="hl opt">*</span>mp_srcptr<span class="hl opt">;</span>

<span class="hl kwc">typedef</span> <span class="hl kwb">struct</span>
<span class="hl opt">{</span>
  <span class="hl kwb">int</span> _mp_alloc<span class="hl opt">;</span>		<span class="hl com">/* Number of *limbs* allocated and pointed</span>
<span class="hl com">				   to by the _mp_d field.  */</span>
  <span class="hl kwb">int</span> _mp_size<span class="hl opt">;</span>			<span class="hl com">/* abs(_mp_size) is the number of limbs the</span>
<span class="hl com">				   last field points to.  If _mp_size is</span>
<span class="hl com">				   negative this is a negative number.  */</span>
  mp_limb_t <span class="hl opt">*</span>_mp_d<span class="hl opt">;</span>		<span class="hl com">/* Pointer to the limbs.  */</span>
<span class="hl opt">}</span> __mpz_struct<span class="hl opt">;</span>

<span class="hl kwc">typedef</span> __mpz_struct mpz_t<span class="hl opt">[</span><span class="hl num">1</span><span class="hl opt">];</span>

<span class="hl kwc">typedef</span> __mpz_struct <span class="hl opt">*</span>mpz_ptr<span class="hl opt">;</span>
<span class="hl kwc">typedef</span> <span class="hl kwb">const</span> __mpz_struct <span class="hl opt">*</span>mpz_srcptr<span class="hl opt">;</span>

<span class="hl kwb">void</span> <span class="hl kwd">mpn_copyi</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>
<span class="hl kwb">void</span> <span class="hl kwd">mpn_copyd</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>

<span class="hl kwb">int</span> <span class="hl kwd">mpn_cmp</span> <span class="hl opt">(</span>mp_srcptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>

mp_limb_t <span class="hl kwd">mpn_add_1</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> mp_limb_t<span class="hl opt">);</span>
mp_limb_t <span class="hl kwd">mpn_add_n</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>
mp_limb_t <span class="hl kwd">mpn_add</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>

mp_limb_t <span class="hl kwd">mpn_sub_1</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> mp_limb_t<span class="hl opt">);</span>
mp_limb_t <span class="hl kwd">mpn_sub_n</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>
mp_limb_t <span class="hl kwd">mpn_sub</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>

mp_limb_t <span class="hl kwd">mpn_mul_1</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> mp_limb_t<span class="hl opt">);</span>
mp_limb_t <span class="hl kwd">mpn_addmul_1</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> mp_limb_t<span class="hl opt">);</span>
mp_limb_t <span class="hl kwd">mpn_submul_1</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> mp_limb_t<span class="hl opt">);</span>

mp_limb_t <span class="hl kwd">mpn_mul</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>
<span class="hl kwb">void</span> <span class="hl kwd">mpn_mul_n</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>
<span class="hl kwb">void</span> <span class="hl kwd">mpn_sqr</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">);</span>

mp_limb_t <span class="hl kwd">mpn_lshift</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> <span class="hl kwb">unsigned int</span><span class="hl opt">);</span>
mp_limb_t <span class="hl kwd">mpn_rshift</span> <span class="hl opt">(</span>mp_ptr<span class="hl opt">,</span> mp_srcptr<span class="hl opt">,</span> mp_size_t<span class="hl opt">,</span> <span class="hl kwb">unsigned int</span>