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

export class NodeUI extends Component {
	constructor(props) {//{{{
		super(props)
		this.menu = signal(false)
		this.node = signal(null)
		this.nodeContent = createRef()
		this.keys = signal([])

		this.page = signal('node')
		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
		document.title = `N: ${node.Name}`

		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'


		// Page to display
		let page = ''
		switch(this.page.value) {
			case 'node':
				if(node.ID == 0) {
					page = html`
						${children.length > 0 ? html`<div class="child-nodes">${children}</div>` : html``}
					`
				} else {
					let padlock = ''
					if(node.CryptoKeyID > 0)
						padlock = html`<img src="/images/${window._VERSION}/padlock-black.svg" style="height: 24px;" />`
					page = html`
						${children.length > 0 ? html`<div class="child-nodes">${children}</div>` : html``}
						<div class="node-name">
							${node.Name} ${padlock}
						</div>
						<${NodeContent} key=${node.ID} node=${node} ref=${this.nodeContent} />
						<${NodeFiles} node=${this.node.value} />
					`
				}
				break

			case 'upload':
				page = html`<${UploadUI} nodeui=${this} />`
				break

			case 'node-properties':
				page = html`<${NodeProperties} nodeui=${this} />`
				break

			case 'keys':
				page = html`<${Keys} nodeui=${this} />`
				break
		}

		let menu = ''
		if(this.menu.value)
			menu = html`<${Menu} nodeui=${this} />`

		return html`
			${menu}
			<header class="${modified}" onclick=${()=>this.saveNode()}>
				<div class="tree"><img src="/images/${window._VERSION}/tree.svg" onclick=${()=>document.getElementById('app').classList.toggle('toggle-tree')} /></div>
				<div class="name">Notes</div>
				<div class="add" onclick=${evt=>this.createNode(evt)}><img src="/images/${window._VERSION}/add.svg" /></div>
				<div class="keys" onclick=${evt=>{ evt.stopPropagation(); this.showPage('keys')}}><img src="/images/${window._VERSION}/padlock.svg" /></div>
				<div class="menu" onclick=${evt=>this.showMenu(evt)}>☰</div>
			</header>

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

			${page}
		`
	}//}}}
	async componentDidMount() {//{{{
		// When rendered and fetching the node, keys could be needed in order to
		// decrypt the content.
		await this.retrieveKeys()

		this.props.app.startNode.retrieve(node=>{
			this.node.value = node

			// The tree isn't guaranteed to have loaded yet. This is also run from
			// the tree code, in case the node hasn't loaded.
			this.props.app.tree.crumbsUpdateNodes(node)
		})
	}//}}}

	keyHandler(evt) {//{{{
		let handled = true
		switch(evt.key.toUpperCase()) {
			case 'E':
				if(evt.shiftKey && evt.altKey)
					this.showPage('keys')
				else
					handled = false
				break

			case 'N':
				if(evt.shiftKey && evt.altKey)
					this.createNode()
				else
					handled = false
				break

			case 'P':
				if(evt.shiftKey && evt.altKey)
					this.showPage('node-properties')
				else
					handled = false
				break

			case 'S':
				if(evt.ctrlKey || (evt.shiftKey && evt.altKey))
					this.saveNode()
				else
					handled = false
				break


			case 'U':
				if(evt.shiftKey && evt.altKey)
					this.showPage('upload')
				else
					handled = false

			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}`)

		// New node is fetched in order to retrieve content and files.
		// Such data is unnecessary to transfer for tree/navigational purposes.
		let node = new Node(this.props.app, nodeID)
		node.retrieve(node=>{
			this.props.app.nodeModified.value = false
			this.node.value = node
			this.showPage('node')

			// Tree needs to know another node is selected, in order to render any
			// previously selected node not selected.
			this.props.app.tree.setSelected(node)

			// Hide tree toggle, as this would be the next natural action to do manually anyway.
			// At least in mobile mode.
			document.getElementById('app').classList.remove('toggle-tree')
		})
	}//}}}
	createNode(evt) {//{{{
		if(evt)
			evt.stopPropagation()
		let name = prompt("Name")
		if(!name)
			return
		this.node.value.create(name, nodeID=>this.goToNode(nodeID))
	}//}}}
	saveNode() {//{{{
		let content = this.nodeContent.current.contentDiv.current.value
		this.node.value.setContent(content)
		this.node.value.save(()=>this.props.app.nodeModified.value = false)
	}//}}}
	renameNode() {//{{{
		let name = prompt("New name")
		if(!name)
			return

		this.node.value.rename(name, ()=>{
			this.goToNode(this.node.value.ID)
			this.menu.value = false
		})
	}//}}}
	deleteNode() {//{{{
		if(!confirm("Do you want to delete this note and all sub-notes?"))
			return
		this.node.value.delete(()=>{
			this.goToNode(this.node.value.ParentID)
			this.menu.value = false
		})
	}//}}}

	async retrieveKeys() {//{{{
		return new Promise((resolve, reject)=>{
			this.props.app.request('/key/retrieve', {})
				.then(res=>{
					this.keys.value = res.Keys.map(keyData=>new Key(keyData, this.keyCounter))
					resolve(this.keys.value)
				})
				.catch(reject)
		})
	}//}}}
	keyCounter() {//{{{
		return window._app.current.request('/key/counter', {})
			.then(res=>BigInt(res.Counter))
			.catch(window._app.current.responseError)
	}//}}}
	getKey(id) {//{{{
		let keys = this.keys.value
		for(let i = 0; i < keys.length; i++)
			if(keys[i].ID == id)
				return keys[i]
		return null
	}//}}}

	showPage(pg) {//{{{
		this.page.value = pg
	}//}}}
}

class NodeContent extends Component {
	constructor(props) {//{{{
		super(props)
		this.contentDiv = createRef()
		this.state = {
			modified: false,
		}
	}//}}}
	render({ node }) {//{{{
		let content = ''
		try {
			content = node.content()
		} catch(err) {
			return html`
				<div id="node-content" class="node-content encrypted">${err.message}</div>
			`
		}

		return html`
			<div class="grow-wrap">
				<textarea id="node-content" class="node-content" ref=${this.contentDiv} oninput=${()=>this.contentChanged()} required rows=1>${content}</textarea>
			</div>
		`
	}//}}}
	componentDidMount() {//{{{
		this.resize()
		window.addEventListener('resize', ()=>this.resize())
	}//}}}
	componentDidUpdate() {//{{{
		this.resize()
	}//}}}
	contentChanged() {//{{{
		window._app.current.nodeModified.value = true
		this.resize()
	}//}}}
	resize() {//{{{
		let textarea = document.getElementById('node-content')
		if(textarea)
			textarea.parentNode.dataset.replicatedValue = textarea.value
	}//}}}
	unlock() {//{{{
		let pass = prompt(`Password for "${this.props.model.description}"`)
		if(!pass)
			return

		try {
			this.props.model.unlock(pass)
			this.forceUpdate()
		} catch(err) {
			alert(err)
		}
	}//}}}
}

class NodeFiles extends Component {
	render({ node }) {//{{{
		if(node.Files === null || node.Files.length == 0)
			return

		let files = node.Files
			.sort((a, b)=>{
				if(a.Filename.toUpperCase() < b.Filename.toUpperCase()) return -1
				if(a.Filename.toUpperCase() > b.Filename.toUpperCase()) return  1
				return 0
			})
			.map(file=>
				html`
					<div class="filename" onclick=${()=>node.download(file.ID)}>${file.Filename}</div>
					<div class="size">${this.formatSize(file.Size)}</div>
				`
			)

		return html`
			<div id="file-section">
				<div class="header">Files</div>
				<div class="files">
					${files}
				</div>
			</div>
		`
	}//}}}
	formatSize(size) {//{{{
		if(size < 1048576) {
			return `${Math.round(size / 1024)} KiB`
		} else {
			return `${Math.round(size / 1048576)} MiB`
		}
	}//}}}
}

export class Node {
	constructor(app, nodeID) {//{{{
		this.app       = app
		this.ID        = nodeID
		this.ParentID  = 0
		this.UserID    = 0
		this.CryptoKeyID = 0
		this.Name      = ''
		this._content  = ''
		this.Children  = []
		this.Crumbs    = []
		this.Files     = []
		this._decrypted = false
		this._expanded = false // start value for the TreeNode component,
		                       // it doesn't control it afterwards.
		                       // Used to expand the crumbs upon site loading.
	}//}}}
	retrieve(callback) {//{{{
		this.app.request('/node/retrieve', { ID: this.ID })
		.then(res=>{
			this.ParentID    = res.Node.ParentID
			this.UserID      = res.Node.UserID
			this.CryptoKeyID = res.Node.CryptoKeyID
			this.Name        = res.Node.Name
			this._content    = res.Node.Content
			this.Children    = res.Node.Children
			this.Crumbs      = res.Node.Crumbs
			this.Files       = res.Node.Files
			callback(this)
		})
		.catch(this.app.responseError)
	}//}}}
	delete(callback) {//{{{
		this.app.request('/node/delete', {
			NodeID: this.ID,
		})
		.then(callback)
		.catch(this.app.responseError)
	}//}}}
	create(name, callback) {//{{{
		this.app.request('/node/create', {
			Name: name.trim(),
			ParentID: this.ID,
		})
		.then(res=>{
			callback(res.Node.ID)
		})
		.catch(this.app.responseError)
	}//}}}
	async save(callback) {//{{{
		try {
			await this.#encrypt()

			let req = {
				NodeID: this.ID,
				Content: this._content,
				CryptoKeyID: this.CryptoKeyID,
			}
			this.app.request('/node/update', req)
				.then(callback)
				.catch(this.app.responseError)
		} catch (err) {
			this.app.responseError(err)
		}
	}//}}}
	rename(name, callback) {//{{{
		this.app.request('/node/rename', {
			Name: name.trim(),
			NodeID: this.ID,
		})
		.then(callback)
		.catch(this.app.responseError)
	}//}}}
	download(fileID) {//{{{
		let headers = {
			'Content-Type': 'application/json',
		}

		if(this.app.session.UUID !== '')
			headers['X-Session-Id'] = this.app.session.UUID

		let fname = ""
		fetch("/node/download", {
			method: 'POST',
			headers,
			body: JSON.stringify({
				NodeID: this.ID,
				FileID: fileID,
			}),
		})
		.then(response=>{
			let match = response.headers.get('content-disposition').match(/filename="([^"]*)"/)
			fname = match[1]
			return response.blob()
		})
		.then(blob=>{
			let url = window.URL.createObjectURL(blob)
			let a = document.createElement('a')
			a.href = url
			a.download = fname
			document.body.appendChild(a) // we need to append the element to the dom -> otherwise it will not work in firefox
			a.click()    
			a.remove()  //afterwards we remove the element again
		})
	}//}}}
	content() {//{{{
		if(this.CryptoKeyID != 0 && !this._decrypted)
			this.#decrypt()
		return this._content
	}//}}}
	setContent(new_content) {//{{{
		this._content = new_content
		if(this.CryptoKeyID == 0)
			// Logic behind plaintext not being decrypted is that
			// only encrypted values can be in a decrypted state.
			this._decrypted = false
		else
			this._decrypted = true
	}//}}}
	async setCryptoKey(new_key) {//{{{
		return this.#encrypt(true, new_key)
	}//}}}
	#decrypt() {//{{{
		if(this.CryptoKeyID == 0 || this._decrypted)
			return

		let obj_key = this.app.nodeUI.current.getKey(this.CryptoKeyID)
		if(obj_key === null || obj_key.ID != this.CryptoKeyID)
			throw('Invalid key')

		// Ask user to unlock key first
		var pass = null
		while(pass || obj_key.status() == 'locked') {
			pass = prompt(`Password for "${obj_key.description}"`)
			if(!pass)
				throw new Error(`Key "${obj_key.description}" is locked`)

			try {
				obj_key.unlock(pass)
			} catch(err) {
				alert(err)
			}
			pass = null
		}

		if(obj_key.status() == 'locked')
			throw new Error(`Key "${obj_key.description}" is locked`)

		let crypto = new Crypto(obj_key.key)
		this._decrypted = true
		this._content = sjcl.codec.utf8String.fromBits(
			crypto.decrypt(this._content)
		)
	}//}}}
	async #encrypt(change_key = false, new_key = null) {//{{{
		// Nothing to do if not changing key and already encrypted.
		if(!change_key && this.CryptoKeyID != 0 && !this._decrypted)
			return this._content

		let content = this.content()

		// Changing key to no encryption or already at no encryption -
		// set to not decrypted (only encrypted values can be
		// decrypted) and return plain value.
		if((change_key && new_key === null) || (!change_key && this.CryptoKeyID == 0)) {
			this._decrypted = false
			this.CryptoKeyID = 0
			return content
		}

		let key_id = change_key ? new_key.ID : this.CryptoKeyID
		let obj_key = this.app.nodeUI.current.getKey(key_id)
		if(obj_key === null || obj_key.ID != key_id)
			throw('Invalid key')

		if(obj_key.status() == 'locked')
			throw new Error(`Key "${obj_key.description}" is locked`)

		let crypto = new Crypto(obj_key.key)
		let content_bits = sjcl.codec.utf8String.toBits(content)
		let counter = await this.app.nodeUI.current.keyCounter()
		this.CryptoKeyID = obj_key.ID
		this._content = crypto.encrypt(content_bits, counter, true)
		this._decrypted = false
		return this._content
	}//}}}
}

class Menu extends Component {
	render({ nodeui }) {//{{{
		return html`
			<div id="blackout" onclick=${()=>nodeui.menu.value = false}></div>
			<div id="menu">
				<div class="item" onclick=${()=>{ nodeui.renameNode(); nodeui.menu.value = false }}>Rename</div>
				<div class="item" onclick=${()=>{ nodeui.deleteNode(); nodeui.menu.value = false }}>Delete</div>
				<div class="item separator" onclick=${()=>{ nodeui.showPage('properties'); nodeui.menu.value = false }}>Properties</div>
				<div class="item separator" onclick=${()=>{ nodeui.upload.value = true; nodeui.menu.value = false }}>Upload</div>
				<div class="item" onclick=${()=>{ nodeui.logout(); nodeui.menu.value = false }}>Log out</div>
			</div>
		`
	}//}}}
}
class UploadUI extends Component {
	constructor(props) {//{{{
		super(props)
		this.file = createRef()
		this.filelist = signal([])
		this.fileRefs = []
		this.progressRefs = []
	}//}}}
	render({ nodeui }) {//{{{
		let filelist = this.filelist.value
		let files = []
		for(let i = 0; i < filelist.length; i++) {
			files.push(html`<div key=file_${i} ref=${this.fileRefs[i]} class="file">${filelist.item(i).name}</div><div class="progress" ref=${this.progressRefs[i]}></div>`)
		}

		return html`
			<div id="blackout" onclick=${()=>nodeui.upload.value = false}></div>
			<div id="upload">
				<input type="file" ref=${this.file} onchange=${()=>this.upload()} multiple />
				<div class="files">
					${files}
				</div>
			</div>
		`
	}//}}}
	componentDidMount() {//{{{
		this.file.current.focus()
	}//}}}

	upload() {//{{{
		let nodeID = this.props.nodeui.node.value.ID
		this.fileRefs = []
		this.progressRefs = []

		let input = this.file.current
		this.filelist.value = input.files
		for(let i = 0; i < input.files.length; i++) {
			this.fileRefs.push(createRef())
			this.progressRefs.push(createRef())

			this.postFile(
				input.files[i],
				nodeID,
				progress=>{
					this.progressRefs[i].current.innerHTML = `${progress}%`
				},
				res=>{
					this.props.nodeui.node.value.Files.push(res.File)
					this.props.nodeui.forceUpdate()

					this.fileRefs[i].current.classList.add("done")
					this.progressRefs[i].current.classList.add("done")

					this.props.nodeui.upload.value = false
				})
		}
	}//}}}
	postFile(file, nodeID, progressCallback, doneCallback) {//{{{
		var formdata = new FormData()
		formdata.append('file', file)
		formdata.append('NodeID', nodeID)

		var request = new XMLHttpRequest()

		request.addEventListener("error", ()=>{
			window._app.current.responseError({ upload: "An unknown error occured" })
		})

		request.addEventListener("loadend", ()=>{
			if(request.status != 200) {
				window._app.current.responseError({ upload: request.statusText })
				return
			}

			let response = JSON.parse(request.response)
			if(!response.OK) {
				window._app.current.responseError({ upload: response.Error })
				return
			}

			doneCallback(response)
		})

		request.upload.addEventListener('progress', evt=>{
			var fileSize = file.size

			if(evt.loaded <= fileSize)
				progressCallback(Math.round(evt.loaded / fileSize * 100))
			if(evt.loaded == evt.total)
				progressCallback(100)
		})   

		request.open('post', '/node/upload')
		request.setRequestHeader("X-Session-Id", window._app.current.session.UUID)
		//request.timeout = 45000
		request.send(formdata)
	}//}}}
}
class NodeProperties extends Component {
	constructor(props) {//{{{
		super(props)
		this.props.nodeui.retrieveKeys()
		this.selected_key_id = 0
	}//}}}
	render({ nodeui }) {//{{{
		let save = true
		let keys = nodeui.keys.value
			.sort((a, b)=>{
				if(a.description < b.description) return -1
				if(a.description > b.description) return  1
				return 0
			})
			.map(key=>{
				this.props.nodeui.keys.value.some(uikey=>{
					if(uikey.ID == nodeui.node.value.ID) {
						save = (uikey.status() == 'unlocked')
						return true
					}
				})

				return html`
					<div class="key ${key.status()}">
						<input type="radio" name="key" id="key-${key.ID}" checked=${nodeui.node.value.CryptoKeyID == key.ID} disabled=${key.status() == 'locked'} oninput=${()=>this.selected_key_id = key.ID} />
						<label for="key-${key.ID}">${key.description}</label>
					</div>`
			})

		return html`
			<div id="properties">
				<h1>Note properties</h1>

				These properties are only for this note.

				<h2>Encryption</h2>
				<div class="key">
					<input type="radio" id="key-none" name="key" checked=${nodeui.node.value.CryptoKeyID == 0} oninput=${()=>this.selected_key_id = 0} />
					<label for="key-none">None</label>
				</div>
				${keys}

				${save ? html`<button style="margin-top: 32px" onclick=${()=>this.save()}>Save</button>` : ''}
			</div>
		`
	}//}}}
	async save() {//{{{
		let nodeui = this.props.nodeui
		let node = nodeui.node.value

		// Find the actual key object used for encryption
		let new_key = nodeui.getKey(this.selected_key_id)
		let current_key = nodeui.getKey(node.CryptoKeyID)

		if(current_key && current_key.status() == 'locked') {
			alert("Decryption key is locked and can not be used.")
			return
		}

		if(new_key && new_key.status() == 'locked') {
			alert("Key is locked and can not be used.")
			return
		}

		await node.setCryptoKey(new_key)
		node.save(()=>this.props.nodeui.showPage('node'))
	}//}}}
}

// vim: foldmethod=marker