local class = require 'class'
local hsluv = require 'hsluv'
local catenary = require 'catenary'

local tau = 2*math.pi
local ZOOM = 200
local G = love.graphics

local function write_at(text,x,y)
	G.push()
	G.translate(x,y)
	G.scale(1/ZOOM)
	G.print(text,0,0)
	G.pop()
end

local Port = class()
Port.R = 0.1
function Port.make(cls, x,y, num)
	return setmetatable({x=x,y=y,n=num,wires={}},cls)
end
function Port.draw(self, istate)
	local c = {0,0,0}
	if istate == 'hover' then
		c[1] = 1
	elseif istate == 'selected' then
		c[2] = 1
	end
	love.graphics.setColor(c)
	G.circle('line',self.x,self.y,self.R)
	write_at(self.n, self.x, self.y)
end
function Port.contains(self, px,py)
	local d = math.sqrt((self.x - px)^2 + (self.y - py)^2)
	return d <= self.R
end

local ports = {}
local n = 10
for i = 1,n do
	local theta = tau * i/n
	table.insert(ports, Port:make(math.cos(theta), math.sin(theta), i))
end
ports[3].wires = {ports[6]}
ports[5].wires = {ports[7],ports[2]}

local function wire_color(n)
	local phi = (1+math.sqrt(5))/2
	local h = (360*phi*n)%360
	return hsluv.hsluv_to_rgb({h, 80, 60})
end

local state = 'normal'
local selected = nil

local function hovering_port(mx,my)
	for i,p in ipairs(ports) do
		if p:contains(mx,my) then
			return p
		end
	end
	return nil
end

function love.mousepressed(x,y,b)
	if b == 2 then
		state = 'normal'
		selected = nil
		return
	end
	local mx,my = G.inverseTransformPoint(x,y)
	local p = hovering_port(mx,my)
	if p then
		if state == 'normal' then
			state = 'joining'
			selected = p.n
		elseif state == 'joining' then
			table.insert(ports[selected].wires, p)
			state = 'normal'
			selected = nil
		end
	end
end



local L = 2
function love.wheelmoved(x,y)
	L = L + (y/15)
end

function love.draw()
	local W,H = G.getDimensions()
	G.clear(1,1,1)
	G.setColor(0,0,0)
	G.origin()
	G.print(L,10,10)
	G.setLineWidth(0.01)
	G.translate(W/2,H/2)
	G.scale(ZOOM)

	local mx,my = G.inverseTransformPoint(love.mouse.getPosition())
	local wn = 0
	for i,p in ipairs(ports) do
		local istate = 'normal'
		if p:contains(mx,my) then istate = 'hover' end
		if state ~= 'normal' and selected == i then istate = 'selected' end
		p:draw(istate)
		for _,q in ipairs(p.wires) do
			G.setColor(wire_color(wn))
			wn = wn + 1
			G.line(catenary.catenary(p.x,p.y,q.x,q.y))
		end
	end

	if state == 'joining' then
		G.setColor(wire_color(wn))
		local p = ports[selected]
		G.line(catenary.catenary(p.x,p.y,mx,my))
	end
end