#include "app.h"

#include <algorithm>
#include <set>

#include "util.h"

namespace telegram_tui {

namespace {

std::string format_download_progress(std::int64_t downloaded_size, std::int64_t size_bytes,
                                     bool is_downloaded) {
	if (is_downloaded) {
		return "100%";
	}
	if (size_bytes > 0) {
		const auto downloaded = std::min(downloaded_size, size_bytes);
		return std::to_string(static_cast<int>((downloaded * 100) / size_bytes)) + "% " +
		       format_file_size(downloaded) + "/" + format_file_size(size_bytes);
	}
	return format_file_size(downloaded_size);
}

} // namespace

bool App::process_updates() {
	bool changed = refresh_update_check_result();
	while (true) {
		auto update = td_.receive(0.0);
		if (!update.has_value()) {
			break;
		}
		changed = true;
		handle_td_object(*update);
	}
	return changed;
}

void App::request_saved_animations(bool force) {
	if (saved_animations_loading_ && !force) {
		return;
	}
	saved_animations_loading_ = true;
	td_.send({
	        {"@type", "getSavedAnimations"},
	        {"@extra", "saved_animations"},
	});
	if (!saved_animation_menu_open_) {
		status_line_ = "Loading saved GIFs...";
	}
}

void App::sync_saved_animations(const json &animations) {
	saved_animations_.clear();
	if (!animations.is_array()) {
		saved_animations_loading_ = false;
		saved_animations_loaded_ = true;
		return;
	}

	for (const auto &item : animations) {
		if (!item.is_object()) {
			continue;
		}
		const json file = item.value("animation", json::object());
		const std::int32_t file_id = safe_i32(file, "id");
		if (file_id == 0) {
			continue;
		}

		SavedAnimationInfo animation;
		animation.file_id = file_id;
		animation.name = safe_string(item, "file_name");
		if (animation.name.empty()) {
			animation.name = "animation";
		}
		animation.mime_type = safe_string(item, "mime_type");
		animation.size_bytes = std::max(safe_i64(file, "size"), safe_i64(file, "expected_size"));
		animation.downloaded_size = safe_i64(file.value("local", json::object()), "downloaded_size");
		animation.duration = safe_i32(item, "duration");
		animation.width = safe_i32(item, "width");
		animation.height = safe_i32(item, "height");
		animation.local_path = safe_string(file.value("local", json::object()), "path");
		animation.is_downloading_active =
		        file.value("local", json::object()).value("is_downloading_active", false);
		animation.can_be_downloaded =
		        file.value("local", json::object()).value("can_be_downloaded", false);
		animation.can_be_deleted =
		        file.value("local", json::object()).value("can_be_deleted", false);
		animation.is_downloaded =
		        file.value("local", json::object()).value("is_downloading_completed", false);
		saved_animations_.push_back(std::move(animation));
	}

	if (saved_animation_selection_index_ < 0) {
		saved_animation_selection_index_ = 0;
	}
	if (saved_animation_selection_index_ >= static_cast<int>(saved_animations_.size())) {
		saved_animation_selection_index_ =
		        std::max(0, static_cast<int>(saved_animations_.size()) - 1);
	}
	saved_animations_loading_ = false;
	saved_animations_loaded_ = true;
	ensure_saved_animation_preview();
}

void App::ensure_saved_animation_preview() {
	if (saved_animation_selection_index_ < 0 ||
	    saved_animation_selection_index_ >= static_cast<int>(saved_animations_.size())) {
		return;
	}

	SavedAnimationInfo &animation =
	        saved_animations_[static_cast<std::size_t>(saved_animation_selection_index_)];
	if (animation.file_id == 0 || animation.is_downloaded || animation.is_downloading_active ||
	    !animation.can_be_downloaded) {
		return;
	}

	td_.send({
	        {"@type", "downloadFile"},
	        {"file_id", animation.file_id},
	        {"priority", 1},
	        {"offset", 0},
	        {"limit", 0},
	        {"synchronous", false},
	});
}

void App::handle_td_object(const json &object) {
	const std::string type = safe_string(object, "@type");
	if (type == "updateAuthorizationState") {
		authorization_state_ = object.value("authorization_state", json::object());
		handle_authorization_state();
		return;
	}
	if (type == "updateConnectionState") {
		status_line_ = "Connection: " + safe_string(object.at("state"), "@type");
		return;
	}
	if (type == "updateChatOnlineMemberCount") {
		ChatInfo &chat = chats_[safe_i64(object, "chat_id")];
		chat.id = safe_i64(object, "chat_id");
		chat.online_member_count = safe_i32(object, "online_member_count");
		chat.has_online_member_count = true;
		return;
	}
	if (type == "updateUser") {
		upsert_user(object.value("user", json::object()));
		return;
	}
	if (type == "updateUserStatus") {
		update_user_status(safe_i64(object, "user_id"),
		                   object.value("status", json::object()));
		return;
	}
	if (type == "updateBasicGroup" || type == "basicGroup") {
		upsert_basic_group(type == "basicGroup"
		                           ? object
		                           : object.value("basic_group", json::object()));
		return;
	}
	if (type == "updateSupergroup" || type == "supergroup") {
		upsert_supergroup(
		        type == "supergroup" ? object : object.value("supergroup", json::object()));
		return;
	}
	if (type == "updateNewChat") {
		upsert_chat(object.value("chat", json::object()));
		return;
	}
	if (type == "updateChatTitle") {
		ChatInfo &chat = chats_[safe_i64(object, "chat_id")];
		chat.id = safe_i64(object, "chat_id");
		chat.title = safe_string(object, "title");
		resort_chats();
		return;
	}
	if (type == "updateChatPosition") {
		ChatInfo &chat = chats_[safe_i64(object, "chat_id")];
		chat.id = safe_i64(object, "chat_id");
		apply_chat_position(chat, object.value("position", json::object()));
		resort_chats();
		return;
	}
	if (type == "updateChatLastMessage") {
		ChatInfo &chat = chats_[safe_i64(object, "chat_id")];
		chat.id = safe_i64(object, "chat_id");
		chat.last_message_preview =
		        preview_message(object.value("last_message", json::object()));
		if (object.contains("positions") && object.at("positions").is_array()) {
			chat.in_main_list = false;
			chat.main_order = 0;
			for (const auto &position : object.at("positions")) {
				apply_chat_position(chat, position);
			}
		}
		resort_chats();
		return;
	}
	if (type == "updateChatReadInbox") {
		ChatInfo &chat = chats_[safe_i64(object, "chat_id")];
		chat.id = safe_i64(object, "chat_id");
		chat.unread_count = safe_i32(object, "unread_count");
		chat.last_read_inbox_message_id = safe_i64(object, "last_read_inbox_message_id");
		return;
	}
	if (type == "updateChatReadOutbox") {
		ChatInfo &chat = chats_[safe_i64(object, "chat_id")];
		chat.id = safe_i64(object, "chat_id");
		chat.last_read_outbox_message_id = safe_i64(object, "last_read_outbox_message_id");
		return;
	}
	if (type == "updateNewMessage") {
		const json message = object.value("message", json::object());
		const std::int64_t chat_id = safe_i64(message, "chat_id");
		if (chat_id == open_chat_id_ && message_scroll_ > 0) {
			++message_scroll_;
		}
		const MessageInfo parsed = parse_message(message);
		append_message(chat_id, parsed);
		chats_[chat_id].last_message_preview = preview_message(message);
		if (chat_id == open_chat_id_ && !parsed.is_outgoing) {
			mark_message_as_read(chat_id, parsed.id);
		}
		return;
	}
	if (type == "updateMessageContent") {
		const std::int64_t chat_id = safe_i64(object, "chat_id");
		const std::int64_t message_id = safe_i64(object, "message_id");
		auto chat_it = chats_.find(chat_id);
		if (chat_it == chats_.end()) {
			return;
		}
		for (auto &message : chat_it->second.messages) {
			if (message.id == message_id) {
				const json content = object.value("new_content", json::object());
				message.text = content_to_text(content, true);
				if (const auto attachment = parse_attachment(content);
				    attachment.has_value()) {
					message.has_attachment = true;
					message.attachment = *attachment;
				} else {
					message.has_attachment = false;
				}
				break;
			}
		}
		return;
	}
	if (type == "updateDeleteMessages") {
		const std::int64_t chat_id = safe_i64(object, "chat_id");
		auto chat_it = chats_.find(chat_id);
		if (chat_it == chats_.end()) {
			return;
		}
		std::set<std::int64_t> deleted;
		for (const auto &id : object.value("message_ids", json::array())) {
			if (id.is_number_integer()) {
				deleted.insert(id.get<std::int64_t>());
			}
		}
		std::vector<MessageInfo> kept;
		kept.reserve(chat_it->second.messages.size());
		for (const auto &message : chat_it->second.messages) {
			if (deleted.find(message.id) == deleted.end()) {
				kept.push_back(message);
			}
		}
		chat_it->second.messages = std::move(kept);
		return;
	}
	if (type == "updateFile") {
		update_attachment_file(object.value("file", json::object()));
		return;
	}
	if (type == "updateSavedAnimations") {
		request_saved_animations(true);
		return;
	}
	if (type == "updateOption" || type == "ok" || type == "userFullInfo" ||
	    type == "updateHavePendingNotifications" || type == "updateUnreadMessageCount" ||
	    type == "updateUnreadChatCount") {
		return;
	}
	if (type == "error") {
		const std::string extra = safe_string(object, "@extra");
		const std::string message = safe_string(object, "message");
		if (extra.rfind("history:", 0) == 0) {
			const auto chat_id = static_cast<std::int64_t>(std::stoll(extra.substr(8)));
			chats_[chat_id].history_loading = false;
			status_line_ = "History unavailable: " + message;
			return;
		}
		status_line_ = "TDLib error: " + message;
		return;
	}
	if (type == "user") {
		upsert_user(object);
		return;
	}
	if (type == "chat") {
		upsert_chat(object);
		return;
	}
	if (type == "chats") {
		const std::string extra = safe_string(object, "@extra");
		if (extra == "main_chats") {
			sync_chat_ids_from_response(object);
		}
		return;
	}
	if (type == "messages") {
		const std::string extra = safe_string(object, "@extra");
		if (extra.rfind("history:", 0) == 0) {
			const auto chat_id = static_cast<std::int64_t>(std::stoll(extra.substr(8)));
			merge_history(chat_id, object.value("messages", json::array()));
		}
		return;
	}
	if (type == "animations") {
		const std::string extra = safe_string(object, "@extra");
		if (extra == "saved_animations") {
			sync_saved_animations(object.value("animations", json::array()));
			if (saved_animation_menu_open_) {
				status_line_ = saved_animations_.empty() ? "No saved GIFs." : "Saved GIFs.";
			}
		}
		return;
	}
	if (type == "updateMessageSendSucceeded") {
		const json message = object.value("message", json::object());
		const std::int64_t chat_id = safe_i64(message, "chat_id");
		remove_message(chat_id, safe_i64(object, "old_message_id"));
		append_message(chat_id, parse_message(message));
		chats_[chat_id].last_message_preview = preview_message(message);
		status_line_ = "Message sent.";
		return;
	}

	const std::string extra = safe_string(object, "@extra");
	if (extra == "getMe" && object.is_object()) {
		my_user_id_ = safe_i64(object, "id");
	}
}

void App::request_more_chats() {
	td_.send({
	        {"@type", "getChats"},
	        {"chat_list", {{"@type", "chatListMain"}}},
	        {"limit", kChatPageSize},
	        {"@extra", "main_chats"},
	});
	status_line_ = "Loading chats...";
}

bool App::request_chat_history(std::int64_t chat_id, bool force) {
	ChatInfo &chat = chats_[chat_id];
	chat.id = chat_id;
	if (chat.history_loading && !force) {
		return false;
	}
	chat.history_loading = true;
	td_.send({
	        {"@type", "getChatHistory"},
	        {"chat_id", chat_id},
	        {"from_message_id", 0},
	        {"offset", 0},
	        {"limit", kHistoryBatchSize},
	        {"only_local", false},
	        {"@extra", "history:" + std::to_string(chat_id)},
	});
	return true;
}

bool App::request_open_chat_history(bool force) {
	const auto chat_id = open_chat_id();
	if (!chat_id.has_value()) {
		return false;
	}
	request_chat_details(*chat_id);
	const bool requested = request_chat_history(*chat_id, force);
	if (requested) {
		status_line_ = force ? "Reloading chat history..." : "Loading chat history...";
	}
	return requested;
}

void App::mark_chat_messages_as_read(std::int64_t chat_id) {
	auto chat_it = chats_.find(chat_id);
	if (chat_it == chats_.end()) {
		return;
	}

	std::vector<std::int64_t> unread_message_ids;
	unread_message_ids.reserve(chat_it->second.messages.size());
	for (const auto &message : chat_it->second.messages) {
		if (message.is_outgoing || message.id == 0) {
			continue;
		}
		if (message.id <= chat_it->second.last_read_inbox_message_id) {
			continue;
		}
		unread_message_ids.push_back(message.id);
	}

	if (!unread_message_ids.empty()) {
		td_.send({
		        {"@type", "viewMessages"},
		        {"chat_id", chat_id},
		        {"message_ids", unread_message_ids},
		        {"source", {{"@type", "messageSourceChatHistory"}}},
		        {"force_read", true},
		});
	}

	td_.send({
	        {"@type", "toggleChatIsMarkedAsUnread"},
	        {"chat_id", chat_id},
	        {"is_marked_as_unread", false},
	});
}

void App::mark_message_as_read(std::int64_t chat_id, std::int64_t message_id) {
	if (chat_id == 0 || message_id == 0) {
		return;
	}

	td_.send({
	        {"@type", "viewMessages"},
	        {"chat_id", chat_id},
	        {"message_ids", json::array({message_id})},
	        {"source", {{"@type", "messageSourceChatHistory"}}},
	        {"force_read", true},
	});
}

void App::set_open_chat(std::int64_t chat_id) {
	if (chat_id == 0) {
		return;
	}

	const bool changed_chat = open_chat_id_ != chat_id;
	ChatInfo &chat = chats_[chat_id];
	chat.id = chat_id;
	if (tdlib_open_chat_id_ != 0 && tdlib_open_chat_id_ != chat_id) {
		td_.send({
		        {"@type", "closeChat"},
		        {"chat_id", tdlib_open_chat_id_},
		});
	}

	open_chat_id_ = chat_id;
	message_scroll_ = 0;
	if (changed_chat) {
		message_attachment_message_id_ = 0;
	}

	if (tdlib_open_chat_id_ != chat_id) {
		td_.send({
		        {"@type", "openChat"},
		        {"chat_id", chat_id},
		});
		tdlib_open_chat_id_ = chat_id;
	}

	mark_chat_messages_as_read(chat_id);

	if (changed_chat) {
		request_chat_details(chat_id);
		const bool should_request_history =
		        auto_reload_chat_history_ || !chat.history_loaded || chat.messages.empty();
		const bool requested = should_request_history &&
		                       request_chat_history(chat_id, auto_reload_chat_history_);
		if (requested) {
			status_line_ = auto_reload_chat_history_ && chat.history_loaded
			                       ? "Reloading chat history..."
			                       : "Loading chat history...";
		}
	}
}

void App::sync_chat_ids_from_response(const json &response) {
	if (!response.contains("chat_ids") || !response.at("chat_ids").is_array()) {
		status_line_ = "Chat list response missing chat ids.";
		return;
	}

	std::vector<std::int64_t> chat_ids;
	for (const auto &entry : response.at("chat_ids")) {
		if (!entry.is_number_integer()) {
			continue;
		}
		const auto chat_id = entry.get<std::int64_t>();
		chat_ids.push_back(chat_id);
		if (chats_.find(chat_id) == chats_.end()) {
			td_.send({
			        {"@type", "getChat"},
			        {"chat_id", chat_id},
			});
		}
	}

	if (!chat_ids.empty()) {
		sorted_chat_ids_ = std::move(chat_ids);
		if (selected_chat_index_ >= static_cast<int>(sorted_chat_ids_.size())) {
			selected_chat_index_ =
			        std::max(0, static_cast<int>(sorted_chat_ids_.size()) - 1);
		}
		if (!open_chat_id().has_value()) {
			const auto chat_id = highlighted_chat_id();
			if (chat_id.has_value()) {
				set_open_chat(*chat_id);
			}
		}
		request_open_chat_history(false);
		status_line_ = "Chats loaded.";
		return;
	}

	status_line_ = "No chats loaded.";
}

void App::append_message(std::int64_t chat_id, MessageInfo message) {
	ChatInfo &chat = chats_[chat_id];
	chat.id = chat_id;
	auto existing =
	        std::find_if(chat.messages.begin(), chat.messages.end(),
	                     [&](const MessageInfo &item) { return item.id == message.id; });
	if (existing != chat.messages.end()) {
		*existing = std::move(message);
	} else {
		chat.messages.push_back(std::move(message));
	}

	std::sort(chat.messages.begin(), chat.messages.end(),
	          [](const MessageInfo &lhs, const MessageInfo &rhs) {
		          if (lhs.date != rhs.date) {
			          return lhs.date < rhs.date;
		          }
		          return lhs.id < rhs.id;
	          });

	if (kMaxMessagesPerChat > 0 && chat.messages.size() > kMaxMessagesPerChat) {
		chat.messages.erase(chat.messages.begin(),
		                    chat.messages.begin() +
		                            static_cast<std::ptrdiff_t>(chat.messages.size() -
		                                                        kMaxMessagesPerChat));
	}
}

void App::remove_message(std::int64_t chat_id, std::int64_t message_id) {
	if (message_id == 0) {
		return;
	}

	auto chat_it = chats_.find(chat_id);
	if (chat_it == chats_.end()) {
		return;
	}

	auto &messages = chat_it->second.messages;
	messages.erase(
	        std::remove_if(messages.begin(), messages.end(),
	                       [&](const MessageInfo &item) { return item.id == message_id; }),
	        messages.end());
}

void App::merge_history(std::int64_t chat_id, const json &messages) {
	ChatInfo &chat = chats_[chat_id];
	chat.history_loading = false;
	chat.history_loaded = true;
	for (const auto &message : messages) {
		append_message(chat_id, parse_message(message));
	}
	if (chat_id == open_chat_id_) {
		mark_chat_messages_as_read(chat_id);
	}
	status_line_ = "History loaded.";
}

void App::update_attachment_file(const json &file) {
	const std::int32_t file_id = safe_i32(file, "id");
	if (file_id == 0) {
		return;
	}

	const std::int64_t size_bytes =
	        std::max(safe_i64(file, "size"), safe_i64(file, "expected_size"));
	const json local = file.value("local", json::object());
	const std::string local_path = safe_string(local, "path");
	const std::int64_t downloaded_size = safe_i64(local, "downloaded_size");
	const bool is_downloading_active = local.value("is_downloading_active", false);
	const bool is_downloaded = local.value("is_downloading_completed", false);
	const bool can_be_downloaded = local.value("can_be_downloaded", false);
	const bool can_be_deleted = local.value("can_be_deleted", false);

	for (auto &[chat_id, chat] : chats_) {
		(void)chat_id;
		for (auto &message : chat.messages) {
			if (!message.has_attachment || message.attachment.file_id != file_id) {
				continue;
			}
			if (size_bytes > 0) {
				message.attachment.size_bytes = size_bytes;
			}
			message.attachment.downloaded_size = downloaded_size;
			message.attachment.local_path = local_path;
			message.attachment.is_downloading_active = is_downloading_active;
			message.attachment.is_downloaded = is_downloaded;
			message.attachment.can_be_downloaded = can_be_downloaded;
			message.attachment.can_be_deleted = can_be_deleted;
		}
	}

	for (auto &animation : saved_animations_) {
		if (animation.file_id != file_id) {
			continue;
		}
		if (size_bytes > 0) {
			animation.size_bytes = size_bytes;
		}
		animation.downloaded_size = downloaded_size;
		animation.local_path = local_path;
		animation.is_downloading_active = is_downloading_active;
		animation.is_downloaded = is_downloaded;
		animation.can_be_downloaded = can_be_downloaded;
		animation.can_be_deleted = can_be_deleted;
	}

	if (pending_attachment_open_.has_value() && pending_attachment_open_->file_id == file_id) {
		pending_attachment_open_->size_bytes =
		        size_bytes > 0 ? size_bytes : pending_attachment_open_->size_bytes;
		pending_attachment_open_->downloaded_size = downloaded_size;
		pending_attachment_open_->local_path = local_path;
		pending_attachment_open_->is_downloading_active = is_downloading_active;
		pending_attachment_open_->is_downloaded = is_downloaded;
		pending_attachment_open_->can_be_downloaded = can_be_downloaded;
		pending_attachment_open_->can_be_deleted = can_be_deleted;
		if (!is_downloaded && is_downloading_active) {
			status_line_ =
			        "Downloading attachment to open " +
			        format_download_progress(pending_attachment_open_->downloaded_size,
			                                 pending_attachment_open_->size_bytes,
			                                 pending_attachment_open_->is_downloaded);
		}
		if (is_downloaded && !local_path.empty()) {
			open_attachment(*pending_attachment_open_);
			pending_attachment_open_.reset();
		}
	}

	if (pending_attachment_download_.has_value() &&
	    pending_attachment_download_->file_id == file_id) {
		pending_attachment_download_->size_bytes =
		        size_bytes > 0 ? size_bytes : pending_attachment_download_->size_bytes;
		pending_attachment_download_->downloaded_size = downloaded_size;
		pending_attachment_download_->local_path = local_path;
		pending_attachment_download_->is_downloading_active = is_downloading_active;
		pending_attachment_download_->is_downloaded = is_downloaded;
		pending_attachment_download_->can_be_downloaded = can_be_downloaded;
		pending_attachment_download_->can_be_deleted = can_be_deleted;
		if (!is_downloaded && is_downloading_active) {
			status_line_ = "Downloading attachment to ~/Downloads " +
			               format_download_progress(
			                       pending_attachment_download_->downloaded_size,
			                       pending_attachment_download_->size_bytes,
			                       pending_attachment_download_->is_downloaded);
		}
		if (is_downloaded && !local_path.empty()) {
			export_attachment_to_downloads(*pending_attachment_download_);
			pending_attachment_download_.reset();
		}
	}
}

} // namespace telegram_tui