<?php
/**
 * Usage report: the analysed result of one scan.
 *
 * @package BlockSieve
 */

namespace BlockSieve\Monitor;

/**
 * Immutable collection of analysed occurrences plus the aggregates the report
 * screen and dashboard widget display.
 *
 * Serialised into a transient by ReportRepository, so it holds only plain data.
 */
final class UsageReport {

	/**
	 * Analysed occurrences.
	 *
	 * @var Occurrence[]
	 */
	private array $occurrences;

	/**
	 * Unix timestamp of the scan.
	 *
	 * @var int
	 * @readonly
	 */
	public int $generated;

	/**
	 * Whether the scan hit its row cap.
	 *
	 * @var bool
	 * @readonly
	 */
	public bool $truncated;

	/**
	 * Number of content items inspected.
	 *
	 * @var int
	 * @readonly
	 */
	public int $scanned;

	/**
	 * Constructor.
	 *
	 * @param Occurrence[] $occurrences Analysed occurrences.
	 * @param int          $generated   Unix timestamp of the scan.
	 * @param bool         $truncated   Whether the scan hit its row cap.
	 * @param int          $scanned     Number of content items inspected.
	 */
	public function __construct(
		array $occurrences = array(),
		int $generated = 0,
		bool $truncated = false,
		int $scanned = 0
	) {
		$this->occurrences = $occurrences;
		$this->generated   = $generated;
		$this->truncated   = $truncated;
		$this->scanned     = $scanned;
	}

	/**
	 * Returns every analysed occurrence.
	 *
	 * @return Occurrence[]
	 */
	public function occurrences(): array {
		return $this->occurrences;
	}

	/**
	 * Total number of controlled blocks.
	 *
	 * @return int
	 */
	public function total_blocks(): int {
		return count( $this->occurrences );
	}

	/**
	 * Number of distinct locations (posts, templates, widgets) involved.
	 *
	 * @return int
	 */
	public function total_locations(): int {
		$seen = array();

		foreach ( $this->occurrences as $occurrence ) {
			$seen[ $occurrence->source_kind . ':' . $occurrence->source_id ] = true;
		}

		return count( $seen );
	}

	/**
	 * Number of occurrences with at least one warning.
	 *
	 * @return int
	 */
	public function total_warnings(): int {
		$count = 0;

		foreach ( $this->occurrences as $occurrence ) {
			if ( $occurrence->has_warnings() ) {
				++$count;
			}
		}

		return $count;
	}

	/**
	 * Number of occurrences whose visibility is switched on.
	 *
	 * @return int
	 */
	public function total_active(): int {
		$count = 0;

		foreach ( $this->occurrences as $occurrence ) {
			if ( $occurrence->is_enabled() ) {
				++$count;
			}
		}

		return $count;
	}

	/**
	 * Usage count per condition type, highest first.
	 *
	 * @return array<string,int> Condition type id → number of blocks using it.
	 */
	public function counts_by_condition_type(): array {
		$counts = array();

		foreach ( $this->occurrences as $occurrence ) {
			// array_unique: a block using a type twice still counts once.
			foreach ( array_unique( $occurrence->condition_types() ) as $type ) {
				$counts[ $type ] = ( $counts[ $type ] ?? 0 ) + 1;
			}
		}

		arsort( $counts );

		return $counts;
	}

	/**
	 * Usage count per source kind.
	 *
	 * @return array<string,int> Source kind → number of blocks.
	 */
	public function counts_by_source_kind(): array {
		$counts = array();

		foreach ( $this->occurrences as $occurrence ) {
			$counts[ $occurrence->source_kind ] = ( $counts[ $occurrence->source_kind ] ?? 0 ) + 1;
		}

		arsort( $counts );

		return $counts;
	}
}