<?php

namespace AcademicCrew\REST;

use AcademicCrew\Core\Loader;
use AcademicCrew\Members\MemberStats;
use AcademicCrew\Members\RoleRegistry;

class MembersArchiveController {

    public function register( Loader $loader ): void {
        $loader->add_action( 'rest_api_init', $this, 'register_routes' );
    }

    public function register_routes(): void {
        register_rest_route( 'academiccrew/v1', '/members', [
            'methods'             => \WP_REST_Server::READABLE,
            'callback'            => [ $this, 'get_members' ],
            'permission_callback' => '__return_true',
            'args'                => $this->args_schema(),
        ] );

        register_rest_route( 'academiccrew/v1', '/members/filters', [
            'methods'             => \WP_REST_Server::READABLE,
            'callback'            => [ $this, 'get_filter_options' ],
            'permission_callback' => '__return_true',
        ] );
    }

    public function get_members( \WP_REST_Request $req ): \WP_REST_Response {
        $meta_query = [ 'relation' => 'AND' ];

        if ( ! empty( $req['role'] ) ) {
            $meta_query[] = [
                'key'     => '_acc_member_role',
                'value'   => sanitize_key( $req['role'] ),
                'compare' => '=',
            ];
        }

        if ( ! empty( $req['area'] ) ) {
            $meta_query[] = [
                'key'     => '_acc_research_areas',
                'value'   => sanitize_text_field( $req['area'] ),
                'compare' => 'LIKE',
            ];
        }

        $search = sanitize_text_field( $req['search'] ?? '' );

        $query_args = [
            'post_type'      => 'academiccrew_member',
            'post_status'    => 'publish',
            'posts_per_page' => -1,
            'orderby'        => 'title',
            'order'          => 'ASC',
            'meta_query'     => $meta_query,
        ];

        if ( $search ) {
            $query_args['s'] = $search;
        }

        $query   = new \WP_Query( $query_args );
        $members = array_map( [ $this, 'prepare_member' ], $query->posts );

        $role_order = array_keys( RoleRegistry::all() );
        usort( $members, function ( $a, $b ) use ( $role_order ) {
            // 1. Role order.
            $ai = array_search( $a['role'], $role_order, true );
            $bi = array_search( $b['role'], $role_order, true );
            $ai = $ai === false ? 99 : (int) $ai;
            $bi = $bi === false ? 99 : (int) $bi;
            if ( $ai !== $bi ) return $ai - $bi;

            // 2. Rank within role (0 = unset → last).
            $ar = $a['rank'] > 0 ? $a['rank'] : PHP_INT_MAX;
            $br = $b['rank'] > 0 ? $b['rank'] : PHP_INT_MAX;
            if ( $ar !== $br ) return $ar - $br;

            // 3. Last name alphabetical.
            $cmp = strcmp( $a['last_name'], $b['last_name'] );
            if ( $cmp !== 0 ) return $cmp;

            // 4. First name alphabetical.
            return strcmp( $a['first_name'], $b['first_name'] );
        } );

        $grouped = [];
        foreach ( $members as $m ) {
            $grouped[ $m['role'] ][] = $m;
        }

        return new \WP_REST_Response( [
            'members' => $members,
            'grouped' => $grouped,
            'total'   => count( $members ),
        ], 200 );
    }

    private function prepare_member( \WP_Post $post ): array {
        $get = fn( string $key ) => get_post_meta( $post->ID, $key, true );

        $role         = $get( '_acc_member_role' ) ?: 'collaborator';
        $research_raw = $get( '_acc_research_areas' );
        $areas        = is_array( $research_raw )
            ? $research_raw
            : ( $research_raw ? array_map( 'trim', explode( ',', $research_raw ) ) : [] );

        $social_raw = $get( '_acc_social_links' );
        $social     = is_array( $social_raw ) ? $social_raw : [];

        $orcid_id       = $get( '_acc_orcid_id' );
        $linked_page_id = (int) $get( '_academiccrew_linked_page_id' );

        global $wpdb;
        $pub_count = (int) $wpdb->get_var( $wpdb->prepare(
            "SELECT COUNT(*) FROM {$wpdb->prefix}academiccrew_member_publications WHERE member_id = %d",
            $post->ID
        ) );

        $first_name = (string) ( $get( '_acc_first_name' ) ?: '' );
        $last_name  = (string) ( $get( '_acc_last_name' )  ?: '' );

        // Derive first/last name from title when meta is not set.
        if ( ! $first_name && ! $last_name ) {
            $parts      = array_values( array_filter( preg_split( '/\s+/', trim( $post->post_title ) ) ) );
            $last_name  = count( $parts ) > 1 ? array_pop( $parts ) : ( $parts[0] ?? '' );
            $first_name = implode( ' ', $parts );
        }

        return [
            'id'             => $post->ID,
            'name'           => html_entity_decode( $post->post_title, ENT_QUOTES | ENT_HTML5, 'UTF-8' ),
            'slug'           => $post->post_name,
            'first_name'     => $first_name,
            'last_name'      => $last_name,
            'rank'           => (int) ( $get( '_acc_role_rank' ) ?: 0 ),
            'role'           => $role,
            'role_label'     => RoleRegistry::label( $role ),
            'role_colors'    => RoleRegistry::colors()[ $role ] ?? [],
            'position'       => $get( '_acc_position' ) ?: RoleRegistry::label( $role ),
            'affiliation'    => $get( '_acc_affiliation' ) ?: '',
            'bio'            => $get( '_acc_bio' ) ?: '',
            'email'          => $get( '_acc_email' ) ?: '',
            'website'        => $get( '_acc_personal_website' ) ?: '',
            'avatar_url'     => $get( '_acc_avatar_url' )
                                 ?: ( get_the_post_thumbnail_url( $post->ID, 'medium' ) ?: null ),
            'initials'       => $this->initials( $post->post_title ),
            'orcid_id'       => $orcid_id ?: null,
            'orcid_url'      => $orcid_id ? "https://orcid.org/{$orcid_id}" : null,
            'research_areas' => $areas,
            'social'         => $social,
            'pub_count'      => $pub_count,
            'citation_count' => (int) ( $get( '_acc_citation_count' ) ?: 0 ),
            'citation_url'   => MemberStats::citation_url( $post->ID ) ?: null,
            'page_url'       => $linked_page_id ? get_permalink( $linked_page_id ) : get_permalink( $post->ID ),
        ];
    }

    public function get_filter_options(): \WP_REST_Response {
        $all_areas = [];
        $member_ids = get_posts( [
            'post_type'      => 'academiccrew_member',
            'post_status'    => 'publish',
            'posts_per_page' => -1,
            'fields'         => 'ids',
        ] );

        foreach ( $member_ids as $id ) {
            $raw   = get_post_meta( $id, '_acc_research_areas', true );
            $areas = is_array( $raw )
                ? $raw
                : array_map( 'trim', explode( ',', $raw ?: '' ) );
            foreach ( array_filter( $areas ) as $area ) {
                $all_areas[ $area ] = ( $all_areas[ $area ] ?? 0 ) + 1;
            }
        }

        arsort( $all_areas );

        return new \WP_REST_Response( [
            'roles' => array_map(
                fn( $key, $label ) => [ 'key' => $key, 'label' => $label ],
                array_keys( RoleRegistry::all() ),
                array_values( RoleRegistry::all() )
            ),
            'areas' => array_map(
                fn( $area, $count ) => [ 'label' => $area, 'count' => $count ],
                array_keys( $all_areas ),
                array_values( $all_areas )
            ),
        ], 200 );
    }

    private function initials( string $name ): string {
        $parts = array_values( array_filter( preg_split( '/\s+/', trim( $name ) ) ) );
        return strtoupper( implode( '', array_map(
            fn( $w ) => mb_substr( $w, 0, 1 ),
            array_slice( $parts, 0, 2 )
        ) ) );
    }

    private function args_schema(): array {
        return [
            'role'   => [ 'type' => 'string', 'sanitize_callback' => 'sanitize_key' ],
            'area'   => [ 'type' => 'string', 'sanitize_callback' => 'sanitize_text_field' ],
            'search' => [ 'type' => 'string', 'sanitize_callback' => 'sanitize_text_field' ],
        ];
    }
}