import subprocess

ORCHE_URL = 'http://127.0.0.1:8080/'
BUILD_SCRIPT = 'build_a_system.sh'
DEPLOY_SCRIPT = 'deploy_a_system.sh'
DEFINITIONS_DIR='definitions'
REF = "cu010-trove/br6/firehose-test-1"

whitelist = [
        'clusters/tlsa.morph',
        'systems/base-system-x86_64-generic.morph',
        'strata/build-essential.morph',
        'strata/core.morph',
        'strata/foundation.morph',
        'strata/bsp-x86_64-generic.morph',
    ]

LOGFILE = '/home/williamholland/orchestration/trigger_log'

log_file = open(LOGFILE,'a')

def log(msg):
    ''' write message to log file with timestamp and script name '''
    import datetime
    global log_file
    dt = str(datetime.datetime.now()).split('.')[0]
    log_file.write("[%s] Builder Trigger: %s\n" % (dt, msg))

def _exit(exit_val):
    if exit_val: log('exiting unhappily')
    exit(exit_val)

def files_changed():
    ''' return a list of files changed in latest commit to definitions'''
    import os
    owd = os.getcwd()
    os.chdir(DEFINITIONS_DIR)
    SHAcmd = ['git', 'log', REF, '--format=format:%H', '-2']
    SHAproc = subprocess.Popen(SHAcmd, stdout=subprocess.PIPE)
    SHAout, SHAerr = SHAproc.communicate()
    SHA = SHAout.split()
    cmd = ['git', 'diff', '--name-only', SHA[0], SHA[1]]
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
    out, err = p.communicate()
    os.chdir(owd)
    return out.split()

def find_systems_affected_by_change():
    # TODO for each file changed, separate into chunks, strata, systems and clusters
    # TODO for each strata get it's system
    pass

def find_clusters_affected_by_change():
    changed_systems = find_systems_affected_by_change()
    # TODO for each system get it's custers

def build(system):
    log('building %s' % system)
    exit_val =  subprocess.call(['sh','%s' % BUILD_SCRIPT, '%s' % system])
    log('build complete')
    return exit_val

def trigger_deploy(system):
    import requests
    global url
    url = '%sbuild_complete' % ORCHE_URL
    if not system: return 0
    payload = {'system':system}
    log('triggering deploy')
    r = requests.post(url,data=payload)
    return not r.ok

if __name__ == '__main__':
    _files_changed = files_changed()
    systems_list = []
    for f in _files_changed:
        if f in whitelist:
            # TODO fix this being hardcoded
            system = 'systems/base-system-x86_64-generic.morph'
            build_exit_val = build(system)
            if build_exit_val: _exit(build_exit_val)
            log('about to trigger deploy ...')
            _exit(trigger_deploy(system))
    log('nothing whitelisted changed. No build started.')