(* HCoop Domtool (http://hcoop.sourceforge.net/)
 * Copyright (c) 2006, Adam Chlipala
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *)

(* Main interface *)

structure Main :> MAIN = struct

open Ast MsgTypes Print

structure SM = StringMap

fun init () = Acl.read Config.aclFile
	    
fun check' G fname =
    let
	val prog = Parse.parse fname
    in
	if !ErrorMsg.anyErrors then
	    G
	else
	    Tycheck.checkFile G (Defaults.tInit ()) prog
    end

fun basis () =
    let
	val dir = Posix.FileSys.opendir Config.libRoot

	fun loop files =
	    case Posix.FileSys.readdir dir of
		NONE => (Posix.FileSys.closedir dir;
			 files)
	      | SOME fname =>
		if String.isSuffix ".dtl" fname then
		    loop (OS.Path.joinDirFile {dir = Config.libRoot,
					       file = fname}
			  :: files)
		else
		    loop files

	val files = loop []
	val (_, files) = Order.order files
    in
	if !ErrorMsg.anyErrors then
	    Env.empty
	else
	    (Tycheck.allowExterns ();
	     foldl (fn (fname, G) => check' G fname) Env.empty files
	     before Tycheck.disallowExterns ())
    end

fun check fname =
    let
	val _ = ErrorMsg.reset ()
	val _ = Env.preTycheck ()

	val b = basis ()
    in
	if !ErrorMsg.anyErrors then
	    raise ErrorMsg.Error
	else
	    let
		val _ = Tycheck.disallowExterns ()
		val _ = ErrorMsg.reset ()
		val prog = Parse.parse fname
	    in
		if !ErrorMsg.anyErrors then
		    raise ErrorMsg.Error
		else
		    let
			val G' = Tycheck.checkFile b (Defaults.tInit ()) prog
		    in
			if !ErrorMsg.anyErrors then
			    raise ErrorMsg.Error
			else
			    (G', #3 prog)
		    end
	    end
    end

fun reduce fname =
    let
	val (G, body) = check fname
    in
	if !ErrorMsg.anyErrors then
	    NONE
	else
	    case body of
		SOME body =>
		let
		    val body' = Reduce.reduceExp G body
		in
		    (*printd (PD.hovBox (PD.PPS.Rel 0,
					 [PD.string "Result:",
					  PD.space 1,
					  p_exp body']))*)
		    SOME body'
		end
	      | _ => NONE
    end

fun eval fname =
    case reduce fname of
	(SOME body') =>
	if !ErrorMsg.anyErrors then
	    raise ErrorMsg.Error
	else
	    Eval.exec (Defaults.eInit ()) body'
      | NONE => raise ErrorMsg.Error

val dispatcher =
    Config.dispatcher ^ ":" ^ Int.toString Config.dispatcherPort

fun request fname =
    let
	val uid = Posix.ProcEnv.getuid ()
	val user = Posix.SysDB.Passwd.name (Posix.SysDB.getpwuid uid)

	val () = Acl.read Config.aclFile
	val () = Domain.setUser user

	val _ = check fname

	val uid = Posix.ProcEnv.getuid ()
	val user = Posix.SysDB.Passwd.name (Posix.SysDB.getpwuid uid)

	val context = OpenSSL.context (Config.certDir ^ "/" ^ user ^ ".pem",
				       Config.keyDir ^ "/" ^ user ^ "/key.pem",
				       Config.trustStore)

	val bio = OpenSSL.connect (context, dispatcher)

	val inf = TextIO.openIn fname

	fun loop lines =
	    case TextIO.inputLine inf of
		NONE => String.concat (List.rev lines)
	      | SOME line => loop (line :: lines)

	val code = loop []
    in
	TextIO.closeIn inf;
	Msg.send (bio, MsgConfig code);
	case Msg.recv bio of
	    NONE => print "Server closed connection unexpectedly.\n"
	  | SOME m =>
	    case m of
		MsgOk => print "Configuration succeeded.\n"
	      | MsgError s => print ("Configuration failed: " ^ s ^ "\n")
	      | _ => print "Unexpected server reply.\n";
	OpenSSL.close bio
    end
    handle ErrorMsg.Error => ()

fun service () =
    let
	val () = Acl.read Config.aclFile
	
	val context = OpenSSL.context (Config.serverCert,
				       Config.serverKey,
				       Config.trustStore)
	val _ = Domain.set_context context

	val sock = OpenSSL.listen (context, Config.dispatcherPort)

	fun loop () =
	    case OpenSSL.accept sock of
		NONE => ()
	      | SOME bio =>
		let
		    val user = OpenSSL.peerCN bio
		    val () = print ("\nConnection from " ^ user ^ "\n")
		    val () = Domain.setUser user

		    fun cmdLoop () =
			case Msg.recv bio of
			    NONE => (OpenSSL.close bio
				     handle OpenSSL.OpenSSL _ => ();
				     loop ())
			  | SOME m =>
			    case m of
				MsgConfig code =>
				let
				    val _ = print "Configuration:\n"
				    val _ = print code
				    val _ = print "\n"

				    val outname = OS.FileSys.tmpName ()
				    val outf = TextIO.openOut outname
				in
				    TextIO.output (outf, code);
				    TextIO.closeOut outf;
				    (eval outname;
				     Msg.send (bio, MsgOk))
				    handle ErrorMsg.Error =>
					   (print "Compilation error\n";
					    Msg.send (bio,
						      MsgError "Error during configuration evaluation"))
					 | OpenSSL.OpenSSL s =>
					   (print "OpenSSL error\n";
					    Msg.send (bio,
						      MsgError
							  ("Error during configuration evaluation: "
							   ^ s)));
					   OS.FileSys.remove outname;
					   (ignore (OpenSSL.readChar bio);
					    OpenSSL.close bio)
					   handle OpenSSL.OpenSSL _ => ();
					   loop ()
				end
			      | _ =>
				(Msg.send (bio, MsgError "Unexpected command")
				 handle OpenSSL.OpenSSL _ => ();
				 OpenSSL.close bio
				 handle OpenSSL.OpenSSL _ => ();
				 loop ())
		in
		    cmdLoop ()
		end
		    handle OpenSSL.OpenSSL s =>
			   (print ("OpenSSL error: " ^ s ^ "\n");
			    OpenSSL.close bio
			    handle OpenSSL.OpenSSL _ => ();
			    loop ())
			 | OS.SysErr (s, _) =>
			   (print ("System error: " ^ s ^ "\n");
			    OpenSSL.close bio
			    handle OpenSSL.OpenSSL _ => ();
			    loop ())
    in
	print "Listening for connections....\n";
	loop ();
	OpenSSL.shutdown sock
    end

fun slave () =
    let
	val host = Slave.hostname ()

	val context = OpenSSL.context (Config.certDir ^ "/" ^ host ^ ".pem",
				       Config.keyDir ^ "/" ^ host ^ "/key.pem",
				       Config.trustStore)

	val sock = OpenSSL.listen (context, Config.slavePort)

	fun loop () =
	    case OpenSSL.accept sock of
		NONE => ()
	      | SOME bio =>
		let
		    val peer = OpenSSL.peerCN bio
		    val () = print ("\nConnection from " ^ peer ^ "\n")
		in
		    if peer <> Config.dispatcherName then
			(print "Not authorized!\n";
			 OpenSSL.close bio;
			 loop ())
		    else let
			    fun loop' files =
				case Msg.recv bio of
				    NONE => print "Dispatcher closed connection unexpectedly\n"
				  | SOME m =>
				    case m of
					MsgFile file => loop' (file :: files)
				      | MsgDoFiles => (Slave.handleChanges files;
						       Msg.send (bio, MsgOk))
				      | _ => (print "Dispatcher sent unexpected command\n";
					      Msg.send (bio, MsgError "Unexpected command"))
			in
			    loop' [];
			    ignore (OpenSSL.readChar bio);
			    OpenSSL.close bio;
			    loop ()
			end
		end handle OpenSSL.OpenSSL s =>
			   (print ("OpenSSL error: "^ s ^ "\n");
			    OpenSSL.close bio
					  handle OpenSSL.OpenSSL _ => ();
			    loop ())
			 | OS.SysErr (s, _) =>
			   (print ("System error: "^ s ^ "\n");
			    OpenSSL.close bio
			    handle OpenSSL.OpenSSL _ => ();
			    loop ())
    in
	loop ();
	OpenSSL.shutdown sock
    end

fun autodocBasis outdir =
    let
	val dir = Posix.FileSys.opendir Config.libRoot

	fun loop files =
	    case Posix.FileSys.readdir dir of
		NONE => (Posix.FileSys.closedir dir;
			 files)
	      | SOME fname =>
		if String.isSuffix ".dtl" fname then
		    loop (OS.Path.joinDirFile {dir = Config.libRoot,
					       file = fname}
			  :: files)
		else
		    loop files

	val files = loop []
    in
	Autodoc.autodoc {outdir = outdir, infiles = files}
    end

end