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

export class Notes2 {
	constructor() {//{{{
		this.startNode = null
		this.tree = createRef()
		this.setStartNode()
	}//}}}
	render() {//{{{
		return html`
			<button onclick=${() => API.logout()}>Log out</button>
			<${Tree} ref=${this.tree} app=${this} />
		`
	}//}}}
	setStartNode() {//{{{
		let urlParams = new URLSearchParams(window.location.search)
		let nodeID = urlParams.get('node')
		this.startNode = new Node(this, nodeID ? parseInt(nodeID) : 0)
	}//}}}

	treeGet() {//{{{
		const req = {}
		API.query('POST', '/node/tree', req)
			.then(response => {
				console.log(response.Nodes)
				nodeStore.add(response.Nodes)
			})
			.catch(e => console.log(e.type, e.error))
	}//}}}
}

class Tree extends Component {
	constructor(props) {//{{{
		super(props)
		this.treeNodes = {}
		this.treeNodeComponents = {}
		this.treeTrunk = []
		this.selectedTreeNode = null

		this.retrieve()
	}//}}}
	render({ app }) {//{{{
		let renderedTreeTrunk = this.treeTrunk.map(node => {
			this.treeNodeComponents[node.ID] = createRef()
			return html`<${TreeNode} key=${"treenode_" + node.ID} tree=${this} node=${node} ref=${this.treeNodeComponents[node.ID]} selected=${node.ID == app.startNode.ID} />`
		})
		return html`<div id="tree">${renderedTreeTrunk}</div>`
	}//}}}

	retrieve(callback = null) {//{{{
		nodeStore.getTreeNodes()
			.then(res => {
				this.treeNodes = {}
				this.treeNodeComponents = {}
				this.treeTrunk = []
				this.selectedTreeNode = null

				//  A tree of nodes is built. This requires the list of nodes
				//  returned from the server to be sorted in such a way that
				//  a parent node always appears before a child node.
				//  The server uses a recursive SQL query delivering this.
				res.forEach(nodeData => {
					let node = new Node(
						this,
						nodeData.ID,
					)
					node.Children = []
					node.Crumbs = []
					node.Files = []
					node.Level = nodeData.Level
					node.Name = nodeData.Name
					node.ParentID = nodeData.ParentID
					node.Updated = nodeData.Updated
					node.UserID = nodeData.UserID

					this.treeNodes[node.ID] = node

					if (node.ParentID == 0)
						this.treeTrunk.push(node)
					else if (this.treeNodes[node.ParentID] !== undefined)
						this.treeNodes[node.ParentID].Children.push(node)
				})
				// When starting with an explicit node value, expanding all nodes
				// on its path gives the user a sense of location. Not necessarily working
				// as the start node isn't guaranteed to have returned data yet.
				// XXX this.crumbsUpdateNodes()
				this.forceUpdate()

				if (callback)
					callback()

			})
			.catch(e => { console.log(e); console.log(e.type, e.error); alert(e.error) })
	}//}}}
	setSelected(node) {//{{{
		if (this.selectedTreeNode)
			this.selectedTreeNode.selected.value = false

		this.selectedTreeNode = this.treeNodeComponents[node.ID].current
		this.selectedTreeNode.selected.value = true
		this.selectedTreeNode.expanded.value = true
		this.expandToTrunk(node.ID)
	}//}}}
	crumbsUpdateNodes(node) {//{{{
		this.props.app.startNode.Crumbs.forEach(crumb => {
			// Start node is loaded before the tree.
			let node = this.treeNodes[crumb.ID]
			if (node)
				node._expanded = true

			// Tree is done before the start node.
			let component = this.treeNodeComponents[crumb.ID]
			if (component && component.current)
				component.current.expanded.value = true
		})

		// Will be undefined when called from tree initialization
		// (as tree nodes aren't rendered yet)
		if (node !== undefined)
			this.setSelected(node)
	}//}}}
	expandToTrunk(nodeID) {//{{{
		let node = this.treeNodes[nodeID]
		if (node === undefined)
			return

		node = this.treeNodes[node.ParentID]
		while (node !== undefined) {
			this.treeNodeComponents[node.ID].current.expanded.value = true
			node = this.treeNodes[node.ParentID]
		}
	}//}}}
}

class TreeNode extends Component {
	constructor(props) {//{{{
		super(props)
		this.selected = signal(props.selected)
		this.expanded = signal(this.props.node._expanded)
	}//}}}
	render({ tree, node }) {//{{{

		let children = node.Children.map(node => {
			tree.treeNodeComponents[node.ID] = createRef()
			return html`<${TreeNode} key=${"treenode_" + node.ID} tree=${tree} node=${node} ref=${tree.treeNodeComponents[node.ID]} selected=${node.ID == tree.props.app.startNode.ID} />`
		})

		let expandImg = ''
		if (node.Children.length == 0)
			expandImg = html`<img src="/images/${window._VERSION}/leaf.svg" />`
		else {
			if (this.expanded.value)
				expandImg = html`<img src="/images/${window._VERSION}/expanded.svg" />`
			else
				expandImg = html`<img src="/images/${window._VERSION}/collapsed.svg" />`
		}


		let selected = (this.selected.value ? 'selected' : '')

		return html`
			<div class="node">
				<div class="expand-toggle" onclick=${() => this.expanded.value ^= true}>${expandImg}</div>
				<div class="name ${selected}" onclick=${() => window._app.current.nodeUI.current.goToNode(node.ID)}>${node.Name}</div>
				<div class="children ${node.Children.length > 0 && this.expanded.value ? 'expanded' : 'collapsed'}">${children}</div>
			</div>`
	}//}}}
}