import { Extension } from '@tiptap/core'

export const INDENT_MAX = 4
export const INDENT_TYPES = ['paragraph', 'heading']

declare module '@tiptap/core' {
	interface Commands<ReturnType> {
		articleIndent: {
			indent: () => ReturnType
			outdent: () => ReturnType
		}
	}
}

function currentIndentableNode(state: { selection: { $from: { parent: unknown } } }) {
	return state.selection.$from.parent as {
		type: { name: string }
		attrs: { indent?: number }
	}
}

export const ArticleIndent = Extension.create({
	name: 'articleIndent',
	addGlobalAttributes() {
		return [
			{
				types: INDENT_TYPES,
				attributes: {
					indent: {
						default: 0,
						parseHTML: (element) => Number(element.getAttribute('data-indent')) || 0,
						renderHTML: (attributes) => {
							if (!attributes.indent) {
								return {}
							}
							return { 'data-indent': String(attributes.indent) }
						},
					},
				},
			},
		]
	},
	addCommands() {
		return {
			indent:
				() =>
				({ state, commands, tr, dispatch }) => {
					if (commands.sinkListItem('listItem')) {
						return true
					}
					const node = currentIndentableNode(state)
					if (!INDENT_TYPES.includes(node.type.name)) {
						return false
					}
					const level = Math.min(INDENT_MAX, (node.attrs.indent ?? 0) + 1)
					if (dispatch) {
						const { $from } = state.selection
						tr.setNodeAttribute($from.before($from.depth), 'indent', level)
						dispatch(tr)
					}
					return true
				},
			outdent:
				() =>
				({ state, commands, tr, dispatch }) => {
					if (commands.liftListItem('listItem')) {
						return true
					}
					const node = currentIndentableNode(state)
					if (!INDENT_TYPES.includes(node.type.name)) {
						return false
					}
					const level = Math.max(0, (node.attrs.indent ?? 0) - 1)
					if (dispatch) {
						const { $from } = state.selection
						tr.setNodeAttribute($from.before($from.depth), 'indent', level)
						dispatch(tr)
					}
					return true
				},
		}
	},
})