/*
 *	Copyright (C) 2014-2016 PCSX2 Dev Team
 *	Copyright (C) 2016-2016 Jason Brown
 *
 *  This Program 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, 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with GNU Make; see the file COPYING.  If not, write to
 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA USA.
 *  http://www.gnu.org/copyleft/gpl.html
 *
 */

#include "stdafx.h"
#include "GSdx.h"
#include "GSOsdManager.h"

void GSOsdManager::LoadFont() {
	FT_Error error = FT_New_Face(m_library, theApp.GetConfigS("osd_fontname").c_str(), 0, &m_face);
	if (error) {
		m_face = NULL;
		fprintf(stderr, "Failed to init the freetype face\n");
		if(error == FT_Err_Unknown_File_Format)
			fprintf(stderr, "\tFreetype unknown file format\n");

		return;
	}

	LoadSize();
}

void GSOsdManager::LoadSize() {
	if (!m_face) return;

	FT_Error error = FT_Set_Pixel_Sizes(m_face, 0, m_size);;
	if (error) {
		fprintf(stderr, "Failed to init the face size\n");
		return;
	}

	/* This is not exact, I'm sure there's some convoluted way to determine these
	 * from FreeType but they don't make it easy. */
	m_atlas_w = m_size * 96; // random guess
	m_atlas_h = m_size; // another random guess
}

GSOsdManager::GSOsdManager() : m_atlas_h(0)
                             , m_atlas_w(0)
                             , m_max_width(0)
                             , m_onscreen_messages(0)
                             , m_texture_dirty(true)
{
	m_monitor_enabled       = theApp.GetConfigB("osd_monitor_enabled");
	m_log_enabled           = theApp.GetConfigB("osd_log_enabled");
	m_size                  = std::max(1, std::min(theApp.GetConfigI("osd_fontsize"), 100));
	m_opacity               = std::max(0, std::min(theApp.GetConfigI("osd_color_opacity"), 100));
	m_log_timeout           = std::max(2, std::min(theApp.GetConfigI("osd_log_timeout"), 10));
	m_max_onscreen_messages = std::max(1, std::min(theApp.GetConfigI("osd_max_log_messages"), 20));

	int r = std::max(0, std::min(theApp.GetConfigI("osd_color_r"), 255));
	int g = std::max(0, std::min(theApp.GetConfigI("osd_color_g"), 255));
	int b = std::max(0, std::min(theApp.GetConfigI("osd_color_b"), 255));

	m_color = r | (g << 8) | (b << 16) | (255 << 24);

	if (FT_Init_FreeType(&m_library)) {
		m_face = NULL;
		fprintf(stderr, "Failed to init the freetype library\n");
		return;
	}

	LoadFont();

	/* The space character's width is used in GeneratePrimitives() */
	AddGlyph(' ');
}

GSOsdManager::~GSOsdManager() {
	FT_Done_FreeType(m_library);
}

GSVector2i GSOsdManager::get_texture_font_size() {
	return GSVector2i(m_atlas_w, m_atlas_h);
}

void GSOsdManager::upload_texture_atlas(GSTexture* t) {
	if (!m_face) return;

	if (m_char_info.size() > 96) // we only reserved space for this many glyphs
		fprintf(stderr, "More than 96 glyphs needed for OSD");

	// This can be sped up a bit by only uploading new glyphs
	int x = 0;
	for(auto &pair : m_char_info) {
		if(FT_Load_Char(m_face, pair.first, FT_LOAD_RENDER)) {
			fprintf(stderr, "failed to load char U%d\n", (int)pair.first);
			continue;
		}

		// Size of char
		pair.second.ax = m_face->glyph->advance.x >> 6;
		pair.second.ay = m_face->glyph->advance.y >> 6;

		pair.second.bw = m_face->glyph->bitmap.width;
		pair.second.bh = m_face->glyph->bitmap.rows;

		pair.second.bl = m_face->glyph->bitmap_left;
		pair.second.bt = m_face->glyph->bitmap_top;

		GSVector4i r(x, 0, x+pair.second.bw, pair.second.bh);
		if (r.width())
			t->Update(r, m_face->glyph->bitmap.buffer, m_face->glyph->bitmap.pitch);

		if (r.width() > m_max_width) m_max_width = r.width();

		pair.second.tx = (float)x / m_atlas_w;
		pair.second.ty = (float)pair.second.bh / m_atlas_h;
		pair.second.tw = (float)pair.second.bw / m_atlas_w;

		x += pair.second.bw;
	}

	m_texture_dirty = false;
}

#if __GNUC__ < 5 || ( __GNUC__ == 5 && __GNUC_MINOR__ < 4 )
/* This is dumb in that it doesn't check for malformed UTF8. This function
 * is not expected to operate on user input, but only on compiled in strings */
void dumb_utf8_to_utf32(const char *utf8, char32_t *utf32, unsigned size) {
	while(*utf8 && --size) {
		if((*utf8 & 0xF1) == 0xF0) {
			*utf32++ = (utf8[0] & 0x07) << 18 | (utf8[1] & 0x3F) << 12 | (utf8[2] & 0x3F) << 6 | utf8[3] & 0x3F;
			utf8 += 4;
		} else if((*utf8 & 0xF0) == 0xE0) {
			*utf32++ =                          (utf8[0] & 0x0F) << 12 | (utf8[1] & 0x3F) << 6 | utf8[2] & 0x3F;
			utf8 += 3;
		} else if((*utf8 & 0xE0) == 0xC0) {
			*utf32++ =                                                   (utf8[0] & 0x1F) << 6 | utf8[1] & 0x3F;
			utf8 += 2;
		} else if((*utf8 & 0x80) == 0x00) {
			*utf32++ =                                                                           utf8[0] & 0x7F;
			utf8 += 1;
		}
	}

	if(size) *utf32 = *utf8; // Copy NUL char
}
#endif

void GSOsdManager::AddGlyph(char32_t codepoint) {
	if (!m_face) return;
	if(m_char_info.count(codepoint) == 0) {
		m_texture_dirty = true;
		m_char_info[codepoint]; // add it
		if(FT_HAS_KERNING(m_face)) {
			FT_UInt new_glyph = FT_Get_Char_Index(m_face, codepoint);
			for(auto pair : m_char_info) {
				FT_Vector delta;

				FT_UInt glyph_index = FT_Get_Char_Index(m_face, pair.first);
				FT_Get_Kerning(m_face, glyph_index, new_glyph, FT_KERNING_DEFAULT, &delta);
				m_kern_info[std::make_pair(pair.first, codepoint)] = delta.x >> 6;
			}
		}
	}
}

void GSOsdManager::Log(const char *utf8) {
	if(!m_log_enabled)
		return;

#if __GNUC__ < 5 || ( __GNUC__ == 5 && __GNUC_MINOR__ < 4 )
	char32_t buffer[256];
	dumb_utf8_to_utf32(utf8, buffer, countof(buffer));
	for(char32_t* c = buffer; *c; ++c) AddGlyph(*c);
#else
#if _MSC_VER == 1900
	std::wstring_convert<std::codecvt_utf8<unsigned int>, unsigned int> conv;
#else
	std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> conv;
#endif
	std::u32string buffer = conv.from_bytes(utf8);
	for(auto const &c : buffer) AddGlyph(c);
#endif
	m_onscreen_messages++;
	m_log.push_back(log_info{buffer, std::chrono::system_clock::time_point()});

}

void GSOsdManager::Monitor(const char *key, const char *value) {
	if(!m_monitor_enabled)
		return;

	if(value && *value) {
#if __GNUC__ < 5 || ( __GNUC__ == 5 && __GNUC_MINOR__ < 4 )
		char32_t buffer[256], vbuffer[256];
		dumb_utf8_to_utf32(key, buffer, countof(buffer));
		dumb_utf8_to_utf32(value, vbuffer, countof(vbuffer));
		for(char32_t* c = buffer; *c; ++c) AddGlyph(*c);
		for(char32_t* c = vbuffer; *c; ++c) AddGlyph(*c);
#else
#if _MSC_VER == 1900
		std::wstring_convert<std::codecvt_utf8<unsigned int>, unsigned int> conv;
#else
		std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> conv;
#endif
		std::u32string buffer = conv.from_bytes(key);
		std::u32string vbuffer = conv.from_bytes(value);
		for(auto const &c : buffer) AddGlyph(c);
		for(auto const &c : vbuffer) AddGlyph(c);
#endif
		m_monitor[buffer] = vbuffer;
	} else {
#if __GNUC__ < 5 || ( __GNUC__ == 5 && __GNUC_MINOR__ < 4 )
		char32_t buffer[256];
		dumb_utf8_to_utf32(key, buffer, countof(buffer));
#else
#if _MSC_VER == 1900
		std::wstring_convert<std::codecvt_utf8<unsigned int>, unsigned int> conv;
#else
		std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> conv;
#endif
		std::u32string buffer = conv.from_bytes(key);
#endif
		m_monitor.erase(buffer);
	}
}

void GSOsdManager::RenderGlyph(GSVertexPT1* dst, const glyph_info g, float x, float y, uint32 color) {
	float x2 = x + g.bl * (2.0f/m_real_size.x);
	float y2 = -y - g.bt * (2.0f/m_real_size.y);
	float w = g.bw * (2.0f/m_real_size.x);
	float h = g.bh * (2.0f/m_real_size.y);

	dst->p = GSVector4(x2    , -y2    , 0.0f, 1.0f);
	dst->t = GSVector2(g.tx       , 0.0f);
	dst->c = color;
	++dst;
	dst->p = GSVector4(x2 + w, -y2    , 0.0f, 1.0f);
	dst->t = GSVector2(g.tx + g.tw, 0.0f);
	dst->c = color;
	++dst;
	dst->p = GSVector4(x2    , -y2 - h, 0.0f, 1.0f);
	dst->t = GSVector2(g.tx       , g.ty);
	dst->c = color;
	++dst;
	dst->p = GSVector4(x2 + w, -y2    , 0.0f, 1.0f);
	dst->t = GSVector2(g.tx + g.tw, 0.0f);
	dst->c = color;
	++dst;
	dst->p = GSVector4(x2    , -y2 - h, 0.0f, 1.0f);
	dst->t = GSVector2(g.tx       , g.ty);
	dst->c = color;
	++dst;
	dst->p = GSVector4(x2 + w, -y2 - h, 0.0f, 1.0f);
	dst->t = GSVector2(g.tx + g.tw, g.ty);
	dst->c = color;
	++dst;
}

void GSOsdManager::RenderString(GSVertexPT1* dst, const std::u32string msg, float x, float y, uint32 color) {
	char32_t p = 0;
	for(const auto & c : msg) {
		if(p) {
			x += m_kern_info[std::make_pair(p, c)] * (2.0f/m_real_size.x);
		}

		RenderGlyph(dst, m_char_info[c], x, y, color);

		/* Advance the cursor to the start of the next character */
		x += m_char_info[c].ax * (2.0f/m_real_size.x);
		y += m_char_info[c].ay * (2.0f/m_real_size.y);

		dst += 6;

		p = c;
	}
}

size_t GSOsdManager::Size() {
	size_t sum = 0;

	if(m_log_enabled) {
		float offset = 0;

		for(auto it = m_log.begin(); it != m_log.end(); ++it) {
			float y = 1 - ((m_size+2)*(it-m_log.begin()+1)) * (2.0f/m_real_size.y);
			if(y + offset < -1) break;

			std::chrono::duration<float> elapsed;
			if(it->OnScreen.time_since_epoch().count() == 0) {
				elapsed = std::chrono::seconds(0);
			} else {
				elapsed = std::chrono::system_clock::now() - it->OnScreen;
				if(elapsed > std::chrono::seconds(m_log_timeout) || m_onscreen_messages > m_max_onscreen_messages) {
					continue;
				}
			}

			float ratio = (elapsed - std::chrono::seconds(m_log_timeout/2)).count() / std::chrono::seconds(m_log_timeout/2).count();
			ratio = ratio > 1.0f ? 1.0f : ratio < 0.0f ? 0.0f : ratio;

			y += offset += ((m_size+2) * (2.0f/m_real_size.y)) * ratio;
			sum += it->msg.size();
		}
	}

	if(m_monitor_enabled) {
		for(const auto &pair : m_monitor) {
			sum += pair.first.size();
			sum += pair.second.size();
		}
	}

	return sum * 6;
}

float GSOsdManager::StringSize(const std::u32string msg) {
	char32_t p = 0;
	float x = 0.0;

	for(auto c : msg) {
		if(p) {
			x += m_kern_info[std::make_pair(p, c)] * (2.0f/m_real_size.x);
		}

		/* Advance the cursor to the start of the next character */
		x += m_char_info[c].ax * (2.0f/m_real_size.x);

		p = c;
	}

	return x;
}

size_t GSOsdManager::GeneratePrimitives(GSVertexPT1* dst, size_t count) {
	size_t drawn = 0;
	float opacity = m_opacity * 0.01f;

	if(m_log_enabled) {
		float offset = 0;

		for(auto it = m_log.begin(); it != m_log.end();) {
			float x = -1 + 8 * (2.0f/m_real_size.x);
			float y = 1 - ((m_size+2)*(it-m_log.begin()+1)) * (2.0f/m_real_size.y);

			if(y + offset < -1) break;

			if(it->OnScreen.time_since_epoch().count() == 0)
				it->OnScreen = std::chrono::system_clock::now();

			std::chrono::duration<float> elapsed = std::chrono::system_clock::now() - it->OnScreen;
			if(elapsed > std::chrono::seconds(m_log_timeout) || m_onscreen_messages > m_max_onscreen_messages) {
				m_onscreen_messages--;
				it = m_log.erase(it);
				continue;
			}

			if(it->msg.size() * 6 > count - drawn) break;

			float ratio = (elapsed - std::chrono::seconds(m_log_timeout/2)).count() / std::chrono::seconds(m_log_timeout/2).count();
			ratio = ratio > 1.0f ? 1.0f : ratio < 0.0f ? 0.0f : ratio;

			y += offset += ((m_size+2) * (2.0f/m_real_size.y)) * ratio;
			uint32 color = m_color;
			((uint8 *)&color)[3] = (uint8)(((uint8 *)&color)[3] * (1.0f - ratio) * opacity);
			RenderString(dst, it->msg, x, y, color);
			dst += it->msg.size() * 6;
			drawn += it->msg.size() * 6;
			++it;
		}
	}

	if(m_monitor_enabled) {
		// pair.first is the key and second is the value and color

		// Since the monitor is right justified, but we render from left to right
		// we need to find the longest string
		float first_max = 0.0, second_max = 0.0;
		for(const auto &pair : m_monitor) {
			float first_len = StringSize(pair.first);
			float second_len = StringSize(pair.second);

			first_max = first_max < first_len ? first_len : first_max;
			second_max = second_max < second_len ? second_len : second_max;
		}

		size_t line = 1;
		for(const auto &pair : m_monitor) {
			if((pair.first.size() + pair.second.size()) * 6 > count - drawn) break;

			// Calculate where to start rendering from by taking the right most position 1.0
			// and subtracting (going left) 8 scaled pixels for a margin, then subtracting
			// the size of the longest key and subtracting a scaled space and finally
			// subtracting the longest value
			float x = 1.0f - 8 * (2.0f/m_real_size.x) - first_max - m_char_info[' '].ax * (2.0f/m_real_size.x) - second_max;
			float y = -1.0f + ((m_size+2)*(2.0f/m_real_size.y)) * line++;

			uint32 color = m_color;
			((uint8 *)&color)[3] = (uint8)(((uint8 *)&color)[3] * opacity);

			// Render the key
			RenderString(dst, pair.first, x, y, color);
			dst += pair.first.size() * 6;
			drawn += pair.first.size() * 6;

			// Calculate the position for the value
			x = 1.0f - 8 * (2.0f/m_real_size.x) - second_max;

			// Render the value
			RenderString(dst, pair.second, x, y, color);
			dst += pair.second.size() * 6;
			drawn += pair.second.size() * 6;
		}
	}

	return drawn;
}