Fantom

//
// Copyright (c) 2008, Brian Frank and Andy Frank
// Licensed under the Academic Free License version 3.0
//
// History:
//   8 Apr 08  Brian Frank  Creation
//

using web
using util

**
** LogMod is used log requests according to the W3C extended log file format.
**
** See [pod doc]`pod-doc#log`
**
const class LogMod : WebMod
{

//////////////////////////////////////////////////////////////////////////
// Construction
//////////////////////////////////////////////////////////////////////////

  **
  ** Constructor with it-block.
  **
  new make(|This|? f := null)
  {
    if (f != null) f.call(this)
    logger = FileLogger
    {
      it.dir      = this.dir
      it.filename = this.filename
      it.onOpen   = |out| { onOpen(out) }
    }
  }

//////////////////////////////////////////////////////////////////////////
// Fields
//////////////////////////////////////////////////////////////////////////

  **
  ** Directory used to store log file(s).
  **
  const File dir := noDir
  private static const File noDir := File(`no-dir-configured`)

  **
  ** Log filename pattern.  The name may contain a pattern between
  ** '{}' using the pattern format of `sys::DateTime.toLocale`.  For
  ** example to maintain a log file per month, use a filename such
  ** as "web-{YYYY-MM}.log".
  **
  const Str filename := ""

  **
  ** Format of the log records as a string of #Fields names.
  ** See [pod doc]`pod-doc#log`
  **
  const Str fields := "date time c-ip cs(X-Real-IP) cs-method cs-uri-stem cs-uri-query sc-status time-taken cs(User-Agent) cs(Referer)"

//////////////////////////////////////////////////////////////////////////
// Lifecycle
//////////////////////////////////////////////////////////////////////////

  private Void onOpen(OutStream out)
  {
    // write prefix
    out.printLine("#Remark ==========================================================================")
    out.printLine("#Remark " + DateTime.now.toLocale)
    out.printLine("#Version 1.0")
    out.printLine("#Software ${Type.of(this)} ${Pod.of(this).version}")
    out.printLine("#Start-Date " + DateTime.nowUtc.toLocale("YYYY-MM-DD hh:mm:ss"))
    out.printLine("#Fields $fields")
  }

  override Void onStop()
  {
    logger.stop
  }

  override Void onService()
  {
    try
    {
      s := StrBuf(256)
      fields.split.each |Str field, Int i|
      {
        if (i != 0) s.add(" ")

        // lookup format method for field
        m := formatters[field]
        if (m != null)
        {
          s.add(m.call(req, res))
          return;
        }

        // cs(HeaderName)
        if (field.startsWith("cs("))
        {
          s.add(formatCsHeader(req, field[3..-2]))
          return
        }

        // unknown field name
        s.add("-")
      }

      logger.writeStr(s.toStr)
    }
    catch (Err e)
    {
      logger.writeStr("# $e")
    }
  }

//////////////////////////////////////////////////////////////////////////
// Formatters
//////////////////////////////////////////////////////////////////////////

  internal static const Str:Method formatters :=
  [
    "date":         #formatDate,
    "time":         #formatTime,
    "c-ip":         #formatCIp,
    "c-port":       #formatCPort,
    "cs-method":    #formatCsMethod,
    "cs-uri":       #formatCsUri,
    "cs-uri-stem":  #formatCsUriStem,
    "cs-uri-query": #formatCsUriQuery,
    "sc-status":    #formatScStatus,
    "time-taken":   #formatTimeTaken,
  ]

  internal static Str formatDate(WebReq req, WebRes res)
  {
    return DateTime.nowUtc.toLocale("YYYY-MM-DD")
  }

  internal static Str formatTime(WebReq req, WebRes res)
  {
    return DateTime.nowUtc.toLocale("hh:mm:ss")
  }

  internal static Str formatCIp(WebReq req, WebRes res)
  {
    return req.remoteAddr.numeric
  }

  internal static Str formatCPort(WebReq req, WebRes res)
  {
    return req.remotePort.toStr
  }

  internal static Str formatCsMethod(WebReq req, WebRes res)
  {
    return req.method
  }

  internal static Str formatCsUri(WebReq req, WebRes res)
  {
    return req.uri.encode
  }

  internal static Str formatCsUriStem(WebReq req, WebRes res)
  {
    return req.uri.pathOnly.encode
  }

  internal static Str formatCsUriQuery(WebReq req, WebRes res)
  {
    if (req.uri.query.isEmpty) return "-"
    return Uri.encodeQuery(req.uri.query)
  }

  internal static Str formatScStatus(WebReq req, WebRes res)
  {
    return res.statusCode.toStr
  }

  internal static Str formatTimeTaken(WebReq req, WebRes res)
  {
    d := Duration.now - req.stash["web.startTime"]
    return d.toMillis.toStr
  }

  internal static Str formatCsHeader(WebReq req, Str headerName)
  {
    s := req.headers[headerName]
    if (s == null || s.isEmpty) return "-"
    return "\"" + s.replace("\"", "\"\"") + "\""
  }

//////////////////////////////////////////////////////////////////////////
// Fields
//////////////////////////////////////////////////////////////////////////

  private const FileLogger logger

}