<?php
/**
 * Reading and updating articles. An "article" is a published post or page. An update from Suiko arrives either as a draft
 * copy linked to the live article (mode 'draft', the default: someone reviews it in WordPress and applies it in one click)
 * or as a direct replacement of the live article (mode 'direct').
 */
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

function suiko_post_types() {
	return apply_filters( 'suiko_post_types', array( 'post', 'page' ) );
}

/** Compact description of a post for the article list. */
function suiko_article_summary( $post ) {
	$seo = suiko_seo_read( $post->ID );
	return array(
		'id'           => (string) $post->ID,
		'type'         => $post->post_type,
		'slug'         => suiko_public_slug( $post ),
		'title'        => $post->post_title, // brut : get_the_title() ajoute des entités HTML (apostrophes), que Suiko afficherait telles quelles
		'url'          => get_permalink( $post ),
		'date'         => suiko_gmt_iso( $post->post_date_gmt ),
		'modified_gmt' => suiko_gmt_iso( $post->post_modified_gmt ),
		'keyword'      => $seo['keyword'],
		'categories'   => wp_get_post_terms( $post->ID, 'category', array( 'fields' => 'names' ) ),
		'format'       => has_blocks( $post->post_content ) ? 'blocks' : 'classic',
		'builder'      => suiko_builder_of( $post ),
	);
}

/** A MySQL GMT datetime as ISO 8601 in UTC, the only form Suiko compares. */
function suiko_gmt_iso( $mysql_gmt ) {
	$ts = strtotime( $mysql_gmt . ' UTC' );
	return $ts ? gmdate( 'Y-m-d\TH:i:s\Z', $ts ) : null;
}

/** The path of the public address, without the domain: what Suiko shows as the page slug. */
function suiko_public_slug( $post ) {
	if ( 'publish' !== $post->post_status ) {
		return $post->post_name;
	}
	$path = wp_parse_url( get_permalink( $post ), PHP_URL_PATH );
	return trim( is_string( $path ) ? $path : $post->post_name, '/' );
}

/** The full article: summary, rendered HTML, SEO fields, authors. */
function suiko_article_full( $post ) {
	$author = get_userdata( $post->post_author );
	return array_merge(
		suiko_article_summary( $post ),
		array(
			'content_html' => suiko_render_content( $post ),
			'excerpt'      => $post->post_excerpt,
			'seo'          => suiko_seo_read( $post->ID ),
			'authors'      => $author ? array( array( 'name' => $author->display_name ) ) : array(),
			'status'       => $post->post_status,
		)
	);
}

/**
 * Applies an update. $input: title?, content_html, seo?, mode? ('draft'|'direct', site default otherwise),
 * expected_modified_gmt? (refused with a conflict when the article changed since Suiko read it).
 * Returns an array for the REST response, or a WP_Error.
 */
function suiko_apply_update( $post, $input ) {
	if ( ! empty( $input['expected_modified_gmt'] ) ) {
		$current = suiko_gmt_iso( $post->post_modified_gmt );
		if ( strtotime( $current ) !== strtotime( $input['expected_modified_gmt'] ) ) {
			return new WP_Error( 'suiko_conflict', 'The article changed since Suiko read it.', array( 'status' => 409, 'modified_gmt' => $current ) );
		}
	}
	$builder = suiko_builder_of( $post );
	if ( $builder ) {
		return new WP_Error( 'suiko_builder', sprintf( 'This article is built with %s: Suiko cannot write it back without breaking the layout. Apply the update by hand in %s.', ucfirst( $builder ), ucfirst( $builder ) ), array( 'status' => 422, 'builder' => $builder ) );
	}
	$html = isset( $input['content_html'] ) && is_string( $input['content_html'] ) ? $input['content_html'] : null;
	if ( null === $html ) {
		return new WP_Error( 'suiko_bad_request', 'content_html is required.', array( 'status' => 400 ) );
	}
	$content = has_blocks( $post->post_content ) ? suiko_html_to_blocks( $html ) : $html;
	$lost    = suiko_lost_tags( $content );
	if ( $lost ) {
		return suiko_lost_tags_error( $lost );
	}
	$title   = isset( $input['title'] ) && is_string( $input['title'] ) && '' !== trim( $input['title'] ) ? $input['title'] : null;
	$mode    = isset( $input['mode'] ) && 'direct' === $input['mode'] ? 'direct' : ( isset( $input['mode'] ) && 'draft' === $input['mode'] ? 'draft' : suiko_mode() );
	$seo     = isset( $input['seo'] ) && is_array( $input['seo'] ) ? $input['seo'] : null;

	if ( 'direct' === $mode ) {
		$data = array( 'ID' => $post->ID, 'post_content' => $content );
		if ( $title ) {
			$data['post_title'] = $title;
		}
		$id = wp_update_post( wp_slash( $data ), true );
		if ( is_wp_error( $id ) ) {
			return $id;
		}
		suiko_seo_write( $post->ID, $seo );
		update_post_meta( $post->ID, '_suiko_updated_at', gmdate( 'c' ) );
		$fresh = get_post( $post->ID );
		return array( 'status' => 'published', 'id' => (string) $post->ID, 'url' => get_permalink( $fresh ), 'modified_gmt' => suiko_gmt_iso( $fresh->post_modified_gmt ) );
	}

	// Draft mode: one pending draft per article. A new update replaces the previous pending draft.
	// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key, WordPress.DB.SlowDBQuery.slow_db_query_meta_value -- one small lookup per update, among drafts only.
	$existing = get_posts( array( 'post_type' => $post->post_type, 'post_status' => 'draft', 'meta_key' => '_suiko_update_of', 'meta_value' => $post->ID, 'numberposts' => 1, 'fields' => 'ids' ) );
	$data     = array(
		'post_type'    => $post->post_type,
		'post_status'  => 'draft',
		'post_title'   => $title ? $title : $post->post_title,
		'post_content' => $content,
		'post_author'  => $post->post_author,
		'post_excerpt' => $post->post_excerpt,
	);
	if ( $existing ) {
		$data['ID'] = $existing[0];
		$id         = wp_update_post( wp_slash( $data ), true );
	} else {
		$id = wp_insert_post( wp_slash( $data ), true );
	}
	if ( is_wp_error( $id ) ) {
		return $id;
	}
	update_post_meta( $id, '_suiko_update_of', $post->ID );
	update_post_meta( $id, '_suiko_received_at', gmdate( 'c' ) );
	if ( $seo ) {
		update_post_meta( $id, '_suiko_seo', wp_json_encode( $seo ) );
		suiko_seo_write( $id, $seo );
	}
	// admin_url() rather than get_edit_post_link(): the latter needs a logged-in user and returns null from the API.
	return array( 'status' => 'draft', 'id' => (string) $post->ID, 'draft_id' => (string) $id, 'edit_url' => admin_url( 'post.php?post=' . (int) $id . '&action=edit' ), 'apply_url' => suiko_apply_url( $id ) );
}

/**
 * Requests from Suiko run with no logged-in user, so WordPress filters their HTML (wp_kses_post): an iframe or a script is
 * removed. Rather than let an embed vanish from a live article, the write is refused. Returns the tags that would be lost.
 */
function suiko_lost_tags( $content ) {
	$count = function ( $html ) {
		preg_match_all( '/<([a-z][a-z0-9-]*)\b/i', $html, $m );
		return array_count_values( array_map( 'strtolower', $m[1] ) );
	};
	$kept = $count( wp_kses_post( $content ) );
	$lost = array();
	foreach ( $count( $content ) as $tag => $n ) {
		if ( ( isset( $kept[ $tag ] ) ? $kept[ $tag ] : 0 ) < $n ) {
			$lost[] = $tag;
		}
	}
	return $lost;
}

function suiko_lost_tags_error( $lost ) {
	return new WP_Error( 'suiko_html', sprintf( 'This content contains elements WordPress does not accept from an outside service (%s). Apply the update by hand in WordPress.', implode( ', ', $lost ) ), array( 'status' => 422, 'tags' => $lost ) );
}

/** Address of the one-click "Apply this update" action for a Suiko draft (admin, capability-checked). */
function suiko_apply_url( $draft_id ) {
	return add_query_arg( array( 'action' => 'suiko_apply', 'draft' => (int) $draft_id, '_wpnonce' => wp_create_nonce( 'suiko_apply_' . (int) $draft_id ) ), admin_url( 'admin-post.php' ) );
}

/** Copies a Suiko draft onto its live article (title, content, SEO fields), then deletes the draft. */
function suiko_apply_draft( $draft_id ) {
	$draft = get_post( $draft_id );
	$of    = $draft ? (int) get_post_meta( $draft_id, '_suiko_update_of', true ) : 0;
	$live  = $of ? get_post( $of ) : null;
	if ( ! $draft || 'draft' !== $draft->post_status || ! $live ) {
		return new WP_Error( 'suiko_not_found', 'This draft is not a Suiko update, or its article no longer exists.' );
	}
	$id = wp_update_post( wp_slash( array( 'ID' => $live->ID, 'post_title' => $draft->post_title, 'post_content' => $draft->post_content ) ), true );
	if ( is_wp_error( $id ) ) {
		return $id;
	}
	$seo = get_post_meta( $draft_id, '_suiko_seo', true );
	if ( $seo ) {
		suiko_seo_write( $live->ID, json_decode( $seo, true ) );
	}
	update_post_meta( $live->ID, '_suiko_updated_at', gmdate( 'c' ) );
	wp_delete_post( $draft_id, true );
	return $live->ID;
}