package solutions.bitbadger.documents.query

import solutions.bitbadger.documents.*
import solutions.bitbadger.documents.query.byFields as byFieldsBase
import solutions.bitbadger.documents.query.byId as byIdBase

/**
 * Functions to create queries to remove fields from documents
 */
object RemoveFields {

    /**
     * Create a query to remove fields based on the given parameters
     *
     * @param tableName The name of the table in which documents should have fields removed
     * @param toRemove The parameters for the fields to be removed
     * @return A query to remove fields from documents in the given table
     */
    private fun removeFields(tableName: String, toRemove: Collection<Parameter<*>>) =
        when (Configuration.dialect("generate field removal query")) {
            Dialect.POSTGRESQL -> "UPDATE $tableName SET data = data - ${toRemove.elementAt(0).name}::text[]"
            Dialect.SQLITE -> toRemove.joinToString(", ") { it.name }.let {
                "UPDATE $tableName SET data = json_remove(data, $it)"
            }
        }

    /**
     * A query to patch (partially update) a JSON document by its ID
     *
     * @param tableName The name of the table where the document is stored
     * @param toRemove The parameters for the fields to be removed
     * @param docId The ID of the document to be updated (optional, used for type checking)
     * @return A query to patch a JSON document by its ID
     */
    fun <TKey> byId(tableName: String, toRemove: Collection<Parameter<*>>, docId: TKey? = null) =
        byIdBase(removeFields(tableName, toRemove), docId)

    /**
     * A query to patch (partially update) a JSON document using field match criteria
     *
     * @param tableName The name of the table where the documents are stored
     * @param toRemove The parameters for the fields to be removed
     * @param fields The field criteria
     * @param howMatched How the fields should be matched (optional, defaults to `ALL`)
     * @return A query to patch JSON documents by field match criteria
     */
    fun byFields(
        tableName: String,
        toRemove: Collection<Parameter<*>>,
        fields: Collection<Field<*>>,
        howMatched: FieldMatch? = null
    ) =
        byFieldsBase(removeFields(tableName, toRemove), fields, howMatched)

    /**
     * A query to patch (partially update) a JSON document by JSON containment (PostgreSQL only)
     *
     * @param tableName The name of the table where the document is stored
     * @param toRemove The parameters for the fields to be removed
     * @return A query to patch JSON documents by JSON containment
     */
    fun byContains(tableName: String, toRemove: Collection<Parameter<*>>) =
        statementWhere(removeFields(tableName, toRemove), Where.jsonContains())

    /**
     * A query to patch (partially update) a JSON document by JSON path match (PostgreSQL only)
     *
     * @param tableName The name of the table where the document is stored
     * @param toRemove The parameters for the fields to be removed
     * @return A query to patch JSON documents by JSON path match
     */
    fun byJsonPath(tableName: String, toRemove: Collection<Parameter<*>>) =
        statementWhere(removeFields(tableName, toRemove), Where.jsonPathMatches())
}