const fs = require('fs')

var cli = require('./cliverse')
var nodeShellExec = cli.nodeShellExec;

var __isElevated = null;
var shell_verse = {
  // getCommonTask is agnostic of whether we are running in an elevated shell or not. It runs in either case.
    getCommonTask( taskToRun ){ return ()=>{ return shell_verse.runTask(taskToRun) }}
  , runTask : ( taskToRun ) => {
    if (__isElevated)  return shell_verse.elevatedRunner( taskToRun )
    else return shell_verse.runNonElevated( taskToRun )
  }

  , elevatedRunner( taskToRun ){
    try {
      var __runasresult = null;
      return taskToRun().then((r)=>{ 
          // PB : TODO -- Every elevation should have its own messaging file. Async writes from multiple processes are a problem here...
          fs.writeFileSync('run.log', ', ' + JSON.stringify( { info : taskToRun.info, success: true }), { 'flag': 'a+' })
          fs.writeFileSync('run.done', 'success')  // PB : TODO -- This should be done conditionally if we are running inproc.
          return __runasresult = r;
        })
        .catch((e) => {
          fs.writeFileSync('run.log', ', ' + JSON.stringify(e), { 'flag': 'a+' })
          fs.writeFileSync('run.done', 'failure')
          console.error(e)
        })
        .finally(() => {
          if(__runasresult && !__runasresult.skipped) fs.unlinkSync('run.done')
        })
    }
    catch (e) {
      console.error('Error Invalid command : ' + e)
      fs.writeFileSync('run.done', 'error')
    }
    finally {
    }
  }
  , getElevatedTask : function( taskToRun ){ return ()=>{ return shell_verse.runElevated(taskToRun) }}
  , runElevated : ( taskToRun ) => {
    // Let shell_verse decide whether to Elevate Out of Proc or In Proc
    
    // taskToRun by default is the launched command and args. Specially in windows out of proc.
    // taskToRun = taskToRun || (()=>{ return op[processedArgs.label || processedArgs._[0] || 'undefined'](processedArgs) }) 

    if(taskToRun.processedArgs.skipelevated) return Promise.resolve({ skipped : true });


    if (__isElevated) {
      return shell_verse.elevatedRunner(taskToRun)
    }
    else {
      console.log('Requesting Elevated Privileges');
      // requesteElevation is acutally request elevation and run. Both In Proc and Out of Proc.
      // Linux doesnt require elevation for most commands...
      return shell_verse.requestElevation(shell_verse.elevatedRunner, taskToRun)
    }
  }
  , runElevatedBatch( batchToRun ){
    // In windows we don't need to run each task. We hand over to another shell which in elevated state rebuilds the whole batch and runs.
    // Irrespective of the batch we just call runElevated once.
    return [runElevated(batchToRun[0])]
  }

  , getNonElevatedTask : function( taskToRun ){ return ()=>{ return shell_verse.runNonElevated(taskToRun) } }
  , runNonElevated : ( taskToRun ) => {
    // Let shell_verse decide whether to Elevate Out of Proc or In Proc
    if(__isElevated) {
      return Promise.resolve( new Error('Cannot Run Task in Elevated Mode.') ) 
    }
    else {
      // taskToRun by default is the launched command and args.
      // taskToRun = taskToRun || (()=>{ return op[processedArgs.label || processedArgs._[0] || 'undefined'](processedArgs) }) 

      return taskToRun().then(r=>{
        taskToRun.statuslog.statuslog(null, taskToRun.info /*repo*/ )
        return r;
      }).catch((e) => {
        e.info = taskToRun.info;
        taskToRun.statuslog.statuslog(e); 
        if(taskToRun.errHandler) throw taskToRun.errHandler(e)
        // console.error(e)
        throw e;
      }).finally(()=>{})
    }
  }

  , isElevated : ()=>{
    return acquireElevationState().then( ()=>{
      shell_verse.isElevated = () => {
        return Promise.resolve(__isElevated)
      }
      return shell_verse.isElevated()
    })
  }

  // , isElevationOutOfProc : ()=>{ return true }
  
  , acquireElevationState : () => {
    return nodeShellExec("fsutil", ["dirty", "query", "C:"], {
      inherit: true
      // , shell: true
      , stdio: 'ignore'
      , env: process.env
      , title: `check privileged execution mode using "fsutil dirty query C:"`
    }).then((exitcode) => {
      console.log('Elevated')
      __isElevated = true;
    }).catch(() => {
      __isElevated = false;
      console.log('Not Elevated');
    }).finally(()=>{
      shell_verse.acquireElevationState = ()=> Promise.resolve(__isElevated); 
      shell_verse.isElevated = () => { return Promise.resolve(__isElevated)}
      return __isElevated;
    })
  }
  
  , getTaskCheckExists : cli.createTask('getTaskCheckExists', 'where')

  , getbash : ()=>{ return "C:\\Program Files\\Git\\bin\\sh.exe" }

  , createJuntionOrLink : (dirOrFile, target, opts) =>{
    return nodeShellExec('mklink', ['/J', dirOrFile, target], opts).catch((e) => { console.error(e) })
  }
  , removeJuncionOrLink : ( junctionOrLink )=>{
    return nodeShellExec('rmdir', [junctionOrLink], { inherit: true, shell: true, env: process.env })
  }

  , requestElevation(elevatedRunner, taskToRun) {
      // PB : TODO -- Multiple parallel request elevations should be queued into a promise.

      var processedArgs = taskToRun.processedArgs, selectedinstance = taskToRun.selectedinstance , statuslog = taskToRun.statuslog 
      // Wait for the runas to complete before we read it.
      try {
        fs.unlinkSync('run.done')
        fs.unlinkSync('run.log')
      }
      catch (e) { } //Ignore 

      // Find node path to send to hta.
      return nodeShellExec('where', ['node']).then(r => {
        var namedArgs = [];
        console.log('result : ' + JSON.stringify(r))
        Object.keys(processedArgs).forEach((v) => { v != '_' ? namedArgs.push('--' + v + '=' + processedArgs[v]) : null; })
        // PB : TODO -- Convert all the cli args back to string.
        var args = [`${selectedinstance.root}/.elxr/run-${taskToRun.runtimestamp}/windowselevate.hta`].concat(processedArgs._)
        namedArgs.length > 0 ? args = args.concat(namedArgs.join(' ')) : null; 
        args.push('--runas=self');
        // args.push('--nodepath=' + r.messages[r.messages.length - 1])
        // if (!processedArgs.node_env) args.push('--node_env=' + ENV.NODE_ENV)
        // if (processedArgs.debug) args.push('--debug=true') // Enable to debug elevated..
        // console.dir(processedArgs._)
        // console.dir(namedArgs.join(' '))
        console.dir(args)
        // throw 'test'

        return nodeShellExec('MSHTA', [`"${args.join('" "')}"`]
          , {
            inherit: true
            , shell: true
            , env: taskToRun.ENV
            , runas: 'self'
            , title: `runas`
          }
        ).then(() => {
          // runas returned.
          try {
            // PB : TODO -- Log is comma prefixed. Needs to be proper JSON.
            var runaslog = JSON.parse('[ { "success" : true, "result" : "started"}' + fs.readFileSync('run.log', { flags: 'a+' }) + ']');
            runaslog.forEach((logEntry) => {
              statuslog.statuslog(logEntry.success ? null : logEntry, logEntry)
              logEntry.success ? (console.log(['success :' + logEntry.result]), console.log((logEntry.messages || []).join(' '))) : (console.error(['error :' + logEntry.result]), console.error((logEntry.messages || []).join(' ')))
            })
          }
          catch (e) {
            // We must have a runas log
            statuslog.statuslog(e)
            console.error('Run log error probably was not created by runas : ' + e)
          }
        })
          .catch(err => console.error('Elevation failed : ' + err));
      })
  }
}

module.exports = shell_verse