import { RawCustomField } from 'backend/database/types';
import { cloneDeep } from 'lodash';
import { getListFromMap, getMapFromList } from 'utils';
import regionalSchemas from './regional';
import { appSchemas, coreSchemas, metaSchemas } from './schemas';
import type {
  DynamicLinkField,
  Field,
  OptionField,
  Schema,
  SchemaMap,
  SchemaStub,
  SchemaStubMap,
  SelectOption,
  TargetField,
} from './types';

const NAME_FIELD = {
  fieldname: 'name',
  label: `ID`,
  fieldtype: 'Data',
  required: true,
  readOnly: true,
};

export function getSchemas(
  countryCode = '-',
  rawCustomFields: RawCustomField[]
): Readonly<SchemaMap> {
  const builtCoreSchemas = getCoreSchemas();
  const builtAppSchemas = getAppSchemas(countryCode);

  let schemaMap = Object.assign({}, builtAppSchemas, builtCoreSchemas);
  schemaMap = addMetaFields(schemaMap);
  schemaMap = removeFields(schemaMap);
  schemaMap = setSchemaNameOnFields(schemaMap);

  addCustomFields(schemaMap, rawCustomFields);
  deepFreeze(schemaMap);
  return schemaMap;
}

export function setSchemaNameOnFields(schemaMap: SchemaMap): SchemaMap {
  for (const schemaName in schemaMap) {
    const schema = schemaMap[schemaName]!;
    schema.fields = schema.fields.map((f) => ({ ...f, schemaName }));
  }
  return schemaMap;
}

function removeFields(schemaMap: SchemaMap): SchemaMap {
  for (const schemaName in schemaMap) {
    const schema = schemaMap[schemaName]!;
    if (schema.removeFields === undefined) {
      continue;
    }

    for (const fieldname of schema.removeFields) {
      schema.fields = schema.fields.filter((f) => f.fieldname !== fieldname);
      schema.tableFields = schema.tableFields?.filter((fn) => fn !== fieldname);
      schema.quickEditFields = schema.quickEditFields?.filter(
        (fn) => fn !== fieldname
      );
      schema.keywordFields = schema.keywordFields?.filter(
        (fn) => fn !== fieldname
      );

      if (schema.linkDisplayField === fieldname) {
        delete schema.linkDisplayField;
      }
    }

    delete schema.removeFields;
  }

  return schemaMap;
}

function deepFreeze(schemaMap: SchemaMap) {
  Object.freeze(schemaMap);
  for (const schemaName in schemaMap) {
    Object.freeze(schemaMap[schemaName]);
    for (const key in schemaMap[schemaName]) {
      // @ts-ignore
      Object.freeze(schemaMap[schemaName][key]);
    }

    for (const field of schemaMap[schemaName]?.fields ?? []) {
      Object.freeze(field);
    }
  }
}

export function addMetaFields(schemaMap: SchemaMap): SchemaMap {
  const metaSchemaMap = getMapFromList(cloneDeep(metaSchemas), 'name');

  const base = metaSchemaMap.base;
  const tree = getCombined(metaSchemaMap.tree, base);
  const child = metaSchemaMap.child;
  const submittable = getCombined(metaSchemaMap.submittable, base);
  const submittableTree = getCombined(tree, metaSchemaMap.submittable);

  for (const name in schemaMap) {
    const schema = schemaMap[name] as Schema;
    if (schema.isSingle) {
      continue;
    }

    if (schema.isTree && schema.isSubmittable) {
      schema.fields = [...schema.fields, ...submittableTree.fields!];
    } else if (schema.isTree) {
      schema.fields = [...schema.fields, ...tree.fields!];
    } else if (schema.isSubmittable) {
      schema.fields = [...schema.fields, ...submittable.fields!];
    } else if (schema.isChild) {
      schema.fields = [...schema.fields, ...child.fields!];
    } else {
      schema.fields = [...schema.fields, ...base.fields!];
    }
  }

  addNameField(schemaMap);
  addTitleField(schemaMap);
  return schemaMap;
}

function addTitleField(schemaMap: SchemaMap) {
  for (const schemaName in schemaMap) {
    schemaMap[schemaName]!.titleField ??= 'name';
  }
}

function addNameField(schemaMap: SchemaMap) {
  for (const name in schemaMap) {
    const schema = schemaMap[name] as Schema;
    if (schema.isSingle) {
      continue;
    }

    const pkField = schema.fields.find((f) => f.fieldname === 'name');
    if (pkField !== undefined) {
      continue;
    }

    schema.fields.unshift(NAME_FIELD as Field);
  }
}

function getCoreSchemas(): SchemaMap {
  const rawSchemaMap = getMapFromList(cloneDeep(coreSchemas), 'name');
  const coreSchemaMap = getAbstractCombinedSchemas(rawSchemaMap);
  return cleanSchemas(coreSchemaMap);
}

function getAppSchemas(countryCode: string): SchemaMap {
  const appSchemaMap = getMapFromList(cloneDeep(appSchemas), 'name');
  const regionalSchemaMap = getRegionalSchemaMap(countryCode);
  const combinedSchemas = getRegionalCombinedSchemas(
    appSchemaMap,
    regionalSchemaMap
  );
  const schemaMap = getAbstractCombinedSchemas(combinedSchemas);
  return cleanSchemas(schemaMap);
}

export function cleanSchemas(schemaMap: SchemaMap): SchemaMap {
  for (const name in schemaMap) {
    const schema = schemaMap[name] as Schema;
    if (schema.isAbstract && !schema.extends) {
      delete schemaMap[name];
      continue;
    }

    delete schema.extends;
    delete schema.isAbstract;
  }

  return schemaMap;
}

function getCombined(
  extendingSchema: SchemaStub,
  abstractSchema: SchemaStub
): SchemaStub {
  abstractSchema = cloneDeep(abstractSchema);
  extendingSchema = cloneDeep(extendingSchema);

  const abstractFields = getMapFromList(
    abstractSchema.fields ?? [],
    'fieldname'
  );
  const extendingFields = getMapFromList(
    extendingSchema.fields ?? [],
    'fieldname'
  );

  const combined = Object.assign(abstractSchema, extendingSchema);

  for (const fieldname in extendingFields) {
    abstractFields[fieldname] = extendingFields[fieldname];
  }

  combined.fields = getListFromMap(abstractFields);
  return combined;
}

export function getAbstractCombinedSchemas(schemas: SchemaStubMap): SchemaMap {
  const abstractSchemaNames: string[] = Object.keys(schemas).filter(
    (n) => schemas[n].isAbstract
  );

  const extendingSchemaNames: string[] = Object.keys(schemas).filter((n) =>
    abstractSchemaNames.includes(schemas[n].extends ?? '')
  );

  const completeSchemas: Schema[] = Object.keys(schemas)
    .filter(
      (n) =>
        !abstractSchemaNames.includes(n) && !extendingSchemaNames.includes(n)
    )
    .map((n) => schemas[n] as Schema);

  const schemaMap = getMapFromList(completeSchemas, 'name') as SchemaMap;

  for (const name of extendingSchemaNames) {
    const extendingSchema = schemas[name] as Schema;
    const abstractSchema = schemas[extendingSchema.extends!];

    schemaMap[name] = getCombined(extendingSchema, abstractSchema) as Schema;
  }

  abstractSchemaNames.forEach((name) => {
    delete schemaMap[name];
  });

  return schemaMap;
}

export function getRegionalCombinedSchemas(
  appSchemaMap: SchemaStubMap,
  regionalSchemaMap: SchemaStubMap
): SchemaStubMap {
  const combined = { ...appSchemaMap };

  for (const name in regionalSchemaMap) {
    const regionalSchema = regionalSchemaMap[name];

    if (!combined.hasOwnProperty(name)) {
      combined[name] = regionalSchema;
      continue;
    }

    combined[name] = getCombined(regionalSchema, combined[name]);
  }

  return combined;
}

function getRegionalSchemaMap(countryCode: string): SchemaStubMap {
  const countrySchemas = cloneDeep(regionalSchemas[countryCode]) as
    | SchemaStub[]
    | undefined;
  if (countrySchemas === undefined) {
    return {};
  }

  return getMapFromList(countrySchemas, 'name');
}

function addCustomFields(
  schemaMap: SchemaMap,
  rawCustomFields: RawCustomField[]
): void {
  const fieldMap = getFieldMapFromRawCustomFields(rawCustomFields, schemaMap);
  for (const schemaName in fieldMap) {
    const fields = fieldMap[schemaName];
    schemaMap[schemaName]?.fields.push(...fields);
  }
}

function getFieldMapFromRawCustomFields(
  rawCustomFields: RawCustomField[],
  schemaMap: SchemaMap
) {
  const schemaFieldMap: Record<string, Record<string, Field>> = {};

  return rawCustomFields.reduce(
    (
      map,
      {
        parent,
        label,
        fieldname,
        fieldtype,
        isRequired,
        section,
        tab,
        options: rawOptions,
        default: defaultValue,
        target,
        references,
      }
    ) => {
      schemaFieldMap[parent] ??= getMapFromList(
        schemaMap[parent]?.fields ?? [],
        'fieldname'
      );

      if (!schemaFieldMap[parent] || schemaFieldMap[parent][fieldname]) {
        return map;
      }

      map[parent] ??= [];
      const options = rawOptions
        ?.split('\n')
        .map((o) => {
          const value = o.trim();
          return { value, label: value } as SelectOption;
        })
        .filter((o) => o.label && o.value);

      const field = {
        label,
        fieldname,
        fieldtype,
        section,
        tab,
        isCustom: true,
      } as Field;

      if (options?.length) {
        (field as OptionField).options = options;
      }

      if (typeof isRequired === 'number' || typeof isRequired === 'boolean') {
        field.required = Boolean(isRequired);
      }

      if (typeof target === 'string') {
        (field as TargetField).target = target;
      }

      if (typeof references === 'string') {
        (field as DynamicLinkField).references = references;
      }

      if (field.required && defaultValue != null) {
        field.default = defaultValue;
      }

      if (field.required && field.default == null) {
        field.required = false;
      }

      map[parent].push(field);
      return map;
    },
    {} as Record<string, Field[]>
  );
}