/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

import { actionTypes as at } from "resource://newtab/common/Actions.mjs";
import { Dedupe } from "resource:///modules/Dedupe.sys.mjs";

export {
  TOP_SITES_DEFAULT_ROWS,
  TOP_SITES_MAX_SITES_PER_ROW,
} from "resource:///modules/topsites/constants.mjs";

const dedupe = new Dedupe(site => site && site.url);

export const INITIAL_STATE = {
  App: {
    // Have we received real data from the app yet?
    initialized: false,
    locale: "",
    isForStartupCache: {
      App: false,
      TopSites: false,
      DiscoveryStream: false,
      Weather: false,
      Wallpaper: false,
    },
    customizeMenuVisible: false,
  },
  Ads: {
    initialized: false,
    lastUpdated: null,
    tiles: {},
    spocs: {},
    spocPlacements: {},
  },
  TopSites: {
    // Have we received real data from history yet?
    initialized: false,
    // The history (and possibly default) links
    rows: [],
    // Used in content only to dispatch action to TopSiteForm.
    editForm: null,
    // Used in content only to open the SearchShortcutsForm modal.
    showSearchShortcutsForm: false,
    // The list of available search shortcuts.
    searchShortcuts: [],
    // The "Share-of-Voice" allocations generated by TopSitesFeed
    sov: {
      ready: false,
      positions: [
        // {position: 0, assignedPartner: "amp"},
        // {position: 1, assignedPartner: "moz-sales"},
      ],
    },
  },
  Prefs: {
    initialized: false,
    values: { featureConfig: {} },
  },
  Dialog: {
    visible: false,
    data: {},
  },
  Sections: [],
  Pocket: {
    pocketCta: {},
    waitingForSpoc: true,
  },
  // This is the new pocket configurable layout state.
  DiscoveryStream: {
    // This is a JSON-parsed copy of the discoverystream.config pref value.
    config: { enabled: false },
    layout: [],
    topicsLoading: false,
    feeds: {
      data: {
        // "https://foo.com/feed1": {lastUpdated: 123, data: [], personalized: false}
      },
      loaded: false,
    },
    // Used to show impressions in newtab devtools.
    impressions: {
      feed: {},
    },
    // Used to show blocks in newtab devtools.
    blocks: {},
    spocs: {
      spocs_endpoint: "",
      lastUpdated: null,
      cacheUpdateTime: null,
      onDemand: {
        enabled: false,
        loaded: false,
      },
      data: {
        // "spocs": {title: "", context: "", items: [], personalized: false},
        // "placement1": {title: "", context: "", items: [], personalized: false},
      },
      loaded: false,
      frequency_caps: [],
      blocked: [],
      placements: [],
    },
    experimentData: {
      utmSource: "pocket-newtab",
      utmCampaign: undefined,
      utmContent: undefined,
    },
    showTopicSelection: false,
    report: {
      visible: false,
      data: {},
    },
    sectionPersonalization: {},
  },
  // Messages received from ASRouter to render in newtab
  Messages: {
    // messages received from ASRouter are initially visible
    isVisible: true,
    // portID for that tab that was sent the message
    portID: "",
    // READONLY Message data received from ASRouter
    messageData: {},
  },
  Notifications: {
    showNotifications: false,
    toastCounter: 0,
    toastId: "",
    // This queue is reset each time SHOW_TOAST_MESSAGE is ran.
    // For can be a queue in the future, but for now is one item
    toastQueue: [],
  },
  InferredPersonalization: {
    initialized: false,
    lastUpdated: null,
    inferredInterests: {},
    coarseInferredInterests: {},
    coarsePrivateInferredInterests: {},
    debugFeatures: null,
    inferredTelemetrySettingsOverrides: {},
  },
  Search: {
    // When search hand-off is enabled, we render a big button that is styled to
    // look like a search textbox. If the button is clicked, we style
    // the button as if it was a focused search box and show a fake cursor but
    // really focus the awesomebar without the focus styles ("hidden focus").
    fakeFocus: false,
    // Hide the search box after handing off to AwesomeBar and user starts typing.
    hide: false,
  },
  Wallpapers: {
    wallpaperList: [],
    highlightSeenCounter: 0,
    categories: [],
    uploadedWallpaper: "",
  },
  SectionsLayout: {
    configs: {},
  },
  Weather: {
    initialized: false,
    lastUpdated: null,
    query: "",
    suggestions: [],
    hourlyForecasts: [],
    locationData: {
      city: "",
      adminArea: "",
      country: "",
    },
    // Display search input in Weather widget
    searchActive: false,
    locationSearchString: "",
    suggestedLocations: [],
  },
  // Widgets
  ListsWidget: {
    // value pointing to last selectled list
    selected: "taskList",
    // Default state of an empty task list
    lists: {
      taskList: {
        label: "",
        tasks: [],
        completed: [],
      },
    },
  },
  TimerWidget: {
    // The timer will have 2 types of states, focus and break.
    // Focus will the default state
    timerType: "focus",
    focus: {
      // Timer duration set by user; 25 mins by default
      duration: 25 * 60,
      // Initial duration - also set by the user; does not update until timer ends or user resets timer
      initialDuration: 25 * 60,
      // the Date.now() value when a user starts/resumes a timer
      startTime: null,
      // Boolean indicating if timer is currently running
      isRunning: false,
    },
    break: {
      duration: 5 * 60,
      initialDuration: 5 * 60,
      startTime: null,
      isRunning: false,
    },
  },
  ExternalComponents: {
    components: [],
  },
};

function App(prevState = INITIAL_STATE.App, action) {
  switch (action.type) {
    case at.INIT:
      return Object.assign({}, prevState, action.data || {}, {
        initialized: true,
      });
    case at.TOP_SITES_UPDATED:
      // Toggle `isForStartupCache.TopSites` when receiving the `TOP_SITES_UPDATE` action
      // so that sponsored tiles can be rendered as usual. See Bug 1826360.
      return {
        ...prevState,
        isForStartupCache: { ...prevState.isForStartupCache, TopSites: false },
      };
    case at.DISCOVERY_STREAM_SPOCS_UPDATE:
      // Toggle `isForStartupCache.DiscoveryStream` when receiving the `DISCOVERY_STREAM_SPOCS_UPDATE` action
      // so that spoc cards can be rendered as usual.
      return {
        ...prevState,
        isForStartupCache: {
          ...prevState.isForStartupCache,
          DiscoveryStream: false,
        },
      };
    case at.WEATHER_UPDATE:
      // Toggle `isForStartupCache.Weather` when receiving the `WEATHER_UPDATE` action
      // so that weather can be rendered as usual.
      return {
        ...prevState,
        isForStartupCache: { ...prevState.isForStartupCache, Weather: false },
      };
    case at.WALLPAPERS_CUSTOM_SET:
      // Toggle `isForStartupCache.Wallpaper` when receiving the `WALLPAPERS_CUSTOM_SET` action
      // so that custom wallpaper can be rendered as usual.
      return {
        ...prevState,
        isForStartupCache: { ...prevState.isForStartupCache, Wallpaper: false },
      };
    case at.SHOW_PERSONALIZE:
      return Object.assign({}, prevState, {
        customizeMenuVisible: true,
      });
    case at.HIDE_PERSONALIZE:
      return Object.assign({}, prevState, {
        customizeMenuVisible: false,
      });
    default:
      return prevState;
  }
}

function TopSites(prevState = INITIAL_STATE.TopSites, action) {
  let hasMatch;
  let newRows;
  switch (action.type) {
    case at.TOP_SITES_UPDATED:
      if (!action.data || !action.data.links) {
        return prevState;
      }
      return Object.assign(
        {},
        prevState,
        { initialized: true, rows: action.data.links },
        action.data.pref ? { pref: action.data.pref } : {}
      );
    case at.TOP_SITES_PREFS_UPDATED:
      return Object.assign({}, prevState, { pref: action.data.pref });
    case at.TOP_SITES_EDIT:
      return Object.assign({}, prevState, {
        editForm: {
          index: action.data.index,
          previewResponse: null,
        },
      });
    case at.TOP_SITES_CANCEL_EDIT:
      return Object.assign({}, prevState, { editForm: null });
    case at.TOP_SITES_OPEN_SEARCH_SHORTCUTS_MODAL:
      return Object.assign({}, prevState, { showSearchShortcutsForm: true });
    case at.TOP_SITES_CLOSE_SEARCH_SHORTCUTS_MODAL:
      return Object.assign({}, prevState, { showSearchShortcutsForm: false });
    case at.PREVIEW_RESPONSE:
      if (
        !prevState.editForm ||
        action.data.url !== prevState.editForm.previewUrl
      ) {
        return prevState;
      }
      return Object.assign({}, prevState, {
        editForm: {
          index: prevState.editForm.index,
          previewResponse: action.data.preview,
          previewUrl: action.data.url,
        },
      });
    case at.PREVIEW_REQUEST:
      if (!prevState.editForm) {
        return prevState;
      }
      return Object.assign({}, prevState, {
        editForm: {
          index: prevState.editForm.index,
          previewResponse: null,
          previewUrl: action.data.url,
        },
      });
    case at.PREVIEW_REQUEST_CANCEL:
      if (!prevState.editForm) {
        return prevState;
      }
      return Object.assign({}, prevState, {
        editForm: {
          index: prevState.editForm.index,
          previewResponse: null,
        },
      });
    case at.SCREENSHOT_UPDATED:
      newRows = prevState.rows.map(row => {
        if (row && row.url === action.data.url) {
          hasMatch = true;
          return Object.assign({}, row, { screenshot: action.data.screenshot });
        }
        return row;
      });
      return hasMatch
        ? Object.assign({}, prevState, { rows: newRows })
        : prevState;
    case at.PLACES_BOOKMARK_ADDED:
      if (!action.data) {
        return prevState;
      }
      newRows = prevState.rows.map(site => {
        if (site && site.url === action.data.url) {
          const { bookmarkGuid, bookmarkTitle, dateAdded } = action.data;
          return Object.assign({}, site, {
            bookmarkGuid,
            bookmarkTitle,
            bookmarkDateCreated: dateAdded,
          });
        }
        return site;
      });
      return Object.assign({}, prevState, { rows: newRows });
    case at.PLACES_BOOKMARKS_REMOVED:
      if (!action.data) {
        return prevState;
      }
      newRows = prevState.rows.map(site => {
        if (site && action.data.urls.includes(site.url)) {
          const newSite = Object.assign({}, site);
          delete newSite.bookmarkGuid;
          delete newSite.bookmarkTitle;
          delete newSite.bookmarkDateCreated;
          return newSite;
        }
        return site;
      });
      return Object.assign({}, prevState, { rows: newRows });
    case at.PLACES_LINKS_DELETED:
      if (!action.data) {
        return prevState;
      }
      newRows = prevState.rows.filter(
        site => !action.data.urls.includes(site.url)
      );
      return Object.assign({}, prevState, { rows: newRows });
    case at.UPDATE_SEARCH_SHORTCUTS:
      return { ...prevState, searchShortcuts: action.data.searchShortcuts };
    case at.SOV_UPDATED: {
      const sov = {
        ready: action.data.ready,
        positions: action.data.positions,
      };
      return { ...prevState, sov };
    }
    default:
      return prevState;
  }
}

function Dialog(prevState = INITIAL_STATE.Dialog, action) {
  switch (action.type) {
    case at.DIALOG_OPEN:
      return Object.assign({}, prevState, { visible: true, data: action.data });
    case at.DIALOG_CANCEL:
      return Object.assign({}, prevState, { visible: false });
    case at.DIALOG_CLOSE:
      // Reset and hide the confirmation dialog once the action is complete.
      return Object.assign({}, INITIAL_STATE.Dialog);
    default:
      return prevState;
  }
}

function Prefs(prevState = INITIAL_STATE.Prefs, action) {
  let newValues;
  switch (action.type) {
    case at.PREFS_INITIAL_VALUES:
      return Object.assign({}, prevState, {
        initialized: true,
        values: action.data,
      });
    case at.PREF_CHANGED:
      newValues = Object.assign({}, prevState.values);
      newValues[action.data.name] = action.data.value;
      return Object.assign({}, prevState, { values: newValues });
    default:
      return prevState;
  }
}

function Sections(prevState = INITIAL_STATE.Sections, action) {
  let hasMatch;
  let newState;
  switch (action.type) {
    case at.SECTION_DEREGISTER:
      return prevState.filter(section => section.id !== action.data);
    case at.SECTION_REGISTER:
      // If section exists in prevState, update it
      newState = prevState.map(section => {
        if (section && section.id === action.data.id) {
          hasMatch = true;
          return Object.assign({}, section, action.data);
        }
        return section;
      });
      // Otherwise, append it
      if (!hasMatch) {
        const initialized = !!(action.data.rows && !!action.data.rows.length);
        const section = Object.assign(
          { title: "", rows: [], enabled: false },
          action.data,
          { initialized }
        );
        newState.push(section);
      }
      return newState;
    case at.SECTION_UPDATE:
      newState = prevState.map(section => {
        if (section && section.id === action.data.id) {
          // If the action is updating rows, we should consider initialized to be true.
          // This can be overridden if initialized is defined in the action.data
          const initialized = action.data.rows ? { initialized: true } : {};

          // Make sure pinned cards stay at their current position when rows are updated.
          // Disabling a section (SECTION_UPDATE with empty rows) does not retain pinned cards.
          if (
            action.data.rows &&
            !!action.data.rows.length &&
            section.rows.find(card => card.pinned)
          ) {
            const rows = Array.from(action.data.rows);
            section.rows.forEach((card, index) => {
              if (card.pinned) {
                // Only add it if it's not already there.
                if (rows[index].guid !== card.guid) {
                  rows.splice(index, 0, card);
                }
              }
            });
            return Object.assign(
              {},
              section,
              initialized,
              Object.assign({}, action.data, { rows })
            );
          }

          return Object.assign({}, section, initialized, action.data);
        }
        return section;
      });

      if (!action.data.dedupeConfigurations) {
        return newState;
      }

      action.data.dedupeConfigurations.forEach(dedupeConf => {
        newState = newState.map(section => {
          if (section.id === dedupeConf.id) {
            const dedupedRows = dedupeConf.dedupeFrom.reduce(
              (rows, dedupeSectionId) => {
                const dedupeSection = newState.find(
                  s => s.id === dedupeSectionId
                );
                const [, newRows] = dedupe.group(dedupeSection.rows, rows);
                return newRows;
              },
              section.rows
            );

            return Object.assign({}, section, { rows: dedupedRows });
          }

          return section;
        });
      });

      return newState;
    case at.SECTION_UPDATE_CARD:
      return prevState.map(section => {
        if (section && section.id === action.data.id && section.rows) {
          const newRows = section.rows.map(card => {
            if (card.url === action.data.url) {
              return Object.assign({}, card, action.data.options);
            }
            return card;
          });
          return Object.assign({}, section, { rows: newRows });
        }
        return section;
      });
    case at.PLACES_BOOKMARK_ADDED:
      if (!action.data) {
        return prevState;
      }
      return prevState.map(section =>
        Object.assign({}, section, {
          rows: section.rows.map(item => {
            // find the item within the rows that is attempted to be bookmarked
            if (item.url === action.data.url) {
              const { bookmarkGuid, bookmarkTitle, dateAdded } = action.data;
              return Object.assign({}, item, {
                bookmarkGuid,
                bookmarkTitle,
                bookmarkDateCreated: dateAdded,
                type: "bookmark",
              });
            }
            return item;
          }),
        })
      );
    case at.PLACES_BOOKMARKS_REMOVED:
      if (!action.data) {
        return prevState;
      }
      return prevState.map(section =>
        Object.assign({}, section, {
          rows: section.rows.map(item => {
            // find the bookmark within the rows that is attempted to be removed
            if (action.data.urls.includes(item.url)) {
              const newSite = Object.assign({}, item);
              delete newSite.bookmarkGuid;
              delete newSite.bookmarkTitle;
              delete newSite.bookmarkDateCreated;
              if (!newSite.type || newSite.type === "bookmark") {
                newSite.type = "history";
              }
              return newSite;
            }
            return item;
          }),
        })
      );
    case at.PLACES_LINKS_DELETED:
      if (!action.data) {
        return prevState;
      }
      return prevState.map(section =>
        Object.assign({}, section, {
          rows: section.rows.filter(
            site => !action.data.urls.includes(site.url)
          ),
        })
      );
    case at.PLACES_LINK_BLOCKED:
      if (!action.data) {
        return prevState;
      }
      return prevState.map(section =>
        Object.assign({}, section, {
          rows: section.rows.filter(site => site.url !== action.data.url),
        })
      );
    default:
      return prevState;
  }
}

function Messages(prevState = INITIAL_STATE.Messages, action) {
  switch (action.type) {
    case at.MESSAGE_SET:
      if (prevState.messageData.messageType) {
        return prevState;
      }
      return {
        ...prevState,
        messageData: action.data.message,
        portID: action.data.portID || "",
      };
    case at.MESSAGE_TOGGLE_VISIBILITY:
      return { ...prevState, isVisible: action.data.isVisible };
    default:
      return prevState;
  }
}

function Pocket(prevState = INITIAL_STATE.Pocket, action) {
  switch (action.type) {
    case at.POCKET_WAITING_FOR_SPOC:
      return { ...prevState, waitingForSpoc: action.data };
    case at.POCKET_CTA:
      return {
        ...prevState,
        pocketCta: {
          ctaButton: action.data.cta_button,
          ctaText: action.data.cta_text,
          ctaUrl: action.data.cta_url,
          useCta: action.data.use_cta,
        },
      };
    default:
      return prevState;
  }
}

function InferredPersonalization(
  prevState = INITIAL_STATE.InferredPersonalization,
  action
) {
  switch (action.type) {
    case at.INFERRED_PERSONALIZATION_UPDATE:
      return {
        ...prevState,
        initialized: true,
        inferredInterests: action.data.inferredInterests,
        coarseInferredInterests: action.data.coarseInferredInterests,
        coarsePrivateInferredInterests:
          action.data.coarsePrivateInferredInterests,
        inferredTelemetrySettingsOverrides:
          action.data.inferredTelemetrySettingsOverrides,
        lastUpdated: action.data.lastUpdated,
      };
    case at.INFERRED_PERSONALIZATION_DEBUG_FEATURES_UPDATE:
      return {
        ...prevState,
        debugFeatures: action.data,
      };
    case at.INFERRED_PERSONALIZATION_RESET:
      return { ...INITIAL_STATE.InferredPersonalization };
    default:
      return prevState;
  }
}

// eslint-disable-next-line complexity
function DiscoveryStream(prevState = INITIAL_STATE.DiscoveryStream, action) {
  // Return if action data is empty, or spocs or feeds data is not loaded
  const isNotReady = () =>
    !action.data || !prevState.spocs.loaded || !prevState.feeds.loaded;

  const handlePlacements = handleSites => {
    const { data, placements } = prevState.spocs;
    const result = {};

    const forPlacement = placement => {
      const placementSpocs = data[placement.name];

      if (
        !placementSpocs ||
        !placementSpocs.items ||
        !placementSpocs.items.length
      ) {
        return;
      }

      result[placement.name] = {
        ...placementSpocs,
        items: handleSites(placementSpocs.items),
      };
    };

    if (!placements || !placements.length) {
      [{ name: "spocs" }].forEach(forPlacement);
    } else {
      placements.forEach(forPlacement);
    }
    return result;
  };

  const nextState = handleSites => ({
    ...prevState,
    spocs: {
      ...prevState.spocs,
      data: handlePlacements(handleSites),
    },
    feeds: {
      ...prevState.feeds,
      data: Object.keys(prevState.feeds.data).reduce(
        (accumulator, feed_url) => {
          accumulator[feed_url] = {
            data: {
              ...prevState.feeds.data[feed_url].data,
              recommendations: handleSites(
                prevState.feeds.data[feed_url].data.recommendations
              ),
            },
          };
          return accumulator;
        },
        {}
      ),
    },
  });

  switch (action.type) {
    case at.DISCOVERY_STREAM_CONFIG_CHANGE:
    // Fall through to a separate action is so it doesn't trigger a listener update on init
    case at.DISCOVERY_STREAM_CONFIG_SETUP:
      return { ...prevState, config: action.data || {} };
    case at.DISCOVERY_STREAM_EXPERIMENT_DATA:
      return { ...prevState, experimentData: action.data || {} };
    case at.DISCOVERY_STREAM_LAYOUT_UPDATE:
      return {
        ...prevState,
        layout: action.data.layout || [],
      };
    case at.DISCOVERY_STREAM_TOPICS_LOADING:
      return {
        ...prevState,
        topicsLoading: action.data,
      };
    case at.DISCOVERY_STREAM_PREFS_SETUP:
      return {
        ...prevState,
        hideDescriptions: action.data.hideDescriptions,
        compactImages: action.data.compactImages,
        imageGradient: action.data.imageGradient,
        newSponsoredLabel: action.data.newSponsoredLabel,
        titleLines: action.data.titleLines,
        descLines: action.data.descLines,
        readTime: action.data.readTime,
      };
    case at.SHOW_PRIVACY_INFO:
      return {
        ...prevState,
      };
    case at.DISCOVERY_STREAM_LAYOUT_RESET:
      return { ...INITIAL_STATE.DiscoveryStream, config: prevState.config };
    case at.DISCOVERY_STREAM_FEEDS_UPDATE:
      return {
        ...prevState,
        feeds: {
          ...prevState.feeds,
          loaded: true,
        },
      };
    case at.DISCOVERY_STREAM_FEED_UPDATE: {
      const newData = {};
      newData[action.data.url] = action.data.feed;
      return {
        ...prevState,
        feeds: {
          ...prevState.feeds,
          data: {
            ...prevState.feeds.data,
            ...newData,
          },
        },
      };
    }
    case at.DISCOVERY_STREAM_DEV_IMPRESSIONS:
      return {
        ...prevState,
        impressions: {
          ...prevState.impressions,
          feed: action.data,
        },
      };
    case at.DISCOVERY_STREAM_DEV_BLOCKS:
      return {
        ...prevState,
        blocks: action.data,
      };
    case at.DISCOVERY_STREAM_SPOCS_CAPS:
      return {
        ...prevState,
        spocs: {
          ...prevState.spocs,
          frequency_caps: [...prevState.spocs.frequency_caps, ...action.data],
        },
      };
    case at.DISCOVERY_STREAM_SPOCS_ENDPOINT:
      return {
        ...prevState,
        spocs: {
          ...INITIAL_STATE.DiscoveryStream.spocs,
          spocs_endpoint:
            action.data.url ||
            INITIAL_STATE.DiscoveryStream.spocs.spocs_endpoint,
        },
      };
    case at.DISCOVERY_STREAM_SPOCS_PLACEMENTS:
      return {
        ...prevState,
        spocs: {
          ...prevState.spocs,
          placements:
            action.data.placements ||
            INITIAL_STATE.DiscoveryStream.spocs.placements,
        },
      };
    case at.DISCOVERY_STREAM_SPOCS_UPDATE:
      if (action.data) {
        // If spocs have been loaded on this tab, we can ignore future updates.
        // This should never be true on the main store, only content pages.
        // We check agasint onDemand just to be safe. It generally shouldn't be needed.
        if (prevState.spocs?.onDemand?.loaded) {
          return prevState;
        }
        return {
          ...prevState,
          spocs: {
            ...prevState.spocs,
            lastUpdated: action.data.lastUpdated,
            data: action.data.spocs,
            cacheUpdateTime: action.data.spocsCacheUpdateTime,
            onDemand: {
              enabled: action.data.spocsOnDemand,
              loaded: false,
            },
            loaded: true,
          },
        };
      }
      return prevState;
    case at.DISCOVERY_STREAM_SPOCS_ONDEMAND_LOAD:
      return {
        ...prevState,
        spocs: {
          ...prevState.spocs,
          onDemand: {
            ...prevState.spocs.onDemand,
            loaded: true,
          },
        },
      };
    case at.DISCOVERY_STREAM_SPOCS_ONDEMAND_RESET:
      if (action.data) {
        return {
          ...prevState,
          spocs: {
            ...prevState.spocs,
            cacheUpdateTime: action.data.spocsCacheUpdateTime,
            onDemand: {
              ...prevState.spocs.onDemand,
              enabled: action.data.spocsOnDemand,
            },
          },
        };
      }
      return prevState;
    case at.DISCOVERY_STREAM_SPOC_BLOCKED:
      return {
        ...prevState,
        spocs: {
          ...prevState.spocs,
          blocked: [...prevState.spocs.blocked, action.data.url],
        },
      };
    case at.DISCOVERY_STREAM_LINK_BLOCKED:
      return isNotReady()
        ? prevState
        : nextState(items =>
            items.filter(item => item.url !== action.data.url)
          );

    case at.PLACES_BOOKMARK_ADDED: {
      const updateBookmarkInfo = item => {
        if (item.url === action.data.url) {
          const { bookmarkGuid, bookmarkTitle, dateAdded } = action.data;
          return Object.assign({}, item, {
            bookmarkGuid,
            bookmarkTitle,
            bookmarkDateCreated: dateAdded,
            context_type: "bookmark",
          });
        }
        return item;
      };
      return isNotReady()
        ? prevState
        : nextState(items => items.map(updateBookmarkInfo));
    }
    case at.PLACES_BOOKMARKS_REMOVED: {
      const removeBookmarkInfo = item => {
        if (action.data.urls.includes(item.url)) {
          const newSite = Object.assign({}, item);
          delete newSite.bookmarkGuid;
          delete newSite.bookmarkTitle;
          delete newSite.bookmarkDateCreated;
          if (!newSite.context_type || newSite.context_type === "bookmark") {
            newSite.context_type = "removedBookmark";
          }
          return newSite;
        }
        return item;
      };
      return isNotReady()
        ? prevState
        : nextState(items => items.map(removeBookmarkInfo));
    }
    case at.TOPIC_SELECTION_SPOTLIGHT_OPEN:
      return {
        ...prevState,
        showTopicSelection: true,
      };
    case at.TOPIC_SELECTION_SPOTLIGHT_CLOSE:
      return {
        ...prevState,
        showTopicSelection: false,
      };
    case at.SECTION_BLOCKED:
      return {
        ...prevState,
        showBlockSectionConfirmation: true,
        sectionPersonalization: action.data,
      };
    case at.REPORT_AD_OPEN:
      return {
        ...prevState,
        report: {
          ...prevState.report,
          card_type: action.data?.card_type,
          position: action.data?.position,
          placement_id: action.data?.placement_id,
          reporting_url: action.data?.reporting_url,
          url: action.data?.url,
          visible: true,
        },
      };
    case at.REPORT_CONTENT_OPEN:
      return {
        ...prevState,
        report: {
          ...prevState.report,
          card_type: action.data?.card_type,
          corpus_item_id: action.data?.corpus_item_id,
          scheduled_corpus_item_id: action.data?.scheduled_corpus_item_id,
          section_position: action.data?.section_position,
          section: action.data?.section,
          title: action.data?.title,
          topic: action.data?.topic,
          url: action.data?.url,
          visible: true,
        },
      };
    case at.REPORT_CLOSE:
    case at.REPORT_AD_SUBMIT:
    case at.REPORT_CONTENT_SUBMIT:
      return {
        ...prevState,
        report: {
          ...prevState.report,
          visible: false,
        },
      };
    case at.SECTION_PERSONALIZATION_UPDATE:
      return { ...prevState, sectionPersonalization: action.data };
    default:
      return prevState;
  }
}

function Search(prevState = INITIAL_STATE.Search, action) {
  switch (action.type) {
    case at.DISABLE_SEARCH:
      return Object.assign({ ...prevState, disable: true });
    case at.SHOW_SEARCH:
      return Object.assign({ ...prevState, disable: false });
    default:
      return prevState;
  }
}

function Wallpapers(prevState = INITIAL_STATE.Wallpapers, action) {
  switch (action.type) {
    case at.WALLPAPERS_SET:
      return {
        ...prevState,
        wallpaperList: action.data,
      };
    case at.WALLPAPERS_FEATURE_HIGHLIGHT_COUNTER_INCREMENT:
      return {
        ...prevState,
        highlightSeenCounter: action.data,
      };
    case at.WALLPAPERS_CATEGORY_SET:
      return { ...prevState, categories: action.data };
    case at.WALLPAPERS_CUSTOM_SET:
      return { ...prevState, uploadedWallpaper: action.data };
    default:
      return prevState;
  }
}

function SectionsLayout(prevState = INITIAL_STATE.SectionsLayout, action) {
  switch (action.type) {
    case at.SECTIONS_LAYOUT_UPDATE:
      return { ...prevState, configs: action.data.configs };
    default:
      return prevState;
  }
}

function Notifications(prevState = INITIAL_STATE.Notifications, action) {
  switch (action.type) {
    case at.SHOW_TOAST_MESSAGE:
      return {
        ...prevState,
        showNotifications: action.data.showNotifications,
        toastCounter: prevState.toastCounter + 1,
        toastId: action.data.toastId,
        toastQueue: [action.data.toastId],
      };
    case at.HIDE_TOAST_MESSAGE: {
      const { showNotifications, toastId: hiddenToastId } = action.data;
      const queuedToasts = [...prevState.toastQueue].filter(
        toastId => toastId !== hiddenToastId
      );
      return {
        ...prevState,
        toastCounter: queuedToasts.length,
        toastQueue: queuedToasts,
        toastId: "",
        showNotifications,
      };
    }
    default:
      return prevState;
  }
}

function Weather(prevState = INITIAL_STATE.Weather, action) {
  switch (action.type) {
    case at.WEATHER_UPDATE:
      return {
        ...prevState,
        suggestions: action.data.suggestions,
        hourlyForecasts: action.data.hourlyForecasts || [],
        lastUpdated: action.data.lastUpdated,
        locationData: action.data.locationData || prevState.locationData,
        initialized: true,
      };
    case at.WEATHER_SEARCH_ACTIVE:
      return { ...prevState, searchActive: action.data };
    case at.WEATHER_LOCATION_SEARCH_UPDATE:
      return { ...prevState, locationSearchString: action.data };
    case at.WEATHER_LOCATION_SUGGESTIONS_UPDATE:
      return { ...prevState, suggestedLocations: action.data };
    case at.WEATHER_LOCATION_DATA_UPDATE:
      return { ...prevState, locationData: action.data };
    default:
      return prevState;
  }
}

function Ads(prevState = INITIAL_STATE.Ads, action) {
  switch (action.type) {
    case at.ADS_INIT:
      return {
        ...prevState,
        initialized: true,
      };
    case at.ADS_UPDATE_TILES:
      return {
        ...prevState,
        tiles: action.data.tiles,
      };
    case at.ADS_UPDATE_SPOCS:
      return {
        ...prevState,
        spocs: action.data.spocs,
        spocPlacements: action.data.spocPlacements,
      };
    case at.ADS_RESET:
      return { ...INITIAL_STATE.Ads };
    default:
      return prevState;
  }
}

function TimerWidget(prevState = INITIAL_STATE.TimerWidget, action) {
  // fallback to current timerType in state if not provided in action
  const timerType = action.data?.timerType || prevState.timerType;
  switch (action.type) {
    case at.WIDGETS_TIMER_SET:
      return {
        ...prevState,
        ...action.data,
      };
    case at.WIDGETS_TIMER_SET_TYPE:
      return {
        ...prevState,
        timerType: action.data.timerType,
      };
    case at.WIDGETS_TIMER_SET_DURATION:
      return {
        ...prevState,
        [timerType]: {
          // setting a dynamic key assignment to let us dynamically update timer type's state based on what is set
          duration: action.data.duration,
          initialDuration: action.data.duration,
          startTime: null,
          isRunning: false,
        },
      };
    case at.WIDGETS_TIMER_PLAY:
      return {
        ...prevState,
        [timerType]: {
          ...prevState[timerType],
          startTime: Math.floor(Date.now() / 1000), // reflected in seconds
          isRunning: true,
        },
      };
    case at.WIDGETS_TIMER_PAUSE:
      if (prevState[timerType]?.isRunning) {
        return {
          ...prevState,
          [timerType]: {
            ...prevState[timerType],
            duration: action.data.duration,
            // setting startTime to null on pause because we need to check the exact time the user presses play,
            // whether it's when the user starts or resumes the timer. This helps get accurate results
            startTime: null,
            isRunning: false,
          },
        };
      }
      return prevState;
    case at.WIDGETS_TIMER_RESET:
      return {
        ...prevState,
        [timerType]: {
          ...prevState[timerType],
          duration: action.data.duration,
          initialDuration: action.data.duration,
          startTime: null,
          isRunning: false,
        },
      };
    case at.WIDGETS_TIMER_END:
      return {
        ...prevState,
        [timerType]: {
          ...prevState[timerType],
          duration: action.data.duration,
          initialDuration: action.data.duration,
          startTime: null,
          isRunning: false,
        },
      };
    default:
      return prevState;
  }
}

function ListsWidget(prevState = INITIAL_STATE.ListsWidget, action) {
  switch (action.type) {
    case at.WIDGETS_LISTS_SET:
      return { ...prevState, lists: action.data };
    case at.WIDGETS_LISTS_SET_SELECTED:
      return { ...prevState, selected: action.data };
    default:
      return prevState;
  }
}

function ExternalComponents(
  prevState = INITIAL_STATE.ExternalComponents,
  action
) {
  switch (action.type) {
    case at.REFRESH_EXTERNAL_COMPONENTS:
      return { ...prevState, components: action.data };
    default:
      return prevState;
  }
}

export const reducers = {
  TopSites,
  App,
  Ads,
  Prefs,
  Dialog,
  Sections,
  Messages,
  Notifications,
  Pocket,
  InferredPersonalization,
  DiscoveryStream,
  Search,
  TimerWidget,
  ListsWidget,
  Wallpapers,
  SectionsLayout,
  Weather,
  ExternalComponents,
};