local cqueues = require 'cqueues'
local websocket = require'http.websocket'
local request = require'http.request'
local json = require 'dkjson'
local class = require 'r.class'

local BasePylon = require 'pylon'
local Channel = require 'channel'
local consts = require 'discord.consts'
local opcodes = consts.opcodes
local exec_webhook = require'discord.the'

local API_BASE = "https://discord.com/api/v10/"

local Discord = class.extend(BasePylon)
function Discord.init(self)
	self:_check_fields "token"
	self.channel_to_webhook = {}
end

local function identify_payload(token)
	local I = consts.intents return json.encode{
		op = opcodes.identify, d = {
			properties = {os="wilson",browser="wilson",device="wilson"},
			intents = I.guilds + I.guild_messages + I.message_content,
			token = token } } end

function Discord._req(self, url, payload)
	local req = request.new_from_uri(API_BASE..url)
	req.headers:upsert(':method',payload and 'POST' or 'GET')
	req.headers:upsert('authorization','Bot '..self.token)
	req.headers:upsert('user-agent','wilson (https://g.gh0.pw/wilson/, v0.0)')
	if payload then
		req.headers:upsert('content-type','application/json')
		req:set_body(assert(json.encode(payload))) end
	local head,body = assert(req:go())
	local status = head:get':status'
	local bod = body:get_body_as_string()
	assert(status:match"^2", 'status was '..status..' body '..bod)
	local val, _, err = json.decode(bod)
	if err then error(err) else return val end
end

function Discord._connect(self)
	local uri = "wss://gateway.discord.gg/?v=10&encoding=json"
	self.ws = websocket.new_from_uri(uri)
	assert(self.ws:connect())
	self.ws:send(identify_payload(self.token), 'text')

	local me = self:_req"users/@me"
	self.bot_id = me.id
	self.log('logged in as ',me.username)

	for busname, bus in pairs(self.wilson.busses) do
		for _, channel in ipairs(bus) do
			if channel.pylon == self then
				self:add_channel(channel)
			end
		end
	end
end

function Discord.add_channel(self, channel)
	local webhooks = self:_req("channels/"..channel.descriptor.."/webhooks")
	for _,wh in pairs(webhooks) do
		if wh.application_id == self.bot_id then
			self.log("Found existing webhook for channel",channel.descriptor)
			self.channel_to_webhook[channel.descriptor] = wh
			return
		end
	end
	self.log("Making webhook for channel",channel.descriptor)
	local wh = self:_req("channels/"..channel.descriptor.."/webhooks", {
		name=self.name:gsub("discord",""):gsub("clyde","").." wilson hook" })
	self.channel_to_webhook[channel.descriptor] = wh
end

function Discord._heartbeating(self, interval_ms)
	local interval = interval_ms / 1000
	cqueues.sleep(interval * math.random())
	while true do
		self.ws:send(json.encode{
			op = opcodes.heartbeat,
			d = self.sequence_number,
		})
		cqueues.sleep(interval)
	end
end

function Discord.recving(self)
	for packet in self.ws:each() do
		local event = json.decode(packet)
		self.log:debug(event.s, event.op, event.t)
		if event.op ~= opcodes.dispatch then
			self.log:debug(event.d)
		end

		if event.s then self.sequence_number = event.s end

		if event.op == opcodes.hello then
			self.cq:wrap(self._heartbeating, self, event.d.heartbeat_interval)
		elseif event.op == opcodes.dispatch then
			self:handle_dispatch(event)
		end
	end
end

function Discord.handle_dispatch(self, event)
	local d = event.d
	if event.t == 'MESSAGE_CREATE' then
		self.log:proto('<',d.channel_id,d.author.username,d.content)
		if
			self.channel_to_webhook[d.channel_id]
			and d.author.id ~= self.channel_to_webhook[d.channel_id].id
			and d.author.id ~= self.bot_id
		then
			self.wilson:deliver(Channel(self, d.channel_id), {
				body = d.content,
				sender = '[d]' .. d.author.username,
			})
		end
	elseif event.t == 'READY' then
		self.log:debug(event.d)
	end
end

function Discord.sending(self)
	for dest_channel, message in self.inbox:iter() do
		self.log:proto('>',dest_channel,message.sender,message.body)
		exec_webhook(self.channel_to_webhook[dest_channel.descriptor].url, {
			username = message.sender,
			content = message.body,
		})
	end
end

return Discord