<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * ACSIL_REST_API — REST APIエンドポイント登録
 */
class ACSIL_REST_API {

	private ACSIL_Database $db;
	private ACSIL_Scanner $scanner;

	public function __construct( ACSIL_Database $db, ACSIL_Scanner $scanner ) {
		$this->db      = $db;
		$this->scanner = $scanner;
	}

	public function register_routes(): void {
		register_rest_route(
			'acsil/v1',
			'/link-map',
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => array( $this, 'get_link_map' ),
				'permission_callback' => array( $this, 'check_edit_posts' ),
				'args'                => array(
					'category' => array(
						'type'              => 'integer',
						'sanitize_callback' => 'absint',
					),
					'status'   => array(
						'type'              => 'string',
						'sanitize_callback' => 'sanitize_text_field',
						'enum'              => array( 'any', 'publish', 'draft' ),
						'default'           => 'any',
					),
					'limit'    => array(
						'type'              => 'integer',
						'sanitize_callback' => 'absint',
						'default'           => 0,
					),
				),
			)
		);

		register_rest_route(
			'acsil/v1',
			'/post-links/(?P<post_id>\d+)',
			array(
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => array( $this, 'get_post_links' ),
				'permission_callback' => array( $this, 'check_edit_post' ),
				'args'                => array(
					'post_id' => array(
						'type'              => 'integer',
						'required'          => true,
						'sanitize_callback' => 'absint',
					),
				),
			)
		);
	}

	// ── GET /acsil/v1/link-map ────────────────────────────────────────────

	public function get_link_map( WP_REST_Request $request ): WP_REST_Response {
		$args = array(
			'status'   => $request->get_param( 'status' ) ?? 'any',
			'category' => $request->get_param( 'category' ),
			'limit'    => $request->get_param( 'limit' ),
		);

		$data  = $this->db->get_all_links( $args );
		$posts = $data['posts'];
		$edges = $data['edges'];

		// リンク数の集計
		$counts = $this->db->get_all_link_counts();

		// カテゴリー情報の取得
		$all_categories  = get_categories( array( 'hide_empty' => false ) );
		$category_colors = array();
		foreach ( $all_categories as $cat ) {
			$category_colors[ $cat->term_id ] = $this->generate_color( $cat->term_id );
		}

		// ノード構築
		$nodes = array();
		foreach ( $posts as $post ) {
			$post_id   = (int) $post['ID'];
			$post_cats = wp_get_post_categories( $post_id, array( 'fields' => 'all' ) );
			$cat_name  = '';
			$cat_id    = 0;
			$cat_color = '#7f8c8d';
			if ( ! empty( $post_cats ) ) {
				$first_cat = $post_cats[0];
				$cat_name  = $first_cat->name;
				$cat_id    = $first_cat->term_id;
				$cat_color = $category_colors[ $cat_id ] ?? $this->generate_color( $cat_id );
			}

			$nodes[] = array(
				'id'             => $post_id,
				'title'          => esc_html( $post['post_title'] ),
				'category'       => esc_html( $cat_name ),
				'category_id'    => $cat_id,
				'category_color' => $cat_color,
				'status'         => $post['post_status'],
				'edit_url'       => esc_url( (string) get_edit_post_link( $post_id, 'raw' ) ),
				'outgoing_count' => $counts[ $post_id ]['outgoing'] ?? 0,
				'incoming_count' => $counts[ $post_id ]['incoming'] ?? 0,
				'date'           => mysql2date( 'Y-m-d', $post['post_date'] ),
			);
		}

		// カテゴリー一覧（凡例用）
		$categories = array();
		foreach ( $all_categories as $cat ) {
			$categories[] = array(
				'id'    => $cat->term_id,
				'name'  => esc_html( $cat->name ),
				'color' => $category_colors[ $cat->term_id ],
			);
		}

		// エッジ整形
		$formatted_edges = array();
		foreach ( $edges as $edge ) {
			$formatted_edges[] = array(
				'source'      => (int) $edge['source'],
				'target'      => (int) $edge['target'],
				'anchor_text' => esc_html( $edge['anchor_text'] ),
			);
		}

		return new WP_REST_Response(
			array(
				'nodes'      => $nodes,
				'edges'      => $formatted_edges,
				'categories' => $categories,
			),
			200
		);
	}

	// ── GET /acsil/v1/post-links/{post_id} ───────────────────────────────

	public function get_post_links( WP_REST_Request $request ): WP_REST_Response {
		$post_id  = (int) $request->get_param( 'post_id' );
		$outgoing = $this->db->get_outgoing_links( $post_id );
		$incoming = $this->db->get_incoming_links( $post_id );

		return new WP_REST_Response(
			array(
				'outgoing' => $outgoing,
				'incoming' => $incoming,
			),
			200
		);
	}

	// ── 権限コールバック ──────────────────────────────────────────────────

	public function check_edit_posts(): bool {
		return current_user_can( 'edit_posts' );
	}

	public function check_edit_post( WP_REST_Request $request ): bool {
		$post_id = (int) $request->get_param( 'post_id' );
		return current_user_can( 'edit_post', $post_id );
	}

	// ── カテゴリーIDからカラー生成 ────────────────────────────────────────

	private function generate_color( int $id ): string {
		$hue        = ( $id * 47 ) % 360;
		$saturation = 55 + ( $id % 20 );
		$lightness  = 45 + ( $id % 15 );
		return "hsl({$hue},{$saturation}%,{$lightness}%)";
	}
}