import { omit } from 'lodash';

import { Dimensions, VariableQuery, VariableQueryType, OldVariableQuery, MultiFilters } from '../types';

const jsonVariable = /\${(\w+):json}/g;

function isVariableQuery(rawQuery: string | VariableQuery | OldVariableQuery): rawQuery is VariableQuery {
  return typeof rawQuery !== 'string' && typeof rawQuery.ec2Filters !== 'string' && typeof rawQuery.tags !== 'string';
}

function migrateMultiFilters(oldFilters: string): MultiFilters {
  const tempFilters = oldFilters.replace(jsonVariable, '"$$$1"');
  const parsedFilters: Dimensions = JSON.parse(tempFilters);
  const newFilters: MultiFilters = {};
  // if the old filter was {key:value} transform it to {key:[value]}
  Object.keys(parsedFilters).forEach((key) => {
    const value = parsedFilters[key];
    if (typeof value === 'string') {
      newFilters[key] = [value];
    } else if (value !== undefined) {
      newFilters[key] = value;
    }
  });
  return newFilters;
}

export function migrateVariableQuery(rawQuery: string | VariableQuery | OldVariableQuery): VariableQuery {
  if (isVariableQuery(rawQuery)) {
    return rawQuery;
  }

  // rawQuery is OldVariableQuery
  if (typeof rawQuery !== 'string') {
    const newQuery: VariableQuery = omit(rawQuery, ['dimensionFilters', 'ec2Filters', 'tags']);
    newQuery.dimensionFilters = {};
    newQuery.ec2Filters = {};
    newQuery.tags = {};

    if (rawQuery.dimensionFilters !== '' && rawQuery.ec2Filters !== '[]') {
      const tempFilters = rawQuery.dimensionFilters.replace(jsonVariable, '"$$$1"');
      try {
        newQuery.dimensionFilters = JSON.parse(tempFilters);
      } catch {
        throw new Error(`unable to migrate poorly formed filters: ${rawQuery.dimensionFilters}`);
      }
    }
    if (rawQuery.ec2Filters !== '' && rawQuery.ec2Filters !== '[]') {
      try {
        newQuery.ec2Filters = migrateMultiFilters(rawQuery.ec2Filters);
      } catch {
        throw new Error(`unable to migrate poorly formed filters: ${rawQuery.ec2Filters}`);
      }
    }
    if (rawQuery.tags !== '' && rawQuery.tags !== '[]') {
      try {
        newQuery.tags = migrateMultiFilters(rawQuery.tags);
      } catch {
        throw new Error(`unable to migrate poorly formed filters: ${rawQuery.tags}`);
      }
    }
    return newQuery;
  }

  const newQuery: VariableQuery = {
    refId: 'CloudWatchVariableQueryEditor-VariableQuery',
    queryType: VariableQueryType.Regions,
    namespace: '',
    region: '',
    metricName: '',
    dimensionKey: '',
    dimensionFilters: {},
    ec2Filters: {},
    instanceID: '',
    attributeName: '',
    resourceType: '',
    tags: {},
  };

  if (rawQuery === '') {
    return newQuery;
  }

  if (rawQuery.match(/^regions\(\)/)) {
    return newQuery;
  }
  if (rawQuery.match(/^namespaces\(\)/)) {
    newQuery.queryType = VariableQueryType.Namespaces;
    return newQuery;
  }
  const metricNameQuery = rawQuery.match(/^metrics\(([^\)]+?)(,\s?([^,]+?))?\)/);
  if (metricNameQuery) {
    newQuery.queryType = VariableQueryType.Metrics;
    newQuery.namespace = metricNameQuery[1];
    newQuery.region = metricNameQuery[3] || '';
    return newQuery;
  }
  const dimensionKeysQuery = rawQuery.match(/^dimension_keys\(([^\)]+?)(,\s?([^,]+?))?\)/);
  if (dimensionKeysQuery) {
    newQuery.queryType = VariableQueryType.DimensionKeys;
    newQuery.namespace = dimensionKeysQuery[1];
    newQuery.region = dimensionKeysQuery[3] || '';
    return newQuery;
  }

  const dimensionValuesQuery = rawQuery.match(
    /^dimension_values\(([^,]+?),\s?([^,]+?),\s?([^,]+?),\s?([^,]+?)(,\s?(.+))?\)/
  );
  if (dimensionValuesQuery) {
    newQuery.queryType = VariableQueryType.DimensionValues;
    newQuery.region = dimensionValuesQuery[1];
    newQuery.namespace = dimensionValuesQuery[2];
    newQuery.metricName = dimensionValuesQuery[3];
    newQuery.dimensionKey = dimensionValuesQuery[4];
    newQuery.dimensionFilters = {};
    if (!!dimensionValuesQuery[6] && dimensionValuesQuery[6] !== '[]') {
      const tempFilters = dimensionValuesQuery[6].replace(jsonVariable, '"$$$1"');
      try {
        newQuery.dimensionFilters = JSON.parse(tempFilters);
      } catch {
        throw new Error(`unable to migrate poorly formed filters: ${dimensionValuesQuery[6]}`);
      }
    }
    return newQuery;
  }

  const ebsVolumeIdsQuery = rawQuery.match(/^ebs_volume_ids\(([^,]+?),\s?([^,]+?)\)/);
  if (ebsVolumeIdsQuery) {
    newQuery.queryType = VariableQueryType.EBSVolumeIDs;
    newQuery.region = ebsVolumeIdsQuery[1];
    newQuery.instanceID = ebsVolumeIdsQuery[2];
    return newQuery;
  }

  const ec2InstanceAttributeQuery = rawQuery.match(/^ec2_instance_attribute\(([^,]+?),\s?([^,]+?),\s?(.+?)\)/);
  if (ec2InstanceAttributeQuery) {
    newQuery.queryType = VariableQueryType.EC2InstanceAttributes;
    newQuery.region = ec2InstanceAttributeQuery[1];
    newQuery.attributeName = ec2InstanceAttributeQuery[2];
    if (ec2InstanceAttributeQuery[3] && ec2InstanceAttributeQuery[3] !== '[]') {
      try {
        newQuery.ec2Filters = migrateMultiFilters(ec2InstanceAttributeQuery[3]);
      } catch {
        throw new Error(`unable to migrate poorly formed filters: ${ec2InstanceAttributeQuery[3]}`);
      }
    }
    return newQuery;
  }

  const resourceARNsQuery = rawQuery.match(/^resource_arns\(([^,]+?),\s?([^,]+?),\s?(.+?)\)/);
  if (resourceARNsQuery) {
    newQuery.queryType = VariableQueryType.ResourceArns;
    newQuery.region = resourceARNsQuery[1];
    newQuery.resourceType = resourceARNsQuery[2];
    if (resourceARNsQuery[3] && resourceARNsQuery[3] !== '[]') {
      try {
        newQuery.tags = migrateMultiFilters(resourceARNsQuery[3]);
      } catch {
        throw new Error(`unable to migrate poorly formed filters: ${resourceARNsQuery[3]}`);
      }
    }
    return newQuery;
  }

  const statsQuery = rawQuery.match(/^statistics\(\)/);
  if (statsQuery) {
    newQuery.queryType = VariableQueryType.Statistics;
    return newQuery;
  }
  throw new Error('unable to parse old variable query');
}