import produce from 'immer';

import { getTemplateSrv } from '@grafana/runtime';

import UrlBuilder from '../../azure_monitor/url_builder';
import { AzureMetricResource, AzureMonitorQuery } from '../../types';

import { ResourceRow, ResourceRowGroup } from './types';

// This regex matches URIs representing:
//  - subscriptions: /subscriptions/44693801-6ee6-49de-9b2d-9106972f9572
//  - resource groups: /subscriptions/44693801-6ee6-49de-9b2d-9106972f9572/resourceGroups/cloud-datasources
//  - resources: /subscriptions/44693801-6ee6-49de-9b2d-9106972f9572/resourceGroups/cloud-datasources/providers/Microsoft.Compute/virtualMachines/GithubTestDataVM
const RESOURCE_URI_REGEX =
  /\/subscriptions\/(?<subscription>[^/]+)(?:\/resourceGroups\/(?<resourceGroup>[^/]+)(?:\/providers\/(?<metricNamespaceAndResource>.+))?)?/;

type RegexGroups = Record<string, string | undefined>;

function parseNamespaceAndName(metricNamespaceAndName?: string) {
  if (!metricNamespaceAndName) {
    return {};
  }
  const stringArray = metricNamespaceAndName.split('/');
  // The first two groups belong to the namespace (e.g. Microsoft.Storage/storageAccounts)
  const namespaceArray = stringArray.splice(0, 2);
  // The next element belong to the resource name (e.g. storageAcc1)
  const resourceNameArray = stringArray.splice(0, 1);
  // If there are more elements, keep adding them to the namespace and resource name, alternatively
  // e.g (blobServices/default)
  while (stringArray.length) {
    const nextElem = stringArray.shift()!;
    stringArray.length % 2 === 0 ? resourceNameArray.push(nextElem) : namespaceArray.push(nextElem);
  }
  return { metricNamespace: namespaceArray.join('/'), resourceName: resourceNameArray.join('/') };
}

export function parseResourceURI(resourceURI: string) {
  const matches = RESOURCE_URI_REGEX.exec(resourceURI);
  const groups: RegexGroups = matches?.groups ?? {};
  const { subscription, resourceGroup, metricNamespaceAndResource } = groups;
  const { metricNamespace, resourceName } = parseNamespaceAndName(metricNamespaceAndResource);

  return { subscription, resourceGroup, metricNamespace, resourceName };
}

export function parseResourceDetails(resource: string | AzureMetricResource) {
  if (typeof resource === 'string') {
    return parseResourceURI(resource);
  }
  return resource;
}

export function resourceToString(resource?: string | AzureMetricResource) {
  return resource
    ? typeof resource === 'string'
      ? resource
      : UrlBuilder.buildResourceUri(getTemplateSrv(), resource)
    : '';
}

export function isGUIDish(input: string) {
  return !!input.match(/^[A-Z0-9]+/i);
}

function matchURI(rowURI: string, resourceURI: string) {
  const targetParams = parseResourceDetails(resourceURI);
  const rowParams = parseResourceDetails(rowURI);

  return (
    rowParams?.subscription === targetParams?.subscription &&
    rowParams?.resourceGroup?.toLowerCase() === targetParams?.resourceGroup?.toLowerCase() &&
    // metricNamespace may include a subresource that we don't need to compare
    rowParams?.metricNamespace?.toLowerCase().split('/')[0] ===
      targetParams?.metricNamespace?.toLowerCase().split('/')[0] &&
    // resourceName may include a subresource that we don't need to compare
    rowParams?.resourceName?.split('/')[0] === targetParams?.resourceName?.split('/')[0]
  );
}

export function findRow(rows: ResourceRowGroup, uri: string): ResourceRow | undefined {
  for (const row of rows) {
    if (matchURI(row.uri, uri)) {
      return row;
    }

    if (row.children) {
      const result = findRow(row.children, uri);

      if (result) {
        return result;
      }
    }
  }

  return undefined;
}

export function addResources(rows: ResourceRowGroup, targetParentId: string, newResources: ResourceRowGroup) {
  return produce(rows, (draftState) => {
    const draftRow = findRow(draftState, targetParentId);

    // we can't find the selected resource in our list of resources,
    // probably means user has either mistyped in the input field
    // or is using template variables.
    // either way no need to throw, just show that none of the resources are checked
    if (!draftRow) {
      return;
    }

    draftRow.children = newResources;
  });
}

export function setResource(query: AzureMonitorQuery, resource?: string | AzureMetricResource): AzureMonitorQuery {
  if (typeof resource === 'string') {
    // Resource URI for LogAnalytics
    return {
      ...query,
      azureLogAnalytics: {
        ...query.azureLogAnalytics,
        resource,
      },
    };
  }
  // Resource object for metrics
  return {
    ...query,
    subscription: resource?.subscription,
    azureMonitor: {
      ...query.azureMonitor,
      resourceGroup: resource?.resourceGroup,
      metricNamespace: resource?.metricNamespace?.toLocaleLowerCase(),
      resourceName: resource?.resourceName,
      metricName: undefined,
      aggregation: undefined,
      timeGrain: '',
      dimensionFilters: [],
    },
  };
}