# /bin/sh
# $Id$
# vim:et:ft=sh:sts=2:sw=2
#
# Copyright 2010 Kate Ward. All Rights Reserved.
# Author: kate.ward@forestent.com (Kate Ward)
#
# Continuous build script for shell library testing.
#
# Sample usages:
# $ blah

# treat unset variables as an error
set -u

# global constants
setglobal ARGV0 = $[basename $0]
setglobal ARGV0_DIR = $[dirname $0]
setglobal SHLIB_DIR = ""$(ARGV0_DIR)/../lib""

# load libraries
source ${SHFLAGS_LIB:-${SHLIB_DIR}/shflags} \
    || shell {echo 'unable to load shflags library' > !2; exit 1}
source ${VERSIONS_LIB:-${SHLIB_DIR}/versions} \
    || shell {echo 'unable to load versions library' > !2; exit 1}

setglobal OUTPUT_FILE = ""$(VERSIONS_OS_NAME)_$(VERSIONS_OS_RELEASE)""

# define flags
DEFINE_string 'command' '' 'the command to start a build' 'c'
DEFINE_string 'watch' '' 'file to watch for changes' 'w'
DEFINE_string 'watch_from' '' 'file containing filenames to watch' 'W'
DEFINE_string 'output' $(OUTPUT_FILE) 'output file to write to' 'o'
DEFINE_string 'output_dir' '.' 'directory to write output file' 'O'
DEFINE_integer 'pause' 60 'pause between successive runs (sec)' 'p'

setglobal FLAGS_HELP = ""USAGE: $(ARGV0) [flags]""

#------------------------------------------------------------------------------
# functions
#

# This function exits the script, optionally printing a message
#
# Args:
#   message: string: an error message to be output (optional)
# Output:
#   string: usable flags
proc die {
  test $Argc -ne 0 && echo @Argv > !2
  flags_help
  exit 1
}

# Function to give the current date in ISO format
#
# Args:
#   none
# Output:
#   string: isodate
proc isodate {
  date -u '+%Y%m%dT%H%M%SZ'
}

proc age {
  setglobal awkScript = ''''
  match $(VERSIONS_OS_NAME) {
    with FreeBSD|Solaris setglobal awkScript = ''{print $6,$7,$8}'' 
    with Linux setglobal awkScript = ''{print $6,$7}'' 
    with * echo "unrecognized OS name ($(VERSIONS_OS_NAME))" > !2 
  }
  ls -l $1 |awk $(awkScript)
}

#------------------------------------------------------------------------------
# main
#

proc main
{
  # checks
  test -n $(FLAGS_command) || die 'command required'
  test -z $(FLAGS_watch) -a -z $(FLAGS_watch_from) \
    && die 'one of watch or watch_from required'
  test -n $(FLAGS_watch) -a -n $(FLAGS_watch_from) \
    && die 'only one of watch or watch_from can be specified'
  test -r $(FLAGS_watch) || die 'unable to read watch file'
  test -w $(FLAGS_output_dir) || die 'unable to write to output directory'

  setglobal watchAge = $[age $(FLAGS_watch)]
  setglobal watchAgePrev = $(watchAge)

  # build
  while true {
    if test ! $(watchAge) == $(watchAgePrev) {
      setglobal date = $[isodate]
      echo "building $(VERSIONS_OS_NAME)-$(VERSIONS_OS_RELEASE) @ $(date)"
      setglobal outputFileDated = ""$(FLAGS_output)-$(date)""
      $(FLAGS_command) >"$(FLAGS_output_dir)/$(outputFileDated)" !2 > !1

      shell { cd $(FLAGS_output_dir);
        rm -f $(FLAGS_output);
        ln -s $(outputFileDated) $(FLAGS_output);
        grep FAIL $(FLAGS_output); }

      setglobal watchAgePrev = $(watchAge)
    }

    setglobal watchAge = $[age $(FLAGS_watch)]
    if test $(watchAge) == $(watchAgePrev) {
      echo 'sleeping...'
      while test $(watchAge) == $(watchAgePrev) {
        sleep $(FLAGS_pause)
        setglobal watchAge = $[age $(FLAGS_watch)]
      }
    }
  }
}

# execute main() if this is run in standalone mode (i.e. not in a unit test)
setglobal argv0 = $[echo $(ARGV0) |sed 's/_test$//;s/_test\.sh$//]
if test $(ARGV0) = $(argv0) {
  FLAGS @Argv || exit $?
  eval set -- $(FLAGS_ARGV)
  if test $Argc -gt 0 { main @Argv; } else { main; }
}