<?php

namespace AcademicCrew\REST;

use AcademicCrew\Core\Loader;

class MemberPublicationsController {

    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/(?P<id>\d+)/publications', [
            'methods'             => \WP_REST_Server::READABLE,
            'callback'            => [ $this, 'get_publications' ],
            'permission_callback' => '__return_true',
            'args'                => $this->args_schema(),
        ] );

        register_rest_route( 'academiccrew/v1', '/members/(?P<id>\d+)/publications/filters', [
            'methods'             => \WP_REST_Server::READABLE,
            'callback'            => [ $this, 'get_filter_options' ],
            'permission_callback' => '__return_true',
        ] );
    }

    public function get_publications( \WP_REST_Request $req ): \WP_REST_Response {
        global $wpdb;

        $member_id = (int) $req['id'];
        if ( ! get_post( $member_id ) ) {
            return new \WP_REST_Response( [ 'error' => 'Member not found' ], 404 );
        }

        $per_page = min( 50, max( 5, (int) ( $req['per_page'] ?? 10 ) ) );
        $page     = max( 1, (int) ( $req['page'] ?? 1 ) );
        $offset   = ( $page - 1 ) * $per_page;

        $where  = [ 'mp.member_id = %d' ];
        $params = [ $member_id ];

        if ( ! empty( $req['type'] ) ) {
            $where[]  = 'p.pub_type = %s';
            $params[] = sanitize_text_field( $req['type'] );
        }

        if ( ! empty( $req['year'] ) ) {
            if ( str_contains( (string) $req['year'], '-' ) ) {
                [ $from, $to ] = explode( '-', $req['year'], 2 );
                $where[]  = 'p.year BETWEEN %d AND %d';
                $params[] = (int) $from;
                $params[] = (int) $to;
            } else {
                $where[]  = 'p.year = %d';
                $params[] = (int) $req['year'];
            }
        }

        if ( ! empty( $req['search'] ) ) {
            $like         = '%' . $wpdb->esc_like( sanitize_text_field( $req['search'] ) ) . '%';
            if ( version_compare( (string) get_option( 'academiccrew_db_version', '1.0' ), '1.5', '>=' ) ) {
                $where[]  = '(p.title LIKE %s OR p.venue LIKE %s OR p.keywords LIKE %s)';
                $params[] = $like;
                $params[] = $like;
                $params[] = $like;
            } else {
                $where[]  = '(p.title LIKE %s OR p.venue LIKE %s)';
                $params[] = $like;
                $params[] = $like;
            }
        }

        $featured = (int) ( $req['featured'] ?? 0 );
        $tag_id   = (int) ( $req['tag_id']   ?? 0 );

        if ( $featured > 0 ) {
            $where[] = 'p.is_featured = 1';
        }
        if ( $tag_id > 0 ) {
            $tag_table = esc_sql( $wpdb->prefix . 'academiccrew_pub_tag_relations' );
            $where[]   = "EXISTS (SELECT 1 FROM {$tag_table} _tr WHERE _tr.publication_id = p.id AND _tr.tag_id = %d)";
            $params[]  = $tag_id;
        }

        $where_sql = esc_sql( 'WHERE ' . implode( ' AND ', $where ) );

        $order_sql = esc_sql( match ( sanitize_key( $req['sort'] ?? 'year_desc' ) ) {
            'year_asc'      => 'p.year ASC, p.title ASC',
            'citations'     => 'COALESCE(p.citations, 0) DESC, p.year DESC',
            'citations_asc' => 'COALESCE(p.citations, 0) ASC, p.year DESC',
            'title'         => 'p.title ASC',
            'title_desc'    => 'p.title DESC',
            default         => 'p.year DESC, p.citations DESC',
        } );

        $pub_table = esc_sql( $wpdb->prefix . 'academiccrew_publications' );
        $rel_table = esc_sql( $wpdb->prefix . 'academiccrew_member_publications' );

        $total = (int) $wpdb->get_var( $wpdb->prepare(
            "SELECT COUNT(*)
             FROM {$pub_table} p
             INNER JOIN {$rel_table} mp ON p.id = mp.publication_id
             {$where_sql}",
            ...$params
        ) );

        $rows = $wpdb->get_results( $wpdb->prepare(
            "SELECT p.*, mp.is_corresponding
             FROM {$pub_table} p
             INNER JOIN {$rel_table} mp ON p.id = mp.publication_id
             {$where_sql}
             ORDER BY {$order_sql}
             LIMIT %d OFFSET %d",
            ...[ ...$params, $per_page, $offset ]
        ), ARRAY_A );

        $publications = array_map( [ $this, 'format_publication' ], $rows ?: [] );

        if ( $publications ) {
            $pub_ids      = array_column( $rows ?: [], 'id' );
            $placeholders = implode( ',', array_fill( 0, count( $pub_ids ), '%d' ) );
            $tag_rows     = $wpdb->get_results( $wpdb->prepare( // phpcs:ignore
                "SELECT r.publication_id, t.name, t.color
                 FROM {$wpdb->prefix}academiccrew_pub_tag_relations r
                 INNER JOIN {$wpdb->prefix}academiccrew_pub_tags t ON t.id = r.tag_id
                 WHERE r.publication_id IN ({$placeholders}) ORDER BY t.name ASC", // phpcs:ignore
                ...$pub_ids
            ), ARRAY_A ) ?: [];
            $tag_map = [];
            foreach ( $tag_rows as $tr ) {
                $tag_map[ (int) $tr['publication_id'] ][] = [ 'name' => $tr['name'], 'color' => $tr['color'] ];
            }
            foreach ( $publications as &$pub ) {
                $pub['tags'] = $tag_map[ $pub['id'] ] ?? [];
            }
            unset( $pub );
        }

        return new \WP_REST_Response( [
            'publications' => $publications,
            'total'        => $total,
            'total_pages'  => (int) ceil( $total / $per_page ),
            'page'         => $page,
            'per_page'     => $per_page,
        ], 200 );
    }

    public function get_filter_options( \WP_REST_Request $req ): \WP_REST_Response {
        global $wpdb;

        $member_id = (int) $req['id'];
        $pub_table = esc_sql( $wpdb->prefix . 'academiccrew_publications' );
        $rel_table = esc_sql( $wpdb->prefix . 'academiccrew_member_publications' );

        $types = $wpdb->get_col( $wpdb->prepare(
            "SELECT DISTINCT p.pub_type FROM {$pub_table} p
             INNER JOIN {$rel_table} mp ON p.id = mp.publication_id
             WHERE mp.member_id = %d AND p.pub_type IS NOT NULL
             ORDER BY p.pub_type",
            $member_id
        ) );

        $years = $wpdb->get_col( $wpdb->prepare(
            "SELECT DISTINCT p.year FROM {$pub_table} p
             INNER JOIN {$rel_table} mp ON p.id = mp.publication_id
             WHERE mp.member_id = %d AND p.year IS NOT NULL
             ORDER BY p.year DESC",
            $member_id
        ) );

        $has_featured = (bool) $wpdb->get_var( $wpdb->prepare(
            "SELECT COUNT(*) FROM {$pub_table} p
             INNER JOIN {$rel_table} mp ON p.id = mp.publication_id
             WHERE mp.member_id = %d AND p.is_featured = 1",
            $member_id
        ) );

        $member_tags = $wpdb->get_results( $wpdb->prepare(
            "SELECT DISTINCT t.id, t.name, t.color
             FROM {$wpdb->prefix}academiccrew_pub_tags t
             INNER JOIN {$wpdb->prefix}academiccrew_pub_tag_relations r ON r.tag_id = t.id
             INNER JOIN {$rel_table} mp ON mp.publication_id = r.publication_id
             WHERE mp.member_id = %d AND EXISTS (
                 SELECT 1 FROM {$pub_table} p2
                 WHERE p2.id = r.publication_id AND p2.is_featured = 1
             )
             ORDER BY t.name ASC",
            $member_id
        ) ) ?: [];

        return new \WP_REST_Response( [
            'types'       => $types,
            'years'       => array_map( 'intval', $years ),
            'hasFeatured' => $has_featured,
            'tags'        => array_map( fn( $t ) => [ 'id' => (int) $t->id, 'name' => $t->name, 'color' => $t->color ], $member_tags ),
        ], 200 );
    }

    private function parse_author_simple( mixed $raw ): array {
        $str = is_array( $raw )
            ? ( isset( $raw['lastName'] ) ? null : (string) ( $raw['name'] ?? '' ) )
            : trim( (string) $raw );

        if ( $str === null ) {
            // Already structured {firstName, lastName}
            return [
                'firstName' => (string) ( $raw['firstName'] ?? '' ),
                'lastName'  => (string) ( $raw['lastName']  ?? '' ),
            ];
        }
        if ( $str === '' ) return [ 'firstName' => '', 'lastName' => '' ];

        if ( str_contains( $str, ',' ) ) {
            [ $last, $first ] = array_map( 'trim', explode( ',', $str, 2 ) );
        } else {
            $parts = preg_split( '/\s+/', $str, -1, PREG_SPLIT_NO_EMPTY );
            $last  = $parts ? (string) array_pop( $parts ) : '';
            $first = implode( ' ', $parts );
        }
        return [ 'firstName' => $first, 'lastName' => $last ];
    }

    private function format_publication( array $row ): array {
        $raw     = json_decode( $row['authors_json'] ?? '[]', true ) ?: [];
        $authors = array_values( array_filter(
            array_map( [ $this, 'parse_author_simple' ], $raw ),
            fn( $a ) => $a['firstName'] !== '' || $a['lastName'] !== ''
        ) );
        $doi  = $row['doi'];

        return [
            'id'               => (int) $row['id'],
            'title'            => html_entity_decode( (string) $row['title'], ENT_QUOTES | ENT_HTML5, 'UTF-8' ),
            'year'             => $row['year'] ? (int) $row['year'] : null,
            'venue'            => isset( $row['venue'] ) ? html_entity_decode( $row['venue'], ENT_QUOTES | ENT_HTML5, 'UTF-8' ) : null,
            'pub_type'         => $row['pub_type'],
            'abstract'         => $row['abstract'],
            'authors'          => $authors,
            'doi'              => $doi,
            'doi_url'          => $doi ? "https://doi.org/{$doi}" : null,
            'pdf_url'          => $row['pdf_url'],
            'url'              => $row['url'],
            'citations'        => $row['citations'] ? (int) $row['citations'] : null,
            'source'           => $row['source_api'],
            'is_corresponding' => (bool) $row['is_corresponding'],
            'keywords'         => ! empty( $row['keywords'] ) ? ( json_decode( $row['keywords'], true ) ?: [] ) : [],
        ];
    }

    private function args_schema(): array {
        return [
            'type'     => [ 'type' => 'string',  'sanitize_callback' => 'sanitize_text_field' ],
            'year'     => [ 'type' => 'string',  'sanitize_callback' => 'sanitize_text_field' ],
            'search'   => [ 'type' => 'string',  'sanitize_callback' => 'sanitize_text_field' ],
            'sort'     => [ 'type' => 'string',  'enum' => [ 'year_desc', 'year_asc', 'citations', 'citations_asc', 'title', 'title_desc' ], 'default' => 'year_desc' ],
            'per_page' => [ 'type' => 'integer', 'default' => 10, 'minimum' => 5, 'maximum' => 50 ],
            'page'     => [ 'type' => 'integer', 'default' => 1,  'minimum' => 1 ],
            'featured' => [ 'type' => 'integer', 'default' => 0 ],
            'tag_id'   => [ 'type' => 'integer', 'default' => 0 ],
        ];
    }
}