import { App, Editor, EditorChange, EditorTransaction, MarkdownFileInfo, MarkdownView } from 'obsidian'
import BindThemPlugin from './main'
import { Direction } from './Entities'
import { selectionToRange } from './Utils'

/**
 * DirectionalMove provides commands to move selection content left or right
 */
export class DirectionalMove {
	public app: App
	private plugin: BindThemPlugin

	constructor(app: App, plugin: BindThemPlugin) {
		this.app = app
		this.plugin = plugin
	}

	/**
	 * Move the current selection(s) in the specified direction (left or right)
	 */
	public directionalMove(
		editor: Editor,
		view: MarkdownView | MarkdownFileInfo,
		direction: Direction.Left | Direction.Right
	): void {
		const selections = editor.listSelections()

		const changes: Array<EditorChange> = []
		for (const selection of selections) {
			const range = selectionToRange(selection)

			let additionChange: EditorChange
			let deletionChange: EditorChange
			switch (direction) {
				case Direction.Left: {
					deletionChange = {
						from: {
							line: range.from.line,
							ch: range.from.ch - 1,
						},
						to: range.from,
						text: '',
					}

					additionChange = {
						from: range.to,
						to: range.to,
						text: editor.getRange(deletionChange.from, deletionChange.to!),
					}
					break
				}

				case Direction.Right: {
					deletionChange = {
						from: range.to,
						to: {
							line: range.to.line,
							ch: range.to.ch + 1,
						},
						text: '',
					}

					additionChange = {
						from: range.from,
						to: range.from,
						text: editor.getRange(deletionChange.from, deletionChange.to!),
					}
					break
				}
			}

			changes.push(deletionChange, additionChange)
		}

		const transaction: EditorTransaction = {
			changes: changes,
		}

		const origin = 'DirectionalMove_' + String(direction)
		editor.transaction(transaction, origin)
	}
}