import ConnectionMutable from './ConnectionMutable.ts'
import {MalformedSQLGrammarError} from './Select.ts'
import {escape, EscapedValue} from "../types.ts";

/**
 * Base query builder class for ALTER DATABASE queries.
 * @extends ConnectionMutable
 */
export class AlterDatabase<T> extends ConnectionMutable<T> {
    protected _name?: string
    protected _rename?: string
    protected _owner?: string
    protected _tablespace?: string
    protected _conn_limit?: number
    protected _is_template?: boolean
    protected _allow_connections?: boolean

    protected _reset_all: boolean = false
    protected _config_resets: string[] = []
    protected _config_from_current: string[] = []
    protected _config_sets: (string|EscapedValue)[][] = []

    constructor(name?: string) {
        super()
        if ( name ) this._name = name
    }

    sql(level: number = 0): string {
        if ( !this._name ) {
            throw new MalformedSQLGrammarError(`Database name to alter is undefined.`)
        }

        const queries = []

        const option_pairs: (string|boolean|number)[][] = []
        if ( typeof this._allow_connections !== 'undefined' ) {
            option_pairs.push(['ALLOW_CONNECTIONS', this._allow_connections])
        }

        if ( typeof this._conn_limit !== 'undefined' ) {
            option_pairs.push(['CONNECTION LIMIT', this._conn_limit])
        }

        if ( typeof this._is_template !== 'undefined' ) {
            option_pairs.push(['IS_TEMPLATE', this._is_template])
        }

        if ( option_pairs.length > 0 ) {
            option_pairs.some(pair => {
                queries.push(`ALTER DATABASE ${this._name} WITH ${pair[0]} ${pair[1]}`)
            })
        }

        if ( this._owner ) {
            queries.push(`ALTER DATABASE ${this._name} OWNER TO ${this._owner}`)
        }

        if ( this._tablespace ) {
            queries.push(`ALTER DATABASE ${this._name} SET TABLESPACE ${this._tablespace}`)
        }

        if ( this._reset_all ) {
            queries.push(`ALTER DATABASE ${this._name} RESET ALL`)
        }

        if ( this._config_resets.length > 0 ) {
            this._config_resets.some(param => {
                queries.push(`ALTER DATABASE ${this._name} RESET ${param}`)
            })
        }

        if ( this._config_from_current.length > 0 ) {
            this._config_from_current.some(param => {
                queries.push(`ALTER DATABASE ${this._name} SET ${param} FROM CURRENT`)
            })
        }

        if ( this._config_sets.length > 0 ) {
            this._config_sets.some(set => {
                queries.push(`ALTER DATABASE ${this._name} SET ${set[0]} TO ${escape(set[1])}`)
            })
        }

        // This needs to happen last
        if ( this._rename ) {
            queries.push(`ALTER DATABASE ${this._name} RENAME TO ${this._rename}`)
        }

        return queries.join(';\n')
    }

    name(name: string): this {
        this._name = name
        return this
    }

    rename_to(name: string): this {
        this._rename = name
        return this
    }

    owner(user: string): this {
        this._owner = user
        return this
    }

    tablespace(name: string): this {
        this._tablespace = name
        return this
    }

    connection_limit(max: number): this {
        this._conn_limit = max
        return this
    }

    as_template(): this {
        this._is_template = true
        return this
    }

    not_as_template(): this {
        this._is_template = false
        return this
    }

    disallow_connections(): this {
        this._allow_connections = false
        return this
    }

    allow_connections(): this {
        this._allow_connections = true
        return this
    }

    reset_all(): this {
        this._reset_all = true
        return this
    }

    reset(parameter: string): this {
        this._config_resets.push(parameter)
        return this
    }

    set_from_current(parameter: string): this {
        this._config_from_current.push(parameter)
        return this
    }

    set(parameter: string, value: EscapedValue): this {
        this._config_sets.push([parameter, value])
        return this
    }
}