import Service from '@ember/service';
import { inject as service } from '@ember/service';
import { isArray } from '@ember/array';
import SessionService from 'dummy/tests/dummy/app/services/session';
import FormsService from './forms';
import { decamelize } from '@ember/string';

interface ICurrentUser {
    [key: string]: string
}

export default class NeedsService extends Service {

    @service private session!: SessionService
    @service private forms!: FormsService

    public test(needs: string | string[]): boolean {
        if (!needs) return true
        if (!isArray(needs)) needs = [needs]

        for (let need of needs) {
            let inverse = false
            if (need.substring(0, 1) === '!') {
                inverse = true
                need = need.substring(1)
            }
            const ok = inverse ? !this.testOne(need) : this.testOne(need)
            if (!ok) return false
        }

        return true
    }

    public testOne(need: string): boolean {

        if (need.substring(0, 9) === 'userlevel') return this.testUserlevel(need.split('=')[1])
        if (need.includes('@')) return this.testFormPrivilege(need)
        if (need.includes('.')) return this.testFieldExistance(need)

        return false
    }

    private testUserlevel(userlevels: string): boolean {
        const splitUserlevels = userlevels.split(',')

        return splitUserlevels.includes((this.session.currentUser as ICurrentUser).userlevel.toString())
    }

    private testFormPrivilege(need: string): boolean {
        const split = need.split('@')
        const form = decamelize(split[0])
        const privilege = split[1]

        if (!this.forms.formExists(form)) return false

        if (privilege === 'errors') return this.forms.forms[form].errors ? true : false
        if (!this.forms.forms[form].privileges) return false

        return !!this.forms.forms[form].privileges![privilege]
    }

    private testFieldExistance(need: string): boolean {
        const split = need.split('.')
        return this.forms.fieldExists(split[0], split[1])
    }
}