//
// All actions in noteController.js
//


const db = require('@config/database')

const Note = require('@models/Note')

let ShareNote = module.exports = {}

const crypto = require('crypto')
const cs = require('@helpers/CryptoString')

ShareNote.migrateNoteToShared = (userId, noteId, shareUserId, masterKey) => {
	return new Promise((resolve, reject) => {

		const Note = require('@models/Note')
		const User = require('@models/User')

		//generate new random salts and password
		const sharedNoteMasterKey = cs.createSmallSalt()

		let encryptedSharedKey = null //new key for note encrypted with shared users pubic key

		//Current note object
		let note = null
		let publicKey = null

		db.promise().query('SELECT id FROM user WHERE id = ?', [shareUserId])
		.then((rows, fields) => {

			if(rows[0].length == 0){
				throw new Error('User Does Not Exist')
			}

			return Note.get(userId, noteId, masterKey)

		})
		.then( noteObject => {

			if(!noteObject){
				throw new Error('Note Not Found')
			}

			note = noteObject

			return db.promise()
				.query('SELECT id FROM note WHERE user_id = ? AND note_raw_text_id = ?', [shareUserId, note.rawTextId])

		})
		.then((rows, fields) => {

			if(rows[0].length >= 1){
				throw new Error('User Already has this note shared with them')
			}

			//All check pass, proceed with sharing note
			return User.getPublicKey(userId)
		})
		.then( userPublicKey => {

			//Get users public key
			publicKey = userPublicKey

			//
			// Modify note to have a shared password, encrypt text with this password
			//
			const sharedNoteSalt = cs.createSmallSalt()

			//Encrypt note text with new password
			const textObject = JSON.stringify([note.title, note.text])
			const encryptedText = cs.encrypt(sharedNoteMasterKey, sharedNoteSalt, textObject)

			//Update note raw text with new data
			return db.promise()
			.query("UPDATE `application`.`note_raw_text` SET `text` = ?, `salt` = ? WHERE (`id` = ?)", 
				[encryptedText, sharedNoteSalt, note.rawTextId])
			
		})
		.then((rows, fields) => {

			//New Encrypted snippet, using new shared password
			const sharedNoteSnippetSalt = cs.createSmallSalt()
			const snippet = JSON.stringify([note.title, note.text.substring(0, 500)])
			const encryptedSnippet = cs.encrypt(sharedNoteMasterKey, sharedNoteSnippetSalt, snippet)

			//Encrypt shared password for this user
			const encryptedSharedKey = crypto.publicEncrypt(publicKey, Buffer.from(sharedNoteMasterKey, 'utf8')).toString('base64')

			//Update note snippet for current user with public key encoded snippet
			return db.promise().query('UPDATE note SET snippet = ?, snippet_salt = ?, encrypted_share_password_key = ? WHERE id = ? AND user_id = ?', 
				[encryptedSnippet, sharedNoteSnippetSalt, encryptedSharedKey, noteId, userId])

		})
		.then((rows, fields) => {

			return User.getPublicKey(shareUserId)

		})
		.then(shareUserPublicKey => {

			//New Encrypted snippet, using new shared password
			const newSnippetSalt = cs.createSmallSalt()
			const snippet = JSON.stringify([note.title, note.text.substring(0, 500)])
			const encryptedSnippet = cs.encrypt(sharedNoteMasterKey, newSnippetSalt, snippet)

			//Encrypt shared password for this user
			const encryptedSharedKey = crypto.publicEncrypt(shareUserPublicKey, Buffer.from(sharedNoteMasterKey, 'utf8')).toString('base64')

			//Insert new note for shared user
			return db.promise().query(`
				INSERT INTO note (user_id, note_raw_text_id, created, color, share_user_id, snippet, snippet_salt, encrypted_share_password_key) VALUES (?,?,?,?,?,?,?,?);
			`, [shareUserId, note.rawTextId, note.created, note.color, userId, encryptedSnippet, newSnippetSalt, encryptedSharedKey])			

		})
		.then((rows, fields) => {

			let success = true
			return resolve({success, shareUserId})

		})
		.catch(error => {
			console.log('Shared Note Error')
			console.log(error)
		})

	})
}

// Get users who see a shared note
ShareNote.getUsers = (userId, rawTextId) => {
	return new Promise((resolve, reject) => {
		db.promise()
		.query(`
			SELECT username, note.id as noteId
			FROM note 
			JOIN user ON (user.id = note.user_id)
			WHERE note_raw_text_id = ?
			AND share_user_id = ?
			AND user_id != ?
			`, [rawTextId, userId, userId])
		.then((rows, fields) => {

			//Return a list of user names
			return resolve (rows[0])
		})
	})
}

// Remove a user from a shared note
ShareNote.removeUser = (userId, noteId) => {
	return new Promise((resolve, reject) => {

		const Note = require('@models/Note')

		let rawTextId = null
		let removeUserId = null
		
		//note.id = noteId, share_user_id = userId
		db.promise()
		.query('SELECT note_raw_text_id, user_id FROM note WHERE id = ? AND share_user_id = ?', [noteId, userId])
		.then( (rows, fields) => {

			rawTextId = rows[0][0]['note_raw_text_id']
			removeUserId = rows[0][0]['user_id']

			//Delete note entry for other user - remove users access
			if(removeUserId && Number.isInteger(removeUserId)){
				//Delete this users access to the note
				return Note.delete(removeUserId, noteId)

			} else {
				
				return new Promise((resolve, reject) => { resolve(true) })
			}

		})
		.then(stuff => {
			resolve(true)
		})
		.catch(error => {
			console.log(error)
			resolve(false)
		})


	})
}