/**
 * @file chatlog.cpp
 *
 * Implementation of the in-game chat log.
 */
#include <ctime>
#include <sstream>
#include <string>
#include <string_view>
#include <vector>

#include <fmt/format.h>

#include "DiabloUI/ui_flags.hpp"
#include "automap.h"
#include "chatlog.h"
#include "control/control.hpp"
#include "diablo_msg.hpp"
#include "doom.h"
#include "engine/render/text_render.hpp"
#include "gamemenu.h"
#include "help.h"
#include "inv.h"
#include "minitext.h"
#include "stores.h"
#include "utils/language.h"
#include "utils/str_cat.hpp"

namespace devilution {

namespace {

struct ColoredText {
	std::string text;
	UiFlags color;
};

struct MultiColoredText {
	std::string text;
	std::vector<ColoredText> colors;
};

bool UnreadFlag = false;
size_t SkipLines;
unsigned int MessageCounter = 0;

std::vector<MultiColoredText> ChatLogLines;

constexpr int PaddingTop = 32;
constexpr int PaddingLeft = 32;

constexpr int PanelHeight = 297;
constexpr int ContentTextWidth = 577;

int LineHeight()
{
	return IsSmallFontTall() ? 18 : 14;
}

int BlankLineHeight()
{
	return 12;
}

int DividerLineMarginY()
{
	return BlankLineHeight() / 2;
}

int HeaderHeight()
{
	return PaddingTop + LineHeight() + 2 * BlankLineHeight() + DividerLineMarginY();
}

int ContentPaddingY()
{
	return BlankLineHeight();
}

int ContentsTextHeight()
{
	return PanelHeight - HeaderHeight() - DividerLineMarginY() - 2 * ContentPaddingY() - BlankLineHeight();
}

int NumVisibleLines()
{
	return (ContentsTextHeight() - 1) / LineHeight() + 1; // Ceil
}

} // namespace

bool ChatLogFlag = false;

void ToggleChatLog()
{
	if (ChatLogFlag) {
		ChatLogFlag = false;
	} else {
		ActiveStore = TalkID::None;
		CloseInventory();
		CloseCharPanel();
		SpellbookFlag = false;
		SpellSelectFlag = false;
		if (qtextflag && leveltype == DTYPE_TOWN) {
			qtextflag = false;
			stream_stop();
		}
		QuestLogIsOpen = false;
		HelpFlag = false;
		CancelCurrentDiabloMsg();
		gamemenu_off();
		SkipLines = 0;
		ChatLogFlag = true;
		doom_close();
	}
}

void AddMessageToChatLog(std::string_view message, Player *player, UiFlags flags)
{
	MessageCounter++;
	const time_t timeResult = time(nullptr);
	const std::tm *localtimeResult = localtime(&timeResult);
	std::string timestamp = localtimeResult != nullptr
	    ? StrCat("[#", MessageCounter, "] ", LeftPad(localtimeResult->tm_hour, 2, '0'), ":", LeftPad(localtimeResult->tm_min, 2, '0'), ":", LeftPad(localtimeResult->tm_sec, 2, '0'))
	    : StrCat("[#", MessageCounter, "] ");
	const size_t oldSize = ChatLogLines.size();
	if (player == nullptr) {
		ChatLogLines.emplace_back(MultiColoredText { "{0} {1}", { { timestamp, UiFlags::ColorRed }, { std::string(message), flags } } });
	} else {
		std::string playerInfo = fmt::format(fmt::runtime(_("{:s} (lvl {:d}): ")), player->_pName, player->getCharacterLevel());
		UiFlags nameColor = player == MyPlayer ? UiFlags::ColorWhitegold : UiFlags::ColorBlue;
		const std::string prefix = timestamp + " - " + playerInfo;
		const std::string text = WordWrapString(prefix + std::string(message), ContentTextWidth);
		std::vector<std::string> lines;
		std::stringstream ss(text);

		for (std::string s; getline(ss, s, '\n');) {
			lines.push_back(s);
		}
		for (int i = static_cast<int>(lines.size()) - 1; i >= 1; i--) {
			ChatLogLines.emplace_back(MultiColoredText { lines[i], {} });
		}
		lines[0].erase(0, prefix.length());
		ChatLogLines.emplace_back(MultiColoredText { "{0} - {1}{2}", { { timestamp, UiFlags::ColorRed }, { playerInfo, nameColor }, { lines[0], UiFlags::ColorWhite } } });
	}

	const size_t diff = ChatLogLines.size() - oldSize;
	// only autoscroll when on top of the log
	if (SkipLines != 0) {
		SkipLines += diff;
		UnreadFlag = true;
	}
}

void DrawChatLog(const Surface &out)
{
	DrawSTextHelp();
	DrawQTextBack(out);

	if (SkipLines == 0) {
		UnreadFlag = false;
	}

	const Point uiPosition = GetUIRectangle().position;
	const int lineHeight = LineHeight();
	const int blankLineHeight = BlankLineHeight();
	const int sx = uiPosition.x + PaddingLeft;
	const int sy = uiPosition.y;

	DrawString(out, fmt::format(fmt::runtime(_("Chat History (Messages: {:d})")), MessageCounter),
	    { { sx, sy + PaddingTop + blankLineHeight }, { ContentTextWidth, lineHeight } },
	    { .flags = (UnreadFlag ? UiFlags::ColorRed : UiFlags::ColorWhitegold) | UiFlags::AlignCenter });

	const time_t timeResult = time(nullptr);
	const std::tm *localtimeResult = localtime(&timeResult);
	if (localtimeResult != nullptr) {
		const std::string timestamp = StrCat(
		    LeftPad(localtimeResult->tm_hour, 2, '0'), ":", LeftPad(localtimeResult->tm_min, 2, '0'), ":", LeftPad(localtimeResult->tm_sec, 2, '0'));
		DrawString(out, timestamp, { { sx, sy + PaddingTop + blankLineHeight }, { ContentTextWidth, lineHeight } },
		    { .flags = UiFlags::ColorWhitegold });
	}

	const int titleBottom = sy + HeaderHeight();
	DrawSLine(out, titleBottom);

	const int numLines = NumVisibleLines();
	const int contentY = titleBottom + DividerLineMarginY() + ContentPaddingY();
	for (int i = 0; i < numLines; i++) {
		if (i + SkipLines >= ChatLogLines.size())
			break;
		const MultiColoredText &text = ChatLogLines[ChatLogLines.size() - (i + SkipLines + 1)];
		const std::string_view line = text.text;

		std::vector<DrawStringFormatArg> args;
		for (auto &x : text.colors) {
			args.emplace_back(DrawStringFormatArg { x.text, x.color });
		}
		DrawStringWithColors(out, line, args, { { sx, contentY + i * lineHeight }, { ContentTextWidth, lineHeight } },
		    { .flags = UiFlags::ColorWhite, .lineHeight = lineHeight });
	}

	DrawString(out, _("Press ESC to end or the arrow keys to scroll."),
	    { { sx, contentY + ContentsTextHeight() + ContentPaddingY() + blankLineHeight }, { ContentTextWidth, lineHeight } },
	    { .flags = UiFlags::ColorWhitegold | UiFlags::AlignCenter });
}

void ChatLogScrollUp()
{
	if (SkipLines > 0)
		SkipLines--;
}

void ChatLogScrollDown()
{
	if (SkipLines + NumVisibleLines() < ChatLogLines.size())
		SkipLines++;
}

void ChatLogScrollTop()
{
	SkipLines = 0;
}

void ChatLogScrollBottom()
{
	SkipLines = ChatLogLines.size() - NumVisibleLines();
}

} // namespace devilution