-- 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 socket = require "socket"

local mime = require "mime"

local url = require "socket.url"

local server = require "net.server"

local connlisteners_get = require "net.connlisteners".get;

local listener = connlisteners_get("httpclient") or error("No httpclient listener!");

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

local tonumber, tostring, pairs, xpcall, select, debug_traceback, char, format =

        tonumber, tostring, pairs, xpcall, select, debug.traceback, string.char, string.format;

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

module "http"

function urlencode(s) return s and (s:gsub("%W", function (c) return format("%%%02x", c:byte()); end)); end

function urldecode(s) return s and (s:gsub("%%(%x%x)", function (c) return char(tonumber(c,16)); end)); end

local function expectbody(reqt, code)

    if reqt.method == "HEAD" then return nil end

    if code == 204 or code == 304 or code == 301 then return nil end

    if code >= 100 and code < 200 then return nil end

    return 1

end

local function request_reader(request, data, startpos)

	if not data then

		if request.body then

			log("debug", "Connection closed, but we have data, calling callback...");

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

		elseif request.state ~= "completed" then

			-- Error.. connection was closed prematurely

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

			return;

		end

		destroy_request(request);

		request.body = nil;

		request.state = "completed";

		return;

	end

	if request.state == "body" and request.state ~= "completed" then

		log("debug", "Reading body...")

		if not request.body then request.body = {}; request.havebodylength, request.bodylength = 0, tonumber(request.responseheaders["content-length"]); end

		if startpos then

			data = data:sub(startpos, -1)

		end

		t_insert(request.body, data);

		if request.bodylength then

			request.havebodylength = request.havebodylength + #data;

			if request.havebodylength >= request.bodylength then

				-- We have the body

				log("debug", "Have full body, calling callback");

				if request.callback then

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

				end

				request.body = nil;

				request.state = "completed";

			else

				log("debug", "Have "..request.havebodylength.." bytes out of "..request.bodylength);

			end

		end

	elseif request.state == "headers" then

		log("debug", "Reading headers...")

		local pos = startpos;

		local headers, headers_complete = request.responseheaders;

		if not headers then

			headers = {};

			request.responseheaders = headers;

		end

		for line in data:sub(startpos, -1):gmatch("(.-)\r\n") do

			startpos = startpos + #line + 2;

			local k, v = line:match("(%S+): (.+)");

			if k and v then

				headers[k:lower()] = v;

				--log("debug", "Header: "..k:lower().." = "..v);

			elseif #line == 0 then

				headers_complete = true;

				break;

			else

				log("warn", "Unhandled header line: "..line);

			end

		end

		if not headers_complete then return; end

		-- Reached the end of the headers

		if not expectbody(request, request.code) then

			request.callback(nil, request.code, request);

			return;

		end

			request.state = "body";

		if #data > startpos then

			return request_reader(request, data, startpos);

		end

	elseif request.state == "status" then

		log("debug", "Reading status...")

		local http, code, text, linelen = data:match("^HTTP/(%S+) (%d+) (.-)\r\n()", startpos);

		code = tonumber(code);

		if not code then

			log("warn", "Invalid HTTP status line, telling callback then closing");

			local ret = request.callback("invalid-status-line", 0, request);

			destroy_request(request);

			return ret;

		end

		request.code, request.responseversion = code, http;

		if request.onlystatus then

			if request.callback then

				request.callback(nil, code, request);

			end

			destroy_request(request);

			return;

		end

		request.state = "headers";

		if #data > linelen then

			return request_reader(request, data, linelen);

		end

	end

end

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

function request(u, ex, callback)

	local req = url.parse(u);

	if not (req and req.host) then

		callback(nil, 0, req);

		return nil, "invalid-url";

	end

	if not req.path then

		req.path = "/";

	end

	local custom_headers, body;

	local default_headers = { ["Host"] = req.host, ["User-Agent"] = "Prosody XMPP Server" }

	if req.userinfo then

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

	end

	if ex then

		custom_headers = ex.headers;

		req.onlystatus = ex.onlystatus;

		body = ex.body;

		if body then

			req.method = "POST ";

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

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

		end

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

	end

	req.handler, req.conn = server.wrapclient(socket.tcp(), req.host, req.port or 80, listener, "*a");

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

	req.conn:settimeout(0);

	local ok, err = req.conn:connect(req.host, req.port or 80);

	if not ok and err ~= "timeout" then

		callback(nil, 0, req);

		return nil, err;

	end

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

	if req.query then

		t_insert(request_line, 4, "?");

		t_insert(request_line, 5, req.query);

	end

	req.write(t_concat(request_line));

	local t = { [2] = ": ", [4] = "\r\n" };

	if custom_headers then

		for k, v in pairs(custom_headers) do

			t[1], t[3] = k, v;

			req.write(t_concat(t));

			default_headers[k] = nil;

		end

	end

	for k, v in pairs(default_headers) do

		t[1], t[3] = k, v;

		req.write(t_concat(t));

		default_headers[k] = nil;

	end

	req.write("\r\n");

	if body then

		req.write(body);

	end

	req.callback = function (content, code, request) log("debug", "Calling callback, status %s", code or "---"); return select(2, xpcall(function () return callback(content, code, request) end, handleerr)); end

	req.reader = request_reader;

	req.state = "status";

	listener.register_request(req.handler, req);

	return req;

end

function destroy_request(request)

	if request.conn then

		request.conn = nil;

		request.handler:close()

		listener.ondisconnect(request.handler, "closed");

	end

end

_M.urlencode = urlencode;

return _M;