#!/usr/bin/env python3

# This script greps the JSON files for the buildbots on the LLVM official
# build master by name and prints an HTML page with the links to the bots
# and the status.
#
# Multiple masters can be used, as well as multiple groups of bots and
# multiple bots per group, all in a json file. See linaro.json in this
# repository to have an idea how the config file is.

import sys
import os
import argparse
import json
import tempfile
import logging
from datetime import datetime, timedelta
# The requests allows HTTP keep-alive which re-uses the same TCP connection
# to download multiple files.
import requests

# The GIT revision length used on 'Commits' error display.
GIT_SHORT_LEN=7

def ignored(s):
  return 'ignore' in s and s['ignore']
def not_ignored(s):
  return not ignored(s)


# Returns the parsed json URL or and error string.
def wget(session, url):
  try:
    req = session.get(url)
  except requests.exceptions.RequestException as e:
    return str(e), True
  return req.json(), False


# Returns a string with the GIT revision usesd on build BUILDID and
# PREV_BUILDID in the form '<id_buildid>-<id_prev_buildid>'.
def get_bot_failure_changes(session, base_url, buildid, prev_buildid):
  def wget_build_rev(bid):
    if bid != -1:
      contents, err = wget(session,
                           "{}/api/v2/builds/{}/changes"
                           .format(base_url, bid))
      if err or len(contents['changes']) == 0:
        return ""
      return contents['changes'][0]['revision']
    return ""

  revision = wget_build_rev(buildid)
  prev_revision = wget_build_rev(prev_buildid)
  if not prev_revision:
    return "{:.{width}}".format(revision, width=GIT_SHORT_LEN)
  else:
    return "{:.{width}}-{:.{width}}".format(revision, prev_revision,
                                            width=GIT_SHORT_LEN)


# Get the status of a individual bot BOT.  Returns a dict with the
# information.
def get_bot_status(session, bot, base_url, builder_url, build_url):
  (contents, err) = wget(session,
                         "{}/api/v2/{}/{}/{}"
                         .format(base_url, builder_url, bot, build_url))
  if err:
    return { 'fail' : err }

  builds = contents

  status = {}
  reversed_builds = reversed(builds['builds'])
  for build in reversed_builds:
    if build['complete']:
      status['builderid'] = build['builderid']
      status['number'] = build['number']
      status['state'] = build['state_string']
      delta = int(build['complete_at']) - int(build['started_at'])
      status['time'] = str(timedelta(seconds=delta))
      if build['state_string'] != 'build successful':
        status['comments'] = build['state_string']
        status['fail'] = True

        try:
          prev_buildid = next(reversed_builds)['buildid']
        except StopIteration:
          prev_buildid = -1;
        status['changes'] = get_bot_failure_changes(session, base_url,
                                                    build['buildid'],
                                                    prev_buildid)
      else:
        status['fail'] = False
      break
  return status


def bot_status(config_file, output_file):
  temp = tempfile.NamedTemporaryFile(mode='w+', delete=False)

  today = "{}\n".format(datetime.today().ctime())

  session = requests.Session()

  # Get status for all bots
  bot_cache = {}
  for server in filter(not_ignored, config):
    base_url = server['base_url']
    builder_url = server['builder_url']
    build_url = server['build_url']
    logging.debug('Parsing server {}...'.format(server['name']))
    for builder in server['builders']:
      logging.debug('  Parsing builders {}...'.format(builder['name']))
      for bot in builder['bots']:
        bot_key = "{}/{}".format(base_url, bot['name'])
        if bot_key in bot_cache:
          continue
        logging.debug('    Parsing bot {}...'.format(bot['name']))
        status = get_bot_status(session, bot['name'], base_url, builder_url,
                                build_url)
        if not_ignored(bot):
          fail = 'fail' in status
        logging.debug("      FAIL" if status['fail'] else "      PASS")
        bot_cache[bot_key] = status

  # Dump all servers / bots
  for server in filter(not_ignored, config):
    base_url = server['base_url']
    builder_url = server['builder_url']
    build_url = server['build_url']
    favicon = 'fail.ico' if fail else 'ok.ico'
    temp.write("<link rel=\"shortcut icon\" href=\"{}\" "
               "type=\"image/x-icon\"/>\n".format(favicon))
    temp.write("<table cellspacing=1 cellpadding=2>\n")
    temp.write("<tr><td colspan=5>&nbsp;</td><tr>\n")
    temp.write("<tr><th colspan=5>{} @ {}</td><tr>\n"
               .format(server['name'], today))

    for builder in server['builders']:
      temp.write("<tr><td colspan=5>&nbsp;</td><tr>\n")
      temp.write("<tr><th colspan=5>{}</td><tr>\n".format(builder['name']))
      temp.write("<tr><th>Buildbot</th><th>Status</th><th>Time</th>"
                 "<th>Build #</th><th>Commits</th><th>Comments</th></tr>\n")
      for bot in builder['bots']:
        temp.write("<tr>\n")
        status = bot_cache["{}/{}".format(base_url, bot['name'])]
        url = "{}/#/{}/{}".format(base_url, builder_url, status['builderid'])
        temp.write("  <td><a href='{}'>{}</a></td>\n".format(url, bot['name']))
        temp.write("  <td><font color='{}'>{}</font></td>\n"
                   .format('red' if status['fail'] else 'green',
                           'FAIL' if status['fail'] else 'PASS'))
        empty_cell="  <td>&nbsp;</td>\n"
        if 'time' in status:
          temp.write("  <td>{}</td>\n".format(status['time']))
        else:
          temp.write(empty_cell)
        if 'number' in status:
          build_url = "{}/builds/{}".format(url, status['number'])
          temp.write("  <td><a href='{}'>{}</a></td>\n".format(build_url, status['number']))
        else:
          temp.write(empty_cell)
        if 'changes' in status:
          temp.write("  <td>{}</td>\n".format(status['changes']))
        else:
          temp.write(empty_cell)
        if status['fail']:
          temp.write("  <td>{:.30}</td>\n".format(status['comments']))
        else:
          temp.write(empty_cell)
        temp.write("</tr>\n")
    temp.write("</table>\n")

  # Move temp to main (atomic change)
  temp.close()
  os.rename(temp.name, sys.argv[2])


if __name__ == "__main__":
  parser = argparse.ArgumentParser()
  parser.add_argument('-d', dest='debug', action='store_true')
  parser.add_argument('config_file',
                      help='Bots description in JSON format')
  parser.add_argument('output_file',
                      help='output HTML path')
  args = parser.parse_args()

  if args.debug:
    logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)

  try:
    with open(args.config_file, "r") as f:
      config = json.load(f)
  except IOError as e:
    print("error: failed to read {} config file: {}".format(sys.argv[1], e))
    sys.exit(os.EX_CONFIG)

  bot_status(config, args.output_file)