import { Database } from 'sqlite3'
import { v4 } from 'uuid'
import Folder from '../../models/Folder'
import Item from '../../models/Item'

export default class FolderService {
	private readonly db = new Database(process.env.DATABASE_PATH)

	async getChildren(id: string): Promise<Folder[]> {
		return new Promise((resolve, reject) => {
			const statement = this.db.prepare(`
				SELECT *
					FROM folders
					WHERE parent_id = (?)
			`)

			statement.all(id, (err, rows) => {
				if (err) {
					reject(err)
					return
				}
				resolve(rows.map(row => Folder.resolve(row)))
			})
		})
	}

	async get(id: string): Promise<Folder> {
		return new Promise((resolve, reject) => {
			const statement = this.db.prepare(`
				SELECT *
					FROM folders
					WHERE id = (?)
			`)

			statement.get(id, (err, row) => {
				if (err) {
					reject(err)
					return
				}
				if (row) {
					resolve(Folder.resolve(row))
					return
				}
				resolve(null)
			})
		})
	}

	async create(name: string, parentId?: string): Promise<Folder> {
		return new Promise((resolve, reject) => {
			const id = v4()
			const statement = this.db.prepare(`
				INSERT INTO folders (id, name, parent_id, created_at, updated_at, deleted_at) VALUES (?, ?, ?, ?, ?, NULL)
			`)

			const now = new Date()
			const createdAt = now.toISOString()
			const updatedAt = now.toISOString()
			statement.run(id, name, parentId, createdAt, updatedAt, async (err) => {
				if (err) {
					reject(err)
					return
				}

				resolve(Folder.resolve({
					'id': id,
					'name': name,
					'parent_id': parentId || null,
					'created_at': createdAt,
					'updated_at': updatedAt,
					'deleted_at': null,
				}))
			})
		})
	}

	async getItems(id: string): Promise<Item[]> {
		return new Promise((resolve, reject) => {
			const statement = this.db.prepare(`
				SELECT *
					FROM items
					WHERE folder_id = (?)
			`)

			statement.all(id, (err, rows) => {
				if (err) {
					reject(err)
					return
				}
				resolve(rows.map(item => Item.resolve(item)))
			})
		})
	}

	async getHierarchy(id: string): Promise<Folder[]> {
		let currentId: string = id as string
		const hierarchy: Folder[] = []
		let selectedFolder: Folder
		while (currentId !== null) {
			selectedFolder = await this.get(currentId)
			hierarchy.unshift(selectedFolder)
			currentId = selectedFolder.parent?.id || null
		}
		return hierarchy
	}
}