import gear
worker = gear.Worker('reverser')
worker.addServer('localhost')
worker.registerFunction("reverse")
worker.registerFunction("build-graph")
worker.registerFunction("build-artifact")
worker.registerFunction("cache-request")
import time
import json
import os
import requests
import urlparse

from subprocess import Popen, PIPE, STDOUT

import distbuild
from contextlib import contextmanager
import paramiko

import logging
logging.basicConfig()

#TODO: values from settings
cache_server = 'http://cache.baserock.org:8080'


@contextmanager
def ssh_manager(host, port, username, key):
    '''
    returns -> ssh connection ready to be used
    '''

    # TODO: use an ssh key!!! It isn't working
    client = paramiko.client.SSHClient()
    client.load_host_keys(key)
    client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    client.connect(host, port=port)

    try:
        yield client
    finally:
        client.close()

def upload_files(cache_key, suffixes):
    print "DEBUG: start upload_files"
    cache_dir = '/src/cache/artifacts'
    remote_cache_dir = '/src/cache_server/'
    files_to_upload = [os.path.join(cache_dir, cache_key + '.' + suffix) for suffix in suffixes]
    with ssh_manager('127.0.0.1', 22, 'root', '/root/gerritbot/gerritbot_rsa') as client:
        sftp = client.open_sftp()
        for single_file in files_to_upload:
            remote_dest = os.path.join(remote_cache_dir, os.path.basename(single_file))
            remote_dest_tmp = os.path.join(remote_cache_dir, os.path.basename(single_file) + '.tmp')
            print "DEBUG: going to upload %s" % single_file
            print "DEBUG: upload destination %s" % remote_dest
            try:
                sftp.stat(remote_dest)
                print "DEBUG: file already exists"
                return
            except:
                print "DEBUG: file not found in cache, uploading"
                sftp.put(single_file, remote_dest_tmp)
                sftp.rename(remote_dest_tmp, remote_dest)

while True:
    print "DEBUG: Waiting for job"
    job = worker.getJob()
    print "DEBUG: Received job '%s'" % job.name
    if job.name == "reverse":
        print "DEBUG: Starting job reverse with '%s'" % job.arguments
        for x in range(0, 100):
            job.sendWorkData("This is: %s" % x)
        job.sendWorkComplete("answer")
    elif job.name == "build-graph":
        bg_request=json.loads(job.arguments)
        print ("DEBUG: Starting build-graph calculation for Repo: '%s' "
               "Ref: '%s' System: '%s'") % (bg_request['repo'],
                                           bg_request['ref'],
                                           bg_request['system'])
        # TODO: There should be another way of doing this.
        cmd = ['morph', 'calculate-build-graph', '--quiet', bg_request['repo'], bg_request['ref'], bg_request['system']]
        p = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=STDOUT, close_fds=True)
        output = p.stdout.read()
        # TODO: catch errors calculating build-graph here instead of sending the error as build-graph :)
        print "DEBUG: finished computing build graph"
        job.sendWorkComplete(output)
    elif job.name == "build-artifact":
        artifact = distbuild.decode_artifact_reference(job.arguments)
        print "building %s" % artifact.name
        cmd = ['morph', 'worker-build', '--build-log-on-stdout', artifact.name]
        p = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=STDOUT, close_fds=True)
        p.stdin.write(job.arguments)
        p.stdin.close()
        while True:
            line = p.stdout.readline()
            if not line: break
            job.sendWorkData(line)

        kind = artifact.kind

        if kind == 'chunk':
            artifact_names = artifact.source_artifact_names

            suffixes = ['%s.%s' % (kind, name) for name in artifact_names]
            suffixes.append('build-log')
        else:
            filename = '%s.%s' % (kind, artifact.name)
            suffixes = [filename]

            if kind == 'stratum':
                suffixes.append(filename + '.meta')
        upload_files(artifact.cache_key, suffixes)
        job.sendWorkComplete(artifact.cache_key)
    elif job.name == 'cache-request':
        artifact_names = json.loads(job.arguments)

        url = urlparse.urljoin(cache_server, '/1.0/artifacts')
        r = requests.post(url, json=artifact_names)
        job.sendWorkComplete(json.dumps(r.json()))