summaryrefslogtreecommitdiffstats
path: root/wp-includes/block-supports/typography.php
blob: e7d081c937ee49aca3f8ccd442604c066d945147 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
<?php
/**
 * Typography block support flag.
 *
 * @package WordPress
 * @since 5.6.0
 */

/**
 * Registers the style and typography block attributes for block types that support it.
 *
 * @since 5.6.0
 * @since 6.3.0 Added support for text-columns.
 * @access private
 *
 * @param WP_Block_Type $block_type Block Type.
 */
function wp_register_typography_support( $block_type ) {
	if ( ! ( $block_type instanceof WP_Block_Type ) ) {
		return;
	}

	$typography_supports = isset( $block_type->supports['typography'] ) ? $block_type->supports['typography'] : false;
	if ( ! $typography_supports ) {
		return;
	}

	$has_font_family_support     = isset( $typography_supports['__experimentalFontFamily'] ) ? $typography_supports['__experimentalFontFamily'] : false;
	$has_font_size_support       = isset( $typography_supports['fontSize'] ) ? $typography_supports['fontSize'] : false;
	$has_font_style_support      = isset( $typography_supports['__experimentalFontStyle'] ) ? $typography_supports['__experimentalFontStyle'] : false;
	$has_font_weight_support     = isset( $typography_supports['__experimentalFontWeight'] ) ? $typography_supports['__experimentalFontWeight'] : false;
	$has_letter_spacing_support  = isset( $typography_supports['__experimentalLetterSpacing'] ) ? $typography_supports['__experimentalLetterSpacing'] : false;
	$has_line_height_support     = isset( $typography_supports['lineHeight'] ) ? $typography_supports['lineHeight'] : false;
	$has_text_columns_support    = isset( $typography_supports['textColumns'] ) ? $typography_supports['textColumns'] : false;
	$has_text_decoration_support = isset( $typography_supports['__experimentalTextDecoration'] ) ? $typography_supports['__experimentalTextDecoration'] : false;
	$has_text_transform_support  = isset( $typography_supports['__experimentalTextTransform'] ) ? $typography_supports['__experimentalTextTransform'] : false;
	$has_writing_mode_support    = isset( $typography_supports['__experimentalWritingMode'] ) ? $typography_supports['__experimentalWritingMode'] : false;

	$has_typography_support = $has_font_family_support
		|| $has_font_size_support
		|| $has_font_style_support
		|| $has_font_weight_support
		|| $has_letter_spacing_support
		|| $has_line_height_support
		|| $has_text_columns_support
		|| $has_text_decoration_support
		|| $has_text_transform_support
		|| $has_writing_mode_support;

	if ( ! $block_type->attributes ) {
		$block_type->attributes = array();
	}

	if ( $has_typography_support && ! array_key_exists( 'style', $block_type->attributes ) ) {
		$block_type->attributes['style'] = array(
			'type' => 'object',
		);
	}

	if ( $has_font_size_support && ! array_key_exists( 'fontSize', $block_type->attributes ) ) {
		$block_type->attributes['fontSize'] = array(
			'type' => 'string',
		);
	}

	if ( $has_font_family_support && ! array_key_exists( 'fontFamily', $block_type->attributes ) ) {
		$block_type->attributes['fontFamily'] = array(
			'type' => 'string',
		);
	}
}

/**
 * Adds CSS classes and inline styles for typography features such as font sizes
 * to the incoming attributes array. This will be applied to the block markup in
 * the front-end.
 *
 * @since 5.6.0
 * @since 6.1.0 Used the style engine to generate CSS and classnames.
 * @since 6.3.0 Added support for text-columns.
 * @access private
 *
 * @param WP_Block_Type $block_type       Block type.
 * @param array         $block_attributes Block attributes.
 * @return array Typography CSS classes and inline styles.
 */
function wp_apply_typography_support( $block_type, $block_attributes ) {
	if ( ! ( $block_type instanceof WP_Block_Type ) ) {
		return array();
	}

	$typography_supports = isset( $block_type->supports['typography'] )
		? $block_type->supports['typography']
		: false;
	if ( ! $typography_supports ) {
		return array();
	}

	if ( wp_should_skip_block_supports_serialization( $block_type, 'typography' ) ) {
		return array();
	}

	$has_font_family_support     = isset( $typography_supports['__experimentalFontFamily'] ) ? $typography_supports['__experimentalFontFamily'] : false;
	$has_font_size_support       = isset( $typography_supports['fontSize'] ) ? $typography_supports['fontSize'] : false;
	$has_font_style_support      = isset( $typography_supports['__experimentalFontStyle'] ) ? $typography_supports['__experimentalFontStyle'] : false;
	$has_font_weight_support     = isset( $typography_supports['__experimentalFontWeight'] ) ? $typography_supports['__experimentalFontWeight'] : false;
	$has_letter_spacing_support  = isset( $typography_supports['__experimentalLetterSpacing'] ) ? $typography_supports['__experimentalLetterSpacing'] : false;
	$has_line_height_support     = isset( $typography_supports['lineHeight'] ) ? $typography_supports['lineHeight'] : false;
	$has_text_columns_support    = isset( $typography_supports['textColumns'] ) ? $typography_supports['textColumns'] : false;
	$has_text_decoration_support = isset( $typography_supports['__experimentalTextDecoration'] ) ? $typography_supports['__experimentalTextDecoration'] : false;
	$has_text_transform_support  = isset( $typography_supports['__experimentalTextTransform'] ) ? $typography_supports['__experimentalTextTransform'] : false;
	$has_writing_mode_support    = isset( $typography_supports['__experimentalWritingMode'] ) ? $typography_supports['__experimentalWritingMode'] : false;

	// Whether to skip individual block support features.
	$should_skip_font_size       = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'fontSize' );
	$should_skip_font_family     = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'fontFamily' );
	$should_skip_font_style      = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'fontStyle' );
	$should_skip_font_weight     = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'fontWeight' );
	$should_skip_line_height     = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'lineHeight' );
	$should_skip_text_columns    = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'textColumns' );
	$should_skip_text_decoration = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'textDecoration' );
	$should_skip_text_transform  = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'textTransform' );
	$should_skip_letter_spacing  = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'letterSpacing' );
	$should_skip_writing_mode    = wp_should_skip_block_supports_serialization( $block_type, 'typography', 'writingMode' );

	$typography_block_styles = array();
	if ( $has_font_size_support && ! $should_skip_font_size ) {
		$preset_font_size                    = array_key_exists( 'fontSize', $block_attributes )
			? "var:preset|font-size|{$block_attributes['fontSize']}"
			: null;
		$custom_font_size                    = isset( $block_attributes['style']['typography']['fontSize'] )
			? $block_attributes['style']['typography']['fontSize']
			: null;
		$typography_block_styles['fontSize'] = $preset_font_size ? $preset_font_size : wp_get_typography_font_size_value(
			array(
				'size' => $custom_font_size,
			)
		);
	}

	if ( $has_font_family_support && ! $should_skip_font_family ) {
		$preset_font_family                    = array_key_exists( 'fontFamily', $block_attributes )
			? "var:preset|font-family|{$block_attributes['fontFamily']}"
			: null;
		$custom_font_family                    = isset( $block_attributes['style']['typography']['fontFamily'] )
			? wp_typography_get_preset_inline_style_value( $block_attributes['style']['typography']['fontFamily'], 'font-family' )
			: null;
		$typography_block_styles['fontFamily'] = $preset_font_family ? $preset_font_family : $custom_font_family;
	}

	if (
		$has_font_style_support &&
		! $should_skip_font_style &&
		isset( $block_attributes['style']['typography']['fontStyle'] )
	) {
		$typography_block_styles['fontStyle'] = wp_typography_get_preset_inline_style_value(
			$block_attributes['style']['typography']['fontStyle'],
			'font-style'
		);
	}

	if (
		$has_font_weight_support &&
		! $should_skip_font_weight &&
		isset( $block_attributes['style']['typography']['fontWeight'] )
	) {
		$typography_block_styles['fontWeight'] = wp_typography_get_preset_inline_style_value(
			$block_attributes['style']['typography']['fontWeight'],
			'font-weight'
		);
	}

	if ( $has_line_height_support && ! $should_skip_line_height ) {
		$typography_block_styles['lineHeight'] = isset( $block_attributes['style']['typography']['lineHeight'] )
			? $block_attributes['style']['typography']['lineHeight']
			: null;
	}

	if ( $has_text_columns_support && ! $should_skip_text_columns && isset( $block_attributes['style']['typography']['textColumns'] ) ) {
		$typography_block_styles['textColumns'] = isset( $block_attributes['style']['typography']['textColumns'] )
			? $block_attributes['style']['typography']['textColumns']
			: null;
	}

	if (
		$has_text_decoration_support &&
		! $should_skip_text_decoration &&
		isset( $block_attributes['style']['typography']['textDecoration'] )
	) {
		$typography_block_styles['textDecoration'] = wp_typography_get_preset_inline_style_value(
			$block_attributes['style']['typography']['textDecoration'],
			'text-decoration'
		);
	}

	if (
		$has_text_transform_support &&
		! $should_skip_text_transform &&
		isset( $block_attributes['style']['typography']['textTransform'] )
	) {
		$typography_block_styles['textTransform'] = wp_typography_get_preset_inline_style_value(
			$block_attributes['style']['typography']['textTransform'],
			'text-transform'
		);
	}

	if (
		$has_letter_spacing_support &&
		! $should_skip_letter_spacing &&
		isset( $block_attributes['style']['typography']['letterSpacing'] )
	) {
		$typography_block_styles['letterSpacing'] = wp_typography_get_preset_inline_style_value(
			$block_attributes['style']['typography']['letterSpacing'],
			'letter-spacing'
		);
	}

	if ( $has_writing_mode_support &&
		! $should_skip_writing_mode &&
		isset( $block_attributes['style']['typography']['writingMode'] )
	) {
		$typography_block_styles['writingMode'] = isset( $block_attributes['style']['typography']['writingMode'] )
			? $block_attributes['style']['typography']['writingMode']
			: null;
	}

	$attributes = array();
	$styles     = wp_style_engine_get_styles(
		array( 'typography' => $typography_block_styles ),
		array( 'convert_vars_to_classnames' => true )
	);

	if ( ! empty( $styles['classnames'] ) ) {
		$attributes['class'] = $styles['classnames'];
	}

	if ( ! empty( $styles['css'] ) ) {
		$attributes['style'] = $styles['css'];
	}

	return $attributes;
}

/**
 * Generates an inline style value for a typography feature e.g. text decoration,
 * text transform, and font style.
 *
 * Note: This function is for backwards compatibility.
 * * It is necessary to parse older blocks whose typography styles contain presets.
 * * It mostly replaces the deprecated `wp_typography_get_css_variable_inline_style()`,
 *   but skips compiling a CSS declaration as the style engine takes over this role.
 * @link https://github.com/wordpress/gutenberg/pull/27555
 *
 * @since 6.1.0
 *
 * @param string $style_value  A raw style value for a single typography feature from a block's style attribute.
 * @param string $css_property Slug for the CSS property the inline style sets.
 * @return string A CSS inline style value.
 */
function wp_typography_get_preset_inline_style_value( $style_value, $css_property ) {
	// If the style value is not a preset CSS variable go no further.
	if ( empty( $style_value ) || ! str_contains( $style_value, "var:preset|{$css_property}|" ) ) {
		return $style_value;
	}

	/*
	 * For backwards compatibility.
	 * Presets were removed in WordPress/gutenberg#27555.
	 * A preset CSS variable is the style.
	 * Gets the style value from the string and return CSS style.
	 */
	$index_to_splice = strrpos( $style_value, '|' ) + 1;
	$slug            = _wp_to_kebab_case( substr( $style_value, $index_to_splice ) );

	// Return the actual CSS inline style value,
	// e.g. `var(--wp--preset--text-decoration--underline);`.
	return sprintf( 'var(--wp--preset--%s--%s);', $css_property, $slug );
}

/**
 * Renders typography styles/content to the block wrapper.
 *
 * @since 6.1.0
 *
 * @param string $block_content Rendered block content.
 * @param array  $block         Block object.
 * @return string Filtered block content.
 */
function wp_render_typography_support( $block_content, $block ) {
	if ( ! isset( $block['attrs']['style']['typography']['fontSize'] ) ) {
		return $block_content;
	}

	$custom_font_size = $block['attrs']['style']['typography']['fontSize'];
	$fluid_font_size  = wp_get_typography_font_size_value( array( 'size' => $custom_font_size ) );

	/*
	 * Checks that $fluid_font_size does not match $custom_font_size,
	 * which means it's been mutated by the fluid font size functions.
	 */
	if ( ! empty( $fluid_font_size ) && $fluid_font_size !== $custom_font_size ) {
		// Replaces the first instance of `font-size:$custom_font_size` with `font-size:$fluid_font_size`.
		return preg_replace( '/font-size\s*:\s*' . preg_quote( $custom_font_size, '/' ) . '\s*;?/', 'font-size:' . esc_attr( $fluid_font_size ) . ';', $block_content, 1 );
	}

	return $block_content;
}

/**
 * Checks a string for a unit and value and returns an array
 * consisting of `'value'` and `'unit'`, e.g. array( '42', 'rem' ).
 *
 * @since 6.1.0
 *
 * @param string|int|float $raw_value Raw size value from theme.json.
 * @param array            $options   {
 *     Optional. An associative array of options. Default is empty array.
 *
 *     @type string   $coerce_to        Coerce the value to rem or px. Default `'rem'`.
 *     @type int      $root_size_value  Value of root font size for rem|em <-> px conversion. Default `16`.
 *     @type string[] $acceptable_units An array of font size units. Default `array( 'rem', 'px', 'em' )`;
 * }
 * @return array|null An array consisting of `'value'` and `'unit'` properties on success.
 *                    `null` on failure.
 */
function wp_get_typography_value_and_unit( $raw_value, $options = array() ) {
	if ( ! is_string( $raw_value ) && ! is_int( $raw_value ) && ! is_float( $raw_value ) ) {
		_doing_it_wrong(
			__FUNCTION__,
			__( 'Raw size value must be a string, integer, or float.' ),
			'6.1.0'
		);
		return null;
	}

	if ( empty( $raw_value ) ) {
		return null;
	}

	// Converts numbers to pixel values by default.
	if ( is_numeric( $raw_value ) ) {
		$raw_value = $raw_value . 'px';
	}

	$defaults = array(
		'coerce_to'        => '',
		'root_size_value'  => 16,
		'acceptable_units' => array( 'rem', 'px', 'em' ),
	);

	$options = wp_parse_args( $options, $defaults );

	$acceptable_units_group = implode( '|', $options['acceptable_units'] );
	$pattern                = '/^(\d*\.?\d+)(' . $acceptable_units_group . '){1,1}$/';

	preg_match( $pattern, $raw_value, $matches );

	// Bails out if not a number value and a px or rem unit.
	if ( ! isset( $matches[1] ) || ! isset( $matches[2] ) ) {
		return null;
	}

	$value = $matches[1];
	$unit  = $matches[2];

	/*
	 * Default browser font size. Later, possibly could inject some JS to
	 * compute this `getComputedStyle( document.querySelector( "html" ) ).fontSize`.
	 */
	if ( 'px' === $options['coerce_to'] && ( 'em' === $unit || 'rem' === $unit ) ) {
		$value = $value * $options['root_size_value'];
		$unit  = $options['coerce_to'];
	}

	if ( 'px' === $unit && ( 'em' === $options['coerce_to'] || 'rem' === $options['coerce_to'] ) ) {
		$value = $value / $options['root_size_value'];
		$unit  = $options['coerce_to'];
	}

	/*
	 * No calculation is required if swapping between em and rem yet,
	 * since we assume a root size value. Later we might like to differentiate between
	 * :root font size (rem) and parent element font size (em) relativity.
	 */
	if ( ( 'em' === $options['coerce_to'] || 'rem' === $options['coerce_to'] ) && ( 'em' === $unit || 'rem' === $unit ) ) {
		$unit = $options['coerce_to'];
	}

	return array(
		'value' => round( $value, 3 ),
		'unit'  => $unit,
	);
}

/**
 * Internal implementation of CSS clamp() based on available min/max viewport
 * width and min/max font sizes.
 *
 * @since 6.1.0
 * @since 6.3.0 Checks for unsupported min/max viewport values that cause invalid clamp values.
 * @since 6.5.0 Returns early when min and max viewport subtraction is zero to avoid division by zero.
 * @access private
 *
 * @param array $args {
 *     Optional. An associative array of values to calculate a fluid formula
 *     for font size. Default is empty array.
 *
 *     @type string $maximum_viewport_width Maximum size up to which type will have fluidity.
 *     @type string $minimum_viewport_width Minimum viewport size from which type will have fluidity.
 *     @type string $maximum_font_size      Maximum font size for any clamp() calculation.
 *     @type string $minimum_font_size      Minimum font size for any clamp() calculation.
 *     @type int    $scale_factor           A scale factor to determine how fast a font scales within boundaries.
 * }
 * @return string|null A font-size value using clamp() on success, otherwise null.
 */
function wp_get_computed_fluid_typography_value( $args = array() ) {
	$maximum_viewport_width_raw = isset( $args['maximum_viewport_width'] ) ? $args['maximum_viewport_width'] : null;
	$minimum_viewport_width_raw = isset( $args['minimum_viewport_width'] ) ? $args['minimum_viewport_width'] : null;
	$maximum_font_size_raw      = isset( $args['maximum_font_size'] ) ? $args['maximum_font_size'] : null;
	$minimum_font_size_raw      = isset( $args['minimum_font_size'] ) ? $args['minimum_font_size'] : null;
	$scale_factor               = isset( $args['scale_factor'] ) ? $args['scale_factor'] : null;

	// Normalizes the minimum font size in order to use the value for calculations.
	$minimum_font_size = wp_get_typography_value_and_unit( $minimum_font_size_raw );

	/*
	 * We get a 'preferred' unit to keep units consistent when calculating,
	 * otherwise the result will not be accurate.
	 */
	$font_size_unit = isset( $minimum_font_size['unit'] ) ? $minimum_font_size['unit'] : 'rem';

	// Normalizes the maximum font size in order to use the value for calculations.
	$maximum_font_size = wp_get_typography_value_and_unit(
		$maximum_font_size_raw,
		array(
			'coerce_to' => $font_size_unit,
		)
	);

	// Checks for mandatory min and max sizes, and protects against unsupported units.
	if ( ! $maximum_font_size || ! $minimum_font_size ) {
		return null;
	}

	// Uses rem for accessible fluid target font scaling.
	$minimum_font_size_rem = wp_get_typography_value_and_unit(
		$minimum_font_size_raw,
		array(
			'coerce_to' => 'rem',
		)
	);

	// Viewport widths defined for fluid typography. Normalize units.
	$maximum_viewport_width = wp_get_typography_value_and_unit(
		$maximum_viewport_width_raw,
		array(
			'coerce_to' => $font_size_unit,
		)
	);
	$minimum_viewport_width = wp_get_typography_value_and_unit(
		$minimum_viewport_width_raw,
		array(
			'coerce_to' => $font_size_unit,
		)
	);

	// Protects against unsupported units in min and max viewport widths.
	if ( ! $minimum_viewport_width || ! $maximum_viewport_width ) {
		return null;
	}

	// Calculates the linear factor denominator. If it's 0, we cannot calculate a fluid value.
	$linear_factor_denominator = $maximum_viewport_width['value'] - $minimum_viewport_width['value'];
	if ( empty( $linear_factor_denominator ) ) {
		return null;
	}

	/*
	 * Build CSS rule.
	 * Borrowed from https://websemantics.uk/tools/responsive-font-calculator/.
	 */
	$view_port_width_offset = round( $minimum_viewport_width['value'] / 100, 3 ) . $font_size_unit;
	$linear_factor          = 100 * ( ( $maximum_font_size['value'] - $minimum_font_size['value'] ) / ( $linear_factor_denominator ) );
	$linear_factor_scaled   = round( $linear_factor * $scale_factor, 3 );
	$linear_factor_scaled   = empty( $linear_factor_scaled ) ? 1 : $linear_factor_scaled;
	$fluid_target_font_size = implode( '', $minimum_font_size_rem ) . " + ((1vw - $view_port_width_offset) * $linear_factor_scaled)";

	return "clamp($minimum_font_size_raw, $fluid_target_font_size, $maximum_font_size_raw)";
}

/**
 * Returns a font-size value based on a given font-size preset.
 * Takes into account fluid typography parameters and attempts to return a CSS
 * formula depending on available, valid values.
 *
 * @since 6.1.0
 * @since 6.1.1 Adjusted rules for min and max font sizes.
 * @since 6.2.0 Added 'settings.typography.fluid.minFontSize' support.
 * @since 6.3.0 Using layout.wideSize as max viewport width, and logarithmic scale factor to calculate minimum font scale.
 * @since 6.4.0 Added configurable min and max viewport width values to the typography.fluid theme.json schema.
 *
 * @param array $preset                     {
 *     Required. fontSizes preset value as seen in theme.json.
 *
 *     @type string           $name Name of the font size preset.
 *     @type string           $slug Kebab-case, unique identifier for the font size preset.
 *     @type string|int|float $size CSS font-size value, including units if applicable.
 * }
 * @param bool  $should_use_fluid_typography An override to switch fluid typography "on". Can be used for unit testing.
 *                                           Default is false.
 * @return string|null Font-size value or null if a size is not passed in $preset.
 */
function wp_get_typography_font_size_value( $preset, $should_use_fluid_typography = false ) {
	if ( ! isset( $preset['size'] ) ) {
		return null;
	}

	/*
	 * Catches empty values and 0/'0'.
	 * Fluid calculations cannot be performed on 0.
	 */
	if ( empty( $preset['size'] ) ) {
		return $preset['size'];
	}

	// Checks if fluid font sizes are activated.
	$global_settings     = wp_get_global_settings();
	$typography_settings = isset( $global_settings['typography'] ) ? $global_settings['typography'] : array();
	$layout_settings     = isset( $global_settings['layout'] ) ? $global_settings['layout'] : array();

	if (
		isset( $typography_settings['fluid'] ) &&
		( true === $typography_settings['fluid'] || is_array( $typography_settings['fluid'] ) )
	) {
		$should_use_fluid_typography = true;
	}

	if ( ! $should_use_fluid_typography ) {
		return $preset['size'];
	}

	$fluid_settings = isset( $typography_settings['fluid'] ) && is_array( $typography_settings['fluid'] )
		? $typography_settings['fluid']
		: array();

	// Defaults.
	$default_maximum_viewport_width       = '1600px';
	$default_minimum_viewport_width       = '320px';
	$default_minimum_font_size_factor_max = 0.75;
	$default_minimum_font_size_factor_min = 0.25;
	$default_scale_factor                 = 1;
	$default_minimum_font_size_limit      = '14px';

	// Defaults overrides.
	$minimum_viewport_width = isset( $fluid_settings['minViewportWidth'] ) ? $fluid_settings['minViewportWidth'] : $default_minimum_viewport_width;
	$maximum_viewport_width = isset( $layout_settings['wideSize'] ) && ! empty( wp_get_typography_value_and_unit( $layout_settings['wideSize'] ) ) ? $layout_settings['wideSize'] : $default_maximum_viewport_width;
	if ( isset( $fluid_settings['maxViewportWidth'] ) ) {
		$maximum_viewport_width = $fluid_settings['maxViewportWidth'];
	}
	$has_min_font_size       = isset( $fluid_settings['minFontSize'] ) && ! empty( wp_get_typography_value_and_unit( $fluid_settings['minFontSize'] ) );
	$minimum_font_size_limit = $has_min_font_size ? $fluid_settings['minFontSize'] : $default_minimum_font_size_limit;

	// Font sizes.
	$fluid_font_size_settings = isset( $preset['fluid'] ) ? $preset['fluid'] : null;

	// A font size has explicitly bypassed fluid calculations.
	if ( false === $fluid_font_size_settings ) {
		return $preset['size'];
	}

	// Try to grab explicit min and max fluid font sizes.
	$minimum_font_size_raw = isset( $fluid_font_size_settings['min'] ) ? $fluid_font_size_settings['min'] : null;
	$maximum_font_size_raw = isset( $fluid_font_size_settings['max'] ) ? $fluid_font_size_settings['max'] : null;

	// Font sizes.
	$preferred_size = wp_get_typography_value_and_unit( $preset['size'] );

	// Protects against unsupported units.
	if ( empty( $preferred_size['unit'] ) ) {
		return $preset['size'];
	}

	/*
	 * Normalizes the minimum font size limit according to the incoming unit,
	 * in order to perform comparative checks.
	 */
	$minimum_font_size_limit = wp_get_typography_value_and_unit(
		$minimum_font_size_limit,
		array(
			'coerce_to' => $preferred_size['unit'],
		)
	);

	// Don't enforce minimum font size if a font size has explicitly set a min and max value.
	if ( ! empty( $minimum_font_size_limit ) && ( ! $minimum_font_size_raw && ! $maximum_font_size_raw ) ) {
		/*
		 * If a minimum size was not passed to this function
		 * and the user-defined font size is lower than $minimum_font_size_limit,
		 * do not calculate a fluid value.
		 */
		if ( $preferred_size['value'] <= $minimum_font_size_limit['value'] ) {
			return $preset['size'];
		}
	}

	// If no fluid max font size is available use the incoming value.
	if ( ! $maximum_font_size_raw ) {
		$maximum_font_size_raw = $preferred_size['value'] . $preferred_size['unit'];
	}

	/*
	 * If no minimumFontSize is provided, create one using
	 * the given font size multiplied by the min font size scale factor.
	 */
	if ( ! $minimum_font_size_raw ) {
		$preferred_font_size_in_px = 'px' === $preferred_size['unit'] ? $preferred_size['value'] : $preferred_size['value'] * 16;

		/*
		 * The scale factor is a multiplier that affects how quickly the curve will move towards the minimum,
		 * that is, how quickly the size factor reaches 0 given increasing font size values.
		 * For a - b * log2(), lower values of b will make the curve move towards the minimum faster.
		 * The scale factor is constrained between min and max values.
		 */
		$minimum_font_size_factor     = min( max( 1 - 0.075 * log( $preferred_font_size_in_px, 2 ), $default_minimum_font_size_factor_min ), $default_minimum_font_size_factor_max );
		$calculated_minimum_font_size = round( $preferred_size['value'] * $minimum_font_size_factor, 3 );

		// Only use calculated min font size if it's > $minimum_font_size_limit value.
		if ( ! empty( $minimum_font_size_limit ) && $calculated_minimum_font_size <= $minimum_font_size_limit['value'] ) {
			$minimum_font_size_raw = $minimum_font_size_limit['value'] . $minimum_font_size_limit['unit'];
		} else {
			$minimum_font_size_raw = $calculated_minimum_font_size . $preferred_size['unit'];
		}
	}

	$fluid_font_size_value = wp_get_computed_fluid_typography_value(
		array(
			'minimum_viewport_width' => $minimum_viewport_width,
			'maximum_viewport_width' => $maximum_viewport_width,
			'minimum_font_size'      => $minimum_font_size_raw,
			'maximum_font_size'      => $maximum_font_size_raw,
			'scale_factor'           => $default_scale_factor,
		)
	);

	if ( ! empty( $fluid_font_size_value ) ) {
		return $fluid_font_size_value;
	}

	return $preset['size'];
}

// Register the block support.
WP_Block_Supports::get_instance()->register(
	'typography',
	array(
		'register_attribute' => 'wp_register_typography_support',
		'apply'              => 'wp_apply_typography_support',
	)
);