<?php
/**
 * Query_Bulder Class
 *
 * @package Booktics/Query_Builders
 */

namespace Booktics\Query_Builders;

use Booktics\Abstracts\Post_Model;
use WP_Query;

class Query_Builder {
    /**
     * Store post model object
     *
     * @var object
     */
    protected object $model;

    /**
     * Store meta query
     *
     * @var array<int,array<string,mixed>>
     */
    protected array $meta_query = array();

    /**
     * Store or meta query data
     *
     * @var array<int,array<string,mixed>>
     */
    protected array $meta_query_or = array();

    /**
     * Store tax query
     *
     * @var array<int,array<string,mixed>>
     */
    protected array $tax_query = array();

    /**
     * Store all args
     *
     * @var array<string,mixed>
     */
    protected array $args = array();

    /**
     * Constructor
     *
     * @param Object $model The model class name
     */
    public function __construct( $model ) {
        $this->model               = $model;
        $this->args['post_type']   = $model->get_post_type();
        $this->args['post_status'] = Post_Model::$accepted_statuses;
    }

    /**
     * Add a meta query condition (AND)
     *
     * @param string|array $key Meta key or array of conditions
     * @param string $compare Comparison operator
     * @param mixed $value Meta value
     *
     * @return  $this
     */
    public function where( $key, $value = null, $compare = '=' ) {
        if ( is_array( $key ) ) {
            foreach ( $key as $condition ) {
                $this->where( ...$condition );
            }

            return $this;
        }

        $this->meta_query[] = compact( 'key', 'value', 'compare' );

        return $this;
    }

    /**
     * Add an OR meta query condition
     *
     * @param string $key
     * @param string $compare
     * @param mixed $value
     *
     * @return  $this
     */
    public function or_where( $key, $value = null, $compare = '=' ) {
        $this->meta_query_or[] = compact( 'key', 'value', 'compare' );

        return $this;
    }

    /**
     * Add a WHERE IN meta query condition
     *
     * @param string $key
     * @param array $values
     *
     * @return  $this
     */
    public function where_in( $key, array $values ) {
        $this->meta_query[] = array(
            'key'     => $key,
            'value'   => $values,
            'compare' => 'IN',
        );

        return $this;
    }

    /**
     * Exclude posts by ID from query results
     *
     * @param int|array $ids Post ID or array of post IDs to exclude
     *
     * @return $this
     */
    public function where_not_ids( $ids ) {
        $this->args['post__not_in'] = (array) $ids;

        return $this;
    }

    /**
     * Add a meta query condition for NULL value
     *
     * @param string $key
     *
     * @return  $this
     */
    public function where_null( $key ) {
        $this->meta_query[] = array(
            'key'     => $key,
            'compare' => 'NOT EXISTS',
        );

        return $this;
    }

    /**
     * Add a taxonomy query (generic)
     *
     * @param string $taxonomy
     * @param string|array $terms
     * @param string $field
     *
     * @return  $this
     */
    public function taxonomy( $taxonomy, $terms, $field = 'slug' ) {
        $this->tax_query[] = array(
            'taxonomy' => $taxonomy,
            'field'    => $field,
            'terms'    => (array) $terms,
        );

        return $this;
    }

    /**
     * Add a category query
     *
     * @param string|int $slug_or_id
     *
     * @return  $this
     */
    public function category( $slug_or_id ) {
        return $this->taxonomy( 'category', $slug_or_id, is_numeric( $slug_or_id ) ? 'term_id' : 'slug' );
    }

    /**
     * Add a tag query
     *
     * @param string|int $slug_or_id
     *
     * @return  $this
     */
    public function tag( $slug_or_id ) {
        return $this->taxonomy( 'post_tag', $slug_or_id, is_numeric( $slug_or_id ) ? 'term_id' : 'slug' );
    }

    /**
     * Set order by custom field
     *
     * @param string $field
     * @param string $direction
     *
     * @return  $this
     */
    public function orderBy( $field, $direction = 'ASC' ) {
        $this->args['orderby']  = 'meta_value';
        $this->args['meta_key'] = $field;
        $this->args['order']    = $direction;

        return $this;
    }

    /**
     * Execute query and return all matched model instances
     *
     * @return  array
     */
    public function get() {
        $this->args['numberposts'] = - 1;

        if ( $meta = $this->build_meta_query() ) {
            $this->args['meta_query'] = $meta;
        }

        if ( $this->tax_query ) {
            $this->args['tax_query'] = count( $this->tax_query ) > 1
                ? array_merge( array( 'relation' => 'AND' ), $this->tax_query )
                : $this->tax_query;
        }

        $posts = get_posts( $this->args );

        return array_map(
            function ( $post ) {
                return new $this->model( $post );
            }, $posts
        );
    }

    /**
     * Paginate the query results
     *
     * @param int $per_page
     * @param int $page
     *
     * @return  array
     */
    public function paginate( $per_page = 10, $page = 1 ) {
        $this->args['posts_per_page'] = $per_page;
        $this->args['paged']          = $page;

        if ( $meta = $this->build_meta_query() ) {
            $this->args['meta_query'] = $meta;
        }

        if ( $this->tax_query ) {
            $this->args['tax_query'] = count( $this->tax_query ) > 1
                ? array_merge( array( 'relation' => 'AND' ), $this->tax_query )
                : $this->tax_query;
        }

        $query = new WP_Query( $this->args );

        return array(
            'items'        => array_map(
                function ( $p ) {
                    return new $this->model( $p );
                }, $query->posts
            ),
            'total'        => $query->found_posts,
            'per_page'     => $per_page,
            'current_page' => $page,
            'last_page'    => ceil( $query->found_posts / $per_page ),
        );
    }

    /**
     * Return first matched model or null
     *
     * @return  null|PostModel
     */
    public function first() {
        $this->args['numberposts'] = 1;

        if ( $meta = $this->build_meta_query() ) {
            $this->args['meta_query'] = $meta;
        }

        if ( $this->tax_query ) {
            $this->args['tax_query'] = $this->tax_query;
        }

        $posts = get_posts( $this->args );

        return $posts ? new $this->model( $posts[0] ) : null;
    }

    /**
     * Count number of matched posts
     *
     * @return  int
     */
    public function count() {
        $this->args['posts_per_page'] = 1;
        $this->args['fields']         = 'ids';

        if ( $meta = $this->build_meta_query() ) {
            $this->args['meta_query'] = $meta;
        }

        if ( $this->tax_query ) {
            $this->args['tax_query'] = $this->tax_query;
        }

        $query = new WP_Query( $this->args );

        return $query->found_posts;
    }

    /**
     * Check if any record exists
     *
     * @return  bool
     */
    public function exists() {
        return $this->count() > 0;
    }

    /**
     * Build meta_query with AND/OR relations
     *
     * @return  array
     */
    protected function build_meta_query() {
        $meta = array();

        if ( $this->meta_query ) {
            $meta[] = count( $this->meta_query ) > 0
                ? array_merge( array( 'relation' => 'AND' ), $this->meta_query )
                : $this->meta_query[0];
        }

        if ( $this->meta_query_or ) {
            $meta[] = count( $this->meta_query_or ) > 0
                ? array_merge( array( 'relation' => 'OR' ), $this->meta_query_or )
                : $this->meta_query_or[0];
        }

        if ( count( $meta ) === 1 ) {
            return $meta[0];
        } elseif ( count( $meta ) > 0 ) {
            return array_merge( array( 'relation' => 'AND' ), $meta );
        }

        return array();
    }
}