/*
This file is part of Telegram Desktop,
the official desktop application for the Telegram messaging service.

For license and copyright information please follow this link:
https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
*/
#include "boxes/gift_credits_box.h"

#include "api/api_credits.h"
#include "api/api_premium.h"
#include "boxes/peer_list_controllers.h"
#include "data/data_peer.h"
#include "data/data_session.h"
#include "data/data_user.h"
#include "data/stickers/data_custom_emoji.h"
#include "lang/lang_keys.h"
#include "main/session/session_show.h"
#include "main/main_session.h"
#include "settings/settings_credits_graphics.h"
#include "settings/settings_credits.h"
#include "settings/settings_premium.h"
#include "ui/controls/userpic_button.h"
#include "ui/effects/premium_graphics.h"
#include "ui/effects/premium_stars_colored.h"
#include "ui/effects/ripple_animation.h"
#include "ui/layers/generic_box.h"
#include "ui/painter.h"
#include "ui/rect.h"
#include "ui/text/text_utilities.h"
#include "ui/vertical_list.h"
#include "ui/widgets/label_with_custom_emoji.h"
#include "window/window_session_controller.h"
#include "styles/style_boxes.h"
#include "styles/style_channel_earn.h"
#include "styles/style_chat.h"
#include "styles/style_credits.h"
#include "styles/style_giveaway.h"
#include "styles/style_layers.h"
#include "styles/style_premium.h"

#include "data/stickers/data_stickers.h"
#include "data/data_document.h"

namespace Ui {
namespace {

constexpr auto kPriceTabAll = 0;
constexpr auto kPriceTabLimited = -1;

struct GiftTypePremium {
	int64 cost = 0;
	QString currency;
	int months = 0;
	int discountPercent = 0;

	[[nodiscard]] friend inline bool operator==(
		const GiftTypePremium &,
		const GiftTypePremium &) = default;
};

struct GiftTypeStars {
	DocumentData *document = nullptr;
	int stars = 0;
	bool limited = false;

	[[nodiscard]] friend inline bool operator==(
		const GiftTypeStars&,
		const GiftTypeStars&) = default;
};

struct GiftDescriptor : std::variant<GiftTypePremium, GiftTypeStars> {
	using variant::variant;

	[[nodiscard]] friend inline bool operator==(
		const GiftDescriptor&,
		const GiftDescriptor&) = default;
};

[[nodiscard]] rpl::producer<std::vector<GiftTypePremium>> GiftsPremium(
		not_null<Main::Session*> session,
		not_null<PeerData*> peer) {
	struct Session {
		std::vector<GiftTypePremium> last;
	};
	static auto Map = base::flat_map<not_null<Main::Session*>, Session>();
	return [=](auto consumer) {
		auto lifetime = rpl::lifetime();

		auto i = Map.find(session);
		if (i == end(Map)) {
			i = Map.emplace(session, Session()).first;
			session->lifetime().add([=] { Map.remove(session); });
		}
		if (!i->second.last.empty()) {
			consumer.put_next_copy(i->second.last);
		}

		using namespace Api;
		const auto api = lifetime.make_state<PremiumGiftCodeOptions>(peer);
		api->request() | rpl::start_with_error_done([=](QString error) {
			consumer.put_next({});
		}, [=] {
			const auto &options = api->optionsForPeer();
			auto list = std::vector<GiftTypePremium>();
			list.reserve(options.size());
			auto minMonthsGift = GiftTypePremium();
			for (const auto &option : options) {
				list.push_back({
					.cost = option.cost,
					.currency = option.currency,
					.months = option.months,
				});
				if (!minMonthsGift.months
					|| option.months < minMonthsGift.months) {
					minMonthsGift = list.back();
				}
			}
			for (auto &gift : list) {
				if (gift.months > minMonthsGift.months
					&& gift.currency == minMonthsGift.currency) {
					const auto costPerMonth = gift.cost / gift.months;
					const auto maxCostPerMonth = minMonthsGift.cost
						/ minMonthsGift.months;
					const auto costRatio = costPerMonth / maxCostPerMonth;
					const auto discount = 1. - costRatio;
					const auto discountPercent = 100 * discount;
					const auto value = int(base::SafeRound(discountPercent));
					if (value > 0 && value < 100) {
						gift.discountPercent = value;
					}
				}
			}
			Map[session].last = list;
			consumer.put_next_copy(list);
		}, lifetime);

		return lifetime;
	};
}

[[nodiscard]] rpl::producer<std::vector<GiftTypeStars>> GiftsStars(
		not_null<Main::Session*> session,
		not_null<PeerData*> peer) {
	//struct Session {
	//	std::vector<GiftTypeStars> last;
	//};
	//static auto Map = base::flat_map<not_null<Main::Session*>, Session>();
	return [=](auto consumer) {
		auto lifetime = rpl::lifetime();

		auto list = std::vector<GiftTypeStars>();

		const auto add = [&](uint64 setId, int price, bool limited) {
			auto &sets = session->data().stickers().setsRef();
			const auto i = sets.find(setId);
			if (i != end(sets)) {
				for (const auto document : i->second->stickers) {
					price = document->isPremiumSticker() ? 1000 : price;
					list.push_back({
						.document = document,
						.stars = price,
						.limited = limited,
					});
				}
			}
		};
		add(Data::Stickers::CloudRecentSetId, 100, false);
		add(Data::Stickers::RecentSetId, 250, false);
		add(Data::Stickers::FavedSetId, 50, true);

		consumer.put_next(std::move(list));

		return lifetime;
	};
}

[[nodiscard]] Text::String TabTextForPrice(
		not_null<Main::Session*> session,
		int price) {
	const auto simple = [](const QString &text) {
		return Text::String(st::semiboldTextStyle, text);
	};
	if (price == kPriceTabAll) {
		return simple(tr::lng_gift_stars_tabs_all(tr::now));
	} else if (price == kPriceTabLimited) {
		return simple(tr::lng_gift_stars_tabs_limited(tr::now));
	}
	auto &manager = session->data().customEmojiManager();
	auto result = Text::String();
	const auto context = Core::MarkedTextContext{
		.session = session,
		.customEmojiRepaint = [] {},
	};
	result.setMarkedText(
		st::semiboldTextStyle,
		manager.creditsEmoji().append(QString::number(price)),
		kMarkupTextOptions,
		context);
	return result;
}

struct GiftPriceTabs {
	rpl::producer<int> priceTab;
	object_ptr<RpWidget> widget;
};
[[nodiscard]] GiftPriceTabs MakeGiftsPriceTabs(
		not_null<Window::SessionController*> window,
		not_null<PeerData*> peer,
		rpl::producer<std::vector<GiftTypeStars>> gifts) {
	auto widget = object_ptr<RpWidget>((QWidget*)nullptr);
	const auto raw = widget.data();

	struct Button {
		QRect geometry;
		Text::String text;
		int price = 0;
		bool active = false;
	};
	struct State {
		rpl::variable<std::vector<int>> prices;
		rpl::variable<int> priceTab = kPriceTabAll;
		std::vector<Button> buttons;
		int selected = -1;
		int active = -1;
	};
	const auto state = raw->lifetime().make_state<State>();
	state->prices = std::move(
		gifts
	) | rpl::map([](const std::vector<GiftTypeStars> &gifts) {
		auto result = std::vector<int>();
		result.push_back(kPriceTabAll);
		auto same = true;
		auto sameKey = 0;
		for (const auto &gift : gifts) {
			if (same) {
				const auto key = gift.stars * (gift.limited ? -1 : 1);
				if (!sameKey) {
					sameKey = key;
				} else if (sameKey != key) {
					same = false;
				}
			}

			if (gift.limited
				&& (result.size() < 2 || result[1] != kPriceTabLimited)) {
				result.insert(begin(result) + 1, kPriceTabLimited);
			}
			if (!ranges::contains(result, gift.stars)) {
				result.push_back(gift.stars);
			}
		}
		if (same) {
			return std::vector<int>();
		}
		ranges::sort(begin(result) + 1, end(result));
		return result;
	});

	const auto setSelected = [=](int index) {
		const auto was = (state->selected >= 0);
		const auto now = (index >= 0);
		state->selected = index;
		if (was != now) {
			raw->setCursor(now ? style::cur_pointer : style::cur_default);
		}
	};
	const auto setActive = [=](int index) {
		const auto was = state->active;
		if (was == index) {
			return;
		}
		if (was >= 0 && was < state->buttons.size()) {
			state->buttons[was].active = false;
		}
		state->active = index;
		state->buttons[index].active = true;
		raw->update();

		state->priceTab = state->buttons[index].price;
	};

	const auto session = &peer->session();
	state->prices.value(
	) | rpl::start_with_next([=](const std::vector<int> &prices) {
		auto x = st::giftBoxTabsMargin.left();
		auto y = st::giftBoxTabsMargin.top();

		setSelected(-1);
		state->buttons.resize(prices.size());
		const auto padding = st::giftBoxTabPadding;
		auto currentPrice = state->priceTab.current();
		if (!ranges::contains(prices, currentPrice)) {
			currentPrice = kPriceTabAll;
		}
		state->active = -1;
		for (auto i = 0, count = int(prices.size()); i != count; ++i) {
			const auto price = prices[i];
			auto &button = state->buttons[i];
			if (button.text.isEmpty() || button.price != price) {
				button.price = price;
				button.text = TabTextForPrice(session, price);
			}
			button.active = (price == currentPrice);
			if (button.active) {
				state->active = i;
			}
			const auto width = button.text.maxWidth();
			const auto height = st::giftBoxTabStyle.font->height;
			const auto r = QRect(0, 0, width, height).marginsAdded(padding);
			button.geometry = QRect(QPoint(x, y), r.size());
			x += r.width() + st::giftBoxTabSkip;
		}
		const auto height = state->buttons.empty()
			? 0
			: (y
				+ state->buttons.back().geometry.height()
				+ st::giftBoxTabsMargin.bottom());
		raw->resize(raw->width(), height);
		raw->update();
	}, raw->lifetime());

	raw->setMouseTracking(true);
	raw->events() | rpl::start_with_next([=](not_null<QEvent*> e) {
		const auto type = e->type();
		switch (type) {
		case QEvent::Leave: setSelected(-1); break;
		case QEvent::MouseMove: {
			const auto position = static_cast<QMouseEvent*>(e.get())->pos();
			for (auto i = 0, c = int(state->buttons.size()); i != c; ++i) {
				if (state->buttons[i].geometry.contains(position)) {
					setSelected(i);
					break;
				}
			}
		} break;
		case QEvent::MouseButtonPress: {
			const auto me = static_cast<QMouseEvent*>(e.get());
			if (me->button() != Qt::LeftButton) {
				break;
			}
			const auto position = me->pos();
			for (auto i = 0, c = int(state->buttons.size()); i != c; ++i) {
				if (state->buttons[i].geometry.contains(position)) {
					setActive(i);
					break;
				}
			}
		} break;
		}
	}, raw->lifetime());

	raw->paintRequest() | rpl::start_with_next([=] {
		auto p = QPainter(raw);
		auto hq = PainterHighQualityEnabler(p);
		const auto padding = st::giftBoxTabPadding;
		for (const auto &button : state->buttons) {
			const auto geometry = button.geometry;
			if (button.active) {
				p.setBrush(st::giftBoxTabBgActive);
				p.setPen(Qt::NoPen);
				const auto radius = geometry.height() / 2.;
				p.drawRoundedRect(geometry, radius, radius);
				p.setPen(st::giftBoxTabFgActive);
			} else {
				p.setPen(st::giftBoxTabFg);
			}
			button.text.draw(p, {
				.position = geometry.marginsRemoved(padding).topLeft(),
				.availableWidth = button.text.maxWidth(),
			});
		}
	}, raw->lifetime());

	return {
		.priceTab = state->priceTab.value(),
		.widget = std::move(widget),
	};
}

[[nodiscard]] object_ptr<RpWidget> MakeGiftsList(
		not_null<Window::SessionController*> window,
		not_null<PeerData*> peer,
		rpl::producer<std::vector<GiftDescriptor>> gifts) {
	auto result = object_ptr<RpWidget>((QWidget*)nullptr);
	const auto raw = result.data();

	raw->paintRequest() | rpl::start_with_next([=] {

	}, raw->lifetime());

	return result;
}

void FillBg(not_null<RpWidget*> box) {
	box->paintRequest() | rpl::start_with_next([=] {
		auto p = QPainter(box);
		auto hq = PainterHighQualityEnabler(p);

		const auto radius = st::boxRadius;
		p.setPen(Qt::NoPen);
		p.setBrush(st::boxDividerBg);
		p.drawRoundedRect(
			box->rect().marginsAdded({ 0, 0, 0, 2 * radius }),
			radius,
			radius);
	}, box->lifetime());
}

struct AddBlockArgs {
	rpl::producer<QString> subtitle;
	rpl::producer<TextWithEntities> about;
	Fn<bool(const ClickHandlerPtr&, Qt::MouseButton)> aboutFilter;
	object_ptr<RpWidget> content;
};

void AddBlock(
		not_null<VerticalLayout*> content,
		not_null<Window::SessionController*> window,
		AddBlockArgs &&args) {
	content->add(
		object_ptr<FlatLabel>(
			content,
			std::move(args.subtitle),
			st::giftBoxSubtitle),
		st::giftBoxSubtitleMargin);
	const auto about = content->add(
		object_ptr<FlatLabel>(
			content,
			std::move(args.about),
			st::giftBoxAbout),
		st::giftBoxAboutMargin);
	about->setClickHandlerFilter(std::move(args.aboutFilter));
	content->add(std::move(args.content));
}

[[nodiscard]] object_ptr<RpWidget> MakePremiumGifts(
		not_null<Window::SessionController*> window,
		not_null<PeerData*> peer) {
	auto result = object_ptr<RpWidget>((QWidget*)nullptr);

	struct State {
		rpl::variable<std::vector<GiftDescriptor>> gifts;
	};
	const auto state = std::make_unique<State>();

	state->gifts = GiftsPremium(&window->session(), peer) | rpl::map([=](
			const std::vector<GiftTypePremium> &gifts) {
		return gifts | ranges::to<std::vector<GiftDescriptor>>;
	});

	return MakeGiftsList(window, peer, state->gifts.value());
}

[[nodiscard]] object_ptr<RpWidget> MakeStarsGifts(
		not_null<Window::SessionController*> window,
		not_null<PeerData*> peer) {
	auto result = object_ptr<VerticalLayout>((QWidget*)nullptr);

	struct State {
		rpl::variable<std::vector<GiftTypeStars>> gifts;
		rpl::variable<int> priceTab = kPriceTabAll;
	};
	const auto state = result->lifetime().make_state<State>();

	state->gifts = GiftsStars(&window->session(), peer);

	auto tabs = MakeGiftsPriceTabs(window, peer, state->gifts.value());
	state->priceTab = std::move(tabs.priceTab);
	result->add(std::move(tabs.widget));
	result->add(MakeGiftsList(window, peer, rpl::combine(
		state->gifts.value(),
		state->priceTab.value()
	) | rpl::map([=](std::vector<GiftTypeStars> &&gifts, int price) {
		gifts.erase(ranges::remove_if(gifts, [&](const GiftTypeStars &gift) {
			return (price == kPriceTabLimited)
				? (!gift.limited)
				: (price && gift.stars != price);
		}), end(gifts));
		return gifts | ranges::to<std::vector<GiftDescriptor>>();
	})));

	return result;
}

void GiftBox(
		not_null<GenericBox*> box,
		not_null<Window::SessionController*> window,
		not_null<PeerData*> peer,
		Fn<void()> gifted) {
	box->setWidth(st::boxWideWidth);
	box->setStyle(st::creditsGiftBox);
	box->setNoContentMargin(true);
	box->setCustomCornersFilling(RectPart::FullTop);
	box->addButton(tr::lng_create_group_back(), [=] { box->closeBox(); });

	FillBg(box);

	const auto &stUser = st::premiumGiftsUserpicButton;
	const auto content = box->verticalLayout();

	AddSkip(content);
	AddSkip(content);

	content->add(
		object_ptr<CenterWrap<>>(
			content,
			object_ptr<UserpicButton>(content, peer, stUser))
	)->setAttribute(Qt::WA_TransparentForMouseEvents);
	AddSkip(content);
	AddSkip(content);

	{
		const auto widget = CreateChild<RpWidget>(content);
		using ColoredMiniStars = Premium::ColoredMiniStars;
		const auto stars = widget->lifetime().make_state<ColoredMiniStars>(
			widget,
			false,
			Premium::MiniStars::Type::BiStars);
		stars->setColorOverride(Premium::CreditsIconGradientStops());
		widget->resize(
			st::boxWidth - stUser.photoSize,
			stUser.photoSize * 2);
		content->sizeValue(
		) | rpl::start_with_next([=](const QSize &size) {
			widget->moveToLeft(stUser.photoSize / 2, 0);
			const auto starsRect = Rect(widget->size());
			stars->setPosition(starsRect.topLeft());
			stars->setSize(starsRect.size());
			widget->lower();
		}, widget->lifetime());
		widget->paintRequest(
		) | rpl::start_with_next([=](const QRect &r) {
			auto p = QPainter(widget);
			p.fillRect(r, Qt::transparent);
			stars->paint(p);
		}, widget->lifetime());
	}
	AddSkip(content);
	AddSkip(box->verticalLayout());

	const auto premiumClickHandlerFilter = [=](const auto &...) {
		Settings::ShowPremium(window, u"gift_send"_q);
		return false;
	};
	const auto starsClickHandlerFilter = [=](const auto &...) {
		window->showSettings(Settings::CreditsId());
		return false;
	};
	AddBlock(content, window, {
		.subtitle = tr::lng_gift_premium_subtitle(),
		.about = tr::lng_gift_premium_about(
			lt_name,
			rpl::single(Text::Bold(peer->shortName())),
			lt_features,
			tr::lng_gift_premium_features() | Text::ToLink(),
			Text::WithEntities),
		.aboutFilter = premiumClickHandlerFilter,
		.content = MakePremiumGifts(window, peer),
	});
	AddBlock(content, window, {
		.subtitle = tr::lng_gift_stars_subtitle(),
		.about = tr::lng_gift_stars_about(
			lt_name,
			rpl::single(Text::Bold(peer->shortName())),
			lt_link,
			tr::lng_gift_stars_link() | Text::ToLink(),
			Text::WithEntities),
		.aboutFilter = starsClickHandlerFilter,
		.content = MakeStarsGifts(window, peer),
	});
}

} // namespace

void ShowGiftCreditsBox(
		not_null<Window::SessionController*> controller,
		Fn<void()> gifted) {

	class Controller final : public ContactsBoxController {
	public:
		Controller(
			not_null<Main::Session*> session,
			Fn<void(not_null<PeerData*>)> choose)
		: ContactsBoxController(session)
		, _choose(std::move(choose)) {
		}

	protected:
		std::unique_ptr<PeerListRow> createRow(
				not_null<UserData*> user) override {
			if (user->isSelf()
				|| user->isBot()
				|| user->isServiceUser()
				|| user->isInaccessible()) {
				return nullptr;
			}
			return ContactsBoxController::createRow(user);
		}

		void rowClicked(not_null<PeerListRow*> row) override {
			_choose(row->peer());
		}

	private:
		const Fn<void(not_null<PeerData*>)> _choose;

	};
	auto initBox = [=](not_null<PeerListBox*> peersBox) {
		peersBox->setTitle(tr::lng_credits_gift_title());
		peersBox->addButton(tr::lng_cancel(), [=] { peersBox->closeBox(); });
	};

	const auto show = controller->uiShow();
	auto listController = std::make_unique<Controller>(
		&controller->session(),
		[=](not_null<PeerData*> peer) {
			show->showBox(Box(GiftBox, controller, peer, gifted));
		});
	show->showBox(
		Box<PeerListBox>(std::move(listController), std::move(initBox)),
		LayerOption::KeepOther);
}

} // namespace Ui