import {
  childScope,
  has,
  makeParser,
  numberIn,
  optionalNumberIn,
  report,
  type Scope,
} from './parse-helpers';
import type { WaterContentConfig } from './rule-config.types';

const MIN_WATER_PERCENT = 10;
const MAX_WATER_PERCENT = 30;
const MAX_HONEY_TYPES = 50;
const MAX_HONEY_TYPE_LENGTH = 100;

export const DEFAULT_WATER_CONTENT_CONFIG: WaterContentConfig = {
  warnAbovePercent: 18,
  confirmAbovePercent: 20,
  byHoneyType: {},
};

function percent(scope: Scope, key: string, fallback: number): number {
  return numberIn(scope, key, fallback, MIN_WATER_PERCENT, MAX_WATER_PERCENT);
}

const ORDER_MESSAGE =
  'Die Warnschwelle darf nicht über der Bestätigungsschwelle liegen.';

function readHoneyTypes(scope: Scope): WaterContentConfig['byHoneyType'] {
  const types = childScope(scope, 'byHoneyType');
  const names = Object.keys(types.raw);
  if (names.length > MAX_HONEY_TYPES) {
    report(scope, 'byHoneyType', `Höchstens ${MAX_HONEY_TYPES} Sorten.`);
    return {};
  }
  const entries: [
    string,
    { warnAbovePercent?: number; confirmAbovePercent?: number },
  ][] = [];
  for (const name of names) {
    if (name.length === 0 || name.length > MAX_HONEY_TYPE_LENGTH) {
      report(types, name.slice(0, 30), 'Der Sortenname ist ungültig.');
      continue;
    }
    const entry = childScope(types, name);
    const before = entry.issues.length;
    const value: { warnAbovePercent?: number; confirmAbovePercent?: number } =
      {};
    const warn = optionalNumberIn(
      entry,
      'warnAbovePercent',
      MIN_WATER_PERCENT,
      MAX_WATER_PERCENT,
    );
    const confirm = optionalNumberIn(
      entry,
      'confirmAbovePercent',
      MIN_WATER_PERCENT,
      MAX_WATER_PERCENT,
    );
    if (warn !== undefined && confirm !== undefined && warn > confirm) {
      report(entry, 'warnAbovePercent', ORDER_MESSAGE);
    }
    if (entry.issues.length > before) {
      continue;
    }
    if (warn !== undefined) {
      value.warnAbovePercent = warn;
    }
    if (confirm !== undefined) {
      value.confirmAbovePercent = confirm;
    }
    entries.push([name, value]);
  }
  // fromEntries defines own properties, so a name like "__proto__" is harmless.
  return Object.fromEntries(entries);
}

export const waterContentParser = makeParser<WaterContentConfig>(
  'HONEY_WATER_CONTENT',
  DEFAULT_WATER_CONTENT_CONFIG,
  (scope) => {
    const d = DEFAULT_WATER_CONTENT_CONFIG;
    let warnAbovePercent = percent(
      scope,
      'warnAbovePercent',
      d.warnAbovePercent,
    );
    let confirmAbovePercent = percent(
      scope,
      'confirmAbovePercent',
      d.confirmAbovePercent,
    );
    if (warnAbovePercent > confirmAbovePercent) {
      report(
        scope,
        has(scope, 'warnAbovePercent')
          ? 'warnAbovePercent'
          : 'confirmAbovePercent',
        ORDER_MESSAGE,
      );
      warnAbovePercent = d.warnAbovePercent;
      confirmAbovePercent = d.confirmAbovePercent;
    }
    return {
      warnAbovePercent,
      confirmAbovePercent,
      byHoneyType: readHoneyTypes(scope),
    };
  },
);