** SETTING: chat-timeline-user    width=10
**
** If this setting is defined and is not an empty string, then
** timeline events are posted to the chat as they arrive. The synthesized
** chat messages appear to come from the user identified by this setting,
** not the user on the timeline event.
**
** All chat messages that come from the chat-timeline-user are
** interpreted as text/x-fossil-wiki instead of as text/x-markdown.
** For this reason, the chat-timeline-user name should probably not be
** a real user.
*/
/*
** WEBPAGE: chat loadavg-exempt
**
** Start up a browser-based chat session.
**
** This is the main page that humans use to access the chatroom.  Simply

    db_finalize(&q);
    blob_reset(&b);
  }
  db_commit_transaction();
}

/*
** This routine receives raw (user-entered) message text and
** transforms it into HTML that is safe to insert using innerHTML. As
** of 2021-09-19, it does so by using wiki_convert() or
** markdown_to_html() to convert wiki/markdown-formatted zMsg to HTML.
**
** Space to hold the returned string is obtained from fossil_malloc()
** and must be freed by the caller.
*/
static char *chat_format_to_html(const char *zMsg, int isWiki){
  Blob out;
  blob_init(&out, "", 0);
  if( zMsg==0 || zMsg[0]==0 ){
    /* No-op */
  }else if( isWiki ){
    /* Used for chat-timeline-user.  The zMsg is text/x-fossil-wiki. */
    Blob bIn;
    blob_init(&bIn, zMsg, (int)strlen(zMsg));
    wiki_convert(&bIn, &out, WIKI_INLINE);
  }else{
    /* The common case:  zMsg is text/x-markdown */
    Blob bIn;
    blob_init(&bIn, zMsg, (int)strlen(zMsg));
    markdown_to_html(&bIn, NULL, &out);
  }
  return blob_str(&out);
}

/*
** WEBPAGE: chat-download hidden loadavg-exempt
**
** Download the CHAT.FILE attachment associated with a single chat
** entry.  The "name" query parameter begins with an integer that
** identifies the particular chat message. The integer may be followed
** by a / and a filename, which will (A) indicate to the browser to
** use the indicated name when saving the file and (B) be used to
** guess the mimetype in some particular cases involving the "render"
** flag.
**
** If the "render" URL parameter is provided, the blob has a size
** greater than zero, and blob meets one of the following conditions
** then the fossil-rendered form of that content is returned, rather
** than the original:
**
** - Mimetype is text/x-markdown or text/markdown: emit HTML.
**
** - Mimetype is text/x-fossil-wiki or P("name") ends with ".wiki":
**   emit HTML.
**
** - Mimetype is text/x-pikchr or P("name") ends with ".pikchr": emit
**   image/svg+xml if rendering succeeds or text/html if rendering
**   fails.
*/
void chat_download_webpage(void){
  int msgid;
  Blob r;
  const char *zMime;
  const char *zName = PD("name","0");
  login_check_credentials();
  if( !g.perm.Chat ){
    style_header("Chat Not Authorized");
    @ <h1>Not Authorized</h1>
    @ <p>You do not have permission to use the chatroom on this
    @ repository.</p>
    style_finish_page();
    return;
  }
  chat_create_tables();
  msgid = atoi(zName);
  blob_zero(&r);
  zMime = db_text(0, "SELECT fmime FROM chat wHERE msgid=%d", msgid);
  if( zMime==0 ) return;
  db_blob(&r, "SELECT file FROM chat WHERE msgid=%d", msgid);
  if( r.nUsed>0 && P("render")!=0 ){
    /* Maybe return fossil-rendered form of the content. */
    Blob r2 = BLOB_INITIALIZER;    /* output target for rendering */
    const char * zMime2 = 0;       /* adjusted response mimetype */
    if(fossil_strcmp(zMime, "text/x-markdown")==0
       /* Firefox uploads md files with the mimetype text/markdown */
       || fossil_strcmp(zMime, "text/markdown")==0){
      markdown_to_html(&r, 0, &r2);
      safe_html(&r2);
      zMime2 = "text/html";
    }else if(fossil_strcmp(zMime, "text/x-fossil-wiki")==0
             || sqlite3_strglob("*.wiki", zName)==0){
      /* .wiki files get uploaded as application/octet-stream */
      wiki_convert(&r, &r2, 0);
      zMime2 = "text/html";
    }else if(fossil_strcmp(zMime, "text/x-pikchr")==0
             || sqlite3_strglob("*.pikchr",zName)==0){
      /* .pikchr files get uploaded as application/octet-stream */
      const char *zPikchr = blob_str(&r);
      int w = 0, h = 0;
      char *zOut = pikchr(zPikchr, "pikchr", 0, &w, &h);
      if(zOut){
        blob_append(&r2, zOut, -1);
      }
      zMime2 = w>0 ? "image/svg+xml" : "text/html";
      free(zOut);
    }
    if(r2.aData!=0){
      blob_swap(&r, &r2);
      blob_reset(&r2);
      zMime = zMime2;
    }
  }
  cgi_set_content_type(zMime);
  cgi_set_content(&r);
}


/*
** WEBPAGE: chat-delete hidden loadavg-exempt

        //'-',pad2(d.getDate()), ' ',
        d.getHours(),":",
        (d.getMinutes()+100).toString().slice(1,3),
        ' ', dowMap[d.getDay()]
      ].join('');
    };

    /**
       Returns true if this page believes it can embed a view of the
       file wrapped by the given message object, else returns false.
    */
    const canEmbedFile = function f(msg){
      if(!f.$rx){
        f.$rx = /\.((html?)|(txt)|(md)|(wiki)|(pikchr))$/i;
        f.$specificTypes = [
          'text/plain',
          'text/html',
          'text/x-markdown',
          /* Firefox sends text/markdown when uploading .md files */
          'text/markdown',
          'text/x-pikchr',
          'text/x-fossil-wiki'
          // add more as we discover which ones Firefox won't
          // force the user to try to download.
        ];
      }
      if(msg.fmime){
        if(msg.fmime.startsWith("image/")
           || f.$specificTypes.indexOf(msg.fmime)>=0){
          return true;
        }
      }
      return (msg.fname && f.$rx.test(msg.fname));
    };

    /**
      Returns true if the given message object "should"
      be embedded in fossil-rendered form instead of
      raw content form. This is only intended to be passed
      message objects for which canEmbedFile() returns true.
    */
    const shouldWikiRenderEmbed = function f(msg){
      if(!f.$rx){
        f.$rx = /\.((md)|(wiki)|(pikchr))$/i;
        f.$specificTypes = [
          'text/x-markdown',
          'text/markdown' /* Firefox-uploaded md files */,
          'text/x-pikchr',
          'text/x-fossil-wiki'
          // add more as we discover which ones Firefox won't
          // force the user to try to download.
        ];
      }
      if(msg.fmime){

        if(f.$specificTypes.indexOf(msg.fmime)>=0) return true;
      }
      return msg.fname && f.$rx.test(msg.fname);
    };

    const adjustIFrameSize = function(msgObj){
      const iframe = msgObj.e.iframe;
      const body = iframe.contentWindow.document.querySelector('body');

            const w = D.addClass(D.div(), 'attachment-link');
            const a = D.a(downloadUri,
              // ^^^ add m.fname to URL to cause downloaded file to have that name.
              "(" + m.fname + " " + m.fsize + " bytes)"
            )
            D.attr(a,'target','_blank');
            D.append(w, a);
            console.warn("canEmbedFile(",m,") =",canEmbedFile(m));
            if(canEmbedFile(m)){
              /* Add an option to embed HTML attachments in an iframe. The primary
                 use case is attached diffs. */
              const shouldWikiRender = shouldWikiRenderEmbed(m);
              const downloadArgs = shouldWikiRender ? '?render' : '';
              console.warn("downloadArgs",downloadArgs,m);
              D.addClass(contentTarget, 'wide');
              const embedTarget = this.e.content;
              const self = this;
              const btnEmbed = D.attr(D.checkbox("1", false), 'id',
                                      'embed-'+ds.msgid);
              const btnLabel = D.label(btnEmbed, shouldWikiRender
                                       ? "Embed (fossil-rendered)" : "Embed");
              /* Maintenance reminder: do not disable the toggle
                 button while the content is loading because that will
                 cause it to get stuck in disabled mode if the browser
                 decides that loading the content should prompt the
                 user to download it, rather than embed it in the
                 iframe. */
              btnEmbed.addEventListener('change',function(){

                }
                const iframe = self.e.iframe = document.createElement('iframe');
                D.append(embedTarget, iframe);
                iframe.addEventListener('load', function(){
                  self.e.$iframeLoaded = true;
                  adjustIFrameSize(self);
                });
                iframe.setAttribute('src', downloadUri + downloadArgs);
              });
              D.append(w, btnEmbed, btnLabel);
            }
            contentTarget.appendChild(w);
          }
        }
        if(m.xmsg){

<title>Change Log</title>

<h2 id='v2_21'>Changes for version 2.21 (pending)</h2>
  *  Add the ability to put text descriptions on ticket report formats.
  *  Upgrade the test-find-pivot command to the [/help/merge-base|merge-base command].
  *  The [/help?cmd=/chat|/chat page] can now embed fossil-rendered
     views of wiki/markdown/pikchr file attachments with the caveat that such
     embedding happens in an iframe and thus does not inherit styles and such
     from the containing browser window.

<h2 id='v2_20'>Changes for version 2.20 (2022-11-16)</h2>
  *  Added the [/help?cmd=chat-timeline-user|chat-timeline-user setting].  If
     it is not an empty string, then any changes that would appear on the timeline
     are announced in [./chat.md|the chat room].
  *  The /unsubscribe page now requests confirmation. [./alerts.md|Email notifications]
     now contain only an "Unsubscribe" link, and not a link to subscription management.