import Error from '@ember/error';
import { inject as service } from '@ember/service';
import RepositoryService from 'consul-ui/services/repository';
import dataSource from 'consul-ui/decorators/data-source';
import {
  HEADERS_DEFAULT_ACL_POLICY as DEFAULT_ACL_POLICY,
} from 'consul-ui/utils/http/consul';


const SECONDS = 1000;
const MODEL_NAME = 'dc';

const zero = {
  Total: 0,
  Passing: 0,
  Warning: 0,
  Critical: 0
};
const aggregate = (prev, body, type) => {

  return body[type].reduce((prev, item) => {

    // for each Partitions, Namespaces
    ['Partition', 'Namespace'].forEach(bucket => {

      // lazily initialize
      let obj = prev[bucket][item[bucket]];
      if(typeof obj === 'undefined') {
        obj = prev[bucket][item[bucket]] = {
          Name: item[bucket],
        };
      }
      if(typeof obj[type] === 'undefined') {
        obj[type] = {
          ...zero
        };
      }
      //

      // accumulate
      obj[type].Total += item.Total;
      obj[type].Passing += item.Passing;
      obj[type].Warning += item.Warning;
      obj[type].Critical += item.Critical;

    });

    // also aggregate the Datacenter, without doubling up
    // for Partitions/Namespaces
    prev.Datacenter[type].Total += item.Total;
    prev.Datacenter[type].Passing += item.Passing;
    prev.Datacenter[type].Warning += item.Warning;
    prev.Datacenter[type].Critical += item.Critical;
    return prev;
  }, prev);
}


export default class DcService extends RepositoryService {
  @service('env') env;

  getModelName() {
    return MODEL_NAME;
  }

  @dataSource('/:partition/:ns/:dc/datacenters')
  async fetchAll({partition, ns, dc}, { uri }, request) {
    const Local = this.env.var('CONSUL_DATACENTER_LOCAL');
    const Primary = this.env.var('CONSUL_DATACENTER_PRIMARY');
    return (await request`
      GET /v1/catalog/datacenters
      X-Request-ID: ${uri}
    `)(
      (headers, body, cache) => {
        // TODO: Not sure nowadays whether we need to keep lowercasing everything
        // I vaguely remember when I last looked it was not needed for browsers anymore
        // but I also vaguely remember something about Pretender lowercasing things still
        // so if we can work around Pretender I think we can remove all the header lowercasing
        // For the moment we lowercase here so as to not effect the ember-data-flavoured-v1 fork
        const entry = Object.entries(headers)
          .find(([key, value]) => key.toLowerCase() === DEFAULT_ACL_POLICY.toLowerCase());
        //
        const DefaultACLPolicy = entry[1] || 'allow';
        return {
          meta: {
            version: 2,
            uri: uri,
          },
          body: body.map(dc => {
            return cache(
              {
                Name: dc,
                Datacenter: '',
                Local: dc === Local,
                Primary: dc === Primary,
                DefaultACLPolicy: DefaultACLPolicy,
              },
              uri => uri`${MODEL_NAME}:///${''}/${''}/${dc}/datacenter`
            );
          })
        };
      });
  }

  @dataSource('/:partition/:ns/:dc/datacenter')
  async fetch({partition, ns, dc}, { uri }, request) {
    return (await request`
      GET /v1/operator/autopilot/state?${{ dc }}
      X-Request-ID: ${uri}
    `)(
      (headers, body, cache) => ({
        meta: {
          version: 2,
          uri: uri,
          interval: 30 * SECONDS
        },
        body: cache(
          {
            ...body,
            // turn servers into an array instead of a map/object
            Servers: Object.values(body.Servers)
          },
          uri => uri`${MODEL_NAME}:///${''}/${''}/${dc}/datacenter`
        )
      })
    );
  }

  @dataSource('/:partition/:ns/:dc/catalog/health')
  async fetchCatalogHealth({partition, ns, dc}, { uri }, request) {
    return (await request`
      GET /v1/internal/ui/catalog-overview?${{ dc, stale: null }}
      X-Request-ID: ${uri}
    `)(
      (headers, body, cache) => {


        // for each Services/Nodes/Checks aggregate
        const agg = ['Nodes', 'Services', 'Checks']
          .reduce((prev, item) => aggregate(prev, body, item), {
            Datacenter: {
              Name: dc,
              Nodes: {
                ...zero
              },
              Services: {
                ...zero
              },
              Checks: {
                ...zero
              }
            },
            Partition: {},
            Namespace: {}
          });


        return {
          meta: {
            version: 2,
            uri: uri,
            interval: 30 * SECONDS
          },
          body: {
            Datacenter: agg.Datacenter,
            Partitions: Object.values(agg.Partition),
            Namespaces: Object.values(agg.Namespace),
            ...body
          }
        };
      }

    );
  }

  @dataSource('/:partition/:ns/:dc/datacenter-cache/:name')
  async find(params) {
    const items = this.store.peekAll('dc');
    const item = items.findBy('Name', params.name);
    if (typeof item === 'undefined') {
      // TODO: We should use a HTTPError error here and remove all occurances of
      // the custom shaped ember-data error throughout the app
      const e = new Error('Page not found');
      e.status = '404';
      throw { errors: [e] };
    }
    return item;
  }

}