// Q: why would you do this
// A: the password on the netflix account I use is long
//    and it doesn't have proper text input support
// Q: how do I use this
// A: bravia.delaySequence(require('netflixkb.js').NetflixPW.sequence("yourpassword"))
"use strict"
const FibonacciHeap = require('@tyriar/fibonacci-heap')
// priority-queue dijkstra, reference https://en.wikipedia.org/wiki/Dijkstra's_algorithm
function find_path(target, prev) {
	const S = []
	let u = {node: target}
	while(prev.has(u.node)) {
		u = prev.get(u.node)
		S.push(u)
	}
	return [S.reverse().map(x => x.label), S[S.length - 1].node]
}
function dijkstra(source, target) {
	const dist = new Map()
	const prev = new Map()
	const heapnodes = new Map()
	const Q = new FibonacciHeap()
	dist.set(source, 0)
	heapnodes.set(source, Q.insert(0, source))
	while(!Q.isEmpty()) {
		const {value: u} = Q.extractMinimum()
		heapnodes.delete(u)
		if (u == target) {
			return find_path(target, prev)
		}
		if (u.transitions) {
			for(const [cost, v, label] of u.transitions()) {
				const alt = dist.get(u) + cost
				if (alt < (dist.has(v) ? dist.get(v) : Infinity)) {
					dist.set(v, alt)
					prev.set(v, Object.freeze({node: u, label}))
					if (heapnodes.has(v)) Q.decreaseKey(heapnodes.get(v), alt)
					else                  heapnodes.set(v, Q.insert(alt, v))
				}
			}
		}
	}
	return undefined
}

// TODO: find better solution for the special keys
// wraps to left and right
// \x1: shift. \x2: symbols, \x11: backspace
// 3: diacritics \x05: uppercase symbols, \x06: uppercase diacritics
// \x10: too lazy, some sort of superscript a
const netflixpw_kb = Object.freeze([[
		"1234567890",
		"qwertyuiop",
		"asdfghjkl-",
		"\x01\x01zxcvbnm'",
		"\x02\x02\x03\x03   \x11\x11\x11"
	],[
		"1234567890",
		"QWERTYUIOP",
		"ASDFGHJKL-",
		"\x00\x00ZXCVBNM'",
		"\x05\x05\x06\x06   \x11\x11\x11"
	],[
		"`~!@#$%^&*",
		"()-_=+[]{}",
		"\\|;:'\",.<>",
		"/?¡¿\x10°¢€£¥",
		"\x00\x00\x03\x03   \x11\x11\x11"
	]
])
// 0: standard. 1: shift. 2: special chars. 3: uppercase special chars
// 11: backspace. 12: @gmail.com. 13: @hotmail.com. 14: @live.nl. 15: .com.
// 16: .ca 17 .net 18 .edu 19 .org 1a .gov 
const netflixemail = Object.freeze([[
		"1234567890",
		"qwertyuiop",
		"asdfghjkl-",
		"\x01\x01zxcvbnm_",
		"\x12\x12\x12\x13\x13\x13\x13\x14\x14\x14",
		"\x02\x02@@.\x15\x15\x11\x11\x11",
	],[
		"1234567890",
		"QWERTYUIOP",
		"ASDFGHJKL-",
		"\x00\x00ZXCVBNM_",
		"\x12\x12\x12\x13\x13\x13\x13\x14\x14\x14",
		"\x03\x03@@.\x15\x15\x11\x11\x11",
	],[
		"1234567890",
		"`~!@#$%^&*",
		"+-_{}|'./?",
		"\x16\x16\x17\x17\x18\x18\x19\x19\x1a\x1a",
		"\x12\x12\x12\x13\x13\x13\x13\x14\x14\x14",
		"\x00\x00@@.\x15\x15\x11\x11\x11",
	]
])
const netflixsearch = Object.freeze([[
	'   \x11\x11\x11',
	'abcdef',
	'ghijkl',
	'mnopqr',
	'stuvwx',
	'yz1234',
	'567890'
]])
class Keyboard {
	constructor(chars, startpos, wraparound = true, centeroffs = true) {
		Object.assign(this, {
			chars, depth: chars.length, height: chars[0].length, width: chars[0][0].length,
			startpos, wraparound, centeroffs // workaround because the search keyboard is different
		})
		this.nodes = chars.map((kb, kbid) =>
				kb.map((row, rowid) =>
					row.split('').map((letter, colid) =>
						this.mkNode(kbid, rowid, colid))))
	}
	findGroupInfo(kb, row, col) {
		const kbrow = this.chars[kb][row]
		const idxs = kbrow.split('').map((ltr,id) => ltr == kbrow[col] ? id : -1).filter(id => id>=0)
		return Object.freeze({left: idxs[0], size: idxs.length})
	}
	findGroupCenter(kb, row, col) {
		col = (col + this.width) % this.width // fix wraparound
		const {left, size} = this.findGroupInfo(kb, row, col)
		if (!this.centeroffs) return this.nodes[kb][row][left]
		return this.nodes[kb][row][left + Math.ceil(size / 2) - 1]
	}
	mkNode(kb, row, col) {
		return Object.freeze({
			letter: this.chars[kb][row][col], kb, row, col,
			transitions: () => {
				const {left, size} = this.findGroupInfo(kb, row, col)
				const transitions = {
					'Left': this.findGroupCenter(kb, row, left - 1),
					'Right': this.findGroupCenter(kb, row, left + size)
				}
				if (!this.wraparound && col == 0)            delete transitions['Left']
				if (!this.wraparound && col == this.width-1) delete transitions['Right']
				if (row != 0)             transitions['Up'] = this.nodes[kb][row-1][col]
				if (row != this.height-1) transitions['Down'] = this.nodes[kb][row+1][col]
				{
					const char = this.chars[kb][row][col]
					const cc = char.charCodeAt(0)
					if (cc < this.depth) transitions['DpadCenter'] = this.findGroupCenter(cc, row, col)
					else if (cc > 15)    transitions['DpadCenter'] = char
				}
				return Object.keys(transitions).map(tname => [1, transitions[tname], tname])
			}
		})
	}
	lookupNode(z, y, x) { return this.nodes[z][y][x] }
	sequence(string, goback = false, start = undefined) {
		if (!start) start = this.lookupNode(...this.startpos)
		let pos = start
		const seq = []
		for(const char of string) {
			let s2;
			[s2, pos] = dijkstra(pos, char)
			seq.push(s2)
		}
		if (goback) return [[].concat(...seq, dijkstra(pos, start)[0]), start]
		return [[].concat(...seq), pos]
	}
}
module.exports = {
	Keyboard,
	NetflixPW: new Keyboard(netflixpw_kb, [0,2,4]),
	NetflixMail: new Keyboard(netflixemail, [0,2,4]),
	NetflixSearch: new Keyboard(netflixsearch, [0, 1, 0], false, false)
}