import { QueryBuilder } from "./QueryBuilder"
import { ObjectLiteral } from "../common/ObjectLiteral"
import { EntityTarget } from "../common/EntityTarget"
import { DataSource } from "../data-source/DataSource"
import { QueryRunner } from "../query-runner/QueryRunner"
import { WhereExpressionBuilder } from "./WhereExpressionBuilder"
import { Brackets } from "./Brackets"
import { UpdateResult } from "./result/UpdateResult"
import { ReturningStatementNotSupportedError } from "../error/ReturningStatementNotSupportedError"
import { ReturningResultsEntityUpdator } from "./ReturningResultsEntityUpdator"
import { OrderByCondition } from "../find-options/OrderByCondition"
import { LimitOnUpdateNotSupportedError } from "../error/LimitOnUpdateNotSupportedError"
import { MissingDeleteDateColumnError } from "../error/MissingDeleteDateColumnError"
import { UpdateValuesMissingError } from "../error/UpdateValuesMissingError"
import { TypeORMError } from "../error"
import { DriverUtils } from "../driver/DriverUtils"
import { InstanceChecker } from "../util/InstanceChecker"

/**
 * Allows to build complex sql queries in a fashion way and execute those queries.
 */
export class SoftDeleteQueryBuilder<Entity extends ObjectLiteral>
    extends QueryBuilder<Entity>
    implements WhereExpressionBuilder
{
    readonly "@instanceof" = Symbol.for("SoftDeleteQueryBuilder")

    // -------------------------------------------------------------------------
    // Constructor
    // -------------------------------------------------------------------------

    constructor(
        connectionOrQueryBuilder: DataSource | QueryBuilder<any>,
        queryRunner?: QueryRunner,
    ) {
        super(connectionOrQueryBuilder as any, queryRunner)
        this.expressionMap.aliasNamePrefixingEnabled = false
    }

    // -------------------------------------------------------------------------
    // Public Implemented Methods
    // -------------------------------------------------------------------------

    /**
     * Gets generated SQL query without parameters being replaced.
     */
    getQuery(): string {
        let sql = this.createUpdateExpression()
        sql += this.createCteExpression()
        sql += this.createOrderByExpression()
        sql += this.createLimitExpression()
        return this.replacePropertyNamesForTheWholeQuery(sql.trim())
    }

    /**
     * Executes sql generated by query builder and returns raw database results.
     */
    async execute(): Promise<UpdateResult> {
        const queryRunner = this.obtainQueryRunner()
        let transactionStartedByUs: boolean = false

        try {
            // start transaction if it was enabled
            if (
                this.expressionMap.useTransaction === true &&
                queryRunner.isTransactionActive === false
            ) {
                await queryRunner.startTransaction()
                transactionStartedByUs = true
            }

            // call before soft remove and recover methods in listeners and subscribers
            if (
                this.expressionMap.callListeners === true &&
                this.expressionMap.mainAlias!.hasMetadata
            ) {
                if (this.expressionMap.queryType === "soft-delete")
                    await queryRunner.broadcaster.broadcast(
                        "BeforeSoftRemove",
                        this.expressionMap.mainAlias!.metadata,
                    )
                else if (this.expressionMap.queryType === "restore")
                    await queryRunner.broadcaster.broadcast(
                        "BeforeRecover",
                        this.expressionMap.mainAlias!.metadata,
                    )
            }

            // if update entity mode is enabled we may need extra columns for the returning statement
            const returningResultsEntityUpdator =
                new ReturningResultsEntityUpdator(
                    queryRunner,
                    this.expressionMap,
                )
            if (
                this.expressionMap.updateEntity === true &&
                this.expressionMap.mainAlias!.hasMetadata &&
                this.expressionMap.whereEntities.length > 0
            ) {
                this.expressionMap.extraReturningColumns =
                    returningResultsEntityUpdator.getSoftDeletionReturningColumns()
            }

            // execute update query
            const [sql, parameters] = this.getQueryAndParameters()

            const queryResult = await queryRunner.query(sql, parameters, true)
            const updateResult = UpdateResult.from(queryResult)

            // if we are updating entities and entity updation is enabled we must update some of entity columns (like version, update date, etc.)
            if (
                this.expressionMap.updateEntity === true &&
                this.expressionMap.mainAlias!.hasMetadata &&
                this.expressionMap.whereEntities.length > 0
            ) {
                await returningResultsEntityUpdator.update(
                    updateResult,
                    this.expressionMap.whereEntities,
                )
            }

            // call after soft remove and recover methods in listeners and subscribers
            if (
                this.expressionMap.callListeners === true &&
                this.expressionMap.mainAlias!.hasMetadata
            ) {
                if (this.expressionMap.queryType === "soft-delete")
                    await queryRunner.broadcaster.broadcast(
                        "AfterSoftRemove",
                        this.expressionMap.mainAlias!.metadata,
                    )
                else if (this.expressionMap.queryType === "restore")
                    await queryRunner.broadcaster.broadcast(
                        "AfterRecover",
                        this.expressionMap.mainAlias!.metadata,
                    )
            }

            // close transaction if we started it
            if (transactionStartedByUs) await queryRunner.commitTransaction()

            return updateResult
        } catch (error) {
            // rollback transaction if we started it
            if (transactionStartedByUs) {
                try {
                    await queryRunner.rollbackTransaction()
                } catch (rollbackError) {}
            }
            throw error
        } finally {
            if (queryRunner !== this.queryRunner) {
                // means we created our own query runner
                await queryRunner.release()
            }
        }
    }

    // -------------------------------------------------------------------------
    // Public Methods
    // -------------------------------------------------------------------------

    /**
     * Specifies FROM which entity's table select/update/delete/soft-delete will be executed.
     * Also sets a main string alias of the selection data.
     */
    from<T extends ObjectLiteral>(
        entityTarget: EntityTarget<T>,
        aliasName?: string,
    ): SoftDeleteQueryBuilder<T> {
        entityTarget = InstanceChecker.isEntitySchema(entityTarget)
            ? entityTarget.options.name
            : entityTarget
        const mainAlias = this.createFromAlias(entityTarget, aliasName)
        this.expressionMap.setMainAlias(mainAlias)
        return this as any as SoftDeleteQueryBuilder<T>
    }

    /**
     * Sets WHERE condition in the query builder.
     * If you had previously WHERE expression defined,
     * calling this function will override previously set WHERE conditions.
     * Additionally you can add parameters used in where expression.
     */
    where(
        where:
            | string
            | ((qb: this) => string)
            | Brackets
            | ObjectLiteral
            | ObjectLiteral[],
        parameters?: ObjectLiteral,
    ): this {
        this.expressionMap.wheres = [] // don't move this block below since computeWhereParameter can add where expressions
        const condition = this.getWhereCondition(where)
        if (condition)
            this.expressionMap.wheres = [
                { type: "simple", condition: condition },
            ]
        if (parameters) this.setParameters(parameters)
        return this
    }

    /**
     * Adds new AND WHERE condition in the query builder.
     * Additionally you can add parameters used in where expression.
     */
    andWhere(
        where:
            | string
            | ((qb: this) => string)
            | Brackets
            | ObjectLiteral
            | ObjectLiteral[],
        parameters?: ObjectLiteral,
    ): this {
        this.expressionMap.wheres.push({
            type: "and",
            condition: this.getWhereCondition(where),
        })
        if (parameters) this.setParameters(parameters)
        return this
    }

    /**
     * Adds new OR WHERE condition in the query builder.
     * Additionally you can add parameters used in where expression.
     */
    orWhere(
        where:
            | string
            | ((qb: this) => string)
            | Brackets
            | ObjectLiteral
            | ObjectLiteral[],
        parameters?: ObjectLiteral,
    ): this {
        this.expressionMap.wheres.push({
            type: "or",
            condition: this.getWhereCondition(where),
        })
        if (parameters) this.setParameters(parameters)
        return this
    }

    /**
     * Adds new AND WHERE with conditions for the given ids.
     */
    whereInIds(ids: any | any[]): this {
        return this.where(this.getWhereInIdsCondition(ids))
    }

    /**
     * Adds new AND WHERE with conditions for the given ids.
     */
    andWhereInIds(ids: any | any[]): this {
        return this.andWhere(this.getWhereInIdsCondition(ids))
    }

    /**
     * Adds new OR WHERE with conditions for the given ids.
     */
    orWhereInIds(ids: any | any[]): this {
        return this.orWhere(this.getWhereInIdsCondition(ids))
    }
    /**
     * Optional returning/output clause.
     * This will return given column values.
     */
    output(columns: string[]): this

    /**
     * Optional returning/output clause.
     * Returning is a SQL string containing returning statement.
     */
    output(output: string): this

    /**
     * Optional returning/output clause.
     */
    output(output: string | string[]): this

    /**
     * Optional returning/output clause.
     */
    output(output: string | string[]): this {
        return this.returning(output)
    }

    /**
     * Optional returning/output clause.
     * This will return given column values.
     */
    returning(columns: string[]): this

    /**
     * Optional returning/output clause.
     * Returning is a SQL string containing returning statement.
     */
    returning(returning: string): this

    /**
     * Optional returning/output clause.
     */
    returning(returning: string | string[]): this

    /**
     * Optional returning/output clause.
     */
    returning(returning: string | string[]): this {
        // not all databases support returning/output cause
        if (!this.connection.driver.isReturningSqlSupported("update")) {
            throw new ReturningStatementNotSupportedError()
        }

        this.expressionMap.returning = returning
        return this
    }

    /**
     * Sets ORDER BY condition in the query builder.
     * If you had previously ORDER BY expression defined,
     * calling this function will override previously set ORDER BY conditions.
     *
     * Calling order by without order set will remove all previously set order bys.
     */
    orderBy(): this

    /**
     * Sets ORDER BY condition in the query builder.
     * If you had previously ORDER BY expression defined,
     * calling this function will override previously set ORDER BY conditions.
     */
    orderBy(
        sort: string,
        order?: "ASC" | "DESC",
        nulls?: "NULLS FIRST" | "NULLS LAST",
    ): this

    /**
     * Sets ORDER BY condition in the query builder.
     * If you had previously ORDER BY expression defined,
     * calling this function will override previously set ORDER BY conditions.
     */
    orderBy(order: OrderByCondition): this

    /**
     * Sets ORDER BY condition in the query builder.
     * If you had previously ORDER BY expression defined,
     * calling this function will override previously set ORDER BY conditions.
     */
    orderBy(
        sort?: string | OrderByCondition,
        order: "ASC" | "DESC" = "ASC",
        nulls?: "NULLS FIRST" | "NULLS LAST",
    ): this {
        if (sort) {
            if (typeof sort === "object") {
                this.expressionMap.orderBys = sort as OrderByCondition
            } else {
                if (nulls) {
                    this.expressionMap.orderBys = {
                        [sort as string]: { order, nulls },
                    }
                } else {
                    this.expressionMap.orderBys = { [sort as string]: order }
                }
            }
        } else {
            this.expressionMap.orderBys = {}
        }
        return this
    }

    /**
     * Adds ORDER BY condition in the query builder.
     */
    addOrderBy(
        sort: string,
        order: "ASC" | "DESC" = "ASC",
        nulls?: "NULLS FIRST" | "NULLS LAST",
    ): this {
        if (nulls) {
            this.expressionMap.orderBys[sort] = { order, nulls }
        } else {
            this.expressionMap.orderBys[sort] = order
        }
        return this
    }

    /**
     * Sets LIMIT - maximum number of rows to be selected.
     */
    limit(limit?: number): this {
        this.expressionMap.limit = limit
        return this
    }

    /**
     * Indicates if entity must be updated after update operation.
     * This may produce extra query or use RETURNING / OUTPUT statement (depend on database).
     * Enabled by default.
     */
    whereEntity(entity: Entity | Entity[]): this {
        if (!this.expressionMap.mainAlias!.hasMetadata)
            throw new TypeORMError(
                `.whereEntity method can only be used on queries which update real entity table.`,
            )

        this.expressionMap.wheres = []
        const entities: Entity[] = Array.isArray(entity) ? entity : [entity]
        entities.forEach((entity) => {
            const entityIdMap =
                this.expressionMap.mainAlias!.metadata.getEntityIdMap(entity)
            if (!entityIdMap)
                throw new TypeORMError(
                    `Provided entity does not have ids set, cannot perform operation.`,
                )

            this.orWhereInIds(entityIdMap)
        })

        this.expressionMap.whereEntities = entities
        return this
    }

    /**
     * Indicates if entity must be updated after update operation.
     * This may produce extra query or use RETURNING / OUTPUT statement (depend on database).
     * Enabled by default.
     */
    updateEntity(enabled: boolean): this {
        this.expressionMap.updateEntity = enabled
        return this
    }

    // -------------------------------------------------------------------------
    // Protected Methods
    // -------------------------------------------------------------------------

    /**
     * Creates UPDATE express used to perform insert query.
     */
    protected createUpdateExpression() {
        const metadata = this.expressionMap.mainAlias!.hasMetadata
            ? this.expressionMap.mainAlias!.metadata
            : undefined
        if (!metadata)
            throw new TypeORMError(
                `Cannot get entity metadata for the given alias "${this.expressionMap.mainAlias}"`,
            )
        if (!metadata.deleteDateColumn) {
            throw new MissingDeleteDateColumnError(metadata)
        }

        // prepare columns and values to be updated
        const updateColumnAndValues: string[] = []

        switch (this.expressionMap.queryType) {
            case "soft-delete":
                updateColumnAndValues.push(
                    this.escape(metadata.deleteDateColumn.databaseName) +
                        " = CURRENT_TIMESTAMP",
                )
                break
            case "restore":
                updateColumnAndValues.push(
                    this.escape(metadata.deleteDateColumn.databaseName) +
                        " = NULL",
                )
                break
            default:
                throw new TypeORMError(
                    `The queryType must be "soft-delete" or "restore"`,
                )
        }
        if (metadata.versionColumn)
            updateColumnAndValues.push(
                this.escape(metadata.versionColumn.databaseName) +
                    " = " +
                    this.escape(metadata.versionColumn.databaseName) +
                    " + 1",
            )
        if (metadata.updateDateColumn)
            updateColumnAndValues.push(
                this.escape(metadata.updateDateColumn.databaseName) +
                    " = CURRENT_TIMESTAMP",
            ) // todo: fix issue with CURRENT_TIMESTAMP(6) being used, can "DEFAULT" be used?!

        if (updateColumnAndValues.length <= 0) {
            throw new UpdateValuesMissingError()
        }

        // get a table name and all column database names
        const whereExpression = this.createWhereExpression()
        const returningExpression = this.createReturningExpression("update")

        if (returningExpression === "") {
            return `UPDATE ${this.getTableName(
                this.getMainTableName(),
            )} SET ${updateColumnAndValues.join(", ")}${whereExpression}` // todo: how do we replace aliases in where to nothing?
        }
        if (this.connection.driver.options.type === "mssql") {
            return `UPDATE ${this.getTableName(
                this.getMainTableName(),
            )} SET ${updateColumnAndValues.join(
                ", ",
            )} OUTPUT ${returningExpression}${whereExpression}`
        }
        return `UPDATE ${this.getTableName(
            this.getMainTableName(),
        )} SET ${updateColumnAndValues.join(
            ", ",
        )}${whereExpression} RETURNING ${returningExpression}`
    }

    /**
     * Creates "ORDER BY" part of SQL query.
     */
    protected createOrderByExpression() {
        const orderBys = this.expressionMap.orderBys
        if (Object.keys(orderBys).length > 0)
            return (
                " ORDER BY " +
                Object.keys(orderBys)
                    .map((columnName) => {
                        if (typeof orderBys[columnName] === "string") {
                            return (
                                this.replacePropertyNames(columnName) +
                                " " +
                                orderBys[columnName]
                            )
                        } else {
                            return (
                                this.replacePropertyNames(columnName) +
                                " " +
                                (orderBys[columnName] as any).order +
                                " " +
                                (orderBys[columnName] as any).nulls
                            )
                        }
                    })
                    .join(", ")
            )

        return ""
    }

    /**
     * Creates "LIMIT" parts of SQL query.
     */
    protected createLimitExpression(): string {
        let limit: number | undefined = this.expressionMap.limit

        if (limit) {
            if (DriverUtils.isMySQLFamily(this.connection.driver)) {
                return " LIMIT " + limit
            } else {
                throw new LimitOnUpdateNotSupportedError()
            }
        }

        return ""
    }
}