<?php

namespace PrintMyBlog\orm\managers;

use PrintMyBlog\db\TableManager;
use PrintMyBlog\entities\DesignTemplate;
use PrintMyBlog\orm\entities\ProjectSection;
use stdClass;
use Twine\helpers\Array2;

// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery -- this class is all about direct DB queries on a custom table.

/**
 * Class ProjectSectionManager
 * @package PrintMyBlog\orm\managers
 */
class ProjectSectionManager
{
    /**
     * Gets ProjectSections for this project.
     *
     * @param int $project_id
     *
     * @param int $max_levels
     * @param int $limit
     * @param int $offset
     * @param bool $include_title
     * @param string $placement
     *
     * @return ProjectSection[]
     */
    public function getSectionsFor(
        $project_id,
        $max_levels = 0,
        $limit = 20,
        $offset = 0,
        $include_title = false,
        $placement = 'main'
    ) {
        $sections = $this->getFlatSectionsFor($project_id, $limit, $offset, $include_title, $placement);
        $index = 0;
        $parent_id = 0;
        return $this->nestSections(
            $sections,
            $index,
            $parent_id,
            $max_levels
        );
    }

    /**
     * @param int $section_id
     *
     * @return ProjectSection|null
     */
    public function getSection($section_id)
    {
        global $wpdb;
        // Custom table so custom query. And the table name is hard-coded.
        // todo: cache
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.NoCaching
        $row = $wpdb->get_row(
            $wpdb->prepare(
                // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- it's just hard-coded.
                'SELECT ID ' . $this->defaultFrom() . 'WHERE ID=%d',
                $section_id
            )
        );
        if (! $row){
            return null;
        }
        return $this->createObjFromRow($row);
    }

    /**
     * Gets a 1-dimensional array of project parts, ignoring parent hierarchy (although the parent_id is included on
     * each object)
     * @param int $project_id
     * @param int $limit
     * @param int $offset
     * @param bool $include_post_title
     * @param string|null $placement
     *
     * @return ProjectSection[] unlike fetchPartsFor(), this is a flat array, objects don't have a 'subs' property
     */
    public function getFlatSectionsFor(
        $project_id,
        $limit = 20,
        $offset = 0,
        $include_post_title = false,
        $placement = null
    ) {
        return $this->createObjsFromRows(
            (array)$this->getFlatSectionRowsFor(
                $project_id,
                $limit,
                $offset,
                $include_post_title,
                $placement
            )
        );
    }

    /**
     * Gets an array of stdClass for all the rows from the project section table that belong to the project.
     * @param int $project_id
     * @param int $limit
     * @param int $offset
     * @param bool $include_post_title
     * @param null $placement
     * @return stdClass[]
     */
    public function getFlatSectionRowsFor(
        $project_id,
        $limit = 20,
        $offset = 0,
        $include_post_title = false,
        $placement = null
    ) {
        global $wpdb;

        $select_sql = $this->defaultSelection();
        $join_sql = '';
        $where_sql = $wpdb->prepare(' WHERE project_id=%d', $project_id);
        if ($include_post_title) {
            $select_sql .= ', posts.post_title';
            $join_sql .= 'INNER JOIN
                  ' . $wpdb->posts . ' posts 
                  ON  sections.post_id=posts.ID';
        }
        if ($placement) {
            $where_sql .= $wpdb->prepare(' AND placement=%s', $placement);
        }
        // too dynamic for non-raw sql.
        //phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching
        $results = $wpdb->get_results(
            $wpdb->prepare(
                // phpcs:disable WordPress.DB.PreparedSQL.NotPrepared -- all prepared earlier.
                $select_sql . $this->defaultFrom()
                . $join_sql . $where_sql .
                ' ORDER BY section_order ASC
                  limit %d, %d',
                $offset,
                $limit
            )
        );
        // phpcs:enable WordPress.DB.PreparedSQL.NotPrepared -- all prepared earlier.
        if($results){
            return $results;
        }
        return array();
    }

    /**
     * @return string
     */
    protected function defaultSelection()
    {
        return 'SELECT 
            sections.ID, 
            sections.post_id, 
            sections.parent_id, 
            sections.placement, 
            sections.template, 
            sections.height, 
            sections.depth, 
            sections.section_order';
    }

    /**
     * @return string
     */
    protected function defaultFrom()
    {
        global $wpdb;
        return ' FROM ' . $wpdb->prefix . TableManager::SECTIONS_TABLE . ' sections ';
    }

    /**
     * @param stdClass[] $rows
     *
     * @return ProjectSection[]
     */
    public function createObjsFromRows($rows)
    {
        $objs = [];
        foreach ((array)$rows as $row) {
            if( $row){
                $objs[] = $this->createObjFromRow($row);
            }
        }
        return $objs;
    }

    /**
     * @param stdClass $row
     *
     * @return ProjectSection
     */
    public function createObjFromRow($row)
    {
        return new ProjectSection($row);
    }

    /**
     * Takes the 2d array of $part_rows (From the DB), and using the parent_id property,
     * creates a tree of rows.
     *
     * @param ProjectSection[] $flat_sections
     * @param int $index
     * @param int $current_parent_id
     *
     * @param int $max_levels
     * @param int $current_level
     *
     * @return ProjectSection[]
     */
    protected function nestSections(
        &$flat_sections,
        &$index = 0,
        $current_parent_id = 0,
        $max_levels = 0,
        $current_level = 0
    ) {
        $nested_sections = [];
        // phpcs:ignore Generic.CodeAnalysis.ForLoopWithTestFunctionCall.NotAllowed
        $num_sections = count($flat_sections);
        for (; $index < $num_sections; $index++) {
            if ($flat_sections[$index]->getParentId() === intval($current_parent_id)) {
                $nested_sections[] = $flat_sections[$index];
            } elseif (intval($flat_sections[$index - 1]->getId()) === intval($flat_sections[$index]->getParentId())) {
                $subs = $this->nestSections(
                    $flat_sections,
                    $index,
                    $flat_sections[$index - 1]->getId(),
                    $max_levels,
                    $current_level + 1
                );
                if ($current_level < $max_levels) {
                    $nested_sections[count($nested_sections) - 1]->cacheSubSections($subs);
                } else {
                    $nested_sections = array_merge($nested_sections, $subs);
                }
            } else {
                // this item isn't a child of $current_parent_id, nor the previous item. Just finish
                $index--;
                return $nested_sections;
            }
        }
        return $nested_sections;
    }

    /**
     * @param string $project_id
     *
     * @return int|false number of rows deleted, or false on error
     */
    public function clearSectionsFor($project_id)
    {
        global $wpdb;
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.NoCaching -- I'm not caching a delete query, sorry.
        return $wpdb->delete(
            $wpdb->prefix . TableManager::SECTIONS_TABLE,
            [
                'project_id' => $project_id,
            ],
            [
                '%d',
            ]
        );
    }

    /**
     * @param int $project_id
     * @param array $sections_data . Top-level array has sub-arrays, each with 5 items: the post ID, its template, its
     * "height" in the tree, its "depth" in the tree, and an array of its sub-items (whose structure is just like the
     * top-level array).
     * @param string $placement see DesignTemplate::validPlacements()
     *
     * @param int $order
     *
     * @return bool|int
     */
    public function setSectionsFor($project_id, $sections_data, $placement, &$order = 1)
    {
        return $this->insertDbRows($project_id, $sections_data, 0, $order, $placement);
    }

    /**
     * @param int $project_id
     * @param array $sections_data
     * @param int $parent_id
     * @param int $order
     * @param string $placement see DesignTemplate::valid
     *
     * @return bool
     */
    protected function insertDbRows($project_id, $sections_data, $parent_id, &$order, $placement)
    {
        global $wpdb;
        foreach ($sections_data as $section_data) {
            $post_id = $section_data[0];
            $template = $section_data[1];
            $height = Array2::setOr($section_data, 2, 0);
            $depth = $section_data[3];
            $subsections = $section_data[4];
            $success = $wpdb->insert(
                $wpdb->prefix . TableManager::SECTIONS_TABLE,
                [
                    'project_id' => $project_id,
                    'post_id' => $post_id,
                    'parent_id' => $parent_id,
                    'section_order' => $order++,
                    'template' => $template,
                    'placement' => $placement,
                    'height' => $height,
                    'depth' => $depth,
                ],
                [
                    '%d', // project_id
                    '%d', // post_id
                    '%d', // parent_id
                    '%d', // section_order
                    '%s', // template
                    '%s', // placement
                    '%d', // height
                    '%d', // depth
                ]
            );
            if (! $success) {
                return false;
            }
            $this->insertDbRows(
                $project_id,
                $subsections,
                $wpdb->insert_id,
                $order,
                $placement
            );
        }
        return true;
    }

    /**
     * Gets the ID of this part's parent.
     * It's usually better to have previously fetched the entire db row which contains parent_id.
     * @param int $part_id
     *
     * @return int
     */
    public function getParentOf($part_id)
    {
        global $wpdb;
        // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- ya, this method isn't used and it's discouraged.
        return (int)$wpdb->get_var(
            $wpdb->prepare(
                // phpcs:ignore -- errrmmm, here I am preparing it, don't say I'm not.
                'SELECT parent_id FROM ' . $wpdb->prefix . TableManager::SECTIONS_TABLE . ' WHERE ID=%d',
                $part_id
            )
        );
    }
}