(* Copyright (C) 2004-2011, HELM Team.
 * 
 * This file is part of HELM, an Hypertextual, Electronic
 * Library of Mathematics, developed at the Computer Science
 * Department, University of Bologna, Italy.
 * 
 * HELM 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.
 * 
 * HELM 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 HELM; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA  02111-1307, USA.
 * 
 * For details, see the HELM World-Wide-Web page,
 * http://helm.cs.unibo.it/
 *)

exception SvnError of string;;

let mutex = Mutex.create ();;

let to_be_committed = ref [];;

let exec_process cmd =
  let (stdout, stdin, stderr) as chs = Unix.open_process_full cmd [||] in
  let outlines = ref [] in
  let errlines = ref [] in
  (try
     while true do
       outlines := input_line stdout :: !outlines;
     done;
     assert false
   with End_of_file -> 
   (try
     while true do
       errlines := input_line stderr :: !errlines;
     done;
     assert false
    with End_of_file -> 
     match (Unix.close_process_full chs) with
     | Unix.WEXITED errno -> errno, !outlines, !errlines 
     | _ -> assert false))

let string_of_output outlines errlines =
  let output = "std out =\n" ^ String.concat "\n" (List.rev outlines) in
  let errors = "std err =\n" ^ String.concat "\n" (List.rev errlines) in
  output ^ "\n\n" ^ errors

type svn_flag = 
| Add
| Conflict
| Modified
| NotAdded
| Delete
| Update
| Merge

type matita_flag =
| MUnversioned
| MSynchronized
| MAdd
| MModified
| MConflict

let string_of_matita_flag = function
| MUnversioned -> "unversioned"
| MSynchronized -> "synchronized"
| MAdd -> "new"
| MModified -> "modified"
| MConflict -> "conflict!"

exception SvnAnomaly of string

let stat_classify line =
  let rec aux n acc =
    match (line.[n], n) with
    | _, n when n = 7 -> String.sub line 8 ((String.length line) - 8), acc
    | ' ', _ -> aux (n+1) acc
    | 'A',0 -> aux (n+1) (Add::acc)
    | 'C',_ when n = 0 || n = 1 -> aux (n+1) (Conflict::acc)
(*  | 'D',0 -> aux (n+1) (Delete::acc) *)
(*  | 'I',0 -> aux (n+1) (Ignore::acc) *)
    | 'M',_ when n = 0 || n = 1 -> aux (n+1) (Modified::acc)
(*  | 'R',0 -> aux (n+1) (Replaced::acc) *)
(*  | 'X',0 -> aux (n+1) (UnversionedDir::acc) *)
    | '?',0 -> aux (n+1) (NotAdded::acc)
(*  | '!',0 -> aux (n+1) (Missing::acc) *)
(*  | '~',0 -> aux (n+1) (Obstructed::acc) *)
(*  | 'L',2 -> aux (n+1) (Lock::acc) *)
(*  | '+',3 -> aux (n+1) (History::acc) *)
(*  | 'S',4 -> aux (n+1) (SwitchedUrl::acc) *)
(*  | 'X',4 -> aux (n+1) (External::acc) *)
(*  | 'K',5 -> aux (n+1) (LockToken::acc) *)
(*  | 'C',6 -> aux (n+1) (TreeConflict::acc) *)
    | _ -> raise (SvnAnomaly line)
  in aux 0 []

let stat_user user =
  let rt_dir = Helm_registry.get "matita.rt_base_dir" in
  let repo = Helm_registry.get "matita.weblib" in

  let errno, outlines, errlines = exec_process 
    ("svn stat " ^ rt_dir ^ "/users/" ^ user ^ "/")
  in
  let files, anomalies = 
    List.fold_left (fun (facc,eacc) line ->
      try
        (stat_classify line::facc), eacc
      with
      | SvnAnomaly l -> facc, l::eacc) ([],[]) outlines
  in
  if errno = 0 then files, anomalies
  else raise (SvnError ("Anomalies: " ^ (String.concat "\n" anomalies) ^ "\n\n" ^ (string_of_output outlines errlines)))
;;

(* update and checkout *)
let up_classify line =
  let rec aux n acc =
    match (line.[n], n) with
    | _, n when n = 4 -> String.sub line 5 ((String.length line) - 5), acc
    | ' ', _ -> aux (n+1) acc
    | 'A',_ when n = 0 || n = 1 -> aux (n+1) (Add::acc)
    | 'C',_ when n = 0 || n = 1 -> aux (n+1) (Conflict::acc)
    | 'D',_ when n = 0 || n = 1 -> aux (n+1) (Delete::acc)
    | 'U',_ when n = 0 || n = 1 -> aux (n+1) (Update::acc)
    | 'G',_ when n = 0 || n = 1 -> aux (n+1) (Merge::acc)
(*  | 'E',_ when n = 0 || n = 1 -> aux (n+1) (Exist::acc) *)
    | _ -> raise (SvnAnomaly line)
  in aux 0 []

(* this should be executed only for a freshly created user so no CS is needed *)
let checkout user =
  let rt_dir = Helm_registry.get "matita.rt_base_dir" in
  let repo = Helm_registry.get "matita.weblib" in

  let errno, outlines, errlines = exec_process 
    ("svn co " ^ repo ^ " " ^ rt_dir ^ "/users/" ^ user ^ "/")
  in
  let files, anomalies = 
    List.fold_left (fun (facc,eacc) line ->
      try
        (up_classify line::facc), eacc
      with
      | SvnAnomaly l -> facc, l::eacc) ([],[]) outlines
  in
  if errno = 0 then List.map (fun (f,_) -> f,MSynchronized) files 
  else raise (SvnError (string_of_output outlines errlines))

let html_of_library uid ft =
  let i = ref 0 in
  let newid () = incr i; ("node" ^ string_of_int !i) in

  let basedir = (Helm_registry.get "matita.rt_base_dir") ^ "/users/" ^ uid in

  let branch lpath children =
    let id = newid () in
    let name = Filename.basename lpath in
    let name = if name <> "." then name else "cic:/matita" in
    let lpath =
      try 
        if String.sub lpath 0 2 <> "./" then lpath 
        else String.sub lpath 2 (String.length lpath - 2)
      with Invalid_argument _ -> lpath
    in
    let flag = 
      try List.assoc lpath ft 
      with Not_found -> MSynchronized in
    let szflag = string_of_matita_flag flag in
    "<span class=\"trigger\" onClick=\"showBranch('" ^ id ^ "','" ^ lpath ^ "/')\">\n" ^
    "<img src=\"treeview/closed.gif\" id=\"I" ^ id ^ "\"/>\n" ^
    name ^ " " ^ szflag ^ "<br/></span>\n" ^
    "<span class=\"branch\" id=\"" ^ id ^ "\">\n" ^
    children ^ "\n</span>"
  in
  let leaf lpath =
    "<img src=\"treeview/doc.gif\"/>\n" ^
    "<a href=\"javascript:void(0)\" onClick=\"selectFile('" ^ lpath ^ "')\" onDblClick=\"dialogBox.callback('" ^ lpath ^ "')\">" ^ 
     (Filename.basename lpath) ^ "</a><br/>"
  in

  let rec aux path =
    let lpath filename = path ^ "/" ^ filename in
    let gpath filename = basedir ^ "/" ^ path ^ "/" ^ filename in
    let dirlist = 
      List.filter (fun x -> String.sub x 0 1 <> ".") 
        (Array.to_list (Sys.readdir (basedir ^ "/" ^ path))) in
    let subdirs = List.filter (fun x -> Sys.is_directory (gpath x)) dirlist in
    let scripts = 
      List.filter (fun x -> 
        try
          let i = String.rindex x '.' in
          let len = String.length x - i in
          not (Sys.is_directory (gpath x)) && 
          (String.sub x 0 1 <> ".") && (String.sub x i len = ".ma")
        with Not_found | Invalid_argument _ -> false) dirlist in
    let subdirtags = 
      String.concat "\n" (List.map (fun x -> aux (lpath x)) subdirs) in
    let scripttags =
      String.concat "\n" 
       (List.map (fun x -> leaf (lpath x)) scripts)
    in
    branch path (subdirtags ^ "\n" ^ scripttags)
  in

  let res = aux "." in
  prerr_endline "BEGIN TREE";prerr_endline res;prerr_endline "END TREE";
  res
;;

let reset_lib () =
  let to_be_removed = (Helm_registry.get "matita.rt_base_dir") ^ "/users/*" in
  ignore (Sys.command ("rm -rf " ^ to_be_removed))
;;

(* adds a user to the commit queue; concurrent instances possible, so we
 * enclose the update in a CS
 *)
let add_user uid =
  Mutex.lock mutex;
  to_be_committed := uid::List.filter (fun x -> x <> uid) !to_be_committed;
  Mutex.unlock mutex;
;;

let update_user user =
  let rt_dir = Helm_registry.get "matita.rt_base_dir" in
  let repo = Helm_registry.get "matita.weblib" in

  let errno, outlines, errlines = exec_process 
    ("svn up " ^ rt_dir ^ "/users/" ^ user ^ "/")
  in
  let files, anomalies = 
    List.fold_left (fun (facc,eacc) line ->
      try
        (up_classify line::facc), eacc
      with
      | SvnAnomaly l -> facc, l::eacc) ([],[]) outlines
  in
  if errno = 0 then files, anomalies
  else raise (SvnError (string_of_output outlines errlines))
;;

(* this function and the next one should only be called by the server itself (or
 * the admin) at a scheduled time, so no concurrent instances and no CS needed
 * also, svn should already be safe as far as concurrency is concerned *)
let commit user =
  let rt_dir = Helm_registry.get "matita.rt_base_dir" in
  let repo = Helm_registry.get "matita.weblib" in

  let errno, outlines, errlines = exec_process 
    ("svn ci --message \"commit by user " ^ user ^ "\" " ^ rt_dir ^ "/users/" ^ user ^ "/")
  in
  if errno = 0 then ()
  else raise (SvnError (string_of_output outlines errlines))
;;

let do_global_commit () =
  prerr_endline ("to be committed: " ^ String.concat " " !to_be_committed);
  List.fold_left
    (fun acc u ->
       try
         commit u;
         acc
       with
       | SvnError outstr -> 
           prerr_endline outstr;
           u::acc)
  [] (List.rev !to_be_committed)
;;