import localDbSvc from './localDbSvc';
import store from '../store';
import utils from './utils';
import networkSvc from './networkSvc';
import exportSvc from './exportSvc';
import providerRegistry from './providers/providerRegistry';

const hasCurrentFilePublishLocations = () => !!store.getters['publishLocation/current'].length;

const loader = type => fileId => localDbSvc.loadItem(`${fileId}/${type}`)
  // Item does not exist, create it
  .catch(() => store.commit(`${type}/setItem`, {
    id: `${fileId}/${type}`,
  }));
const loadContent = loader('content');

const ensureArray = (value) => {
  if (!value) {
    return [];
  }
  if (!Array.isArray(value)) {
    return `${value}`.trim().split(/\s*,\s*/);
  }
  return value;
};

const ensureString = (value, defaultValue) => {
  if (!value) {
    return defaultValue;
  }
  return `${value}`;
};

const ensureDate = (value, defaultValue) => {
  if (!value) {
    return defaultValue;
  }
  return new Date(`${value}`);
};

function publish(publishLocation) {
  const fileId = publishLocation.fileId;
  const template = store.getters['data/allTemplates'][publishLocation.templateId];
  return exportSvc.applyTemplate(fileId, template)
    .then(html => localDbSvc.loadItem(`${fileId}/content`)
      .then((content) => {
        const file = store.state.file.itemMap[fileId];
        const properties = utils.computeProperties(content.properties);
        const provider = providerRegistry.providers[publishLocation.providerId];
        const token = provider.getToken(publishLocation);
        const metadata = {
          title: ensureString(properties.title, file.name),
          author: ensureString(properties.author),
          tags: ensureArray(properties.tags),
          categories: ensureArray(properties.categories),
          excerpt: ensureString(properties.excerpt),
          featuredImage: ensureString(properties.featuredImage),
          status: ensureString(properties.status),
          date: ensureDate(properties.date, new Date()),
        };
        return provider.publish(token, html, metadata, publishLocation);
      }));
}

function publishFile(fileId) {
  let counter = 0;
  return loadContent(fileId)
    .then(() => {
      const publishLocations = [
        ...store.getters['publishLocation/groupedByFileId'][fileId] || [],
      ];
      const publishOneContentLocation = () => {
        const publishLocation = publishLocations.shift();
        if (!publishLocation) {
          return null;
        }
        return store.dispatch('queue/doWithLocation', {
          location: publishLocation,
          promise: publish(publishLocation)
            .then((publishLocationToStore) => {
              // Replace publish location if modified
              if (utils.serializeObject(publishLocation) !==
                utils.serializeObject(publishLocationToStore)
              ) {
                store.commit('publishLocation/patchItem', publishLocationToStore);
              }
              counter += 1;
              return publishOneContentLocation();
            }, (err) => {
              if (store.state.offline) {
                throw err;
              }
              console.error(err); // eslint-disable-line no-console
              store.dispatch('notification/error', err);
              return publishOneContentLocation();
            }),
        });
      };
      return publishOneContentLocation();
    })
    .then(() => {
      const file = store.state.file.itemMap[fileId];
      store.dispatch('notification/info', `"${file.name}" was published to ${counter} location(s).`);
    })
    .then(
      () => localDbSvc.unloadContents(),
      err => localDbSvc.unloadContents()
        .then(() => {
          throw err;
        }));
}

function requestPublish() {
  store.dispatch('queue/enqueuePublishRequest', () => new Promise((resolve, reject) => {
    let intervalId;
    const attempt = () => {
      // Only start publishing when these conditions are met
      if (networkSvc.isUserActive()) {
        clearInterval(intervalId);
        if (!hasCurrentFilePublishLocations()) {
          // Cancel sync
          reject('Publish not possible.');
          return;
        }
        publishFile(store.getters['file/current'].id)
          .then(resolve, reject);
      }
    };
    intervalId = utils.setInterval(() => attempt(), 1000);
    attempt();
  }));
}

function createPublishLocation(publishLocation) {
  publishLocation.id = utils.uid();
  const currentFile = store.getters['file/current'];
  publishLocation.fileId = currentFile.id;
  store.dispatch('queue/enqueue',
    () => publish(publishLocation)
      .then((publishLocationToStore) => {
        store.commit('publishLocation/setItem', publishLocationToStore);
        store.dispatch('notification/info', `A new publication location was added to "${currentFile.name}".`);
      }));
}

export default {
  requestPublish,
  createPublishLocation,
};