-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

--

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local b64 = require "util.encodings".base64.encode;

local url = require "socket.url"

local httpstream_new = require "net.http.parser".new;

local util_http = require "util.http";

local events = require "util.events";

local verify_identity = require"util.x509".verify_identity;

local promise = require "util.promise";

local http_errors = require "net.http.errors";

local basic_resolver = require "net.resolvers.basic";

local connect = require "net.connect".connect;

local ssl_available = pcall(require, "ssl");

local t_insert, t_concat = table.insert, table.concat;

local pairs = pairs;

local tonumber, tostring, traceback =

      tonumber, tostring, debug.traceback;

local os_time = os.time;

local xpcall = require "util.xpcall".xpcall;

local error = error

local log = require "util.logger".init("http");

local _ENV = nil;

-- luacheck: std none

local requests = {}; -- Open requests

local function make_id(req) return (tostring(req):match("%x+$")); end

local listener = { default_port = 80, default_mode = "*a" };

-- Request-related helper functions

local function handleerr(err) log("error", "Traceback[http]: %s", traceback(tostring(err), 2)); return err; end

local function log_if_failed(req, ret, ...)

	if not ret then

		log("error", "Request '%s': error in callback: %s", req.id, (...));

		if not req.suppress_errors then

			error(...);

		end

	end

	return ...;

end

local function destroy_request(request)

	local conn = request.conn;

	if conn then

		request.conn = nil;

		conn:close()

	end

end

local function cancel_request(request, reason)

	if request.callback then

		request.callback(reason or "cancelled", 0, request);

		request.callback = nil;

	end

	if request.conn then

		destroy_request(request);

	end

end

local function request_reader(request, data, err)

	if not request.parser then

		local function error_cb(reason)

			if request.callback then

				request.callback(reason or "connection-closed", 0, request);

				request.callback = nil;

			end

			destroy_request(request);

		end

		if not data then

			error_cb(err);

			return;

		end

		local finalize_sink;

		local function success_cb(r)

			if r.partial then

				-- Request should be streamed

				log("debug", "Request '%s': partial response (%s%s)",

					request.id,

					r.chunked and "chunked, " or "",

					r.body_length and ("%d bytes"):format(r.body_length) or "unknown length"

				);

				if request.streaming_handler then

					log("debug", "Request '%s': Streaming via handler", request.id);

					r.body_sink, finalize_sink = request.streaming_handler(r);

				end

				return;

			elseif finalize_sink then

				log("debug", "Request '%s': Finalizing response stream");

				finalize_sink(r);

			end

			if request.callback then

				request.callback(r.body, r.code, r, request);

				request.callback = nil;

			end

			destroy_request(request);

		end

		local function options_cb()

			return request;

		end

		request.parser = httpstream_new(success_cb, error_cb, "client", options_cb);

	end

	request.parser:feed(data);

end

-- Connection listener callbacks

function listener.onconnect(conn)

	local req = requests[conn];

	-- Initialize request object

	req.write = function (...) return req.conn:write(...); end

	local callback = req.callback;

	req.callback = function (content, code, response, request)

		do

			local event = { http = req.http, url = req.url, request = req, response = response, content = content, code = code, callback = req.callback };

			req.http.events.fire_event("response", event);

			content, code, response = event.content, event.code, event.response;

		end

		log("debug", "Request '%s': Calling callback, status %s", req.id, code or "---");

		return log_if_failed(req.id, xpcall(callback, handleerr, content, code, response, request));

	end

	req.reader = request_reader;

	req.state = "status";

	req.cancel = cancel_request;

	requests[req.conn] = req;

	-- Validate certificate

	if not req.insecure and conn:ssl() then

		local sock = conn:socket();

		local chain_valid = sock.getpeerverification and sock:getpeerverification();

		if not chain_valid then

			req.callback("certificate-chain-invalid", 0, req);

			req.callback = nil;

			conn:close();

			return;

		end

		local cert = sock.getpeercertificate and sock:getpeercertificate();

		if not cert or not verify_identity(req.host, false, cert) then

			req.callback("certificate-verify-failed", 0, req);

			req.callback = nil;

			conn:close();

			return;

		end

	end

	-- Send the request

	local request_line = { req.method or "GET", " ", req.path, " HTTP/1.1\r\n" };

	if req.query then

		t_insert(request_line, 4, "?"..req.query);

	end

	for k, v in pairs(req.headers) do

		t_insert(request_line, k .. ": " .. v .. "\r\n");

	end

	t_insert(request_line, "\r\n")

	conn:write(t_concat(request_line));

	if req.body then

		conn:write(req.body);

	end

end

function listener.onincoming(conn, data)

	local request = requests[conn];

	if not request then

		log("warn", "Received response from connection %s with no request attached!", conn);

		return;

	end

	if data and request.reader then

		request:reader(data);

	end

end

function listener.ondisconnect(conn, err)

	local request = requests[conn];

	if request and request.conn then

		request:reader(nil, err or "closed");

	end

	requests[conn] = nil;

end

function listener.onattach(conn, req)

	requests[conn] = req;

	req.conn = conn;

end

function listener.ondetach(conn)

	requests[conn] = nil;

end

function listener.onfail(req, reason)

	req.http.events.fire_event("request-connection-error", { http = req.http, request = req, url = req.url, err = reason });

	req.callback(reason or "connection failed", 0, req);

end

local function request(self, u, ex, callback)

	local req = url.parse(u);

	if not (req and req.host) then

		callback("invalid-url", 0, req);

		return nil, "invalid-url";

	end

	req.url = u;

	req.http = self;

	req.time = os_time();

	if not req.path then

		req.path = "/";

	end

	req.id = ex and ex.id or make_id(req);

	do

		local event = { http = self, url = u, request = req, options = ex, callback = callback };

		local ret = self.events.fire_event("pre-request", event);

		if ret then

			return ret;

		end

		req, u, ex, req.callback = event.request, event.url, event.options, event.callback;

	end

	local method, headers, body;

	local host, port = req.host, req.port;

	local host_header = host;

	if (port == "80" and req.scheme == "http")

	or (port == "443" and req.scheme == "https") then

		port = nil;

	elseif port then

		host_header = host_header..":"..port;

	end

	headers = {

		["Host"] = host_header;

		["User-Agent"] = "Prosody XMPP Server";

	};

	if req.userinfo then

		headers["Authorization"] = "Basic "..b64(req.userinfo);

	end

	if ex then

		req.onlystatus = ex.onlystatus;

		body = ex.body;

		if body then

			method = "POST";

			headers["Content-Length"] = tostring(#body);

			headers["Content-Type"] = "application/x-www-form-urlencoded";

		end

		if ex.method then method = ex.method; end

		if ex.headers then

			for k, v in pairs(ex.headers) do

				headers[k] = v;

			end

		end

		req.insecure = ex.insecure;

		req.suppress_errors = ex.suppress_errors;

		req.streaming_handler = ex.streaming_handler;

	end

	log("debug", "Making %s %s request '%s' to %s", req.scheme:upper(), method or "GET", req.id, (ex and ex.suppress_url and host_header) or u);

	-- Attach to request object

	req.method, req.headers, req.body = method, headers, body;

	local using_https = req.scheme == "https";

	if using_https and not ssl_available then

		error("SSL not available, unable to contact https URL");

	end

	local port_number = port and tonumber(port) or (using_https and 443 or 80);

	local use_dane = self.options and self.options.use_dane;

	local sslctx = false;

	if using_https then

		sslctx = ex and ex.sslctx or self.options and self.options.sslctx;

		if ex and ex.use_dane ~= nil then

			use_dane = ex.use_dane;

		end

	end

	local http_service = basic_resolver.new(host, port_number, "tcp", { servername = req.host; use_dane = use_dane });

	connect(http_service, listener, { sslctx = sslctx }, req);

	self.events.fire_event("request", { http = self, request = req, url = u });

	return req;

end

local function new(options)

	local http = {

		options = options;

		request = function (self, u, ex, callback)

			if callback ~= nil then

				return request(self, u, ex, callback);

			else

				return promise.new(function (resolve, reject)

					request(self, u, ex, function (body, code, a, b)

						if code == 0 then

							reject(http_errors.new(body, { request = a }));

						else

							a.request = b;

							resolve(a);

						end

					end);

				end);

			end

		end;

		new = options and function (new_options)

			local final_options = {};

			for k, v in pairs(options) do final_options[k] = v; end

			if new_options then

				for k, v in pairs(new_options) do final_options[k] = v; end

			end

			return new(final_options);

		end or new;

		events = events.new();

	};

	return http;

end

local default_http = new({

	sslctx = { mode = "client", protocol = "sslv23", options = { "no_sslv2", "no_sslv3" }, alpn = "http/1.1", verify = "peer" };

	suppress_errors = true;

});

return {

	request = function (u, ex, callback)

		return default_http:request(u, ex, callback);

	end;

	default = default_http;

	new = new;

	events = default_http.events;

	-- COMPAT

	urlencode = util_http.urlencode;

	urldecode = util_http.urldecode;

	formencode = util_http.formencode;

	formdecode = util_http.formdecode;

	destroy_request = destroy_request;

	features = {

		sni = true;

	};

};