#!/usr/bin/env node
'use strict';

var fs = require('fs');
var webppl = require('./src/main');
var parseArgs = require('minimist');
var path = require('path');
var git = require('git-rev-2');

function asArray(xs) {
  return (xs ? ((xs instanceof Array) ? xs : [xs]) : []);
}

function requireAsGlobal(modulePath) {
  var runtime = require(modulePath);
  for (var prop in runtime) {
    if (runtime.hasOwnProperty(prop)) {
      global[prop] = runtime[prop];
    }
  }
}

function addModulePaths(names) {
  var namesWithPaths = [];
  for (var i = 0; i < names.length; i++) {
    var name = names[i];
    namesWithPaths.push({
      name: getModuleName(name),
      path: getModulePath(name)
    });
  }
  return namesWithPaths;
}

function isErp(x) {
  return (x && (x.score != undefined) && (x.sample != undefined));
}

function isErpWithSupport(x) {
  return (isErp(x) && (x.support != undefined));
}

function printWebPPLValue(x) {
  if (isErpWithSupport(x)) {
    console.log('ERP:');
    var erpValues = x.support([])
      .map(function(v) {
          return [JSON.stringify(v), Math.exp(x.score([], v))]
        })
      .sort(function(a, b) {
          return b[1] - a[1]
        });
    erpValues.forEach(function(val) {
      console.log('    ' + val[0] + ': ' + val[1]);
    });
  } else {
    console.log(x);
  }
}

function getRequireName(req) {
  var name, xs;
  xs = req.split('/');
  name = xs[xs.length - 1];
  xs = name.split('.');
  name = xs[0];
  return name;
}

function getRequirePath(req) {
  if (req.indexOf('/') != -1) {
    try {
      return require.resolve(path.join(process.cwd(), req));
    } catch (e) {
      return require.resolve(req);
    }
  } else {
    return req;
  }
}

function run(code, requires, headers, verbose) {
  headers.forEach(
      function(header) {
        requireAsGlobal(header.path);
      });
  requires.forEach(
      function(req) {
        global[req.name] = require(req.path);
      });
  webppl.webppl_eval(
      function(s, x) {
        console.log('\n* Program return value:\n');
        printWebPPLValue(x);
      },
      code,
      verbose);
}

function compile(code, requires, headers, verbose, outputFile) {
  var compiledCode = '';
  requires.push({
    name: 'webppl', // this makes header.js exports globally available
    path: require.resolve('./src/main'),
    type: 'require-js'
  });
  requires.forEach(
      function(req) {
        if (req.type === 'require-js') {
          compiledCode += 'var ' + req.name + " = require('" + req.path + "');\n";
        } else if (req.type === 'require-header') {
          compiledCode += "requireAsGlobal('" + req.path + "');\n";
        } else if (req.type === 'require-wppl') {
          var reqCode = fs.readFileSync(req.path, 'utf8');
          code = reqCode + ';' + code;
        } else {
          throw 'unknown require type: ' + req.type;
        }
      });
  compiledCode += (
      isErp.toString() + '\n' +
      isErpWithSupport.toString() + '\n' +
      printWebPPLValue.toString() + '\n' +
      'var topK = function(s, x){ \n' +
      " console.log('\\n* Program return value:\\n'); \n" +
      ' printWebPPLValue(x); \n};\n\n');
  compiledCode += 'var main = ' + webppl.compile(code, verbose) + '\n\n';
  compiledCode += "main({}, topK, '');";
  // Write Javascript code to file
  fs.writeFile(
      outputFile,
      compiledCode,
      function(err) {
        if (err) {
          console.log(err);
        } else {
          console.log('Wrote webppl code to', outputFile);
        }
      });
}

function main() {

  var argv = parseArgs(process.argv.slice(2));

  // Print version if requested
  if (argv.version) {
    git.branch(
        __dirname,
        function(err, branch) {
          __dirname,
          git.short(
              function(err, shortName) {
                console.log(branch, shortName, __dirname);
              });
        }
    );
    return;
  }

  // Return if no file argument given
  if (argv._[0] === undefined) {
    console.log('No file argument given! Run webppl as follows:');
    console.log('webppl file.wppl [--compile] [--out file.js] [--require file2.js] [--header file3.js]');
    return;
  }

  // Load webppl code
  var programFile = argv._[0];
  console.log('Processing', programFile);
  var code = fs.readFileSync(programFile);

  var requireTypes = ['require-js', 'require-wppl', 'require-header'];
  var requires = [];
  requireTypes.forEach(
      function(requireType) {
        asArray(argv[requireType]).forEach(
            function(id) {
              requires.push(
                  {
                    name: getRequireName(id),
                    path: getRequirePath(id),
                    type: requireType
                  });
            });
      });

  var requires = addModulePaths(asArray(argv.require));
  var headers = addModulePaths(asArray(argv.header));

  var processCode = argv.compile ? compile : run;
  var outputFile = argv.out ? argv.out : 'tmp.js';

  processCode(code, requires, headers, argv.verbose, outputFile);
}

main();