import {logger} from '../../service/logging/global.ts'

/**
 * Base type for session data.
 */
export type SessionData = { [key: string]: any }

/**
 * Base type for the abstract session interface.
 */
export default interface SessionInterface {
    get_key(): string
    set_key(key: string): void
    persist(): Promise<void>
    get_data(): SessionData
    set_data(data: SessionData): void
    get_attribute(key: string): any
    set_attribute(key: string, value: any): void
    init_session(): Promise<void>
}

/**
 * Returns true if the given object is a valid session.
 * @param what
 * @return boolean
 */
export function isSessionInterface(what: any): what is SessionInterface {
    const name_length_checks = [
        { name: 'get_key', length: 0 },
        { name: 'set_key', length: 1 },
        { name: 'persist', length: 0 },
        { name: 'get_data', length: 0 },
        { name: 'set_data', length: 1 },
        { name: 'get_attribute', length: 1 },
        { name: 'set_attribute', length: 2 },
        { name: 'init_session', length: 0 },
    ]

    for ( const check of name_length_checks ) {
        const { name, length } = check
        if ( !(typeof what[name] === 'function') ) {
            logger.debug(`Invalid session interface: typeof ${name} is not a function.`)
            return false
        }

        if ( what[name].length !== length ) {
            logger.debug(`Invalid session interface: method ${name} should expect ${length} arguments, ${what[name].length} actual.`)
            return false
        }
    }

    return true
}