import { openDB, deleteDB } from 'idb';

export let db;

const dbName = !isDevServer ? 'oeffisearch' : 'oeffisearch_dev';

class DataStorage {
	constructor(idb) { this.idb = idb; }

	static async open() {
		const idb = await openDB(dbName, 1, {
			upgrade: async (db, oldVersion, newVersion, transaction) => {
				console.log(`upgrading database from ${oldVersion} to ${newVersion}`);

				switch (oldVersion) {
					case 0:
						db.createObjectStore('journey',          { keyPath: 'refreshToken' });
						db.createObjectStore('journeysOverview', { keyPath: 'slug' });
						db.createObjectStore('journeysHistory',  { autoIncrement: true });
				}
			}
		});

		return new DataStorage(idb);
	}

	async addJourneys(journeyEntries, overviewEntry, historyEntry) {
		const tx                    = this.idb.transaction(['journey', 'journeysOverview', 'journeysHistory'], 'readwrite');
		const journeyStore          = tx.objectStore('journey');
		const journeysOverviewStore = tx.objectStore('journeysOverview');
		const journeysHistoryStore  = tx.objectStore('journeysHistory');

		let proms = journeyEntries.map(j => journeyStore.put(j));

		if (overviewEntry.historyEntryId === undefined)
			overviewEntry.historyEntryId = await journeysHistoryStore.put(historyEntry);

		proms.push(journeysOverviewStore.put(overviewEntry));
		proms.push(tx.done);

		await Promise.all(proms);
	}

	async getHistory(profile) {
		const tx      = this.idb.transaction('journeysHistory');
		const history = [];

		for await (const cursor of tx.store) {
			if (profile !== undefined && profile !== cursor.value.profile) continue;
			history.push({
				...cursor.value,
				key: cursor.key,
			});
		}

		return history;
	}

	async addHistoryEntry(entry) {
		return await this.idb.put('journeysHistory', entry);
	}

	async updateHistoryEntry(id, entry) {
		return await this.idb.put('journeysHistory', entry, id);
	}

	async getHistoryEntry(id) {
		return await this.idb.get('journeysHistory', id);
	}

	async getJourneysOverview(slug) {
		return await this.idb.get('journeysOverview', slug);
	}

	async getJourney(refreshToken) {
		return await this.idb.get('journey', refreshToken);
	}

	async updateJourney(data) {
		return await this.idb.put('journey', data);
	}
}

export const clearDataStorage = async () => await deleteDB(dbName);
export const initDataStorage  = async () => {
	try {
		db = await DataStorage.open();
	} catch(e) {
		console.log("IndexedDB initialization failed: ", e);
		alert("IndexedDB initialization failed!");
	}
};