/*

Copyright (c) 2018, Alden Torres
Copyright (c) 2014-2021, Arvid Norberg
Copyright (c) 2016, Andrei Kurushin
All rights reserved.

You may use, distribute and modify this code under the terms of the BSD license,
see LICENSE file.
*/

#include "session_view.hpp"
#include "print.hpp"
#include "libtorrent/torrent_handle.hpp"

#include <algorithm> // for std::max

using lt::span;

session_view::session_view()
{
	std::vector<lt::stats_metric> metrics = lt::session_stats_metrics();
	m_cnt[0].resize(metrics.size(), 0);
	m_cnt[1].resize(metrics.size(), 0);
}

void session_view::set_pos(int pos)
{
	m_position = pos;
}

void session_view::set_width(int width)
{
	m_width = width;
}

int session_view::pos() const { return m_position; }

int session_view::height() const
{
	return 3;
}

std::int64_t session_view::value(int idx) const
{
	if (idx < 0) return 0;
	return m_cnt[0][std::size_t(idx)];
}

std::int64_t session_view::prev_value(int idx) const
{
	if (idx < 0) return 0;
	return m_cnt[1][std::size_t(idx)];
}

void session_view::render()
{
	char str[1024];

	int y = m_position;

	using std::chrono::duration_cast;
	double const seconds = double(duration_cast<lt::milliseconds>(m_timestamp[0] - m_timestamp[1]).count()) / 1000.0;

	int const download_rate = int(double(value(m_recv_idx) - prev_value(m_recv_idx))
		/ seconds);
	int const upload_rate = int(double(value(m_sent_idx) - prev_value(m_sent_idx))
		/ seconds);

	std::snprintf(str, sizeof(str), "%s%s fail: %s down: %s (%s) "
		"  bw queue: %s | %s conns: %3d  unchoked: %2d / %2d queued-trackers: %02d%*s\x1b[K"
		, esc("48;5;238")
		, esc("1")
		, add_suffix(value(m_failed_bytes_idx)).c_str()
		, color(add_suffix(download_rate, "/s"), col_green).c_str()
		, color(add_suffix(value(m_recv_idx)), col_green).c_str()
		, color(to_string(int(value(m_limiter_up_queue_idx)), 3), col_red).c_str()
		, color(to_string(int(value(m_limiter_down_queue_idx)), 3), col_green).c_str()
		, int(value(m_num_peers_idx))
		, int(value(m_unchoked_idx))
		, int(value(m_unchoke_slots_idx))
		, int(value(m_queued_tracker_announces))
		, std::max(0, m_width - 86)
		, esc("0"));

	set_cursor_pos(0, y++);
	print(str);

	std::snprintf(str, sizeof(str), "%s%swaste: %s   up: %s (%s) "
		"disk queue: %s | %s cache w: %3d%% total: %s %*s\x1b[K"
#ifdef _WIN32
		, esc("40")
#else
		, esc("48;5;238")
#endif
		, esc("1")
		, add_suffix(value(m_wasted_bytes_idx)).c_str()
		, color(add_suffix(upload_rate, "/s"), col_red).c_str()
		, color(add_suffix(value(m_sent_idx)), col_red).c_str()
		, color(to_string(int(value(m_queued_reads_idx)), 3), col_red).c_str()
		, color(to_string(int(value(m_queued_writes_idx)), 3), col_green).c_str()
		, int((value(m_blocks_written_idx) - value(m_write_ops_idx)) * 100
			/ std::max(std::int64_t(1), value(m_blocks_written_idx)))
		, add_suffix(value(m_blocks_in_use_idx) * 16 * 1024).c_str()
		, std::max(0, m_width - 85)
		, esc("0"));
	set_cursor_pos(0, y++);
	print(str);

	std::snprintf(str, sizeof(str), "%s%suTP idle: %d syn: %d est: %d fin: %d wait: %d%*s\x1b[K"
		, esc("48;5;238")
		, esc("1")
		, int(value(m_utp_idle))
		, int(value(m_utp_syn_sent))
		, int(value(m_utp_connected))
		, int(value(m_utp_fin_sent))
		, int(value(m_utp_close_wait))
		, int(m_width - 37)
		, esc("0"));
	set_cursor_pos(0, y++);
	print(str);
}

void session_view::update_counters(span<std::int64_t const> stats_counters
	, lt::clock_type::time_point const t)
{
	// only update the previous counters if there's been enough
	// time since it was last updated
	if (t - m_timestamp[1] > lt::seconds(2))
	{
		m_cnt[1].swap(m_cnt[0]);
		m_timestamp[1] = m_timestamp[0];
	}

	m_cnt[0].assign(stats_counters.begin(), stats_counters.end());
	m_timestamp[0] = t;
	render();
}