<?php
/**
 * The data the AI Advisor sends with a question.
 *
 * @package TurtleReport
 */

namespace TurtleReport\Advisor;

use TurtleReport\Attention\AlertStore;
use TurtleReport\Attention\Monitor;
use TurtleReport\Attention\Presenter;
use TurtleReport\Reports\Summary;
use TurtleReport\Profiles\Profile;
use TurtleReport\Reports\Report;

defined( 'ABSPATH' ) || exit;

/**
 * Builds a compact, numbers-only summary of one client or all of them, from
 * the same cached report data the report screen uses, plus the Client
 * Monitor's open issues.
 *
 * What it includes: each client's name and website, Search Console totals,
 * pages and keywords that moved, GA4 conversions and traffic, AI assistant
 * visits, Business Profile actions, and open issues. What it never includes:
 * email addresses, user names, Google account details, tokens or keys.
 *
 * Alongside the data it returns what the screen shows under each answer:
 * the sources and dates used, headline numbers, and what was missing.
 */
final class Context {

	/** Clients included in an "all clients" question. */
	const MAX_SITES = 40;

	/** Seconds spent loading report data for "all clients"; the rest go without numbers. */
	const AGENCY_BUDGET = 25;

	/** Keywords that lost the most, sent with a question. */
	const ROWS = 8;

	/** Keywords that gained the most. */
	const ROWS_UP = 5;

	/**
	 * Report summaries.
	 *
	 * @var Summary
	 */
	private $summary;

	/**
	 * Reports by ID.
	 *
	 * @var Report[]
	 */
	private $reports = array();

	/**
	 * Client Monitor, or null when it's off.
	 *
	 * @var Monitor|null
	 */
	private $monitor;

	/**
	 * Constructor.
	 *
	 * @param Summary      $summary Summaries.
	 * @param Report[]     $reports Reports.
	 * @param Monitor|null $monitor Client Monitor.
	 */
	public function __construct( Summary $summary, array $reports, ?Monitor $monitor = null ) {
		$this->summary = $summary;
		foreach ( $reports as $r ) {
			$this->reports[ $r->id() ] = $r;
		}
		$this->monitor = $monitor;
	}

	/**
	 * One client in detail.
	 *
	 * @param Profile     $site   Client.
	 * @param array       $period Period (s, e, ps, pe).
	 * @param string|null $issue  Alert ID to focus on.
	 * @return array{data:array,basis:array}
	 */
	public function site( Profile $site, array $period, $issue = null ) {
		$missing = array();
		$sources = array();
		$data    = array(
			'client'  => $site->display_name(),
			'website' => self::website( $site ),
			'period'  => self::period_data( $period ),
		);
		$summary = $this->summary->build( $site, $period, false );
		$this->add_sections( $data, $summary, $site, $period, $missing, $sources, true );

		if ( $issue && $this->monitor ) {
			$alert = $this->monitor->store()->find( $site->id, $issue );
			if ( $alert ) {
				$data['issue'] = self::issue( Presenter::present( $alert, $site ), true );
			}
		}
		$alerts = $this->alerts( $site, false );
		if ( null !== $alerts ) {
			// The other open issues, briefly; the one asked about is already in full above.
			$data['open_issues'] = array_values(
				array_filter(
					$alerts,
					static function ( $a ) use ( $issue ) {
						return $a['id'] !== $issue;
					}
				)
			);
			$sources[]           = __( 'Client Monitor', 'turtlereport' );
		}

		return array(
			'data'  => $data,
			'basis' => array(
				'period'  => self::period_label( $period ),
				'sources' => array_values( array_unique( $sources ) ),
				'missing' => array_values( array_unique( $missing ) ),
				'metrics' => self::tiles( $summary ),
				'clients' => 1,
			),
		);
	}

	/**
	 * Every client the person may see, briefly. Clients with open issues
	 * come first; report data loads until a time budget runs out.
	 *
	 * @param Profile[] $sites  Clients.
	 * @param array     $period Period.
	 * @return array{data:array,basis:array}
	 */
	public function agency( array $sites, array $period ) {
		$rows    = array();
		$missing = array();
		$sources = array();
		$issues  = array();
		foreach ( $sites as $site ) {
			$a                   = $this->alerts( $site, false );
			$issues[ $site->id ] = $a ? $a : array();
		}
		usort(
			$sites,
			static function ( $x, $y ) use ( $issues ) {
				$high     = static function ( $id ) use ( $issues ) {
					return count(
						array_filter(
							$issues[ $id ],
							static function ( $i ) {
								return 'high' === $i['severity'] && 'active' === $i['status'];
							}
						)
					);
				};
				$severity = $high( $y->id ) <=> $high( $x->id );
				if ( 0 !== $severity ) {
					return $severity;
				}
				$count = count( $issues[ $y->id ] ) <=> count( $issues[ $x->id ] );
				return 0 !== $count ? $count : strnatcasecmp( $x->display_name(), $y->display_name() );
			}
		);
		$left  = count( $sites ) - self::MAX_SITES;
		$sites = array_slice( $sites, 0, self::MAX_SITES );
		$start = microtime( true );
		$late  = 0;
		foreach ( $sites as $site ) {
			$row = array(
				'client'  => $site->display_name(),
				'website' => self::website( $site ),
			);
			if ( microtime( true ) - $start < self::AGENCY_BUDGET ) {
				$summary = $this->summary->build( $site, $period, false );
				$miss    = array();
				$this->add_sections( $row, $summary, $site, $period, $miss, $sources, false );
				foreach ( $miss as $m ) {
					$missing[] = $site->display_name() . ': ' . $m;
				}
			} else {
				++$late;
				$row['numbers'] = 'not loaded';
			}
			if ( null !== $this->alerts( $site, false ) ) {
				$row['open_issues'] = $issues[ $site->id ];
				$sources[]          = __( 'Client Monitor', 'turtlereport' );
			}
			$rows[] = $row;
		}
		if ( $late ) {
			/* translators: %d: number of clients. */
			$missing[] = sprintf( _n( 'Report numbers for %d client didn\'t load in time; only its Client Monitor issues were used.', 'Report numbers for %d clients didn\'t load in time; only their Client Monitor issues were used.', $late, 'turtlereport' ), $late );
		}
		if ( $left > 0 ) {
			/* translators: %d: number of clients. */
			$missing[] = sprintf( _n( '%d more client wasn\'t included. Ask about it on its own.', '%d more clients weren\'t included. Ask about them one at a time.', $left, 'turtlereport' ), $left );
		}
		if ( ! $this->monitor ) {
			$missing[] = __( 'The Client Monitor is switched off, so there is no list of open issues.', 'turtlereport' );
		}
		return array(
			'data'  => array(
				'period'  => self::period_data( $period ),
				'clients' => $rows,
			),
			'basis' => array(
				'period'  => self::period_label( $period ),
				'sources' => array_values( array_unique( $sources ) ),
				'missing' => array_values( array_unique( $missing ) ),
				'metrics' => array(),
				'clients' => count( $rows ),
			),
		);
	}

	/**
	 * Adds the report sections to a client's data.
	 *
	 * @param array    $data    Data (changed).
	 * @param array    $summary Summary output.
	 * @param Profile  $site    Client.
	 * @param array    $period  Period.
	 * @param string[] $missing Missing data (changed).
	 * @param string[] $sources Sources used (changed).
	 * @param bool     $detail  Pages and keywords too.
	 * @return void
	 */
	private function add_sections( array &$data, array $summary, Profile $site, array $period, array &$missing, array &$sources, $detail ) {
		$names = array(
			'search'      => __( 'Search Console', 'turtlereport' ),
			'conversions' => __( 'GA4 conversions', 'turtlereport' ),
			'traffic'     => __( 'GA4 traffic', 'turtlereport' ),
			'ai'          => __( 'AI assistant traffic (GA4)', 'turtlereport' ),
			'business'    => __( 'Google Business Profile', 'turtlereport' ),
		);
		foreach ( $detail ? array( 'search', 'conversions', 'business' ) : array() as $key ) {
			$wanted = array(
				'search'      => Profile::SECTION_SEARCH,
				'conversions' => Profile::SECTION_CONVERSIONS,
				'business'    => Profile::SECTION_BUSINESS,
			);
			if ( ! $site->wants( $wanted[ $key ] ) ) {
				/* translators: %s: data source. */
				$missing[] = sprintf( __( '%s isn\'t set up for this client.', 'turtlereport' ), $names[ $key ] );
			}
		}
		foreach ( $summary as $key => $sec ) {
			if ( ! isset( $names[ $key ] ) || ! is_array( $sec ) ) {
				continue;
			}
			if ( isset( $sec['error'] ) ) {
				/* translators: 1: data source, 2: error. */
				$missing[] = sprintf( __( '%1$s couldn\'t be read: %2$s', 'turtlereport' ), $names[ $key ], (string) $sec['error'] );
				continue;
			}
			if ( isset( $sec['status'] ) && in_array( $sec['status'], array( 'no_data', 'no_events' ), true ) ) {
				/* translators: %s: data source. */
				$missing[] = sprintf( __( '%s has no data for this client in this period.', 'turtlereport' ), $names[ $key ] );
				continue;
			}
			if ( ! $detail && ! in_array( $key, array( 'search', 'conversions', 'business' ), true ) ) {
				continue; // Not sent for "all clients", so not listed as a source either.
			}
			$sources[] = $names[ $key ];
			if ( ! $detail ) {
				// For a question about every client, only the headline numbers.
				if ( 'search' === $key ) {
					$data['google_clicks']      = self::pair( $sec['cur']['clicks'], $sec['prev']['clicks'] );
					$data['google_impressions'] = self::pair( $sec['cur']['impressions'], $sec['prev']['impressions'] );
				} elseif ( 'conversions' === $key ) {
					$data[ 'ga4_' . sanitize_key( (string) $sec['label'] ) ] = self::pair( $sec['cur'], $sec['prev'] );
				} elseif ( 'business' === $key ) {
					$data['business_profile_calls'] = self::pair( isset( $sec['cur']['calls'] ) ? $sec['cur']['calls'] : 0, isset( $sec['prev']['calls'] ) ? $sec['prev']['calls'] : 0 );
				}
				continue;
			}
			switch ( $key ) {
				case 'search':
					$data['search_console'] = self::search( $sec, $this->keywords( $site, $period ), true );
					break;
				case 'conversions':
					$data['ga4_conversions'] = self::conversions( $sec, $detail );
					break;
				case 'traffic':
					$data['ga4_traffic'] = self::traffic( $sec );
					break;
				case 'ai':
					$data['ai_assistant_visits'] = array(
						'sessions'    => self::pair( $sec['cur'], $sec['prev'] ),
						'conversions' => self::pair( isset( $sec['conv'] ) ? $sec['conv'] : 0, isset( $sec['conv_prev'] ) ? $sec['conv_prev'] : 0 ),
					);
					break;
				case 'business':
					$data['business_profile'] = self::business( $sec );
					break;
			}
		}
	}

	/**
	 * Search Console section.
	 *
	 * @param array      $s        Section.
	 * @param array|null $keywords Keyword movers, or null.
	 * @param bool       $detail   Include pages.
	 * @return array
	 */
	private static function search( array $s, $keywords, $detail ) {
		$out = array(
			'clicks'       => self::pair( $s['cur']['clicks'], $s['prev']['clicks'] ),
			'impressions'  => self::pair( $s['cur']['impressions'], $s['prev']['impressions'] ),
			'ctr_percent'  => self::pair( round( $s['cur']['ctr'] * 100, 2 ), round( $s['prev']['ctr'] * 100, 2 ), false ),
			'avg_position' => self::pair( round( $s['cur']['position'], 1 ), round( $s['prev']['position'], 1 ), false ),
		);
		if ( $detail ) {
			$page  = static function ( $r ) {
				return array( self::path( $r['page'] ), (int) round( $r['clicks'] - $r['delta'] ), (int) round( $r['clicks'] ) );
			};
			$moved = static function ( $r ) {
				return abs( (float) $r['delta'] ) >= 2;
			};
			$cols  = array( 'page', 'clicks_before', 'clicks_now' );
			$up    = array_values( array_filter( (array) $s['winners'], $moved ) );
			$down  = array_values( array_filter( (array) $s['losers'], $moved ) );
			if ( $up ) {
				$out['pages_gaining_clicks'] = array(
					'columns' => $cols,
					'rows'    => array_map( $page, $up ),
				);
			}
			if ( $down ) {
				$out['pages_losing_clicks'] = array(
					'columns' => $cols,
					'rows'    => array_map( $page, $down ),
				);
			}
		}
		if ( $keywords ) {
			$out = array_merge( $out, $keywords );
		}
		return $out;
	}

	/**
	 * The keywords that gained and lost the most clicks.
	 *
	 * @param Profile $site   Client.
	 * @param array   $period Period.
	 * @return array|null
	 */
	private function keywords( Profile $site, array $period ) {
		if ( ! isset( $this->reports['search-console'] ) ) {
			return null;
		}
		try {
			$q    = function ( $s, $e ) use ( $site ) {
				return (array) $this->reports['search-console']->run(
					$site,
					array(
						'segment'   => '',
						'dimension' => 'query',
						'start'     => $s,
						'end'       => $e,
					)
				);
			};
			$rows = Summary::join_rows( $q( $period['s'], $period['e'] ), $q( $period['ps'], $period['pe'] ) );
		} catch ( \Throwable $e ) {
			return null;
		}
		$fmt  = static function ( $r ) {
			return array(
				$r['key'],
				(int) round( $r['pClicks'] ),
				(int) round( $r['clicks'] ),
				(int) round( $r['pImpr'] ),
				(int) round( $r['impressions'] ),
				null === $r['pPos'] || ! $r['inPrev'] ? null : round( $r['pPos'], 1 ),
				$r['inCur'] ? round( (float) $r['position'], 1 ) : null,
			);
		};
		$up   = array_values(
			array_filter(
				$rows,
				static function ( $r ) {
					return $r['dClicks'] >= 2;
				}
			)
		);
		$down = array_values(
			array_filter(
				$rows,
				static function ( $r ) {
					return $r['dClicks'] <= -2 || ( $r['pImpr'] - $r['impressions'] ) >= 100;
				}
			)
		);
		usort(
			$up,
			static function ( $a, $b ) {
				return $b['dClicks'] <=> $a['dClicks'];
			}
		);
		usort(
			$down,
			static function ( $a, $b ) {
				$clicks = $a['dClicks'] <=> $b['dClicks'];
				return 0 !== $clicks ? $clicks : ( ( $b['pImpr'] - $b['impressions'] ) <=> ( $a['pImpr'] - $a['impressions'] ) );
			}
		);
		$cols = array( 'keyword', 'clicks_before', 'clicks_now', 'impressions_before', 'impressions_now', 'position_before', 'position_now' );
		return array(
			'keywords_gaining' => array(
				'columns' => $cols,
				'rows'    => array_map( $fmt, array_slice( $up, 0, self::ROWS_UP ) ),
			),
			'keywords_losing'  => array(
				'columns' => $cols,
				'rows'    => array_map( $fmt, array_slice( $down, 0, self::ROWS ) ),
			),
		);
	}

	/**
	 * Conversions section.
	 *
	 * @param array $c      Section.
	 * @param bool  $detail Per event.
	 * @return array
	 */
	private static function conversions( array $c, $detail ) {
		$out = array(
			'label' => (string) $c['label'],
			'total' => self::pair( $c['cur'], $c['prev'] ),
		);
		if ( count( (array) $c['groups'] ) > 1 ) {
			$out['groups'] = array();
			foreach ( $c['groups'] as $g ) {
				$out['groups'][ (string) $g['label'] ] = self::pair( $g['cur'], $g['prev'] );
			}
		}
		if ( $detail && ! empty( $c['by_event'] ) ) {
			$out['by_event'] = array();
			foreach ( array_slice( (array) $c['events'], 0, 12 ) as $ev ) {
				$out['by_event'][ (string) $ev ] = self::pair( isset( $c['by_event']['cur'][ $ev ] ) ? $c['by_event']['cur'][ $ev ] : 0, isset( $c['by_event']['prev'][ $ev ] ) ? $c['by_event']['prev'][ $ev ] : 0 );
			}
		}
		if ( ! empty( $c['missing_events'] ) ) {
			$out['events_never_recorded_in_90_days'] = array_values( (array) $c['missing_events'] );
		}
		return $out;
	}

	/**
	 * Traffic section.
	 *
	 * @param array $t Section.
	 * @return array
	 */
	private static function traffic( array $t ) {
		$out = array( 'scope' => (string) $t['scope'] );
		foreach ( (array) $t['metrics'] as $m ) {
			$label         = isset( $m[0] ) ? (string) $m[0] : (string) $m['key'];
			$ratio         = isset( $m[1] ) && 'pct' === $m[1];
			$out[ $label ] = self::pair( $ratio ? round( $m['cur'] * 100, 1 ) : $m['cur'], $ratio ? round( $m['prev'] * 100, 1 ) : $m['prev'], ! $ratio );
		}
		return $out;
	}

	/**
	 * Business Profile section.
	 *
	 * @param array $b Section.
	 * @return array
	 */
	private static function business( array $b ) {
		$out = array();
		foreach ( array(
			'calls' => 'calls',
			'web'   => 'website_clicks',
			'dirs'  => 'direction_requests',
			'views' => 'profile_views',
		) as $k => $name ) {
			$out[ $name ] = self::pair( isset( $b['cur'][ $k ] ) ? $b['cur'][ $k ] : 0, isset( $b['prev'][ $k ] ) ? $b['prev'][ $k ] : 0 );
		}
		if ( ! empty( $b['last_date'] ) ) {
			$out['data_until'] = (string) $b['last_date'];
		}
		return $out;
	}

	/**
	 * The client's open issues from the Client Monitor, or null when it's off.
	 *
	 * @param Profile $site   Client.
	 * @param bool    $detail With insights and checks.
	 * @return array[]|null
	 */
	private function alerts( Profile $site, $detail ) {
		if ( ! $this->monitor || ! $this->monitor->enabled() ) {
			return null;
		}
		$out = array();
		foreach ( $this->monitor->store()->site( $site->id )['alerts'] as $alert ) {
			$state = AlertStore::state( $alert );
			if ( AlertStore::RESOLVED === $state ) {
				continue;
			}
			$out[] = self::issue( Presenter::present( $alert, $site ), $detail );
		}
		return $out;
	}

	/**
	 * An issue, for the model.
	 *
	 * @param array $p      Presented alert.
	 * @param bool  $detail With insights, checks and tables.
	 * @return array
	 */
	private static function issue( array $p, $detail ) {
		$out = array(
			'id'       => $p['id'],
			'type'     => $p['kind'],
			'severity' => $p['severity'],
			'status'   => $p['state'],
			'headline' => $p['headline'],
			'page'     => $p['url'],
			'numbers'  => array_map(
				static function ( $m ) {
					return $m['label'] . ': ' . $m['value'] . ( '' !== (string) $m['change'] ? ' (' . $m['change'] . ')' : '' );
				},
				$p['metrics']
			),
		);
		if ( $detail ) {
			$out['what_the_data_suggests'] = $p['insights'];
			$out['recommended_checks']     = $p['checks'];
			$out['confidence']             = $p['confidence']['text'];
			foreach ( array_slice( $p['tables'], 0, 1 ) as $t ) {
				$out['tables'][] = array(
					'title'   => $t['title'],
					'columns' => $t['cols'],
					'rows'    => array_slice( $t['rows'], 0, 6 ),
				);
			}
		}
		if ( '' === (string) $out['page'] ) {
			unset( $out['page'] );
		}
		return $out;
	}

	/**
	 * Headline numbers shown under an answer.
	 *
	 * @param array $summary Summary output.
	 * @return array[]
	 */
	private static function tiles( array $summary ) {
		$out = array();
		if ( isset( $summary['search']['cur'] ) && empty( $summary['search']['error'] ) ) {
			$s     = $summary['search'];
			$out[] = self::tile( __( 'Google clicks', 'turtlereport' ), $s['cur']['clicks'], $s['prev']['clicks'] );
			$out[] = self::tile( __( 'Impressions', 'turtlereport' ), $s['cur']['impressions'], $s['prev']['impressions'] );
		}
		if ( isset( $summary['conversions']['cur'] ) && empty( $summary['conversions']['error'] ) && 'no_events' !== $summary['conversions']['status'] ) {
			$out[] = self::tile( (string) $summary['conversions']['label'], $summary['conversions']['cur'], $summary['conversions']['prev'] );
		}
		if ( isset( $summary['business']['cur'] ) && empty( $summary['business']['error'] ) ) {
			$out[] = self::tile( __( 'Calls (Business Profile)', 'turtlereport' ), $summary['business']['cur']['calls'], $summary['business']['prev']['calls'] );
		}
		return $out;
	}

	/**
	 * A headline number.
	 *
	 * @param string $label Label.
	 * @param float  $now   Now.
	 * @param float  $prev  Before.
	 * @return array
	 */
	private static function tile( $label, $now, $prev ) {
		$change = $prev > 0 ? round( ( $now - $prev ) / $prev * 100 ) : null;
		return array(
			'label'  => $label,
			'value'  => number_format_i18n( round( (float) $now ) ),
			'change' => null === $change ? '' : ( $change > 0 ? '+' : '' ) . number_format_i18n( $change ) . '%',
			'tone'   => null === $change || abs( $change ) < 1 ? 'flat' : ( $change < 0 ? 'bad' : 'good' ),
		);
	}

	/**
	 * Before, now and the change.
	 *
	 * @param float $now    Now.
	 * @param float $prev   Before.
	 * @param bool  $change Add the percentage change.
	 * @return array
	 */
	private static function pair( $now, $prev, $change = true ) {
		$now  = round( (float) $now, 2 );
		$prev = round( (float) $prev, 2 );
		// A short list instead of named fields: the same facts in about half the tokens.
		$out = array(
			$prev == (int) $prev ? (int) $prev : $prev, // phpcs:ignore Universal.Operators.StrictComparisons.LooseEqual -- Whole numbers read better without ".0".
			$now == (int) $now ? (int) $now : $now, // phpcs:ignore Universal.Operators.StrictComparisons.LooseEqual -- As above.
		);
		if ( $change ) {
			$out[] = $prev > 0 ? round( ( $now - $prev ) / $prev * 100 ) : null;
		}
		return $out;
	}

	/**
	 * Dates for the model.
	 *
	 * @param array $p Period.
	 * @return array
	 */
	private static function period_data( array $p ) {
		return array(
			'current'  => $p['s'] . ' to ' . $p['e'],
			'previous' => $p['ps'] . ' to ' . $p['pe'],
			'numbers'  => '[previous, current, % change]; % change is null when previous was 0. GA4 conversions and sessions are organic search only.',
		);
	}

	/**
	 * "15 Sep – 12 Oct vs 18 Aug – 14 Sep".
	 *
	 * @param array $p Period.
	 * @return string
	 */
	public static function period_label( array $p ) {
		$f = static function ( $ymd ) {
			return wp_date( 'j M Y', strtotime( $ymd . ' 12:00:00 UTC' ), new \DateTimeZone( 'UTC' ) );
		};
		/* translators: 1: current dates, 2: earlier dates. */
		return sprintf( __( '%1$s vs %2$s', 'turtlereport' ), $f( $p['s'] ) . ' – ' . $f( $p['e'] ), $f( $p['ps'] ) . ' – ' . $f( $p['pe'] ) );
	}

	/**
	 * The website's address from its Search Console property.
	 *
	 * @param Profile $site Client.
	 * @return string
	 */
	private static function website( Profile $site ) {
		$prop = (string) $site->gsc_site;
		if ( 0 === strpos( $prop, 'sc-domain:' ) ) {
			return substr( $prop, 10 );
		}
		$host = wp_parse_url( $prop, PHP_URL_HOST );
		return $host ? (string) $host : '';
	}

	/**
	 * A page URL as its path.
	 *
	 * @param string $url URL.
	 * @return string
	 */
	private static function path( $url ) {
		$path = wp_parse_url( (string) $url, PHP_URL_PATH );
		return $path ? (string) $path : (string) $url;
	}
}