<?php
/**
 * Run entity.
 *
 * @package Recast\WCS
 */

namespace Recast\WCS\Run;

use Recast\WCS\Cohort\CohortSpec;
use Recast\WCS\Cohort\InvalidSpecException;
use Recast\WCS\Cohort\SpecSummary;
use Recast\WCS\Support\Json;

defined( 'ABSPATH' ) || exit;

/**
 * A run: one operation over one cohort snapshot, with its lifecycle and summary.
 */
final class Run {

	const RELATION_OPERATION = 'operation';
	const RELATION_UNDO      = 'undo';
	const RELATION_REPREVIEW = 'repreview';
	const RELATION_RETRY     = 'retry';

	/**
	 * Row ID.
	 *
	 * @var int
	 */
	public $id = 0;

	/**
	 * Public identifier.
	 *
	 * @var string
	 */
	public $uuid = '';

	/**
	 * Relation to a parent run.
	 *
	 * @var string
	 */
	public $relation = self::RELATION_OPERATION;

	/**
	 * Parent run.
	 *
	 * @var int|null
	 */
	public $parent_run_id = null;

	/**
	 * Status.
	 *
	 * @var string
	 */
	public $status = RunStatus::DRAFT;

	/**
	 * Operation id.
	 *
	 * @var string
	 */
	public $operation_id = '';

	/**
	 * Normalised params.
	 *
	 * @var array<string, mixed>
	 */
	public $operation_params = array();

	/**
	 * Cohort spec (array form).
	 *
	 * @var array<string, mixed>
	 */
	public $cohort_spec = array();

	/**
	 * Cohort hash.
	 *
	 * @var string
	 */
	public $cohort_hash = '';

	/**
	 * Fingerprinted fields.
	 *
	 * @var string[]
	 */
	public $fingerprint_fields = array();

	/**
	 * Fingerprint version.
	 *
	 * @var int
	 */
	public $fp_version = 1;

	/**
	 * Summary: counts, money, warnings, confirmation_required.
	 *
	 * @var array<string, mixed>
	 */
	public $summary = array();

	/**
	 * Cohort resolution offset cursor.
	 *
	 * @var int
	 */
	public $resolve_offset = 0;

	/**
	 * Highest item id processed by apply.
	 *
	 * @var int
	 */
	public $cursor_item_id = 0;

	/**
	 * Apply chunk size.
	 *
	 * @var int
	 */
	public $chunk_size = 25;

	/**
	 * Apply lanes.
	 *
	 * @var int
	 */
	public $lanes = 1;

	/**
	 * Creator user id.
	 *
	 * @var int
	 */
	public $created_by = 0;

	/**
	 * Timestamps (GMT 'Y-m-d H:i:s' or null).
	 *
	 * @var string|null
	 */
	public $created_at = null;
	/**
	 * Updated.
	 *
	 * @var string|null
	 */
	public $updated_at = null;
	/**
	 * Previewed.
	 *
	 * @var string|null
	 */
	public $previewed_at = null;
	/**
	 * Preview expiry.
	 *
	 * @var string|null
	 */
	public $expires_at = null;
	/**
	 * Apply start.
	 *
	 * @var string|null
	 */
	public $started_at = null;
	/**
	 * Finish.
	 *
	 * @var string|null
	 */
	public $finished_at = null;

	/**
	 * Last error.
	 *
	 * @var string|null
	 */
	public $last_error = null;

	/**
	 * Resolve-time cursor state for background resolution (stored inside summary['resolve_cursor']).
	 *
	 * @return array<string, mixed>
	 */
	public function resolve_cursor() {
		return isset( $this->summary['resolve_cursor'] ) && is_array( $this->summary['resolve_cursor'] ) ? $this->summary['resolve_cursor'] : array();
	}

	/**
	 * Builds from a database row.
	 *
	 * @param array<string, mixed>|object $row Row.
	 * @return Run
	 */
	public static function from_row( $row ) {
		$row = (array) $row;
		$run = new self();
		foreach ( array( 'id', 'resolve_offset', 'cursor_item_id', 'chunk_size', 'lanes', 'created_by', 'fp_version' ) as $int ) {
			if ( isset( $row[ $int ] ) ) {
				$run->$int = (int) $row[ $int ];
			}
		}
		$run->parent_run_id = isset( $row['parent_run_id'] ) ? (int) $row['parent_run_id'] : null;
		foreach ( array( 'uuid', 'relation', 'status', 'operation_id', 'cohort_hash' ) as $str ) {
			if ( isset( $row[ $str ] ) ) {
				$run->$str = (string) $row[ $str ];
			}
		}
		foreach ( array( 'created_at', 'updated_at', 'previewed_at', 'expires_at', 'started_at', 'finished_at', 'last_error' ) as $nullable ) {
			$run->$nullable = isset( $row[ $nullable ] ) ? $row[ $nullable ] : null;
		}
		$run->operation_params   = Json::decode( isset( $row['operation_params'] ) ? $row['operation_params'] : null, array() );
		$run->cohort_spec        = Json::decode( isset( $row['cohort_spec'] ) ? $row['cohort_spec'] : null, array() );
		$run->fingerprint_fields = Json::decode( isset( $row['fingerprint_fields'] ) ? $row['fingerprint_fields'] : null, array() );
		$run->summary            = Json::decode( isset( $row['summary'] ) ? $row['summary'] : null, array() );
		return $run;
	}

	/**
	 * Spec object.
	 *
	 * @return CohortSpec|null
	 */
	public function spec() {
		try {
			return CohortSpec::from_array( $this->cohort_spec );
		} catch ( InvalidSpecException $e ) {
			return null;
		}
	}

	/**
	 * Counts by item status (from summary).
	 *
	 * @return array<string, int>
	 */
	public function counts() {
		$counts = isset( $this->summary['counts'] ) && is_array( $this->summary['counts'] ) ? $this->summary['counts'] : array();
		foreach ( ItemStatus::all() as $status ) {
			$counts[ $status ] = isset( $counts[ $status ] ) ? (int) $counts[ $status ] : 0;
		}
		$counts['total'] = isset( $this->summary['total'] ) ? (int) $this->summary['total'] : array_sum( $counts );
		return $counts;
	}

	/**
	 * Whether the preview is still valid for applying.
	 *
	 * @return bool
	 */
	public function preview_is_current() {
		return RunStatus::PREVIEWED === $this->status && ( ! $this->expires_at || strtotime( $this->expires_at . ' UTC' ) > time() );
	}

	/**
	 * Whether apply may start.
	 *
	 * @return bool
	 */
	public function can_apply() {
		if ( ! $this->preview_is_current() ) {
			return false;
		}
		$counts = $this->counts();
		return $counts[ ItemStatus::READY ] > 0;
	}

	/**
	 * Whether undo may start.
	 *
	 * @return bool
	 */
	public function can_undo() {
		$counts = $this->counts();
		return in_array( $this->status, array( RunStatus::APPLIED, RunStatus::APPLIED_WITH_ISSUES, RunStatus::PARTIALLY_UNDONE ), true )
			&& $counts[ ItemStatus::APPLIED ] > 0
			&& empty( $this->summary['items_purged_at'] );
	}

	/**
	 * Progress: processed/total for the current phase.
	 *
	 * @return array{percent: int, processed: int, total: int, phase: string}
	 */
	public function progress() {
		$counts = $this->counts();
		$total  = $counts['total'];
		if ( in_array( $this->status, RunStatus::previewing(), true ) ) {
			$processed = $total - $counts[ ItemStatus::PENDING ];
			$phase     = 'preview';
		} else {
			$processed = $counts[ ItemStatus::APPLIED ] + $counts[ ItemStatus::STALE ] + $counts[ ItemStatus::FAILED ] + $counts[ ItemStatus::SKIPPED ] + $counts[ ItemStatus::REVERTED ];
			$total     = $counts[ ItemStatus::READY ] + $counts[ ItemStatus::CLAIMED ] + $processed;
			$phase     = 'apply';
		}
		return array(
			'percent'   => $total > 0 ? (int) floor( $processed * 100 / $total ) : 0,
			'processed' => (int) $processed,
			'total'     => (int) $total,
			'phase'     => $phase,
		);
	}

	/**
	 * REST form.
	 *
	 * @return array<string, mixed>
	 */
	public function to_array() {
		$spec    = $this->spec();
		$creator = $this->created_by ? get_userdata( $this->created_by ) : null;
		$summary = $this->summary;
		unset( $summary['resolve_cursor'] );
		return array(
			'id'                    => $this->id,
			'uuid'                  => $this->uuid,
			'relation'              => $this->relation,
			'parent_run_id'         => $this->parent_run_id,
			'status'                => $this->status,
			'operation'             => $this->operation_id,
			'params'                => $this->operation_params,
			'spec'                  => $this->cohort_spec,
			'spec_summary'          => $spec ? SpecSummary::describe( $spec ) : '',
			'cohort_hash'           => $this->cohort_hash,
			'counts'                => $this->counts(),
			'summary'               => $summary,
			'confirmation_required' => isset( $summary['confirmation_required'] ) ? array_values( (array) $summary['confirmation_required'] ) : array(),
			'progress'              => $this->progress(),
			'can_apply'             => $this->can_apply(),
			'can_undo'              => $this->can_undo(),
			'created_by'            => array(
				'id'   => $this->created_by,
				'name' => $creator ? $creator->display_name : '',
			),
			'created_at'            => $this->created_at,
			'previewed_at'          => $this->previewed_at,
			'expires_at'            => $this->expires_at,
			'started_at'            => $this->started_at,
			'finished_at'           => $this->finished_at,
			'error'                 => $this->last_error,
		);
	}
}