'use strict';

function buildRegexp(patterns, options) {
  options = options || {};
  var prefix = options.prefix !== undefined ? options.prefix : '^';
  var suffix = options.suffix !== undefined ? options.suffix : '\\b';

  for (var i = 0; i < patterns.length; i++) {
    if (patterns[i] instanceof RegExp) {
      patterns[i] = patterns[i].source;
    }
    else {
      patterns[i] = patterns[i].replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
    }
  }

  return new RegExp(prefix + '(' + patterns.join('|') + ')' + suffix, 'i');
}

var notCharacterOrDash = '(?=[^A-Za-z\\d\\-_]|$)';
var varNames = /[\w\-:]/;
var keywords = buildRegexp([
  /begin|break|catch|continue|data|default|do|dynamicparam/,
  /else|elseif|end|exit|filter|finally|for|foreach|from|function|if|in/,
  /param|process|return|switch|throw|trap|try|until|where|while/
], { suffix: notCharacterOrDash });

var punctuation = /[\[\]{},;`\\\.]|@[({]/;
var wordOperators = buildRegexp([
  'f',
  /b?not/,
  /[ic]?split/, 'join',
  /is(not)?/, 'as',
  /[ic]?(eq|ne|[gl][te])/,
  /[ic]?(not)?(like|match|contains)/,
  /[ic]?replace/,
  /b?(and|or|xor)/
], { prefix: '-' });
var symbolOperators = /[+\-*\/%]=|\+\+|--|\.\.|[+\-*&^%:=!|\/]|<(?!#)|(?!#)>/;
var operators = buildRegexp([wordOperators, symbolOperators], { suffix: '' });

var numbers = /^((0x[\da-f]+)|((\d+\.\d+|\d\.|\.\d+|\d+)(e[\+\-]?\d+)?))[ld]?([kmgtp]b)?/i;

var identifiers = /^[A-Za-z\_][A-Za-z\-\_\d]*\b/;

var symbolBuiltins = /[A-Z]:|%|\?/i;
var namedBuiltins = buildRegexp([
  /Add-(Computer|Content|History|Member|PSSnapin|Type)/,
  /Checkpoint-Computer/,
  /Clear-(Content|EventLog|History|Host|Item(Property)?|Variable)/,
  /Compare-Object/,
  /Complete-Transaction/,
  /Connect-PSSession/,
  /ConvertFrom-(Csv|Json|SecureString|StringData)/,
  /Convert-Path/,
  /ConvertTo-(Csv|Html|Json|SecureString|Xml)/,
  /Copy-Item(Property)?/,
  /Debug-Process/,
  /Disable-(ComputerRestore|PSBreakpoint|PSRemoting|PSSessionConfiguration)/,
  /Disconnect-PSSession/,
  /Enable-(ComputerRestore|PSBreakpoint|PSRemoting|PSSessionConfiguration)/,
  /(Enter|Exit)-PSSession/,
  /Export-(Alias|Clixml|Console|Counter|Csv|FormatData|ModuleMember|PSSession)/,
  /ForEach-Object/,
  /Format-(Custom|List|Table|Wide)/,
  new RegExp('Get-(Acl|Alias|AuthenticodeSignature|ChildItem|Command|ComputerRestorePoint|Content|ControlPanelItem|Counter|Credential'
             + '|Culture|Date|Event|EventLog|EventSubscriber|ExecutionPolicy|FormatData|Help|History|Host|HotFix|Item|ItemProperty|Job'
             + '|Location|Member|Module|PfxCertificate|Process|PSBreakpoint|PSCallStack|PSDrive|PSProvider|PSSession|PSSessionConfiguration'
             + '|PSSnapin|Random|Service|TraceSource|Transaction|TypeData|UICulture|Unique|Variable|Verb|WinEvent|WmiObject)'),
  /Group-Object/,
  /Import-(Alias|Clixml|Counter|Csv|LocalizedData|Module|PSSession)/,
  /ImportSystemModules/,
  /Invoke-(Command|Expression|History|Item|RestMethod|WebRequest|WmiMethod)/,
  /Join-Path/,
  /Limit-EventLog/,
  /Measure-(Command|Object)/,
  /Move-Item(Property)?/,
  new RegExp('New-(Alias|Event|EventLog|Item(Property)?|Module|ModuleManifest|Object|PSDrive|PSSession|PSSessionConfigurationFile'
             + '|PSSessionOption|PSTransportOption|Service|TimeSpan|Variable|WebServiceProxy|WinEvent)'),
  /Out-(Default|File|GridView|Host|Null|Printer|String)/,
  /Pause/,
  /(Pop|Push)-Location/,
  /Read-Host/,
  /Receive-(Job|PSSession)/,
  /Register-(EngineEvent|ObjectEvent|PSSessionConfiguration|WmiEvent)/,
  /Remove-(Computer|Event|EventLog|Item(Property)?|Job|Module|PSBreakpoint|PSDrive|PSSession|PSSnapin|TypeData|Variable|WmiObject)/,
  /Rename-(Computer|Item(Property)?)/,
  /Reset-ComputerMachinePassword/,
  /Resolve-Path/,
  /Restart-(Computer|Service)/,
  /Restore-Computer/,
  /Resume-(Job|Service)/,
  /Save-Help/,
  /Select-(Object|String|Xml)/,
  /Send-MailMessage/,
  new RegExp('Set-(Acl|Alias|AuthenticodeSignature|Content|Date|ExecutionPolicy|Item(Property)?|Location|PSBreakpoint|PSDebug' +
             '|PSSessionConfiguration|Service|StrictMode|TraceSource|Variable|WmiInstance)'),
  /Show-(Command|ControlPanelItem|EventLog)/,
  /Sort-Object/,
  /Split-Path/,
  /Start-(Job|Process|Service|Sleep|Transaction|Transcript)/,
  /Stop-(Computer|Job|Process|Service|Transcript)/,
  /Suspend-(Job|Service)/,
  /TabExpansion2/,
  /Tee-Object/,
  /Test-(ComputerSecureChannel|Connection|ModuleManifest|Path|PSSessionConfigurationFile)/,
  /Trace-Command/,
  /Unblock-File/,
  /Undo-Transaction/,
  /Unregister-(Event|PSSessionConfiguration)/,
  /Update-(FormatData|Help|List|TypeData)/,
  /Use-Transaction/,
  /Wait-(Event|Job|Process)/,
  /Where-Object/,
  /Write-(Debug|Error|EventLog|Host|Output|Progress|Verbose|Warning)/,
  /cd|help|mkdir|more|oss|prompt/,
  /ac|asnp|cat|cd|chdir|clc|clear|clhy|cli|clp|cls|clv|cnsn|compare|copy|cp|cpi|cpp|cvpa|dbp|del|diff|dir|dnsn|ebp/,
  /echo|epal|epcsv|epsn|erase|etsn|exsn|fc|fl|foreach|ft|fw|gal|gbp|gc|gci|gcm|gcs|gdr|ghy|gi|gjb|gl|gm|gmo|gp|gps/,
  /group|gsn|gsnp|gsv|gu|gv|gwmi|h|history|icm|iex|ihy|ii|ipal|ipcsv|ipmo|ipsn|irm|ise|iwmi|iwr|kill|lp|ls|man|md/,
  /measure|mi|mount|move|mp|mv|nal|ndr|ni|nmo|npssc|nsn|nv|ogv|oh|popd|ps|pushd|pwd|r|rbp|rcjb|rcsn|rd|rdr|ren|ri/,
  /rjb|rm|rmdir|rmo|rni|rnp|rp|rsn|rsnp|rujb|rv|rvpa|rwmi|sajb|sal|saps|sasv|sbp|sc|select|set|shcm|si|sl|sleep|sls/,
  /sort|sp|spjb|spps|spsv|start|sujb|sv|swmi|tee|trcm|type|where|wjb|write/
], { prefix: '', suffix: '' });
var variableBuiltins = buildRegexp([
  /[$?^_]|Args|ConfirmPreference|ConsoleFileName|DebugPreference|Error|ErrorActionPreference|ErrorView|ExecutionContext/,
  /FormatEnumerationLimit|Home|Host|Input|MaximumAliasCount|MaximumDriveCount|MaximumErrorCount|MaximumFunctionCount/,
  /MaximumHistoryCount|MaximumVariableCount|MyInvocation|NestedPromptLevel|OutputEncoding|Pid|Profile|ProgressPreference/,
  /PSBoundParameters|PSCommandPath|PSCulture|PSDefaultParameterValues|PSEmailServer|PSHome|PSScriptRoot|PSSessionApplicationName/,
  /PSSessionConfigurationName|PSSessionOption|PSUICulture|PSVersionTable|Pwd|ShellId|StackTrace|VerbosePreference/,
  /WarningPreference|WhatIfPreference/,

  /Event|EventArgs|EventSubscriber|Sender/,
  /Matches|Ofs|ForEach|LastExitCode|PSCmdlet|PSItem|PSSenderInfo|This/,
  /true|false|null/
], { prefix: '\\$', suffix: '' });

var builtins = buildRegexp([symbolBuiltins, namedBuiltins, variableBuiltins], { suffix: notCharacterOrDash });

var grammar = {
  keyword: keywords,
  number: numbers,
  operator: operators,
  builtin: builtins,
  punctuation: punctuation,
  variable: identifiers
};

// tokenizers
function tokenBase(stream, state) {
  // Handle Comments
  //var ch = stream.peek();

  var parent = state.returnStack[state.returnStack.length - 1];
  if (parent && parent.shouldReturnFrom(state)) {
    state.tokenize = parent.tokenize;
    state.returnStack.pop();
    return state.tokenize(stream, state);
  }

  if (stream.eatSpace()) {
    return null;
  }

  if (stream.eat('(')) {
    state.bracketNesting += 1;
    return 'punctuation';
  }

  if (stream.eat(')')) {
    state.bracketNesting -= 1;
    return 'punctuation';
  }

  for (var key in grammar) {
    if (stream.match(grammar[key])) {
      return key;
    }
  }

  var ch = stream.next();

  // single-quote string
  if (ch === "'") {
    return tokenSingleQuoteString(stream, state);
  }

  if (ch === '$') {
    return tokenVariable(stream, state);
  }

  // double-quote string
  if (ch === '"') {
    return tokenDoubleQuoteString(stream, state);
  }

  if (ch === '<' && stream.eat('#')) {
    state.tokenize = tokenComment;
    return tokenComment(stream, state);
  }

  if (ch === '#') {
    stream.skipToEnd();
    return 'comment';
  }

  if (ch === '@') {
    var quoteMatch = stream.eat(/["']/);
    if (quoteMatch && stream.eol()) {
      state.tokenize = tokenMultiString;
      state.startQuote = quoteMatch[0];
      return tokenMultiString(stream, state);
    } else if (stream.eol()) {
      return 'error';
    } else if (stream.peek().match(/[({]/)) {
      return 'punctuation';
    } else if (stream.peek().match(varNames)) {
      // splatted variable
      return tokenVariable(stream, state);
    }
  }
  return 'error';
}

function tokenSingleQuoteString(stream, state) {
  var ch;
  while ((ch = stream.peek()) != null) {
    stream.next();

    if (ch === "'" && !stream.eat("'")) {
      state.tokenize = tokenBase;
      return 'string';
    }
  }

  return 'error';
}

function tokenDoubleQuoteString(stream, state) {
  var ch;
  while ((ch = stream.peek()) != null) {
    if (ch === '$') {
      state.tokenize = tokenStringInterpolation;
      return 'string';
    }

    stream.next();
    if (ch === '`') {
      stream.next();
      continue;
    }

    if (ch === '"' && !stream.eat('"')) {
      state.tokenize = tokenBase;
      return 'string';
    }
  }

  return 'error';
}

function tokenStringInterpolation(stream, state) {
  return tokenInterpolation(stream, state, tokenDoubleQuoteString);
}

function tokenMultiStringReturn(stream, state) {
  state.tokenize = tokenMultiString;
  state.startQuote = '"';
  return tokenMultiString(stream, state);
}

function tokenHereStringInterpolation(stream, state) {
  return tokenInterpolation(stream, state, tokenMultiStringReturn);
}

function tokenInterpolation(stream, state, parentTokenize) {
  if (stream.match('$(')) {
    var savedBracketNesting = state.bracketNesting;
    state.returnStack.push({
      /*jshint loopfunc:true */
      shouldReturnFrom: function(state) {
        return state.bracketNesting === savedBracketNesting;
      },
      tokenize: parentTokenize
    });
    state.tokenize = tokenBase;
    state.bracketNesting += 1;
    return 'punctuation';
  } else {
    stream.next();
    state.returnStack.push({
      shouldReturnFrom: function() { return true; },
      tokenize: parentTokenize
    });
    state.tokenize = tokenVariable;
    return state.tokenize(stream, state);
  }
}

function tokenComment(stream, state) {
  var maybeEnd = false, ch;
  while ((ch = stream.next()) != null) {
    if (maybeEnd && ch == '>') {
      state.tokenize = tokenBase;
      break;
    }
    maybeEnd = (ch === '#');
  }
  return 'comment';
}

function tokenVariable(stream, state) {
  var ch = stream.peek();
  if (stream.eat('{')) {
    state.tokenize = tokenVariableWithBraces;
    return tokenVariableWithBraces(stream, state);
  } else if (ch != undefined && ch.match(varNames)) {
    stream.eatWhile(varNames);
    state.tokenize = tokenBase;
    return 'variable';
  } else {
    state.tokenize = tokenBase;
    return 'error';
  }
}

function tokenVariableWithBraces(stream, state) {
  var ch;
  while ((ch = stream.next()) != null) {
    if (ch === '}') {
      state.tokenize = tokenBase;
      break;
    }
  }
  return 'variable';
}

function tokenMultiString(stream, state) {
  var quote = state.startQuote;
  if (stream.sol() && stream.match(new RegExp(quote + '@'))) {
    state.tokenize = tokenBase;
  }
  else if (quote === '"') {
    while (!stream.eol()) {
      var ch = stream.peek();
      if (ch === '$') {
        state.tokenize = tokenHereStringInterpolation;
        return 'string';
      }

      stream.next();
      if (ch === '`') {
        stream.next();
      }
    }
  }
  else {
    stream.skipToEnd();
  }

  return 'string';
}

const powerShell = {
  startState: function() {
    return {
      returnStack: [],
      bracketNesting: 0,
      tokenize: tokenBase
    };
  },

  token: function(stream, state) {
    return state.tokenize(stream, state);
  },

  languageData: {
    commentTokens: {line: "#", block: {open: "<#", close: "#>"}}
  }
};

exports.powerShell = powerShell;
