<?php
/**
 * @author Daniel J. Summers <daniel@bitbadger.solutions>
 * @license MIT
 */

declare(strict_types=1);

namespace BitBadger\PDODocument\Query;

use BitBadger\PDODocument\{Configuration, DocumentException, Field, FieldMatch, Mode, Query};
use Exception;

/**
 * Queries to remove fields from documents
 *
 * _NOTE: When using these queries to build custom functions, be aware that different databases use significantly
 *        different syntax. The `$parameters` passed to these functions should be run through `Parameters::fieldNames`
 *        function to generate them appropriately for the database currently being targeted._
 */
class RemoveFields
{
    /**
     * Create an UPDATE statement to remove fields from a JSON document
     *
     * @param string $tableName The name of the table in which documents should be manipulated
     * @param array<string, mixed> $parameters The parameter list for the query
     * @param string $whereClause The body of the WHERE clause for the update
     * @return string The UPDATE statement to remove fields from a JSON document
     * @throws Exception If the database mode has not been set
     */
    public static function update(string $tableName, array $parameters, string $whereClause): string
    {
        return match (Configuration::mode('generate field removal query')) {
            Mode::PgSQL  => "UPDATE $tableName SET data = data - " . array_keys($parameters)[0]
                                . "::text[] WHERE $whereClause",
            Mode::SQLite => "UPDATE $tableName SET data = json_remove(data, " . implode(', ', array_keys($parameters))
                                . ") WHERE $whereClause",
        };
    }

    /**
     * Query to remove fields from a document by the document's ID
     *
     * @param string $tableName The name of the table in which the document should be manipulated
     * @param array<string, mixed> $parameters The parameter list for the query
     * @param mixed $docId The ID of the document from which fields should be removed (optional; string ID assumed)
     * @return string The UPDATE statement to remove fields from a document by its ID
     * @throws DocumentException If the database mode has not been set
     */
    public static function byId(string $tableName, array $parameters, mixed $docId = null): string
    {
        return self::update($tableName, $parameters, Query::whereById(docId: $docId));
    }

    /**
     * Query to remove fields from documents via a comparison on JSON fields within the document
     *
     * @param string $tableName The name of the table in which documents should be manipulated
     * @param Field[] $fields The field comparison to match
     * @param array<string, mixed> $parameters The parameter list for the query
     * @param FieldMatch|null $match How to handle multiple conditions (optional; defaults to All)
     * @return string The UPDATE statement to remove fields from documents via field comparison
     * @throws DocumentException If the database mode has not been set
     */
    public static function byFields(string $tableName, array $fields, array $parameters,
                                    ?FieldMatch $match = null): string
    {
        return self::update($tableName, $parameters, Query::whereByFields($fields, $match));
    }

    /**
     * Query to remove fields from documents via a JSON containment query (PostgreSQL only)
     *
     * @param string $tableName The name of the table in which documents should be manipulated
     * @param array<string, mixed> $parameters The parameter list for the query
     * @return string The UPDATE statement to remove fields from documents via a JSON containment query
     * @throws DocumentException If the database mode is not PostgreSQL
     */
    public static function byContains(string $tableName, array $parameters): string
    {
        return self::update($tableName, $parameters, Query::whereDataContains());
    }

    /**
     * Query to remove fields from documents via a JSON Path match query (PostgreSQL only)
     *
     * @param string $tableName The name of the table in which documents should be manipulated
     * @param array<string, mixed> $parameters The parameter list for the query
     * @return string The UPDATE statement to remove fields from documents via a JSON Path match
     * @throws DocumentException
     */
    public static function byJsonPath(string $tableName, array $parameters): string
    {
        return self::update($tableName, $parameters, Query::whereJsonPathMatches());
    }
}