<?php
/**
 * Builds a report's numbers, verdict, insights, PDF and wording.
 *
 * @package TurtleReport
 */

namespace TurtleReport\Delivery;

use TurtleReport\Pdf\ReportPdf;
use TurtleReport\Policy\Format;
use TurtleReport\Policy\Options;
use TurtleReport\Policy\Schedule;
use TurtleReport\Profiles\Profile;
use TurtleReport\Reports\Insights;
use TurtleReport\Reports\Links;
use TurtleReport\Reports\Summary;
use TurtleReport\Settings\Settings;
use TurtleReport\Support\ErrorText;
use TurtleReport\Support\Periods;

defined( 'ABSPATH' ) || exit;

/**
 * The one place that turns a site and a period into a report: the summary
 * from Google (Summary), the readiness verdict, rule-based insights,
 * titles for the email and PDF, the date-specific report link and the PDF
 * itself. The email, the PDF attachment, secure links and the review screen
 * all read from here, so they always agree.
 */
final class ReportBuilder {

	/**
	 * Summary builder.
	 *
	 * @var Summary
	 */
	private $summary;

	/**
	 * Install settings (branding).
	 *
	 * @var Settings
	 */
	private $settings;

	/**
	 * Constructor.
	 *
	 * @param Summary  $summary  Summary builder.
	 * @param Settings $settings Install settings.
	 */
	public function __construct( Summary $summary, Settings $settings ) {
		$this->summary  = $summary;
		$this->settings = $settings;
	}

	/**
	 * Install settings.
	 *
	 * @return Settings
	 */
	public function settings() {
		return $this->settings;
	}

	/**
	 * Whether a site's reports need the full detail (PDF, secure link or insights).
	 *
	 * @param Profile $site Site.
	 * @return bool
	 */
	public static function needs_full( Profile $site ) {
		$d = $site->delivery;
		return ! empty( $d['attach_pdf'] ) || ! empty( $d['share_link'] ) || ! empty( $d['insights'] ) || Options::MODE_REVIEW === $d['mode'];
	}

	/**
	 * Fetches the numbers and checks them.
	 *
	 * @param Profile     $site   Site.
	 * @param array       $period Period.
	 * @param bool|null   $full   Full detail; null decides from the site's options.
	 * @param string|null $today  Override for "today".
	 * @return array{data:array,readiness:array,insights:array[],full:bool}
	 */
	public function prepare( Profile $site, array $period, $full = null, $today = null ) {
		$full      = null === $full ? self::needs_full( $site ) : (bool) $full;
		$data      = $this->summary->build( $site, $period, $full );
		$readiness = Readiness::check( $site, $data, $period, $today );
		$insights  = ! empty( $site->delivery['insights'] ) || Options::MODE_REVIEW === $site->delivery['mode'] ? Insights::generate( $site, $data, $period ) : array();
		return array(
			'data'      => $data,
			'readiness' => $readiness,
			'insights'  => $insights,
			'full'      => $full,
		);
	}

	/**
	 * Everything templates and the PDF need for a run.
	 *
	 * @param Profile $site Site.
	 * @param array   $run  Run with snapshot, checks, insights and notes.
	 * @param bool    $test Test send.
	 * @return array
	 */
	public function context( Profile $site, array $run, $test = false ) {
		$period    = RunRepository::period( $run );
		$snapshot  = is_array( $run['snapshot'] ) ? $run['snapshot'] : array();
		$data      = isset( $snapshot['data'] ) ? (array) $snapshot['data'] : array();
		$readiness = is_array( $run['checks'] ) && isset( $run['checks']['level'] ) ? $run['checks'] : array(
			'level'  => '',
			'checks' => array(),
		);
		$meta      = is_array( $run['meta'] ) ? $run['meta'] : array();
		$frequency = isset( $meta['frequency'] ) ? (string) $meta['frequency'] : '';
		$compare   = isset( $meta['compare'] ) ? (string) $meta['compare'] : self::compare_of( $period );
		$label     = self::label( $period, $frequency );
		$show      = ! empty( $site->delivery['insights'] ) || ! empty( $run['reviewed_at'] );
		$notes     = trim( (string) $run['notes'] );
		$site_note = isset( $site->email['note'] ) ? trim( (string) $site->email['note'] ) : '';
		return array(
			'site'          => $site,
			'run'           => $run,
			'period'        => $period,
			'data'          => $data,
			'label'         => $label,
			'title'         => self::title( $label ),
			'kind'          => self::kind( $period, $frequency ),
			'compare'       => $compare,
			'compare_label' => Insights::versus( $period ),
			'readiness'     => $readiness,
			'problems'      => Readiness::problems( $readiness ),
			'insights'      => $show && is_array( $run['insights'] ) ? $run['insights'] : array(),
			'notes'         => $notes,
			'site_note'     => $site_note,
			'test'          => (bool) $test,
			'report_url'    => self::report_url( $site, $period, $compare ),
			'brand'         => array(
				'name'             => $this->settings->brand_name(),
				'color'            => $this->settings->brand_color(),
				'logo'             => $this->settings->logo_url(),
				'logo_path'        => Settings::attachment_file( (int) $this->settings->get( 'brand_logo_id' ) ),
				'client_logo'      => Settings::attachment_url( $site->client_logo_id ),
				'client_logo_path' => Settings::attachment_file( $site->client_logo_id ),
				'footer'           => (string) $this->settings->get( 'footer_text' ),
				'credit'           => $this->settings->show_credit(),
			),
			'prepared'      => wp_date( 'j M Y' ),
		);
	}

	/**
	 * The PDF for a run.
	 *
	 * @param Profile $site Site.
	 * @param array   $run  Run (with snapshot).
	 * @return string|\WP_Error PDF bytes.
	 */
	public function pdf( Profile $site, array $run ) {
		if ( ! is_array( $run['snapshot'] ) || empty( $run['snapshot']['full'] ) ) {
			if ( null === $run['snapshot'] && ! empty( $run['sent_at'] ) ) {
				return new \WP_Error( 'turtlereport_pdf_gone', __( 'The numbers behind this PDF were cleared after 120 days, so it can\'t be shown again. The recipients still have their copy.', 'turtlereport' ) );
			}
			return new \WP_Error( 'turtlereport_pdf_data', __( 'This report was built without the detail a PDF needs. Prepare it again.', 'turtlereport' ) );
		}
		if ( function_exists( 'wp_raise_memory_limit' ) ) {
			wp_raise_memory_limit( 'turtlereport_pdf' );
		}
		$ctx          = $this->context( $site, $run );
		$ctx['notes'] = trim( $ctx['site_note'] . ( '' !== $ctx['site_note'] && '' !== $ctx['notes'] ? "\n\n" : '' ) . $ctx['notes'] );
		$ctx['brand'] = array_intersect_key( $ctx['brand'], array_flip( array( 'name', 'color', 'logo_path', 'client_logo_path', 'footer', 'credit' ) ) );
		try {
			return ReportPdf::render( $ctx );
		} catch ( \Throwable $e ) {
			/* translators: %s: error message. */
			return new \WP_Error( 'turtlereport_pdf_failed', sprintf( __( 'The PDF couldn\'t be created: %s', 'turtlereport' ), ErrorText::from( $e ) ) );
		}
	}

	/**
	 * File name for a run's PDF, e.g. "acme-widgets-september-2026.pdf".
	 *
	 * @param Profile $site Site.
	 * @param array   $run  Run.
	 * @return string
	 */
	public static function pdf_name( Profile $site, array $run ) {
		$meta = is_array( $run['meta'] ) ? $run['meta'] : array();
		$name = sanitize_title( $site->display_name() . ' ' . self::label( RunRepository::period( $run ), isset( $meta['frequency'] ) ? (string) $meta['frequency'] : '' ) );
		return ( '' !== $name ? $name : 'report' ) . '.pdf';
	}

	/**
	 * Name of the period: "September 2026", "Q3 2026", or a date range.
	 *
	 * @param array  $period    Period.
	 * @param string $frequency Schedule interval, if known.
	 * @return string
	 */
	public static function label( array $period, $frequency = '' ) {
		$s = $period['s'];
		$e = $period['e'];
		if ( '01' === substr( $s, 8 ) && gmdate( 'Y-m-t', strtotime( $s . ' 12:00:00 UTC' ) ) === $e ) {
			return wp_date( 'F Y', strtotime( $s . ' 12:00:00 UTC' ), new \DateTimeZone( 'UTC' ) );
		}
		$m = (int) substr( $s, 5, 2 );
		if ( '01' === substr( $s, 8 ) && 1 === $m % 3 && Periods::add_days( Periods::add_months( $s, 3 ), -1 ) === $e ) {
			/* translators: 1: quarter number (1-4), 2: year. */
			return sprintf( __( 'Q%1$d %2$s', 'turtlereport' ), (int) ceil( $m / 3 ), substr( $s, 0, 4 ) );
		}
		unset( $frequency );
		return Format::range( $s, $e );
	}

	/**
	 * Report title: "September 2026 report".
	 *
	 * @param string $label Period name.
	 * @return string
	 */
	public static function title( $label ) {
		/* translators: %s: period name, e.g. "September 2026" or a date range. */
		return sprintf( __( '%s report', 'turtlereport' ), $label );
	}

	/**
	 * What the period is: "Full month", "Last 7 days"…
	 *
	 * @param array  $period    Period.
	 * @param string $frequency Schedule interval.
	 * @return string
	 */
	public static function kind( array $period, $frequency = '' ) {
		switch ( $frequency ) {
			case Schedule::WEEKLY:
				return __( 'Last 7 days', 'turtlereport' );
			case Schedule::BIWEEKLY:
				return __( 'Last 14 days', 'turtlereport' );
			case Schedule::QUARTERLY:
				return __( 'Full quarter', 'turtlereport' );
			case Schedule::MONTHLY:
				return __( 'Full month', 'turtlereport' );
		}
		$label = self::label( $period );
		return Format::range( $period['s'], $period['e'] ) === $label ? __( 'Custom range', 'turtlereport' ) : __( 'Full period', 'turtlereport' );
	}

	/**
	 * How a period's comparison was chosen: previous or year.
	 *
	 * @param array $period Period.
	 * @return string previous|year
	 */
	public static function compare_of( array $period ) {
		return Periods::shift_year( $period['s'], -1 ) === $period['ps'] && Periods::shift_year( $period['e'], -1 ) === $period['pe'] ? 'year' : 'previous';
	}

	/**
	 * Report screen URL that opens exactly this period and comparison.
	 *
	 * @param Profile $site    Site.
	 * @param array   $period  Period.
	 * @param string  $compare previous|year.
	 * @return string
	 */
	public static function report_url( Profile $site, array $period, $compare = 'previous' ) {
		return Links::url(
			array(
				'site'    => $site->id,
				'start'   => $period['s'],
				'end'     => $period['e'],
				'compare' => 'year' === $compare ? 'year' : 'previous',
				'cstart'  => $period['ps'],
				'cend'    => $period['pe'],
			)
		);
	}
}