<?php

declare(strict_types=1);

/**
 * Hsl.php
 *
 * @since     2015-02-21
 * @category  Library
 * @package   Color
 * @author    Nicola Asuni <info@tecnick.com>
 * @copyright 2015-2026 Nicola Asuni - Tecnick.com LTD
 * @license   https://www.gnu.org/copyleft/lesser.html GNU-LGPL v3 (see LICENSE)
 * @link      https://github.com/tecnickcom/tc-lib-color
 *
 * This file is part of tc-lib-color software library.
 */

namespace Com\Tecnick\Color\Model;

/**
 * Com\Tecnick\Color\Model\Hsl
 *
 * HSL Color Model class
 *
 * @since     2015-02-21
 * @category  Library
 * @package   Color
 * @author    Nicola Asuni <info@tecnick.com>
 * @copyright 2015-2026 Nicola Asuni - Tecnick.com LTD
 * @license   https://www.gnu.org/copyleft/lesser.html GNU-LGPL v3 (see LICENSE)
 * @link      https://github.com/tecnickcom/tc-lib-color
 */
class Hsl extends \Com\Tecnick\Color\Model
{
    /**
     * Color Model type
     *
     * @var string
     */
    protected $type = 'HSL';

    /**
     * Value of the Hue color component [0..1]
     *
     * @var float
     */
    protected float $cmp_hue = 0.0;

    /**
     * Value of the Saturation color component [0..1]
     *
     * @var float
     */
    protected float $cmp_saturation = 0.0;

    /**
     * Value of the Lightness color component [0..1]
     *
     * @var float
     */
    protected float $cmp_lightness = 0.0;

    /**
     * Get an array with all color components.
     *
     * @return array<string, float> with keys ('H', 'S', 'L', 'A')
     */
    public function getArray(): array
    {
        return [
            'H' => $this->cmp_hue,
            'S' => $this->cmp_saturation,
            'L' => $this->cmp_lightness,
            'A' => $this->cmp_alpha,
        ];
    }

    /**
     * Get an array with all color components for
     * the PDF appearance characteristics dictionary.
     *
     * The numbers that shall be in the range 0.0 to 1.0.
     * The number of array elements determines the colour space
     * in which the colour shall be defined:
     * 3 = DeviceRGB
     *
     * @return array<float> DeviceRGB color components ('R', 'G', 'B')
     */
    public function getPDFacArray(): array
    {
        $rgb = $this->toRgbArray();
        return [
            $rgb['red'] ?? 0.0,
            $rgb['green'] ?? 0.0,
            $rgb['blue'] ?? 0.0,
        ];
    }

    /**
     * Get an array with color components values normalized.
     *
     * NOTE: the $max argument is intentionally not applied here. Hue is an angle
     * and is always returned in degrees [0..360], while saturation, lightness and
     * alpha are fraction components kept in the [0..1] range.
     *
     * @param int $max Unused; kept for interface compatibility.
     *
     * @return array<string, float> with keys ('H', 'S', 'L', 'A')
     */
    public function getNormalizedArray(int $max): array
    {
        return [
            'H' => $this->getNormalizedValue($this->cmp_hue, 360),
            'S' => $this->cmp_saturation,
            'L' => $this->cmp_lightness,
            'A' => $this->cmp_alpha,
        ];
    }

    /**
     * Get the CSS representation of the color: hsl(H, S, L) or hsla(H, S, L, A)
     */
    public function getCssColor(): string
    {
        $colorType = 'hsl';
        $alpha = '';
        if ($this->cmp_alpha < 1.0) {
            $colorType = 'hsla';
            $alpha = ',' . $this->cmp_alpha;
        }

        return (
            $colorType
            . '('
            . $this->getNormalizedValue($this->cmp_hue, 360)
            . ','
            . $this->getNormalizedValue($this->cmp_saturation, 100)
            . '%,'
            . $this->getNormalizedValue($this->cmp_lightness, 100)
            . '%'
            . $alpha
            . ')'
        );
    }

    /**
     * Get the color format used in Acrobat JavaScript
     * NOTE: the alpha channel is omitted from this representation unless it is 0 = transparent
     */
    public function getJsPdfColor(): string
    {
        $rgb = $this->toRgbArray();
        if ($this->cmp_alpha === 0.0) {
            return '["T"]'; // transparent color
        }

        return \sprintf('["RGB",%F,%F,%F]', $rgb['red'] ?? 0.0, $rgb['green'] ?? 0.0, $rgb['blue'] ?? 0.0);
    }

    /**
     * Get a space separated string with color component values.
     */
    public function getComponentsString(): string
    {
        $rgb = $this->toRgbArray();
        return \sprintf('%F %F %F', $rgb['red'] ?? 0.0, $rgb['green'] ?? 0.0, $rgb['blue'] ?? 0.0);
    }

    /**
     * Get the color components format used in PDF documents (RGB)
     * NOTE: the alpha channel is omitted
     *
     * @param bool $stroke True for stroking (lines, drawing) and false for non-stroking (text and area filling).
     */
    public function getPdfColor(bool $stroke = false): string
    {
        $mode = 'rg';
        if ($stroke) {
            $mode = \strtoupper($mode);
        }

        return $this->getComponentsString() . ' ' . $mode . "\n";
    }

    /**
     * Get an array with Gray color components
     *
     * @return array<string, float> with keys ('gray', 'alpha')
     */
    public function toGrayArray(): array
    {
        $rgb = new \Com\Tecnick\Color\Model\Rgb($this->toRgbArray());
        return $rgb->toGrayArray();
    }

    /**
     * Get an array with RGB color components
     *
     * @return array<string, float> with keys ('red', 'green', 'blue', 'alpha')
     */
    public function toRgbArray(): array
    {
        if ($this->cmp_saturation === 0.0) {
            return [
                'red' => $this->cmp_lightness,
                'green' => $this->cmp_lightness,
                'blue' => $this->cmp_lightness,
                'alpha' => $this->cmp_alpha,
            ];
        }

        $valb = $this->cmp_lightness * (1 + $this->cmp_saturation);
        if ($this->cmp_lightness >= 0.5) {
            $valb = $this->cmp_lightness + $this->cmp_saturation - ($this->cmp_lightness * $this->cmp_saturation);
        }

        $vala = (2 * $this->cmp_lightness) - $valb;
        return [
            'red' => $this->convertHuetoRgb($vala, $valb, $this->cmp_hue + (1 / 3)),
            'green' => $this->convertHuetoRgb($vala, $valb, $this->cmp_hue),
            'blue' => $this->convertHuetoRgb($vala, $valb, $this->cmp_hue - (1 / 3)),
            'alpha' => $this->cmp_alpha,
        ];
    }

    /**
     * Convert Hue to RGB
     *
     * @param float $vala Temporary value A
     * @param float $valb Temporary value B
     * @param float $hue  Hue value
     */
    private function convertHuetoRgb(float $vala, float $valb, float $hue): float
    {
        if ($hue < 0) {
            ++$hue;
        }

        if ($hue > 1) {
            --$hue;
        }

        if ((6 * $hue) < 1) {
            return \max(0, \min(1, $vala + (($valb - $vala) * 6 * $hue)));
        }

        if ((2 * $hue) < 1) {
            return \max(0, \min(1, $valb));
        }

        if ((3 * $hue) < 2) {
            return \max(0, \min(1, $vala + (($valb - $vala) * ((2 / 3) - $hue) * 6)));
        }

        return \max(0, \min(1, $vala));
    }

    /**
     * Get an array with HSL color components
     *
     * @return array<string, float> with keys ('hue', 'saturation', 'lightness', 'alpha')
     */
    public function toHslArray(): array
    {
        return [
            'hue' => $this->cmp_hue,
            'saturation' => $this->cmp_saturation,
            'lightness' => $this->cmp_lightness,
            'alpha' => $this->cmp_alpha,
        ];
    }

    /**
     * Get an array with CMYK color components
     *
     * @return array<string, float> with keys ('cyan', 'magenta', 'yellow', 'key', 'alpha')
     */
    public function toCmykArray(): array
    {
        $rgb = new \Com\Tecnick\Color\Model\Rgb($this->toRgbArray());
        return $rgb->toCmykArray();
    }

    /**
     * Get an array with Lab color components
     *
     * @return array<string, float> with keys ('lstar', 'astar', 'bstar', 'alpha')
     */
    public function toLabArray(): array
    {
        $rgb = new \Com\Tecnick\Color\Model\Rgb($this->toRgbArray());
        return $rgb->toLabArray();
    }

    /**
     * Invert the color
     */
    public function invertColor(): self
    {
        $this->cmp_hue = $this->cmp_hue >= 0.5 ? $this->cmp_hue - 0.5 : $this->cmp_hue + 0.5;
        return $this;
    }
}
