import { Fyo } from 'fyo';
import { DocValue } from 'fyo/core/types';
import { isPesa } from 'fyo/utils';
import { cloneDeep, isEqual } from 'lodash';
import { Field, FieldType, FieldTypeEnum } from 'schemas/types';
import { getIsNullOrUndef } from 'utils';
import { Doc } from './doc';
import { FormulaMap } from './types';

export function areDocValuesEqual(
  dvOne: DocValue | Doc[],
  dvTwo: DocValue | Doc[]
): boolean {
  if (['string', 'number'].includes(typeof dvOne) || dvOne instanceof Date) {
    return dvOne === dvTwo;
  }

  if (isPesa(dvOne)) {
    try {
      return dvOne.eq(dvTwo as string | number);
    } catch {
      return false;
    }
  }

  return isEqual(dvOne, dvTwo);
}

export function getPreDefaultValues(
  fieldtype: FieldType,
  fyo: Fyo
): DocValue | Doc[] {
  switch (fieldtype) {
    case FieldTypeEnum.Table:
      return [] as Doc[];
    case FieldTypeEnum.Currency:
      return fyo.pesa(0.0);
    case FieldTypeEnum.Int:
    case FieldTypeEnum.Float:
      return 0;
    default:
      return null;
  }
}

export function getMissingMandatoryMessage(doc: Doc) {
  const mandatoryFields = getMandatory(doc);
  const message = mandatoryFields
    .filter((f) => {
      const value = doc.get(f.fieldname);
      const isNullOrUndef = getIsNullOrUndef(value);

      if (f.fieldtype === FieldTypeEnum.Table) {
        return isNullOrUndef || (value as Doc[])?.length === 0;
      }

      return isNullOrUndef || value === '';
    })
    .map((f) => f.label ?? f.fieldname)
    .join(', ');

  if (message && doc.schema.isChild && doc.parentdoc && doc.parentFieldname) {
    const parentfield = doc.parentdoc.fieldMap[doc.parentFieldname];
    return `${parentfield.label} Row ${(doc.idx ?? 0) + 1}: ${message}`;
  }

  return message;
}

function getMandatory(doc: Doc): Field[] {
  const mandatoryFields: Field[] = [];
  for (const field of doc.schema.fields) {
    if (field.required) {
      mandatoryFields.push(field);
    }

    const requiredFunction = doc.required[field.fieldname];
    if (requiredFunction?.()) {
      mandatoryFields.push(field);
    }
  }

  return mandatoryFields;
}

export function shouldApplyFormula(field: Field, doc: Doc, fieldname?: string) {
  if (!doc.formulas[field.fieldname]) {
    return false;
  }

  if (field.readOnly) {
    return true;
  }

  const { dependsOn } = doc.formulas[field.fieldname] ?? {};
  if (dependsOn === undefined) {
    return true;
  }

  if (dependsOn.length === 0) {
    return false;
  }

  if (fieldname && dependsOn.includes(fieldname)) {
    return true;
  }

  if (doc.isSyncing && dependsOn.length > 0) {
    return shouldApplyFormulaPreSync(field.fieldname, dependsOn, doc);
  }

  const value = doc.get(field.fieldname);
  return getIsNullOrUndef(value);
}

function shouldApplyFormulaPreSync(
  fieldname: string,
  dependsOn: string[],
  doc: Doc
): boolean {
  if (isDocValueTruthy(doc.get(fieldname))) {
    return false;
  }

  for (const d of dependsOn) {
    const isSet = isDocValueTruthy(doc.get(d));
    if (isSet) {
      return true;
    }
  }

  return false;
}

export function isDocValueTruthy(docValue: DocValue | Doc[]) {
  if (isPesa(docValue)) {
    return !docValue.isZero();
  }

  if (Array.isArray(docValue)) {
    return docValue.length > 0;
  }

  return !!docValue;
}

export function setChildDocIdx(childDocs: Doc[]) {
  childDocs.forEach((cd, idx) => {
    cd.idx = idx;
  });
}

export function getFormulaSequence(formulas: FormulaMap) {
  const depMap = Object.keys(formulas).reduce((acc, k) => {
    acc[k] = formulas[k]?.dependsOn;
    return acc;
  }, {} as Record<string, string[] | undefined>);
  return sequenceDependencies(cloneDeep(depMap));
}

function sequenceDependencies(
  depMap: Record<string, string[] | undefined>
): string[] {
  /**
   * Sufficiently okay algo to sequence dependents after
   * their dependencies
   */
  const keys = Object.keys(depMap);

  const independent = keys.filter((k) => !depMap[k]?.length);
  const dependent = keys.filter((k) => depMap[k]?.length);

  const keyset = new Set(independent);

  for (const k of dependent) {
    const deps = depMap[k] ?? [];
    deps.push(k);

    while (deps.length) {
      const d = deps.shift()!;
      if (keyset.has(d)) {
        continue;
      }

      keyset.add(d);
    }
  }

  return Array.from(keyset).filter((k) => k in depMap);
}