(* COCANWIKI - a wiki written in Objective CAML.
 * Written by Richard W.M. Jones <rich@merjis.com>.
 * Copyright (C) 2004 Merjis Ltd.
 * $Id: search.ml,v 1.10 2006/03/28 16:24:08 rich Exp $
 *
 * 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; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *)

open Apache
open Registry
open Cgi
open Cgi_escape
open Printf

open Cocanwiki
open Cocanwiki_template
open Cocanwiki_strings
open Cocanwiki_date

let split_words = Pcre.regexp "\\W+"

let run r (q : cgi) dbh hostid host user =
  let template = get_template dbh hostid "search.html" in

  template#set "canonical_hostname" host.canonical_hostname;

  (* Get the query, if it exists. *)
  let query = try q#param "q" with Not_found -> "" in
  let have_query = not (string_is_whitespace query) in
  template#set "query" query;
  template#conditional "have_query" have_query;

  (* Permissions. *)
  let can_edit = can_edit host user in
  template#conditional "can_edit" can_edit;

  (* Search old versions?  Only permit this if can_edit is true. *)
  let old_versions =
    if can_edit then (
      try q#param_true "old_versions"
      with Not_found -> false
    )
    else false in

  (* If we have a query, make some results. *)
  let have_results =
    if have_query then (
      (* Get the keywords from the query string. *)
      let keywords = Pcre.split ~rex:split_words query in
      let keywords =
	List.filter (fun s -> not (string_is_whitespace s)) keywords in
      let keywords = List.map String.lowercase keywords in

      (* Turn the keywords into a tsearch2 ts_query string. *)
      let tsquery = String.concat "&" keywords in

      (* Search the titles first. *)
      let rows =
	if not old_versions then
	  PGSQL(dbh)
	    "select id, url, url_deleted, title, last_modified_date,
                    (lower (title) = lower ($query)) as exact
               from pages
              where hostid = $hostid
	        and url is not null
	        and redirect is null
                and title_description_fti @@ to_tsquery ('default', $tsquery)
              order by exact desc, last_modified_date desc, title"
	else
	  PGSQL(dbh)
	    "select id, url, url_deleted, title, last_modified_date,
                    (lower (title) = lower ($query)) as exact
               from pages
              where hostid = $hostid
	        and redirect is null
                and title_description_fti @@ to_tsquery ('default', $tsquery)
              order by exact desc, last_modified_date desc, title" in

      let titles =
	List.map (function
		  | (_, Some url, None, title, last_modified, _) ->
		      url, title, None, last_modified
		  | (version, None, Some url, title, last_modified, _) ->
		      url, title, Some version, last_modified
		  | _ -> assert false) rows in

      let have_titles = titles <> [] in
      template#conditional "have_titles" have_titles;

      (* Search the contents. *)
      let rows =
	if not old_versions then
	  PGSQL(dbh)
	  "select c.id, p.id, p.url, p.url_deleted, p.title,
                  p.last_modified_date
             from contents c, pages p
            where c.pageid = p.id
              and p.hostid = $hostid
              and url is not null
              and p.redirect is null
              and c.content_fti @@ to_tsquery ('default', $tsquery)
            order by p.last_modified_date desc, p.title
            limit 50"
	else
	  PGSQL(dbh)
	  "select c.id, p.id, p.url, p.url_deleted, p.title,
                  p.last_modified_date
             from contents c, pages p
            where c.pageid = p.id
              and p.hostid = $hostid
              and p.redirect is null
              and c.content_fti @@ to_tsquery ('default', $tsquery)
            order by p.last_modified_date desc, p.title
            limit 50" in

      let contents =
	List.map (function
		   | (contentid, _, Some url, None, title, last_modified) ->
		       contentid, url, title, None, last_modified
		   | (contentid, version, None, Some url, title,
		      last_modified) ->
		       contentid, url, title, Some version, last_modified
		   | _ -> assert false) rows in

      let have_contents = contents <> [] in
      template#conditional "have_contents" have_contents;

      (* Pull out the actual text which matched so we can generate a summary.
       * XXX tsearch2 can actually do better than this by emboldening
       * the text which maps.
       *)
      let content_map =
	if contents = [] then []
	else (
	  let rows =
	    let contentids =
	      List.map (fun (contentid, _,_,_,_) -> contentid) contents in
	    PGSQL(dbh)
	      "select id, sectionname, content from contents
                where id in $@contentids" in
	  List.map (fun (id, sectionname, content) ->
		      id, (sectionname, content)) rows
	) in

      (* Generate the final tables. *)
      let table =
	List.map (fun (url, title, version, last_modified) ->
		    let have_version, version =
		      match version with
			  None -> false, 0l
			| Some version -> true, version in
		    let last_modified = printable_date last_modified in
		    [ "url", Template.VarString url;
		      "title", Template.VarString title;
		      "have_version", Template.VarConditional have_version;
		      "version", Template.VarString (Int32.to_string version);
		      "last_modified", Template.VarString last_modified ]
		 ) titles in
      template#table "titles" table;

      let table =
	List.map
	  (fun (contentid, url, title, version, last_modified) ->
	     let have_version, version =
	       match version with
		   None -> false, 0l
		 | Some version -> true, version in
	     let sectionname, content = List.assoc contentid content_map in
	     let have_sectionname, sectionname =
	       match sectionname with
		   None -> false, ""
		 | Some sectionname -> true, sectionname in
	     let content =
	       truncate 160
		 (Wikilib.text_of_xhtml
		    (Wikilib.xhtml_of_content dbh hostid content)) in
	     let linkname = linkname_of_sectionname sectionname in
	     let last_modified = printable_date last_modified in
	     [ "url", Template.VarString url;
	       "title", Template.VarString title;
	       "have_version", Template.VarConditional have_version;
	       "version", Template.VarString (Int32.to_string version);
	       "have_sectionname", Template.VarConditional have_sectionname;
	       "sectionname", Template.VarString sectionname;
	       "linkname", Template.VarString linkname;
	       "content", Template.VarString content;
	       "last_modified", Template.VarString last_modified ]
	  ) contents in
      template#table "contents" table;

      (* Do we have any results? *)
      let have_results = have_titles || have_contents in
      have_results
    )
    else false in
  template#conditional "have_results" have_results;

  q#template template

let () =
  register_script ~restrict:[CanView] run