import {Singleton} from '../di'
import {CanonicalRecursive} from './CanonicalRecursive'

/**
 * Canonical unit that loads configuration files from `app/configs`.
 */
@Singleton()
export class Config extends CanonicalRecursive {
    protected appPath: string[] = ['configs']

    protected suffix = '.config'

    protected canonicalItem = 'config'

    /** If true, all the unique configuration keys will be stored for debugging. */
    protected recordConfigAccesses = false

    /** Array of all unique accessed config keys, if `recordConfigAccesses` is true. */
    protected accessedKeys: string[] = []

    public async up(): Promise<void> {
        await super.up()

        if ( this.get('server.debug', false) ) {
            Error.stackTraceLimit = Infinity
            this.recordConfigAccesses = true
        }
    }

    public async down(): Promise<void> {
        await super.down()

        if ( this.recordConfigAccesses && this.accessedKeys.length ) {
            this.logging.debug(`The following configuration keys were accessed while this application was online:`)
            this.accessedKeys.forEach(key => this.logging.debug(`    - ${key}`))
        }
    }

    public get(key: string, fallback?: unknown): any {
        if ( this.recordConfigAccesses && !this.accessedKeys.includes(key) ) {
            this.accessedKeys.push(key)
        }

        return super.get(key, fallback)
    }
}