import browser from "webextension-polyfill";
import {migrate, type Migration} from "@holllo/migration-helper";
import {createValue} from "@holllo/webextension-storage";

import type {ItemKeyPrefix} from "../item/item.js";

/** The Queue Item type for versions `<0.3.0`. */
export type QueueItemPre030 = {
  added: Date;
  id: number;
  text: string;
  url: string;
};

/** The Queue Item type for versions `>=0.3.0 <1.0.0`. */
export type QueueItem030 = {
  sortIndex: number;
} & QueueItemPre030;

/** The Queue Item type for versions `>=1.0.0`. */
export type QueueItem100 = {
  dateAdded: Date;
  id: number;
  text: string | undefined;
  url: string;
};

/** All migrations for Queue storage. */
export const dataMigrations: Array<Migration<string>> = [
  {
    version: "0.1.7",
    async migrate(data: Record<string, any>) {
      const migrated: Record<string, any> = {
        version: "0.1.7",
      };

      const items = (data.queue as QueueItemPre030[]) ?? [];
      for (const item of items) {
        const key = `qi${item.id}`;
        migrated[key] = item;
      }

      return migrated;
    },
  },
  {
    version: "0.3.0",
    async migrate(data: Record<string, any>) {
      const migrated: Record<string, any> = {
        version: "0.3.0",
      };

      for (const [key, value] of Object.entries<QueueItemPre030>(data)) {
        if (key.startsWith("qi")) {
          const item: QueueItem030 = {
            sortIndex: value.id,
            ...value,
          };
          migrated[key] = item;
        }
      }

      return migrated;
    },
  },
  {
    version: "1.0.0",
    async migrate(data: Record<string, any>) {
      const migrated: Record<string, any> = {
        version: "1.0.0",
      };

      for (const [key, value] of Object.entries<QueueItem030>(data)) {
        if (key.startsWith("qi")) {
          const item: QueueItem100 = {
            dateAdded: new Date(value.added),
            id: value.id,
            text: value.text === "" ? undefined : value.text,
            url: value.url,
          };
          const prefix: ItemKeyPrefix = "item-";
          migrated[`${prefix}${item.id}`] = item;
        }
      }

      return migrated;
    },
  },
];

/** Run the migrations and apply the result to storage. */
export async function runMigrations(): Promise<void> {
  const manifest = browser.runtime.getManifest();

  const version = await createValue<string>({
    deserialize: (input) => input,
    serialize: (input) => input,
    key: "version",
    storage: browser.storage.sync,
    value: manifest.version,
  });

  // Only when the current data version is lower than the manifest version
  // should the migrations run.
  if (version.value >= manifest.version) {
    return;
  }

  const migrated = await migrate(
    await browser.storage.sync.get(),
    version.value,
    dataMigrations,
  );

  await browser.storage.sync.clear();
  await browser.storage.sync.set(migrated as Record<string, any>);
}