<?php
namespace AfFulltext;

/**
 * A parsed FiveFilters site-config rule.
 *
 * Field names track the ftr-site-config directive names so a rule file and this
 * object read the same way. Directives that may repeat accumulate into arrays,
 * exactly as Full-Text RSS treats them.
 */
final class Rule {
	/** @var string[] */ public array $titles = [];
	/** @var string[] */ public array $bodies = [];
	/** @var string[] */ public array $authors = [];
	/** @var string[] */ public array $dates = [];
	/** @var string[] */ public array $strips = [];
	/** @var string[] */ public array $strip_id_or_class = [];
	/** @var string[] */ public array $strip_image_src = [];
	/** @var string[] */ public array $dissolve = [];
	/** @var string[] */ public array $single_page_links = [];
	/** @var string[] */ public array $next_page_links = [];
	/** @var string[] */ public array $find_strings = [];
	/** @var string[] */ public array $replace_strings = [];
	/** @var string[] */ public array $test_urls = [];
	/** @var array<string,string> */ public array $http_headers = [];
	/** @var array<string,string> map of xpath => wrapper spec e.g. "div.foo" */
	public array $wrap_in = [];

	public bool $prune = true;
	public bool $tidy = true;
	public bool $autodetect_on_failure = true;

	/**
	 * Files this rule was assembled from, nearest-match first. Surfaced in the
	 * UI so a stale rule is visible rather than silently falling through to
	 * Readability -- the exact failure mode that hid a broken comic rule for
	 * years.
	 *
	 * @var string[]
	 */
	public array $sources = [];

	public function is_empty(): bool {
		return !$this->bodies && !$this->strips && !$this->strip_id_or_class
			&& !$this->strip_image_src && !$this->titles && !$this->dissolve;
	}

	/** Merge $other UNDER $this: existing scalars win, list directives concatenate. */
	public function merge_under(self $other): self {
		$m = clone $this;

		foreach (['titles', 'bodies', 'authors', 'dates', 'single_page_links', 'next_page_links'] as $f)
			if (!$m->$f) $m->$f = $other->$f;

		foreach (['strips', 'strip_id_or_class', 'strip_image_src', 'dissolve', 'test_urls'] as $f)
			$m->$f = array_values(array_unique([...$m->$f, ...$other->$f]));

		// find/replace are positional pairs -- appending keeps them aligned.
		$m->find_strings = [...$m->find_strings, ...$other->find_strings];
		$m->replace_strings = [...$m->replace_strings, ...$other->replace_strings];

		$m->http_headers = $m->http_headers + $other->http_headers;
		$m->wrap_in = $m->wrap_in + $other->wrap_in;
		$m->sources = [...$m->sources, ...$other->sources];

		return $m;
	}
}