import { isNonEmptyString } from '@sniptt/guards';
import isEmpty from 'lodash.isempty';
import { STANDARD_OBJECTS } from 'twenty-shared/metadata';
import {
  type ObjectsPermissions,
  type RestrictedFieldsPermissions,
} from 'twenty-shared/types';
import { isDefined } from 'twenty-shared/utils';
import { type QueryExpressionMap } from 'typeorm/query-builder/QueryExpressionMap';

import { ProcessAggregateHelper } from 'src/engine/api/graphql/graphql-query-runner/helpers/process-aggregate.helper';
import { InternalServerError } from 'src/engine/core-modules/graphql/utils/graphql-errors.util';
import { type FlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/types/flat-entity-maps.type';
import { findFlatEntityByIdInFlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/utils/find-flat-entity-by-id-in-flat-entity-maps.util';
import { type FlatFieldMetadata } from 'src/engine/metadata-modules/flat-field-metadata/types/flat-field-metadata.type';
import { type FlatObjectMetadata } from 'src/engine/metadata-modules/flat-object-metadata/types/flat-object-metadata.type';
import {
  PermissionsException,
  PermissionsExceptionCode,
  PermissionsExceptionMessage,
} from 'src/engine/metadata-modules/permissions/permissions.exception';
import { getColumnNameToFieldMetadataIdMap } from 'src/engine/twenty-orm/utils/get-column-name-to-field-metadata-id.util';

const WORKSPACE_MEMBER_OBJECT_UNIVERSAL_IDENTIFIER =
  STANDARD_OBJECTS.workspaceMember.universalIdentifier;

const getTargetEntityAndOperationType = (
  expressionMap: QueryExpressionMap,
):
  | {
      isSubQuery: true;
      mainEntity?: undefined;
      operationType?: undefined;
    }
  | {
      isSubQuery?: undefined;
      mainEntity: string;
      operationType:
        | 'select'
        | 'insert'
        | 'update'
        | 'delete'
        | 'restore'
        | 'soft-delete'
        | 'relation';
    } => {
  const isSubQuery = expressionMap.aliases[0].subQuery;

  if (isSubQuery) {
    return {
      isSubQuery: true, // will bypass permission checks because subQuery permissions will be evaluated when it is executed. This is valid for groupBy with records usecase. If your usecase is different, make sure permission checks are run.
    };
  }

  const mainEntity = expressionMap.aliases[0].metadata.name;
  const operationType = expressionMap.queryType;

  return {
    mainEntity,
    operationType,
  };
};

export type OperationType =
  | 'select'
  | 'insert'
  | 'update'
  | 'delete'
  | 'restore'
  | 'soft-delete';

type ValidateOperationIsPermittedOrThrowArgs = {
  entityName: string;
  operationType: OperationType;
  objectsPermissions: ObjectsPermissions;
  flatObjectMetadataMaps: FlatEntityMaps<FlatObjectMetadata>;
  flatFieldMetadataMaps: FlatEntityMaps<FlatFieldMetadata>;
  objectIdByNameSingular: Record<string, string>;
  selectedColumns: string[] | '*';
  allFieldsSelected: boolean;
  updatedColumns: string[];
};

export const validateOperationIsPermittedOrThrow = ({
  entityName,
  operationType,
  objectsPermissions,
  flatObjectMetadataMaps,
  flatFieldMetadataMaps,
  objectIdByNameSingular,
  selectedColumns,
  allFieldsSelected,
  updatedColumns,
}: ValidateOperationIsPermittedOrThrowArgs) => {
  const objectMetadataIdForEntity = objectIdByNameSingular[entityName];

  if (!isNonEmptyString(objectMetadataIdForEntity)) {
    throw new PermissionsException(
      PermissionsExceptionMessage.PERMISSION_DENIED,
      PermissionsExceptionCode.PERMISSION_DENIED,
    );
  }

  const objectMetadata = findFlatEntityByIdInFlatEntityMaps({
    flatEntityId: objectMetadataIdForEntity,
    flatEntityMaps: flatObjectMetadataMaps,
  });

  if (!isDefined(objectMetadata)) {
    throw new PermissionsException(
      PermissionsExceptionMessage.PERMISSION_DENIED,
      PermissionsExceptionCode.PERMISSION_DENIED,
    );
  }

  const objectMetadataIsSystem = objectMetadata.isSystem === true;
  const isWorkspaceMemberObject =
    objectMetadata.universalIdentifier ===
    WORKSPACE_MEMBER_OBJECT_UNIVERSAL_IDENTIFIER;

  if (objectMetadataIsSystem && !isWorkspaceMemberObject) {
    return;
  }

  const columnNameToFieldMetadataIdMap = getColumnNameToFieldMetadataIdMap(
    objectMetadata,
    flatFieldMetadataMaps,
  );

  const permissionsForEntity = objectsPermissions[objectMetadataIdForEntity];

  switch (operationType) {
    case 'select':
      if (!permissionsForEntity?.canReadObjectRecords) {
        throw new PermissionsException(
          PermissionsExceptionMessage.PERMISSION_DENIED,
          PermissionsExceptionCode.PERMISSION_DENIED,
        );
      }

      validateReadFieldPermissionOrThrow({
        restrictedFields: permissionsForEntity.restrictedFields,
        selectedColumns,
        columnNameToFieldMetadataIdMap,
        allFieldsSelected,
      });
      break;
    case 'insert':
      if (!permissionsForEntity?.canUpdateObjectRecords) {
        throw new PermissionsException(
          PermissionsExceptionMessage.PERMISSION_DENIED,
          PermissionsExceptionCode.PERMISSION_DENIED,
        );
      }

      validateReadFieldPermissionOrThrow({
        restrictedFields: permissionsForEntity.restrictedFields,
        selectedColumns,
        columnNameToFieldMetadataIdMap,
      });

      if (updatedColumns.length > 0) {
        const rlsFieldMetadataIds = new Set(
          permissionsForEntity.rowLevelPermissionPredicates.map(
            (predicate) => predicate.fieldMetadataId,
          ),
        );

        const updatedColumnsWithoutRlsFields = updatedColumns.filter(
          (column) =>
            !rlsFieldMetadataIds.has(columnNameToFieldMetadataIdMap[column]),
        );

        if (updatedColumnsWithoutRlsFields.length > 0) {
          validateUpdateFieldPermissionOrThrow({
            restrictedFields: permissionsForEntity.restrictedFields,
            updatedColumns: updatedColumnsWithoutRlsFields,
            columnNameToFieldMetadataIdMap,
          });
        }
      }
      break;
    case 'update':
      if (!permissionsForEntity?.canUpdateObjectRecords) {
        throw new PermissionsException(
          PermissionsExceptionMessage.PERMISSION_DENIED,
          PermissionsExceptionCode.PERMISSION_DENIED,
        );
      }

      validateReadFieldPermissionOrThrow({
        restrictedFields: permissionsForEntity.restrictedFields,
        selectedColumns,
        columnNameToFieldMetadataIdMap,
      });

      if (updatedColumns.length > 0) {
        validateUpdateFieldPermissionOrThrow({
          restrictedFields: permissionsForEntity.restrictedFields,
          updatedColumns,
          columnNameToFieldMetadataIdMap,
        });
      }
      break;
    case 'delete':
      if (!permissionsForEntity?.canDestroyObjectRecords) {
        throw new PermissionsException(
          PermissionsExceptionMessage.PERMISSION_DENIED,
          PermissionsExceptionCode.PERMISSION_DENIED,
        );
      }

      validateReadFieldPermissionOrThrow({
        restrictedFields: permissionsForEntity.restrictedFields,
        selectedColumns,
        columnNameToFieldMetadataIdMap,
      });
      break;
    case 'restore':
    case 'soft-delete':
      if (!permissionsForEntity?.canSoftDeleteObjectRecords) {
        throw new PermissionsException(
          PermissionsExceptionMessage.PERMISSION_DENIED,
          PermissionsExceptionCode.PERMISSION_DENIED,
        );
      }

      validateReadFieldPermissionOrThrow({
        restrictedFields: permissionsForEntity.restrictedFields,
        selectedColumns,
        columnNameToFieldMetadataIdMap,
      });
      break;
    default:
      throw new PermissionsException(
        PermissionsExceptionMessage.UNKNOWN_OPERATION_NAME,
        PermissionsExceptionCode.UNKNOWN_OPERATION_NAME,
      );
  }

  if (isEmpty(permissionsForEntity.restrictedFields)) {
    return;
  }
};

type ValidateQueryIsPermittedOrThrowArgs = {
  expressionMap: QueryExpressionMap;
  objectsPermissions: ObjectsPermissions;
  flatObjectMetadataMaps: FlatEntityMaps<FlatObjectMetadata>;
  flatFieldMetadataMaps: FlatEntityMaps<FlatFieldMetadata>;
  objectIdByNameSingular: Record<string, string>;
  shouldBypassPermissionChecks: boolean;
};

export const validateQueryIsPermittedOrThrow = ({
  expressionMap,
  objectsPermissions,
  flatObjectMetadataMaps,
  flatFieldMetadataMaps,
  objectIdByNameSingular,
  shouldBypassPermissionChecks,
}: ValidateQueryIsPermittedOrThrowArgs) => {
  if (shouldBypassPermissionChecks) {
    return;
  }

  const { mainEntity, operationType, isSubQuery } =
    getTargetEntityAndOperationType(expressionMap);

  if (isSubQuery) {
    return;
  }

  let expressionMapSelectsOnMainEntity = expressionMap.selects;

  if (!isEmpty(expressionMap.joinAttributes)) {
    const { selectsWithoutJoinedAliases } =
      validatePermissionsForJoinsAndReturnSelectsWithoutJoins({
        expressionMap,
        objectsPermissions,
        flatObjectMetadataMaps,
        flatFieldMetadataMaps,
        objectIdByNameSingular,
      });

    expressionMapSelectsOnMainEntity = selectsWithoutJoinedAliases;
  }

  const allFieldsSelected = expressionMapSelectsOnMainEntity.some(
    (select) => select.selection === mainEntity,
  );

  let selectedColumns: string[] | '*' = [];
  let updatedColumns: string[] = [];

  selectedColumns = getSelectedColumnsFromExpressionMap({
    operationType,
    expressionMapReturning: expressionMap.returning,
    expressionMapSelects: expressionMapSelectsOnMainEntity,
    allFieldsSelected,
  });

  if (operationType !== 'select') {
    const valuesSet = expressionMap.valuesSet;

    if (Array.isArray(valuesSet)) {
      updatedColumns = valuesSet.reduce((acc, value) => {
        const keys = Object.keys(value);

        keys.forEach((key) => {
          if (!acc.includes(key)) {
            acc.push(key);
          }
        });

        return acc;
      }, []);
    } else {
      updatedColumns = Object.keys(valuesSet ?? {});
    }
  }

  validateOperationIsPermittedOrThrow({
    entityName: mainEntity,
    operationType: operationType as OperationType,
    objectsPermissions,
    flatObjectMetadataMaps,
    flatFieldMetadataMaps,
    objectIdByNameSingular,
    selectedColumns,
    allFieldsSelected,
    updatedColumns,
  });
};

const validatePermissionsForJoinsAndReturnSelectsWithoutJoins = ({
  expressionMap,
  objectsPermissions,
  flatObjectMetadataMaps,
  flatFieldMetadataMaps,
  objectIdByNameSingular,
}: {
  expressionMap: QueryExpressionMap;
  objectsPermissions: ObjectsPermissions;
  flatObjectMetadataMaps: FlatEntityMaps<FlatObjectMetadata>;
  flatFieldMetadataMaps: FlatEntityMaps<FlatFieldMetadata>;
  objectIdByNameSingular: Record<string, string>;
}) => {
  const joinAttributesAliases = new Set(
    expressionMap.joinAttributes.map((join) => join.alias.name),
  );

  const indexesOfSelectsForJoinedAlias: number[] = [];

  for (const [_index, joinedAlias] of joinAttributesAliases.entries()) {
    const entity = expressionMap.aliases.find(
      (alias) => alias.type === 'join' && alias.name === joinedAlias,
    )?.metadata;

    if (isDefined(entity)) {
      for (const [index, select] of expressionMap.selects.entries()) {
        const regex = /"(\w+)"\."(\w+)"/;
        const extractedAlias = select.selection.match(regex)?.[1]; // "person"."name" -> "person"

        if (isDefined(extractedAlias) && extractedAlias === joinedAlias) {
          indexesOfSelectsForJoinedAlias.push(index);

          const selectedColumns = getSelectedColumnsFromExpressionMap({
            operationType: 'select',
            expressionMapSelects: expressionMap.selects.filter(
              (_select, indexOfSelect) => indexOfSelect === index,
            ),
            allFieldsSelected: false,
          });

          validateOperationIsPermittedOrThrow({
            entityName: entity.name,
            operationType: 'select' as OperationType,
            objectsPermissions,
            flatObjectMetadataMaps,
            flatFieldMetadataMaps,
            objectIdByNameSingular,
            selectedColumns,
            allFieldsSelected: false,
            updatedColumns: [],
          });
        }
      }
    }
  }

  const selectsWithoutJoinedAliases = expressionMap.selects.filter(
    (_select, index) => !indexesOfSelectsForJoinedAlias.includes(index),
  );

  return { selectsWithoutJoinedAliases };
};

const validateReadFieldPermissionOrThrow = ({
  restrictedFields,
  selectedColumns,
  columnNameToFieldMetadataIdMap,
  allFieldsSelected,
}: {
  restrictedFields: RestrictedFieldsPermissions;
  selectedColumns: string[] | '*';
  columnNameToFieldMetadataIdMap: Record<string, string>;
  allFieldsSelected?: boolean;
}) => {
  const noReadRestrictions =
    isEmpty(restrictedFields) ||
    Object.values(restrictedFields).every((field) => field.canRead !== false);

  if (noReadRestrictions) {
    return;
  }

  if (allFieldsSelected || selectedColumns === '*') {
    throw new PermissionsException(
      PermissionsExceptionMessage.PERMISSION_DENIED,
      PermissionsExceptionCode.PERMISSION_DENIED,
    );
  }

  for (const column of selectedColumns) {
    const fieldMetadataId = columnNameToFieldMetadataIdMap[column];

    if (!fieldMetadataId) {
      throw new InternalServerError(
        `Field metadata id not found for column name ${column}`,
      );
    }

    if (restrictedFields[fieldMetadataId]?.canRead === false) {
      throw new PermissionsException(
        PermissionsExceptionMessage.PERMISSION_DENIED,
        PermissionsExceptionCode.PERMISSION_DENIED,
      );
    }
  }
};

const validateUpdateFieldPermissionOrThrow = ({
  restrictedFields,
  updatedColumns,
  columnNameToFieldMetadataIdMap,
}: {
  restrictedFields: RestrictedFieldsPermissions;
  updatedColumns: string[];
  columnNameToFieldMetadataIdMap: Record<string, string>;
}) => {
  if (isEmpty(restrictedFields)) {
    return;
  }

  for (const column of updatedColumns) {
    const fieldMetadataId = columnNameToFieldMetadataIdMap[column];

    if (!fieldMetadataId) {
      throw new InternalServerError(
        `Field metadata id not found for column name ${column}`,
      );
    }

    if (restrictedFields[fieldMetadataId]?.canUpdate === false) {
      throw new PermissionsException(
        PermissionsExceptionMessage.PERMISSION_DENIED,
        PermissionsExceptionCode.PERMISSION_DENIED,
      );
    }
  }
};

const getSelectedColumnsFromExpressionMap = ({
  operationType,
  expressionMapReturning,
  expressionMapSelects,
  allFieldsSelected,
}: {
  operationType: string;
  expressionMapSelects: { selection: string }[];
  allFieldsSelected: boolean;
  expressionMapReturning?: string | string[];
}) => {
  let selectedColumns: string[] | '*' = [];

  if (
    ['update', 'insert', 'delete', 'soft-delete', 'restore'].includes(
      operationType,
    )
  ) {
    if (!isDefined(expressionMapReturning)) {
      throw new InternalServerError(
        'Returning columns are not set for update query',
      );
    }
    selectedColumns =
      expressionMapReturning === '*' ? '*' : [expressionMapReturning].flat();
  } else if (!allFieldsSelected) {
    selectedColumns =
      getSelectedColumnsFromExpressionMapSelects(expressionMapSelects);
  }

  return selectedColumns;
};

const getSelectedColumnsFromExpressionMapSelects = (
  selects: { selection: string }[],
) => {
  return selects
    ?.map((select) => {
      const columnsFromAggregateExpression =
        ProcessAggregateHelper.extractColumnNamesFromAggregateExpression(
          select.selection,
        );

      if (columnsFromAggregateExpression) {
        return columnsFromAggregateExpression;
      }

      const parts = select.selection.split('.');

      return parts[parts.length - 1];
    })
    .flat();
};