#!/usr/bin/env node
//
// bunyan -- filter and pretty-print JSON logs, like Bunyan logs.
//
// See <https://github.com/trentm/node-bunyan>.
//

var VERSION = "0.1.0";

var util = require('util');
var pathlib = require('path');
var vm = require('vm');
var warn = console.warn;



//---- globals and constants

// Output modes.
var OM_PAUL = 1;
var OM_JSON = 2;
var OM_INSPECT = 3;
var OM_SIMPLE = 4;
var OM_FROM_NAME = {
  "paul": OM_PAUL,
  "json": OM_JSON,
  "inspect": OM_INSPECT,
  "simple": OM_SIMPLE
}


// Levels
var DEBUG = 1;
var INFO = 2;
var WARN = 3;
var ERROR = 4;
var FATAL = 5;

var levelFromName = {
  'debug': DEBUG,
  'info': INFO,
  'warn': WARN,
  'error': ERROR,
  'fatal': FATAL
};
var nameFromLevel = [undefined].concat(Object.keys(levelFromName));
var upperNameFromLevel = [undefined].concat(
  Object.keys(levelFromName).map(function (l) { return l.toUpperCase(); }));



//---- support functions

function getVersion() {
  return VERSION;
}


var format = util.format;
if (!format) {
  // If not node 0.6, then use its `util.format`:
  // <https://github.com/joyent/node/blob/master/lib/util.js#L22>:
  var inspect = util.inspect;
  var formatRegExp = /%[sdj%]/g;
  format = function format(f) {
    if (typeof f !== 'string') {
      var objects = [];
      for (var i = 0; i < arguments.length; i++) {
        objects.push(inspect(arguments[i]));
      }
      return objects.join(' ');
    }
  
    var i = 1;
    var args = arguments;
    var len = args.length;
    var str = String(f).replace(formatRegExp, function(x) {
      if (i >= len) return x;
      switch (x) {
        case '%s': return String(args[i++]);
        case '%d': return Number(args[i++]);
        case '%j': return JSON.stringify(args[i++]);
        case '%%': return '%';
        default:
          return x;
      }
    });
    for (var x = args[i]; i < len; x = args[++i]) {
      if (x === null || typeof x !== 'object') {
        str += ' ' + x;
      } else {
        str += ' ' + inspect(x);
      }
    }
    return str;
  };
}


function isArray(ar) {
  return ar instanceof Array ||
         Array.isArray(ar) ||
         (ar && ar !== Object.prototype && isArray(ar.__proto__));
}

// json_parse.js (<https://github.com/douglascrockford/JSON-js>)
// START json_parse
var json_parse=function(){"use strict";var a,b,c={'"':'"',"\\":"\\","/":"/",b:"\b",f:"\f",n:"\n",r:"\r",t:"\t"},d,e=function(b){throw{name:"SyntaxError",message:b,at:a,text:d}},f=function(c){return c&&c!==b&&e("Expected '"+c+"' instead of '"+b+"'"),b=d.charAt(a),a+=1,b},g=function(){var a,c="";b==="-"&&(c="-",f("-"));while(b>="0"&&b<="9")c+=b,f();if(b==="."){c+=".";while(f()&&b>="0"&&b<="9")c+=b}if(b==="e"||b==="E"){c+=b,f();if(b==="-"||b==="+")c+=b,f();while(b>="0"&&b<="9")c+=b,f()}a=+c;if(!isFinite(a))e("Bad number");else return a},h=function(){var a,d,g="",h;if(b==='"')while(f()){if(b==='"')return f(),g;if(b==="\\"){f();if(b==="u"){h=0;for(d=0;d<4;d+=1){a=parseInt(f(),16);if(!isFinite(a))break;h=h*16+a}g+=String.fromCharCode(h)}else if(typeof c[b]=="string")g+=c[b];else break}else g+=b}e("Bad string")},i=function(){while(b&&b<=" ")f()},j=function(){switch(b){case"t":return f("t"),f("r"),f("u"),f("e"),!0;case"f":return f("f"),f("a"),f("l"),f("s"),f("e"),!1;case"n":return f("n"),f("u"),f("l"),f("l"),null}e("Unexpected '"+b+"'")},k,l=function(){var a=[];if(b==="["){f("["),i();if(b==="]")return f("]"),a;while(b){a.push(k()),i();if(b==="]")return f("]"),a;f(","),i()}}e("Bad array")},m=function(){var a,c={};if(b==="{"){f("{"),i();if(b==="}")return f("}"),c;while(b){a=h(),i(),f(":"),Object.hasOwnProperty.call(c,a)&&e('Duplicate key "'+a+'"'),c[a]=k(),i();if(b==="}")return f("}"),c;f(","),i()}}e("Bad object")};return k=function(){i();switch(b){case"{":return m();case"[":return l();case'"':return h();case"-":return g();default:return b>="0"&&b<="9"?g():j()}},function(c,f){var g;return d=c,a=0,b=" ",g=k(),i(),b&&e("Syntax error"),typeof f=="function"?function h(a,b){var c,d,e=a[b];if(e&&typeof e=="object")for(c in e)Object.prototype.hasOwnProperty.call(e,c)&&(d=h(e,c),d!==undefined?e[c]=d:delete e[c]);return f.call(a,b,e)}({"":g},""):g}}();
// END json_parse

function printHelp() {
  util.puts("Usage:");
  util.puts("  cat some-json-log-file.log | bunyan [OPTIONS]");
  util.puts("");
  util.puts("Pipe in your JSON log file content (e.g. bunyan logs) for nicer ");
  util.puts("output");
  util.puts("");
  util.puts("Options:");
  util.puts("  -h, --help    print this help info and exit");
  util.puts("  --version     print version of this command and exit");
  util.puts("");
  util.puts("  -e CODE       execute the given code on input, on each array item");
  util.puts("                if '-a' is used. This execution is run before ");
  util.puts("                filtering.");
  util.puts("");
  util.puts("  -o, --output MODE   Specify an output mode. One of");
  util.puts("                  json: JSON output, 2-space indent");
  util.puts("                  json-N: JSON output, N-space indent, e.g. 'json-4'");
  util.puts("                  inspect: node.js `util.inspect` output");
  util.puts("  -j            shortcut for `-o json`");
  util.puts("");
  util.puts("See <https://github.com/trentm/json> for more complete docs.");
}


/**
 * Parse the command-line options and arguments into an object.
 *
 *    {
 *      'args': [...]       // arguments
 *      'help': true,       // true if '-h' option given
 *       // etc.
 *    }
 *
 * @return {Object} The parsed options. `.args` is the argument list.
 * @throws {Error} If there is an error parsing argv.
 */
function parseArgv(argv) {
  var parsed = {
    args: [],
    help: false,
    quiet: false,
    dropHeaders: false,
    executableSnippets: [],
    outputMode: OM_PAUL,
    jsonIndent: 2
  };
  
  // Turn '-iH' into '-i -H', except for argument-accepting options.
  var args = argv.slice(2);  // drop ['node', 'scriptname']
  var newArgs = [];
  var optTakesArg = {'d': true, 'o': true};
  for (var i = 0; i < args.length; i++) {
    if (args[i].charAt(0) === "-" && args[i].charAt(1) !== '-' && args[i].length > 2) {
      var splitOpts = args[i].slice(1).split("");
      for (var j = 0; j < splitOpts.length; j++) {
        newArgs.push('-' + splitOpts[j])
        if (optTakesArg[splitOpts[j]]) {
          var optArg = splitOpts.slice(j+1).join("");
          if (optArg.length) {
            newArgs.push(optArg);
          }
          break;
        }
      }
    } else {
      newArgs.push(args[i]);
    }
  }
  args = newArgs;

  endOfOptions = false;
  while (args.length > 0) {
    var arg = args.shift();
    switch(arg) {
      case "--":
        endOfOptions = true;
        break;
      case "-h": // display help and exit
      case "--help":
        parsed.help = true;
        break;
      case "--version":
        parsed.version = true;
        break;
      case "-q":
      case "--quiet":
        parsed.quiet = true;
        break;
      case "-H": // drop any headers
        parsed.dropHeaders = true;
        break;
      case "-o":
      case "--output":
        var name = args.shift();
        var idx = name.lastIndexOf('-');
        if (idx !== -1) {
          var indent = Number(name.slice(idx+1));
          if (! isNaN(indent)) {
            parsed.jsonIndent = indent;
            name = name.slice(0, idx);
          }
        }
        parsed.outputMode = OM_FROM_NAME[name];
        if (parsed.outputMode === undefined) {
          throw new Error("unknown output mode: '"+name+"'");
        }
        break;
      case "-j": // output with JSON.stringify
        parsed.outputMode = OM_JSON;
        break;
      case "-e":
        parsed.executableSnippets.push(args.shift());
        break;
      default: // arguments
        if (!endOfOptions && arg.length > 0 && arg[0] === '-') {
          throw new Error("unknown option '"+arg+"'");
        }
        parsed.args.push(arg);
        break;
    } 
  }
  //TODO: '--' handling and error on a first arg that looks like an option.

  return parsed;
}


function isInteger(s) {
  return (s.search(/^-?[0-9]+$/) == 0);
}


/**
 * Print out a single result, considering input options.
 */
function handleLogLine(line, opts) {
  // Handle non-JSON lines.
  var rec;
  if (!line) {
    return emit(line + '\n');
  } else if (line[0] !== '{') {
    return emit(line + '\n');  // not JSON
  } else {
    try {
      rec = JSON.parse(line);
    } catch(e) {
      return emit(line + '\n');
    }
  }

  switch (opts.outputMode) {
  case OM_PAUL:
    // Single-line msg:
    //    [time] LEVEL: service[/component] on hostname: msg (request_id, $latencyms)
    // Multi-line msg:
    //    [time] LEVEL: service[/component] on hostname: (request_id, $latencyms)
    //        msg
    // Request/HTTP info:
    //    TODO
    var svc = rec.service;
    if (rec.component) {
      svc += '/' + rec.component;
    }
    var levelStr = (upperNameFromLevel[rec.level]
      || "<unknown-level " + rec.level + ">");
    var extras = [
      rec.request_id || "<no-request_id>"
    ];
    if (rec.latency) {
      extras.push(rec.latency + "ms");
    }
    extras = extras.join(', ')
    if (rec.msg.indexOf('\n') !== -1) {
      XXX
    } else {
      emit(format("[%s] %s: %s on %s: %s (%s)\n",
        rec.time,
        upperNameFromLevel[rec.level] || "<unknown-level " + rec.level + ">",
        svc,
        rec.hostname || "<no-hostname>",
        rec.msg,
        extras));
    }
    break;
  case OM_INSPECT:
    emit(util.inspect(rec, false, Infinity, true) + '\n');
    break;
  case OM_JSON:
    emit(JSON.stringify(rec, null, opts.jsonIndent) + '\n');
    break;
  case OM_SIMPLE:
    // <http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/SimpleLayout.html>
    emit(format("%s - %s",
      upperNameFromLevel[rec.level] || "???",
      rec.msg));
    break;
  default:
    throw new Error("unknown output mode: "+opts.outputMode);
  }
}


var stdoutFlushed = true;
function emit(s) {
  // TODO:PERF If this is try/catch is too slow (too granular): move up to
  //    mainline and be sure to only catch this particular error.
  try {
    stdoutFlushed = process.stdout.write(s);
  } catch (e) {
    // Handle any exceptions in stdout writing in the "error" event above.
  }
}

process.stdout.on("error", function (err) {
  if (err.code === "EPIPE") {
    // Pass. See <https://github.com/trentm/json/issues/9>.
  } else {
    warn(err)
    drainStdoutAndExit(1);
  }
});


/**
 * A hacked up version of "process.exit" that will first drain stdout
 * before exiting. *WARNING: This doesn't stop event processing.* IOW,
 * callers have to be careful that code following this call isn't
 * accidentally executed.
 *
 * In node v0.6 "process.stdout and process.stderr are blocking when they
 * refer to regular files or TTY file descriptors." However, this hack might
 * still be necessary in a shell pipeline.
 */
function drainStdoutAndExit(code) {
  process.stdout.on('drain', function () {
    process.exit(code);
  });
  if (stdoutFlushed) {
    process.exit(code);
  }
}



//---- mainline

function main(argv) {
  var opts;
  try {
    opts = parseArgv(argv);
  } catch (e) {
    warn("json: error: %s", e.message)
    return drainStdoutAndExit(1);
  }
  //warn(opts);
  if (opts.help) {
    printHelp();
    return;
  }
  if (opts.version) {
    util.puts("bunyan " + getVersion());
    return;
  }
  
  var leftover = "";  // Left-over partial line from last chunk.
  var stdin = process.openStdin();
  stdin.setEncoding('utf8');
  stdin.on('data', function (chunk) {
    var lines = chunk.split(/\r\n|\n/);
    var length = lines.length;
    if (length === 1) {
      leftover += lines[0];
      return;
    }
    
    if (length > 1) {
      handleLogLine(leftover + lines[0], opts);
    }
    leftover = lines.pop();
    length -= 1;
    for (var i=1; i < length; i++) {
      handleLogLine(lines[i], opts);
    }
  });
  
  stdin.on('end', function () {
    if (leftover) {
      handleLogLine(leftover, opts);
      leftover = '';
    }
  });
}

if (require.main === module) {
  // HACK guard for <https://github.com/trentm/json/issues/24>.
  // We override the `process.stdout.end` guard that core node.js puts in
  // place. The real fix is that `.end()` shouldn't be called on stdout
  // in node core. Hopefully node v0.6.9 will fix that. Only guard
  // for v0.6.0..v0.6.8.
  var nodeVer = process.versions.node.split('.').map(Number);
  if ([0,6,0] <= nodeVer && nodeVer <= [0,6,8]) {
    var stdout = process.stdout;
    stdout.end = stdout.destroy = stdout.destroySoon = function() {
      /* pass */
    };
  }
  
  main(process.argv);
}