<?php
/**
 * Theme Generator - Builds and caches a CSS file from saved design tokens.
 *
 * Reads theme-mods written by the admin settings page and produces a
 * static CSS file in the uploads directory.  The file is enqueued after
 * main.css so that custom values override defaults.
 *
 * @package OTS_Theme
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Return the absolute filesystem path of the generated CSS file.
 *
 * Multi-site aware - each site gets its own file.
 *
 * @return string
 */
function oribi_generated_css_path() {
	$upload_dir = wp_upload_dir();
	$blog_id    = get_current_blog_id();
	return trailingslashit( $upload_dir['basedir'] ) . "oribi-theme-{$blog_id}-custom.css";
}

/**
 * Return the public URL of the generated CSS file.
 *
 * @return string
 */
function oribi_generated_css_url() {
	$upload_dir = wp_upload_dir();
	$blog_id    = get_current_blog_id();
	return trailingslashit( $upload_dir['baseurl'] ) . "oribi-theme-{$blog_id}-custom.css";
}

/**
 * Helper: convert a hex colour like #004225 to its "r,g,b" string.
 *
 * @param string $hex Hex colour with or without leading #.
 * @return string e.g. "0,66,37"
 */
function oribi_hex_to_rgb( $hex ) {
	$hex = ltrim( $hex, '#' );
	if ( strlen( $hex ) === 3 ) {
		$hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
	}
	if ( strlen( $hex ) !== 6 ) {
		return '0,0,0';
	}
	$r = hexdec( substr( $hex, 0, 2 ) );
	$g = hexdec( substr( $hex, 2, 2 ) );
	$b = hexdec( substr( $hex, 4, 2 ) );
	return "{$r},{$g},{$b}";
}

/**
 * Build the CSS string from current theme-mod values.
 *
 * @return string Complete CSS content.
 */
function oribi_build_css() {

	$s = 'oribi_get_setting'; // shorthand

	// Gather values.
	$primary     = $s( 'color_primary' );
	$primary_dk  = $s( 'color_primary_dk' );
	$primary_lt  = $s( 'color_primary_lt' );
	$accent      = $s( 'color_accent' );
	$accent_dk   = $s( 'color_accent_dk' );
	$accent_lt   = $s( 'color_accent_lt' );
	$dark        = $s( 'color_dark' );
	$dark_2      = $s( 'color_dark_2' );
	$text        = $s( 'color_text' );
	$text_muted  = $s( 'color_text_muted' );
	$border      = $s( 'color_border' );
	$bg          = $s( 'color_bg' );
	$bg_alt      = $s( 'color_bg_alt' );

	// Dark mode.
	$dk_primary     = $s( 'dark_primary' );
	$dk_primary_dk  = $s( 'dark_primary_dk' );
	$dk_primary_lt  = $s( 'dark_primary_lt' );
	$dk_accent      = $s( 'dark_accent' );
	$dk_accent_dk   = $s( 'dark_accent_dk' );
	$dk_accent_lt   = $s( 'dark_accent_lt' );
	$dk_dark        = $s( 'dark_dark' );
	$dk_dark_2      = $s( 'dark_dark_2' );
	$dk_text        = $s( 'dark_text' );
	$dk_text_muted  = $s( 'dark_text_muted' );
	$dk_border      = $s( 'dark_border' );
	$dk_bg          = $s( 'dark_bg' );
	$dk_bg_alt      = $s( 'dark_bg_alt' );
	$dk_bg_dark     = $s( 'dark_bg_dark' );
	$dk_heading     = $s( 'dark_heading' );
	$dk_card_bg     = $s( 'dark_card_bg' );

	// Typography.
	$body_font_slug    = $s( 'font_family' );
	$heading_font_slug = $s( 'font_heading' );
	$body_font_css     = oribi_get_font_family_css( $body_font_slug );
	$heading_font_css  = $heading_font_slug ? oribi_get_font_family_css( $heading_font_slug ) : $body_font_css;

	// Border radii.
	$r_sm = intval( $s( 'radius_sm' ) );
	$r_md = intval( $s( 'radius_md' ) );
	$r_lg = intval( $s( 'radius_lg' ) );
	$r_xl = intval( $s( 'radius_xl' ) );

	// Layout.
	$c_max      = intval( $s( 'container_max' ) );
	$c_pad_min  = floatval( $s( 'container_pad_min' ) );
	$c_pad_max  = floatval( $s( 'container_pad_max' ) );
	$wide       = intval( $s( 'wide_size' ) );

	$primary_rgb = oribi_hex_to_rgb( $primary );
	$accent_rgb  = oribi_hex_to_rgb( $accent );
	$dk_primary_rgb = oribi_hex_to_rgb( $dk_primary );

	// Build CSS.
	$css = <<<CSS
/* ================================================================
   OTS Theme - Generated Theme Overrides
   Generated: %s
   ================================================================ */

/* ── WordPress preset colour overrides ─────────────────────────── */
:root {
  --wp--preset--color--primary:    {$primary};
  --wp--preset--color--primary-dk: {$primary_dk};
  --wp--preset--color--primary-lt: {$primary_lt};
  --wp--preset--color--accent:     {$accent};
  --wp--preset--color--accent-dk:  {$accent_dk};
  --wp--preset--color--accent-lt:  {$accent_lt};
  --wp--preset--color--dark:       {$dark};
  --wp--preset--color--dark-2:     {$dark_2};
  --wp--preset--color--text:       {$text};
  --wp--preset--color--text-muted: {$text_muted};
  --wp--preset--color--border:     {$border};
  --wp--preset--color--bg:         {$bg};
  --wp--preset--color--bg-alt:     {$bg_alt};
}

/* ── Light-mode aliases (consumed by main.css) ─────────────────── */
:root,
[data-theme="light"] {
  --color-primary:     {$primary};
  --color-primary-dk:  {$primary_dk};
  --color-primary-lt:  {$primary_lt};
  --color-primary-rgb: {$primary_rgb};
  --color-accent:      {$accent};
  --color-accent-dk:   {$accent_dk};
  --color-accent-lt:   {$accent_lt};
  --color-accent-rgb:  {$accent_rgb};
  --color-dark:        {$dark};
  --color-dark-2:      {$dark_2};
  --color-text:        {$text};
  --color-text-muted:  {$text_muted};
  --color-border:      {$border};
  --color-bg:          {$bg};
  --color-bg-alt:      {$bg_alt};
  --color-bg-dark:     {$dark};
  --color-heading:     {$dark};
  --header-scrolled-bg: rgba(255,255,255,.97);
  --header-scrolled-text: {$text};
  --card-bg:           {$bg};
  --form-bg:           {$bg_alt};
  --form-bg-focus:     {$bg};

  /* ── Typography ── */
  --font-sans:    {$body_font_css};
  --font-heading: {$heading_font_css};

  /* ── Border radii ── */
  --radius-sm: {$r_sm}px;
  --radius-md: {$r_md}px;
  --radius-lg: {$r_lg}px;
  --radius-xl: {$r_xl}px;
  --wp--custom--radius--sm: {$r_sm}px;
  --wp--custom--radius--md: {$r_md}px;
  --wp--custom--radius--lg: {$r_lg}px;
  --wp--custom--radius--xl: {$r_xl}px;

  /* ── Layout ── */
  --container-max: {$c_max}px;
  --container-pad: clamp({$c_pad_min}rem, 5vw, {$c_pad_max}rem);
  --wp--custom--container--max: {$c_max}px;
  --wp--custom--container--pad: clamp({$c_pad_min}rem, 5vw, {$c_pad_max}rem);
}

/* ── Dark mode overrides ───────────────────────────────────────── */
[data-theme="dark"] {
  --wp--custom--dark--primary:    {$dk_primary};
  --wp--custom--dark--primary-dk: {$dk_primary_dk};
  --wp--custom--dark--primary-lt: {$dk_primary_lt};
  --wp--custom--dark--accent:     {$dk_accent};
  --wp--custom--dark--accent-dk:  {$dk_accent_dk};
  --wp--custom--dark--accent-lt:  {$dk_accent_lt};
  --wp--custom--dark--dark:       {$dk_dark};
  --wp--custom--dark--dark-2:     {$dk_dark_2};
  --wp--custom--dark--text:       {$dk_text};
  --wp--custom--dark--text-muted: {$dk_text_muted};
  --wp--custom--dark--border:     {$dk_border};
  --wp--custom--dark--bg:         {$dk_bg};
  --wp--custom--dark--bg-alt:     {$dk_bg_alt};
  --wp--custom--dark--bg-dark:    {$dk_bg_dark};
  --wp--custom--dark--heading:    {$dk_heading};
  --wp--custom--dark--card-bg:    {$dk_card_bg};

  --color-primary:     {$dk_primary};
  --color-primary-dk:  {$dk_primary_dk};
  --color-primary-lt:  {$dk_primary_lt};
  --color-primary-rgb: {$dk_primary_rgb};
  --color-accent:      {$dk_accent};
  --color-accent-dk:   {$dk_accent_dk};
  --color-accent-lt:   {$dk_accent_lt};
  --color-dark:        {$dk_dark};
  --color-dark-2:      {$dk_dark_2};
  --color-text:        {$dk_text};
  --color-text-muted:  {$dk_text_muted};
  --color-border:      {$dk_border};
  --color-bg:          {$dk_bg};
  --color-bg-alt:      {$dk_bg_alt};
  --color-bg-dark:     {$dk_bg_dark};
  --color-heading:     {$dk_heading};
  --header-scrolled-bg: rgba(26,26,26,.97);
  --header-scrolled-text: {$dk_text};
  --card-bg:           {$dk_card_bg};
  --form-bg:           {$dk_card_bg};
  --form-bg-focus:     {$dk_card_bg};
}

/* ── Typography application ────────────────────────────────────── */
body {
  font-family: var(--font-sans);
}

h1, h2, h3, h4, h5, h6,
.wp-block-heading {
  font-family: var(--font-heading, var(--font-sans));
}

/* ── WordPress layout overrides ────────────────────────────────── */
.wp-site-blocks > .wp-block-group,
.wp-site-blocks > .alignfull {
  max-width: none;
}

body > .is-layout-constrained > :where(:not(.alignleft):not(.alignright):not(.alignfull)) {
  max-width: {$c_max}px;
}

CSS;

	return sprintf( $css, gmdate( 'Y-m-d H:i:s' ) );
}

/**
 * Write the generated CSS file to disk.
 *
 * @return bool|WP_Error True on success, WP_Error on failure.
 */
function oribi_write_generated_css() {

	$css  = oribi_build_css();
	$path = oribi_generated_css_path();

	// Ensure directory exists.
	$dir = dirname( $path );
	if ( ! file_exists( $dir ) ) {
		wp_mkdir_p( $dir );
	}

	// Use WP_Filesystem for safe file writing.
	require_once ABSPATH . 'wp-admin/includes/file.php';
	global $wp_filesystem;
	if ( ! WP_Filesystem() ) {
		return new WP_Error( 'fs', __( 'Could not initialise filesystem.', 'ots-theme' ) );
	}

	$result = $wp_filesystem->put_contents( $path, $css, FS_CHMOD_FILE );
	if ( ! $result ) {
		return new WP_Error( 'write', __( 'Could not write generated CSS file.', 'ots-theme' ) );
	}

	// Bump version number so browsers cache-bust.
	$version = intval( get_theme_mod( 'oribi_css_version', 0 ) ) + 1;
	set_theme_mod( 'oribi_css_version', $version );

	return true;
}

/**
 * Regenerate the CSS file when it is missing or the theme version has changed.
 *
 * Hooked early so the file is ready before wp_enqueue_scripts fires.
 * Also re-seeds defaults if the palette has changed, so the generated
 * CSS always reflects the current default values.
 */
add_action( 'init', function () {

	// Re-seed defaults if the defaults array has changed (e.g. new palette).
	if ( function_exists( 'oribi_maybe_seed_defaults' ) ) {
		oribi_maybe_seed_defaults();
	}

	$needs_regen = ! file_exists( oribi_generated_css_path() );

	if ( ! $needs_regen && defined( 'ORIBI_VERSION' ) ) {
		$stored = get_theme_mod( 'oribi_css_theme_version', '' );
		if ( $stored !== ORIBI_VERSION ) {
			$needs_regen = true;
		}
	}

	if ( $needs_regen ) {
		oribi_write_generated_css();
		if ( defined( 'ORIBI_VERSION' ) ) {
			set_theme_mod( 'oribi_css_theme_version', ORIBI_VERSION );
		}
	}
} );