// gomuks - A Matrix client written in Go.
// Copyright (C) 2024 Tulir Asokan
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
import React, { JSX, createContext, useCallback, useLayoutEffect, useReducer, useRef } from "react"

export interface ModalState {
	content: JSX.Element
	dimmed?: boolean
	boxed?: boolean
	boxClass?: string
	innerBoxClass?: string
	onClose?: () => void
}

type openModal = (state: ModalState) => void

export const ModalContext = createContext<openModal>(() =>
	console.error("Tried to open modal without being inside context"))

export const ModalCloseContext = createContext<() => void>(() => {})

export const ModalWrapper = ({ children }: { children: React.ReactNode }) => {
	const [state, setState] = useReducer((prevState: ModalState | null, newState: ModalState | null) => {
		prevState?.onClose?.()
		return newState
	}, null)
	const onClickWrapper = useCallback((evt?: React.MouseEvent) => {
		if (evt && evt.target !== evt.currentTarget) {
			return
		}
		setState(null)
	}, [])
	const onKeyWrapper = useCallback((evt: React.KeyboardEvent<HTMLDivElement>) => {
		if (evt.key === "Escape") {
			setState(null)
		}
		evt.stopPropagation()
	}, [])
	const wrapperRef = useRef<HTMLDivElement>(null)
	useLayoutEffect(() => {
		if (wrapperRef.current && (!document.activeElement || !wrapperRef.current.contains(document.activeElement))) {
			wrapperRef.current.focus()
		}
	}, [state])
	let modal: JSX.Element | null = null
	if (state) {
		let content = <ModalCloseContext value={onClickWrapper}>{state.content}</ModalCloseContext>
		if (state.boxed) {
			content = <div className={`modal-box ${state.boxClass ?? ""}`}>
				<div className={`modal-box-inner ${state.innerBoxClass ?? ""}`}>
					{content}
				</div>
			</div>
		}
		modal = <div
			className={`overlay modal ${state.dimmed ? "dimmed" : ""}`}
			onClick={onClickWrapper}
			onKeyDown={onKeyWrapper}
			tabIndex={-1}
			ref={wrapperRef}
		>
			{content}
		</div>
	}
	return <ModalContext value={setState}>
		{children}
		{modal}
	</ModalContext>
}
