"use strict"

// TODO: intermediate regroup moves

// https://www.redblobgames.com/grids/hexagons/

const svgNS = "http://www.w3.org/2000/svg"
const round = Math.round
const sqrt = Math.sqrt

function set_has(set, item) {
	let a = 0
	let b = set.length - 1
	while (a <= b) {
		let m = (a + b) >> 1
		let x = set[m]
		if (item < x)
			b = m - 1
		else if (item > x)
			a = m + 1
		else
			return true
	}
	return false
}

let ui = {
	hexes: [],
	sides: [],
	hex_x: [],
	hex_y: [],
	units: [],
	battle_units: [],
	battle: document.getElementById("battle"),
	battle_hits: [
		document.getElementById("hits_armor"),
		document.getElementById("hits_infantry"),
		document.getElementById("hits_antitank"),
		document.getElementById("hits_artillery")
	],
	battle_buttons: [
		document.getElementById("target_armor_button"),
		document.getElementById("target_infantry_button"),
		document.getElementById("target_antitank_button"),
		document.getElementById("target_artillery_button")
	],
	battle_header: document.getElementById("battle_header"),
	battle_message: document.getElementById("battle_message"),
	battle_line_1: document.getElementById("battle_line_1"),
	battle_line_2: document.getElementById("battle_line_2"),
	onmap: document.getElementById("units"),
	focus: null,
}

const AXIS = 'Axis'
const ALLIED = 'Allied'

function unit_hex(u) {
	return view.units[u] >>> 5
}

function unit_lost_steps(u) {
	return view.units[u] & 3
}

function is_unit_supplied(u) {
	return (view.units[u] & 4) === 4
}

function is_unit_disrupted(u) {
	return (view.units[u] & 8) === 8
}

function is_unit_moved(u) {
	return (view.units[u] & 16) === 16
}

function is_unit_fired(u) {
	return set_has(view.fired, u)
}

function is_unit_action(unit) {
	return !!(view.actions && view.actions.unit && view.actions.unit.includes(unit))
}

function is_unit_selected(unit) {
	return !!(view.selected && view.selected.includes(unit))
}

function is_allied_unit(u) {
	return units[u].nationality === 'allied'
}

function is_axis_unit(u) {
	return units[u].nationality !== 'allied'
}

function is_hex_action(hex) {
	return !!(view.actions && view.actions.hex && view.actions.hex.includes(hex))
}

function is_hex_axis_supply(hex) {
	return view.axis_supply[hex] > 0
}

function is_hex_axis_controlled(hex) {
	return set_has(view.axis_hexes, hex)
}

function is_hex_allied_controlled(hex) {
	return set_has(view.allied_hexes, hex)
}

function is_side_axis_controlled(side) {
	return set_has(view.axis_sides, side)
}

function is_side_allied_controlled(side) {
	return set_has(view.allied_sides, side)
}

function is_side_axis_supply_line(side) {
	return view.axis_supply_line[side] > 0
}

function is_hex_allied_supply(hex) {
	return view.allied_supply[hex] > 0
}

function is_side_allied_supply_line(side) {
	return view.allied_supply_line[side] > 0
}

function focus_stack(stack) {
	if (ui.focus !== stack) {
		console.log("FOCUS STACK", stack)
		ui.focus = stack
		update_map()
		return stack.length <= 1
	}
	return true
}

function blur_stack() {
	if (ui.focus !== null) {
		console.log("BLUR STACK")
		ui.focus = null
		update_map()
	}
}

function on_blur(evt) {
	document.getElementById("status").textContent = ""
}

function on_click_hex(evt) {
	if (evt.button === 0) {
		send_action('hex', evt.target.hex)
	}
}

function on_click_unit(evt) {
	if (evt.button === 0) {
		evt.stopPropagation()
		if (focus_stack(evt.target.stack))
			send_action('unit', evt.target.unit)
		return true
	}
}

function on_click_battle_unit(evt) {
	if (evt.button === 0) {
		send_action('unit', evt.target.unit)
	}
}

document.getElementById("map").addEventListener("mousedown", function (evt) {
	if (evt.button === 0) {
		blur_stack()
	}
})

function on_focus_hex(evt) {
	let h = evt.target.hex
	let text = "(" + h + ") " + hex_name[h]
	for (let r in regions)
		if (regions[r].includes(h))
			text += " - " + r
	document.getElementById("status").textContent = text
}

function on_focus_unit(evt) {
	let u = evt.target.unit
	let data = units[u]
	document.getElementById("status").textContent = `(${u}) ${data.nationality} ${data.elite ? "elite " : ""}${data.type} - ${data.steps} - ${data.name}`
}

function on_focus_battle_unit(evt) {
	let u = evt.target.unit
	let data = units[u]
	document.getElementById("status").textContent = `(${u}) ${data.nationality} ${data.elite ? "elite " : ""}${data.type} - ${data.steps} - ${data.name}`
}

function toggle_units() {
	document.getElementById("units").classList.toggle("hide")
}

const CLEAR = 2
const PASS = 1
const ROUGH = 0

const TRAIL = 1
const TRACK = 2
const HIGHWAY = 4

// visible map width = 22 hexes: el agheila -> alexandria
// visible map height = 9 hexes: oasis to derne

const map_w = 25
const map_h = 9

let hexnext = [ 1, map_w, map_w-1, -1, -map_w, -(map_w-1) ]

function build_hexes() {
	let yoff = 4
	let xoff = 62
	let hex_w = 121.5
	let hex_r = hex_w / sqrt(3)
	let hex_h = hex_r * 2

	let w = hex_w / 2
	let a = hex_h / 2
	let b = hex_h / 4

	function add_line(x, y, s, side_id) {
		let x1, y1, x2, y2
		switch (s) {
		case 0: x1 = (x+w); y1 = (y+b); x2 = (x+w); y2 = (y-b); break; // E
		case 1: x1 = (x+0); y1 = (y+a); x2 = (x+w); y2 = (y+b); break; // SE
		case 2: x1 = (x-w); y1 = (y+b); x2 = (x+0); y2 = (y+a); break; // SW
		case 3: x1 = (x-w); y1 = (y+b); x2 = (x-w); y2 = (y-b); break; // W
		case 4: x1 = (x-w); y1 = (y-b); x2 = (x+0); y2 = (y-a); break; // NW
		case 5: x1 = (x+0); y1 = (y-a); x2 = (x+w); y2 = (y-b); break; // NE
		}
		path.push("M", x1, y1, x2, y2)

		let side = ui.sides[side_id] = document.createElementNS(svgNS, "line")
		document.getElementById("mapsvg").getElementById("sides").appendChild(side)

		let cn = "side"
		if (side_limit[side_id] === 0) cn += " rough"
		else if (side_limit[side_id] === 1) cn += " gap"
		else if (side_limit[side_id] === 2) cn += " clear"
		if (side_road[side_id] === 1) cn += " trail"
		else if (side_road[side_id] === 2) cn += " track"
		else if (side_road[side_id] === 4) cn += " highway"

		side.setAttribute("class", cn)
		side.setAttribute("x1", x1)
		side.setAttribute("y1", y1)
		side.setAttribute("x2", x2)
		side.setAttribute("y2", y2)
		side.side = side_id
	}

	function add_hex(x, y) {
		return [
			[ round(x),   round(y-a) ],
			[ round(x+w), round(y-b) ],
			[ round(x+w), round(y+b) ],
			[ round(x),   round(y+a) ],
			[ round(x-w), round(y+b) ],
			[ round(x-w), round(y-b) ]
		].join(" ")
	}

	let path = []
	for (let y = 0; y < map_h+1; ++y) {
		for (let x = 0; x < map_w+1; ++x) {
			let hex_id = y * map_w + x
			let xx = x + y/2 - 4.5
			let hex_x = (xoff + hex_w * xx + hex_w/2)
			let hex_y = (yoff + hex_h * 3 / 4 * y + hex_h/2)

			ui.hex_x[hex_id] = round(hex_x)
			ui.hex_y[hex_id] = round(hex_y)

			// Add hex cell
			if (hex_exists[hex_id])
			{
				let hex = ui.hexes[hex_id] = document.createElementNS(svgNS, "polygon")
				hex.setAttribute("class", "hex")
				hex.setAttribute("points", add_hex(hex_x, hex_y))
				hex.addEventListener("mousedown", on_click_hex)
				hex.addEventListener("mouseenter", on_focus_hex)
				hex.addEventListener("mouseleave", on_blur)
				hex.hex = hex_id
				document.getElementById("mapsvg").getElementById("hexes").appendChild(hex)
			}

			// Add hex sides
			// if (hex_exists[hex_id])
			{
				for (let s = 0; s < 3; ++s) {
					let next_id = hex_id + hexnext[s]
					// if (hex_exists[next_id])
					{
						let side_id = hex_id * 3 + s
						add_line(hex_x, hex_y, s, side_id)
					}
				}
			}
		}
	}

	for (let month = 1; month <= 20; ++month) {
		ui.hex_y[map_w * map_h + month] = 24 + 37
		ui.hex_x[map_w * map_h + month] = 1840 + 37 + (month-1) * 81
	}

	document.getElementById("mapsvg").getElementById("grid").setAttribute("d", path.join(" "))
}

function build_units() {
	function build_unit(u, data) {
		let elt = ui.units[u] = document.createElement("div")
		elt.className = `unit ${data.nationality} u${u} r0 m`
		elt.addEventListener("mousedown", on_click_unit)
		elt.addEventListener("mouseenter", on_focus_unit)
		elt.addEventListener("mouseleave", on_blur)
		elt.unit = u

		elt = ui.battle_units[u] = document.createElement("div")
		elt.className = `unit ${data.nationality} u${u} r0`
		elt.addEventListener("mousedown", on_click_battle_unit)
		elt.addEventListener("mouseenter", on_focus_battle_unit)
		elt.addEventListener("mouseleave", on_blur)
		elt.unit = u
	}
	for (let u = 0; u < units.length; ++u) {
		build_unit(u, units[u])
	}
}

build_hexes()
build_units()

let stack = new Array(map_w * map_h + 21)
for (let i = 0; i < stack.length; ++i)
	stack[i] = []

function update_map() {
	for (let i = 0; i < stack.length; ++i)
		stack[i].length = 0
	for (let u = 0; u < units.length; ++u) {
		let e = ui.units[u]
		let hex = unit_hex(u)
		if (hex) {
			if (!ui.onmap.contains(e))
				ui.onmap.appendChild(e)
			stack[hex].push(u)
			e.stack = stack[hex]
		} else {
			e.remove()
		}
	}

	for (let hex = 0; hex < stack.length; ++hex) {
		for (let i = 0; i < stack[hex].length; ++i) {
			let u = stack[hex][i]
			let e = ui.units[u]
			let x, y, z

			if (stack[hex] === ui.focus) {
				x = ui.hex_x[hex] - 25
				y = ui.hex_y[hex] - 25 + i * 56
				z = 100
			} else {
				if (stack[hex].length <= 1) {
					x = ui.hex_x[hex] - 25 + i * 11
					y = ui.hex_y[hex] - 25 + i * 14
				} else if (stack[hex].length <= 4) {
					x = ui.hex_x[hex] - 30 + i * 11
					y = ui.hex_y[hex] - 30 + i * 14
				} else if (stack[hex].length <= 8) {
					x = ui.hex_x[hex] - 30 + i * 4
					y = ui.hex_y[hex] - 30 + i * 4
				} else {
					x = ui.hex_x[hex] - 35 + i * 3
					y = ui.hex_y[hex] - 35 + i * 3
				}
				z = 1 + i
			}

			e.style.top = y + "px"
			e.style.left = x + "px"
			e.style.zIndex = z

			let r = unit_lost_steps(u)
			e.classList.toggle("r0", r === 0)
			e.classList.toggle("r1", r === 1)
			e.classList.toggle("r2", r === 2)
			e.classList.toggle("r3", r === 3)

			e.classList.toggle("action", !view.battle && is_unit_action(u))
			e.classList.toggle("selected", !view.battle && is_unit_selected(u))
			e.classList.toggle("disrupted", is_unit_disrupted(u))
			e.classList.toggle("moved", is_unit_moved(u))
			// e.classList.toggle("unsupplied", !is_unit_supplied(u))
		}

		if (ui.hexes[hex]) {
			ui.hexes[hex].classList.toggle("action", is_hex_action(hex))
			ui.hexes[hex].classList.toggle("from", hex === view.from1 || hex === view.from2)
			ui.hexes[hex].classList.toggle("to", hex === view.to1 || hex === view.to2)
			ui.hexes[hex].classList.toggle("axis_control", is_hex_axis_controlled(hex))
			ui.hexes[hex].classList.toggle("allied_control", is_hex_allied_controlled(hex))
			if (view.axis_supply) {
				ui.hexes[hex].classList.toggle("axis_supply", is_hex_axis_supply(hex))
				for (let s = 0; s < 3; ++s)
					ui.sides[hex*3+s].classList.toggle("axis_supply", is_side_axis_supply_line(hex*3+s))
			}
			if (view.allied_supply) {
				ui.hexes[hex].classList.toggle("allied_supply", is_hex_allied_supply(hex))
				for (let s = 0; s < 3; ++s)
					ui.sides[hex*3+s].classList.toggle("allied_supply", is_side_allied_supply_line(hex*3+s))
			}
			for (let s = 0; s < 3; ++s) {
				ui.sides[hex*3+s].classList.toggle("axis_control", is_side_axis_controlled(hex*3+s))
				ui.sides[hex*3+s].classList.toggle("allied_control", is_side_allied_controlled(hex*3+s))
			}
		}
	}
}

function update_battle_line(line, test) {
	for (let u = 0; u < units.length; ++u) {
		let e = ui.battle_units[u]
		if (unit_hex(u) === view.battle && test(u)) {
			if (!line.contains(e))
				line.appendChild(e)

			let r = unit_lost_steps(u)
			e.classList.toggle("r0", r === 0)
			e.classList.toggle("r1", r === 1)
			e.classList.toggle("r2", r === 2)
			e.classList.toggle("r3", r === 3)

			e.classList.toggle("action", is_unit_action(u))
			e.classList.toggle("selected", is_unit_selected(u))
			e.classList.toggle("disrupted", is_unit_disrupted(u))
			e.classList.toggle("fire", is_unit_fired(u))
		} else {
			if (line.contains(e))
				line.removeChild(e)
		}
	}
}

function update_battle() {
	ui.battle.classList.remove("hide")
	ui.battle_header.textContent = hex_name[view.battle]
	ui.battle_message.textContent = view.flash
	if (player === ALLIED) {
		update_battle_line(ui.battle_line_1, is_axis_unit)
		update_battle_line(ui.battle_line_2, is_allied_unit)
	} else {
		update_battle_line(ui.battle_line_1, is_allied_unit)
		update_battle_line(ui.battle_line_2, is_axis_unit)
	}
	target_button("armor")
	target_button("infantry")
	target_button("antitank")
	target_button("artillery")
	for (let i = 0; i < 4; ++i)
		ui.battle_hits[i].textContent = view.hits[i]
}

function target_button(action) {
	let button = document.getElementById("target_" + action + "_button")
	if (view.actions) {
		button.classList.remove("hide")
		if (view.actions[action])
			button.disabled = false
		else
			button.disabled = true
	} else {
		button.classList.add("hide")
	}
}

function on_update() {
	update_map()

	if (view.battle)
		update_battle()
	else
		ui.battle.classList.add("hide")

	action_button("overrun", "Overrun")
	action_button("rommel", "Rommel")
	action_button("stop", "Stop")
	action_button("end_move", "End move")

	action_button("end_combat", "End combat")

	action_button("group", "Group")
	action_button("regroup", "Regroup")

	action_button("basic", "Basic")
	action_button("offensive", "Offensive")
	action_button("assault", "Assault")
	action_button("blitz", "Blitz")
	action_button("pass", "Pass")

	action_button("next", "Next")
	action_button("undo", "Undo")
}

drag_element_with_mouse("#battle", "#battle_header")
scroll_with_middle_mouse("main")