import { h, Component, createRef } from 'preact'
import htm from 'htm'
import { signal } from 'preact/signals'
const html = htm.bind(h)

export class NodeUI extends Component {
	constructor() {//{{{
		super()
		this.menu = signal(false)
		this.tree = signal(null)
		this.node = signal(null)
		this.nodeContent = createRef()
		window.addEventListener('popstate', evt=>{
			if(evt.state && evt.state.hasOwnProperty('nodeID'))
				this.goToNode(evt.state.nodeID, true)
			else
				this.goToNode(0, true)
		})
		window.addEventListener('keydown', evt=>this.keyHandler(evt))
	}//}}}
	render() {//{{{
		if(this.node.value === null)
			return

		let node = this.node.value
		let tree = this.tree.value

		let treeHTML = html`Tree`
		if(tree !== null)
			treeHTML = this.renderTree(tree)

		let crumbs = [
			html`<div class="crumb" onclick=${()=>this.goToNode(0)}>Start</div>`
		]
	
		crumbs = crumbs.concat(node.Crumbs.slice(0).map(node=>
			html`<div class="crumb" onclick=${()=>this.goToNode(node.ID)}>${node.Name}</div>`
		).reverse())

		let children = node.Children.sort((a,b)=>{
			if(a.Name.toLowerCase() > b.Name.toLowerCase()) return  1;
			if(a.Name.toLowerCase() < b.Name.toLowerCase()) return -1;
			return 0
		}).map(child=>html`
			<div class="child-node" onclick=${()=>this.goToNode(child.ID)}>${child.Name}</div>
		`)

		let modified = ''
		if(this.props.app.nodeModified.value)
			modified = 'modified';

		return html`
			<div id="menu-blackout" class="${this.menu.value ? 'show' : ''}" onclick=${()=>this.menu.value = false}></div>
			<div id="menu" class="${this.menu.value ? 'show' : ''}">
				<div class="item" onclick=${()=>this.renameNode()}>Rename</div>
				<div class="item separator" onclick=${()=>this.deleteNode()}>Delete</div>
				<div class="item" onclick=${()=>this.logout()}>Log out</div>
			</div>

			<header class="${modified}" onclick=${()=>this.saveNode()}>
				<div class="name">Notes</div>
				<div class="add" onclick=${evt=>this.createNode(evt)}>+</div>
				<div class="menu" onclick=${evt=>this.showMenu(evt)}>☰</div>
			</header>

			<div class="crumbs">${crumbs}</crumbs>

			${children.length > 0 ? html`<div class="child-nodes">${children}</div>` : html``}

			${node.ID > 0 ? html`
				<div class="node-name">${node.Name}</div>
				<${NodeContent} key=${node.ID} content=${node.Content} ref=${this.nodeContent} />
			` : html``}
		`
	}//}}}
	componentDidMount() {//{{{
		let urlParams = new URLSearchParams(window.location.search)
		let nodeID = urlParams.get('node')
		let root = new Node(this.props.app, nodeID ? parseInt(nodeID) : 0)

		root.retrieve(node=>{
			this.node.value = node
		})
	}//}}}

	keyHandler(evt) {//{{{
		let handled = true
		switch(evt.key.toUpperCase()) {
			case 'S':
				if(!evt.ctrlKey) {
					handled = false
					break
				}
				this.saveNode()
				break

			case 'N':
				if(!evt.ctrlKey && !evt.AltKey) {
					handled = false
					break
				}
				this.createNode()
				break

			default:
				handled = false
		}

		if(handled) {
			evt.preventDefault()
			evt.stopPropagation()
		}
	}//}}}
	showMenu(evt) {//{{{
		evt.stopPropagation()
		this.menu.value = true
	}//}}}
	logout() {//{{{
		window.localStorage.removeItem('session.UUID')
		location.href = '/'
	}//}}}

	goToNode(nodeID, dontPush) {//{{{
		if(this.props.app.nodeModified.value) {
			if(!confirm("Changes not saved. Do you want to discard changes?"))
				return
		}

		if(!dontPush)
			history.pushState({ nodeID }, '', `/?node=${nodeID}`)
		let node = new Node(this.props.app, nodeID)
		node.retrieve(node=>{
			this.props.app.nodeModified.value = false
			this.node.value = node
		})
	}//}}}
	createNode(evt) {//{{{
		evt.stopPropagation()
		let name = prompt("Name")
		if(!name)
			return

		this.props.app.request('/node/create', {
			Name: name.trim(),
			ParentID: this.node.value.ID,
		})
		.then(res=>{
			this.goToNode(res.Node.ID)
		})
		.catch(this.props.app.responseError)
	}//}}}
	saveNode() {//{{{
		let content = this.nodeContent.current.contentDiv.current.value
		this.props.app.request('/node/update', {
			NodeID: this.node.value.ID,
			Content: content,
		})
		.then(res=>{
			this.props.app.nodeModified.value = false
		})
		.catch(this.props.app.responseError)
	}//}}}
	renameNode() {//{{{
		let name = prompt("New name")
		if(!name)
			return

		this.props.app.request('/node/rename', {
			Name: name.trim(),
			NodeID: this.node.value.ID,
		})
		.then(_=>{
			this.goToNode(this.node.value.ID)
			this.menu.value = false
		})
		.catch(this.props.app.responseError)
	}//}}}
	deleteNode() {//{{{
		if(!confirm("Do you want to delete this note and all sub-notes?"))
			return

		this.props.app.request('/node/delete', {
			NodeID: this.node.value.ID,
		})
		.then(_=>{
			this.goToNode(this.node.value.ParentID)
			this.menu.value = false
		})
		.catch(this.props.app.responseError)
	}//}}}
	retrieveTree() {//{{{
		this.props.app.request('/node/tree', { StartNodeID: this.node.value.ID })
		.then(res=>{
			this.tree.value = res.Nodes
		})
		.catch(this.props.app.responseError)
	}//}}}
	renderTree(tree) {//{{{
		return tree.map(node=>html`<div class="node" style="margin-left: ${(node.Level+1) * 32}px">${node.Name}</div>`)
	}//}}}
}

class NodeContent extends Component {
	constructor(props) {//{{{
		super(props)
		this.contentDiv = createRef()
		this.state = {
			modified: false,
			//content: props.content,
		}
	}//}}}
	render({ content }) {//{{{
		return html`
			<textarea class="node-content" ref=${this.contentDiv} oninput=${()=>this.contentChanged()} required rows=1>${content}</textarea>
		`
	}//}}}
	componentDidMount() {//{{{
		this.resize()
	}//}}}
	componentDidUpdate() {//{{{
		this.resize()
	}//}}}
	contentChanged() {//{{{
		window._app.current.nodeModified.value = true
		this.resize()
	}//}}}
	resize() {//{{{
		let textarea = this.contentDiv.current;
		textarea.style.height = "auto";
		textarea.style.height = textarea.scrollHeight + 16 + "px";
	}//}}}
}

class Node {
	constructor(app, nodeID) {//{{{
		this.app      = app
		this.ID       = nodeID
		this.ParentID = 0
		this.UserID   = 0
		this.Name     = ''
		this.Content  = ''
		this.Children = []
		this.Crumbs   = []
	}//}}}
	retrieve(callback) {//{{{
		this.app.request('/node/retrieve', { ID: this.ID })
		.then(res=>{
			this.ParentID = res.Node.ParentID
			this.UserID   = res.Node.UserID
			this.Name     = res.Node.Name
			this.Content  = res.Node.Content
			this.Children = res.Node.Children
			this.Crumbs   = res.Node.Crumbs
			callback(this)
		})
		.catch(this.app.responseError)
	}//}}}
}

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