<?php
/**
 * Report output: the HTML report, and the same report as a PDF download.
 *
 * PDFs are made on the site with Dompdf (bundled in vendor/). Nothing is sent anywhere:
 * remote images and files are switched off, and the agency logo is embedded from the
 * media library.
 *
 * @package Monthwrap
 */

defined( 'ABSPATH' ) || exit;

/**
 * Renders reports.
 */
class Monthwrap_Pdf {

	/**
	 * The report as a complete HTML document, for a browser.
	 *
	 * @param array $report From Monthwrap_Report::build().
	 * @return string
	 */
	public static function html( array $report ) {
		wp_register_style( 'monthwrap-report', plugins_url( 'assets/report.css', MONTHWRAP_FILE ), array(), MONTHWRAP_VERSION );
		wp_register_style( 'monthwrap-report-screen', plugins_url( 'assets/report-screen.css', MONTHWRAP_FILE ), array( 'monthwrap-report' ), MONTHWRAP_VERSION, 'screen' );
		wp_add_inline_style( 'monthwrap-report', self::brand_css( $report ) );
		return self::document( $report, true );
	}

	/**
	 * Fills in the report template.
	 *
	 * @param array $report From Monthwrap_Report::build().
	 * @param bool  $screen Whether a browser will show it, so the template prints the styles.
	 * @return string
	 */
	private static function document( array $report, $screen ) {
		$logo = self::logo( (int) $report['settings']['logo_id'] );
		ob_start();
		include MONTHWRAP_DIR . 'templates/report.php';
		return (string) ob_get_clean();
	}

	/**
	 * The agency's colour.
	 *
	 * @param array $report From Monthwrap_Report::build().
	 * @return string
	 */
	public static function color( array $report ) {
		$color = sanitize_hex_color( $report['settings']['color'] );
		return $color ? $color : '#4f46e5';
	}

	/**
	 * The styles that use the agency's colour, with text that reads on it: dark on light
	 * colours, white on the rest.
	 *
	 * @param array $report From Monthwrap_Report::build().
	 * @return string
	 */
	private static function brand_css( array $report ) {
		$color = self::color( $report );
		$hex   = ltrim( $color, '#' );
		if ( 3 === strlen( $hex ) ) {
			$hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
		}
		$rgb   = array_map( 'hexdec', str_split( $hex, 2 ) );
		$light = ( 0.299 * $rgb[0] + 0.587 * $rgb[1] + 0.114 * $rgb[2] ) / 255 > 0.62;
		$on    = $light ? '#18213a' : '#ffffff';
		$soft  = $light ? 'rgba(24, 33, 58, 0.72)' : 'rgba(255, 255, 255, 0.82)';
		$split = $light ? 'rgba(24, 33, 58, 0.16)' : 'rgba(255, 255, 255, 0.24)';

		return ".agency { color: $color; }\n"
			. ".rule { background: $color; }\n"
			. ".band { background: $color; color: $on; }\n"
			. ".band td + td { border-left: 1px solid $split; }\n"
			. ".band .n span { color: $soft; }\n"
			. ".band .s { color: $soft; }\n"
			. ".bar div { background: $color; }\n";
	}

	/**
	 * The report as PDF bytes.
	 *
	 * @param array $report From Monthwrap_Report::build().
	 * @return string
	 */
	public static function pdf( array $report ) {
		try {
			return self::render( $report );
		} catch ( Throwable $e ) {
			if ( empty( $report['settings']['logo_id'] ) ) {
				throw $e;
			}
			// A logo the server can't process must never stop the report: make it without.
			$report['settings']['logo_id'] = 0;
			return self::render( $report );
		}
	}

	/**
	 * Runs Dompdf.
	 *
	 * @param array $report From Monthwrap_Report::build().
	 * @return string
	 */
	private static function render( array $report ) {
		require_once MONTHWRAP_DIR . 'vendor/autoload.php';
		$temp    = trailingslashit( get_temp_dir() );
		$options = new \Dompdf\Options();
		$options->setIsRemoteEnabled( false );
		$options->setIsPhpEnabled( false );
		$options->setIsJavascriptEnabled( false );
		$options->setDefaultFont( 'DejaVu Sans' );
		$options->setDefaultMediaType( 'print' );
		$options->setChroot( array( MONTHWRAP_DIR ) );
		$options->setTempDir( $temp );
		$options->setFontCache( $temp );

		$dompdf = new \Dompdf\Dompdf( $options );
		$dompdf->loadHtml( self::document( $report, false ), 'UTF-8' );
		$css   = $dompdf->getCss();
		$brand = self::brand_css( $report );
		// Dompdf's own styles go first and load only once: read later, their page margin wins.
		$css->load_css_file( $css->getDefaultStylesheet(), \Dompdf\Css\Stylesheet::ORIG_UA );
		$css->load_css_file( MONTHWRAP_DIR . 'assets/report.css' );
		$css->load_css( $brand );
		$dompdf->setPaper( self::paper(), 'portrait' );
		$dompdf->render();
		return (string) $dompdf->output();
	}

	/**
	 * A file name like "mikes-plumbing-website-report-2026-10.pdf".
	 *
	 * @param array $report From Monthwrap_Report::build().
	 * @return string
	 */
	public static function filename( array $report ) {
		$site = sanitize_title( $report['site']['name'] );
		return ( '' !== $site ? $site . '-' : '' ) . 'website-report-' . $report['period']['start']->format( 'Y-m' ) . '.pdf';
	}

	/**
	 * Letter paper in the US and Canada, A4 everywhere else.
	 *
	 * @return string
	 */
	private static function paper() {
		return in_array( get_locale(), array( 'en_US', 'en_CA', 'es_MX', 'fr_CA' ), true ) ? 'letter' : 'a4';
	}

	/**
	 * The agency logo from the media library, embedded as a data: URI.
	 *
	 * PNG, JPEG or GIF up to 5 MB. It's flattened onto white (the page is white) and made at
	 * most 600 pixels wide with PHP's GD, then embedded as a PNG without transparency.
	 * Transparent PNGs would otherwise go through ImageMagick, which on many hosts can't read
	 * PNGs and stops the PDF.
	 * Without GD, or for anything else, the logo is left out and the agency name shows.
	 *
	 * @param int $attachment_id Attachment ID.
	 * @return string
	 */
	public static function logo( $attachment_id ) {
		if ( ! $attachment_id || ! function_exists( 'imagecreatefromstring' ) ) {
			return '';
		}
		$path = get_attached_file( $attachment_id );
		$type = get_post_mime_type( $attachment_id );
		if ( ! $path || ! in_array( $type, array( 'image/png', 'image/jpeg', 'image/gif' ), true ) || ! is_readable( $path ) || filesize( $path ) > 5 * MB_IN_BYTES ) {
			return '';
		}
		global $wp_filesystem;
		if ( ! function_exists( 'WP_Filesystem' ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
		}
		if ( ! WP_Filesystem() || ! $wp_filesystem ) {
			return '';
		}
		$source = @imagecreatefromstring( (string) $wp_filesystem->get_contents( $path ) ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged -- a broken image just means no logo.
		if ( ! $source ) {
			return '';
		}
		$width  = imagesx( $source );
		$height = imagesy( $source );
		$scale  = min( 1, 600 / max( 1, $width ) );
		$canvas = imagecreatetruecolor( max( 1, (int) round( $width * $scale ) ), max( 1, (int) round( $height * $scale ) ) );
		imagefill( $canvas, 0, 0, imagecolorallocate( $canvas, 255, 255, 255 ) );
		imagecopyresampled( $canvas, $source, 0, 0, 0, 0, imagesx( $canvas ), imagesy( $canvas ), $width, $height );
		imagesavealpha( $canvas, false );
		ob_start();
		imagepng( $canvas, null, 9 );
		$png = (string) ob_get_clean();
		imagedestroy( $source );
		imagedestroy( $canvas );
		return '' !== $png ? 'data:image/png;base64,' . base64_encode( $png ) : ''; // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode -- embedding the logo image in the PDF, not hiding code.
	}
}