<?php declare(strict_types = 0);
/*
** Copyright (C) 2001-2025 Zabbix SIA
**
** This program is free software: you can redistribute it and/or modify it under the terms of
** the GNU Affero General Public License as published by the Free Software Foundation, version 3.
**
** 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 Affero General Public License for more details.
**
** You should have received a copy of the GNU Affero General Public License along with this program.
** If not, see <https://www.gnu.org/licenses/>.
**/

namespace Widgets\SvgGraph\Includes;

use CDiv,
	CSpan;

class CSvgGraphLegend extends CDiv {

	// Legend single line height is 18px. Value should be synchronized with $svg-legend-line-height in scss.
	private const LINE_HEIGHT = 18;

	private const ZBX_STYLE_CLASS = 'svg-graph-legend';

	private const ZBX_STYLE_GRAPH_LEGEND_STATISTIC = 'svg-graph-legend-statistic';
	private const ZBX_STYLE_GRAPH_LEGEND_HEADER = 'svg-graph-legend-header';
	private const ZBX_STYLE_GRAPH_LEGEND_ITEM = 'svg-graph-legend-item';
	private const ZBX_STYLE_GRAPH_LEGEND_NO_DATA = 'svg-graph-legend-no-data';
	private const ZBX_STYLE_GRAPH_LEGEND_VALUE = 'svg-graph-legend-value';

	private array $legend_items;

	private int $columns_count = 0;
	private int $lines_count = 0;
	private int $lines_mode = 0;
	private bool $show_statistic = false;

	/**
	 * @param array  $legend_items
	 * @param string $legend_items[]['name']
	 * @param string $legend_items[]['color']
	 * @param string $legend_items[]['units']
	 * @param string $legend_items[]['min']
	 * @param string $legend_items[]['avg']
	 * @param string $legend_items[]['max']
	 */
	public function __construct(array $legend_items) {
		parent::__construct();

		$this->legend_items = $legend_items;
	}

	public function setColumnsCount(int $columns_count): self {
		$this->columns_count = $columns_count;

		return $this;
	}

	private function getLinesCount(): int {
		if ($this->lines_mode == WidgetForm::LEGEND_LINES_MODE_FIXED) {
			return $this->lines_count;
		}

		return max(WidgetForm::LEGEND_LINES_MIN, min($this->lines_count, $this->show_statistic
			? count($this->legend_items)
			: ceil(count($this->legend_items) / $this->columns_count)
		));
	}

	public function setLinesCount(int $lines_count): self {
		$this->lines_count = $lines_count;

		return $this;
	}

	public function setLinesMode(int $lines_mode): self {
		$this->lines_mode = $lines_mode;

		return $this;
	}

	public function getHeight(): int {
		return ($this->getLinesCount() + ($this->show_statistic ? 1 : 0)) * self::LINE_HEIGHT;
	}

	public function showStatistic(int $show_statistic): self {
		$this->show_statistic = ($show_statistic == WidgetForm::LEGEND_STATISTIC_ON);

		return $this;
	}

	private function draw(): void {
		if ($this->show_statistic) {
			$this->addItem([
				(new CDiv(_('min')))->addClass(self::ZBX_STYLE_GRAPH_LEGEND_HEADER),
				(new CDiv(_('avg')))->addClass(self::ZBX_STYLE_GRAPH_LEGEND_HEADER),
				(new CDiv(_('max')))->addClass(self::ZBX_STYLE_GRAPH_LEGEND_HEADER)
			]);
		}

		foreach ($this->legend_items as $item) {
			// border-color is for legend element ::before pseudo element.
			$this->addItem(
				(new CDiv(new CSpan($item['name'])))
					->addClass(self::ZBX_STYLE_GRAPH_LEGEND_ITEM)
					->setAttribute('style', '--color: '.$item['color'])
			);

			if ($this->show_statistic) {
				if (array_key_exists('units', $item)) {
					$this->addItem([
						(new CDiv(convertUnits([
							'value' => $item['min'],
							'units' => $item['units'],
							'convert' => ITEM_CONVERT_NO_UNITS
						])))->addClass(self::ZBX_STYLE_GRAPH_LEGEND_VALUE),
						(new CDiv(convertUnits([
							'value' => $item['avg'],
							'units' => $item['units'],
							'convert' => ITEM_CONVERT_NO_UNITS
						])))->addClass(self::ZBX_STYLE_GRAPH_LEGEND_VALUE),
						(new CDiv(convertUnits([
							'value' => $item['max'],
							'units' => $item['units'],
							'convert' => ITEM_CONVERT_NO_UNITS
						])))->addClass(self::ZBX_STYLE_GRAPH_LEGEND_VALUE)
					]);
				}
				else {
					$this->addItem(
						(new CDiv('['._('no data').']'))->addClass(self::ZBX_STYLE_GRAPH_LEGEND_NO_DATA)
					);
				}
			}
		}
	}

	public function toString($destroy = true): string {
		$this
			->addClass(self::ZBX_STYLE_CLASS)
			->addClass($this->show_statistic ? self::ZBX_STYLE_GRAPH_LEGEND_STATISTIC : null)
			->addStyle('--lines: '.($this->getLinesCount() + ($this->show_statistic ? 1 : 0)).';');

		if (!$this->show_statistic) {
			$this->addStyle('--columns: '.min($this->columns_count, count($this->legend_items)).';');
		}

		$this->draw();

		return parent::toString($destroy);
	}
}