#!/usr/bin/env zsh
#
# Generates trace log to debug zim and zsh issues
#

cat >&2 <<EOF

This function creates a trace log to debug
Zsh and Zim functionality.

It will copy your .zshrc to /tmp/ztrace/, ammend profiling
code, launch a new shell, log the trace, close the shell,
archive the logs, and finally print the path to the archive.

EOF

read \?"Press [Enter] to begin trace."

mkdir -p /tmp/ztrace
# make sure that we were able to create the directory
if [[ ! -d /tmp/ztrace ]]; then
  print 'failed to create /tmp/ztrace directory. Aborting.'
  return 1
else
  # check if known output file, if exists
  # rm all directory contents
  if [[ -e /tmp/ztrace/ztrace.log ]]; then
    print "\nLogs from previous run of trace-zim are present"
    print "Deleting old logs now..."
    # use of anonymous function for dotglob opt
    () {
      setopt dotglob
      rm -rf /tmp/ztrace/*
    }
  fi
fi

# get some basic system information (kernel and zsh version)
print 'Zsh version:' > /tmp/ztrace/sysinfo
print $(zsh --version) >> /tmp/ztrace/sysinfo
print "\nkernel information:" >> /tmp/ztrace/sysinfo
print $(uname -mosr) >> /tmp/ztrace/sysinfo
print "\n$fpath info:" >> /tmp/ztrace/sysinfo
print -l ${fpath} >> /tmp/ztrace/sysinfo

cp ${ZDOTDIR:-${HOME}}/.zshrc /tmp/ztrace/.zshrc.orig
cp ${ZDOTDIR:-${HOME}}/.zimrc /tmp/ztrace/.zimrc
# rsync will allow us to not have to copy the .git folder; use if available 
if (( $+commands[rsync] )); then
  rsync -az --exclude .git "${ZDOTDIR:-$HOME}/.zim" "/tmp/ztrace/"
else
  cp -R "${ZDOTDIR:-$HOME}/.zim" "/tmp/ztrace/"
fi

# trace code to add to modified .zshrc
if [[ "$OSTYPE" == linux-gnu ]]; then
  read -d '' tracetop << EOF || true
#######################
# zim trace start #
#######################
exec 3>&2 2> >(tee /tmp/ztrace/sample-time.\$\$.log |
  sed -u 's/^.*$/now/' |
  date -f - +%s.%N >/tmp/ztrace/sample-time.\$\$.tim)
zmodload zsh/zprof
set -x
EOF

# we need gnu-utils to do this, so we must check for darwin/bsd.
# if these platforms, we need to call gsed and gdate explicitly.
elif [[ "$OSTYPE" == (darwin*|*bsd*) ]]; then
  if (( $+commands[gdate] && $+commands[gsed] )); then
    read -d '' tracetop << EOF || true
#######################
# zim trace start #
#######################
exec 3>&2 2> >(tee /tmp/ztrace/sample-time.\$\$.log |
  gsed -u 's/^.*$/now/' |
  gdate -f - +%s.%N >/tmp/ztrace/sample-time.\$\$.tim)
zmodload zsh/zprof
set -x
EOF
  else
    print "debug module requires both gnu-sed (gsed) and gnu-date (gdate)."
    print "please install these with brew before attempting to trace."
    return 1
  fi
else
  print "your system, ${OSTYPE}, is an unknown system."
  print "please create an issue at:"
  print "\thttps://github.com/Eriner/zim/issues"
  print "Please paste the following output in your report:"
  print "\t${OSTYPE} -  $(uname -mosr)"
  return 1
fi

read -d '' tracebot << EOF || true
#####################
# zim trace end #
#####################

set +x
zprof >! /tmp/ztrace/zprof
#non-linux systems have weird fd; also, no real need to redirect back
#prompt is (practically speaking) non-interactive, fd exists only for that process
#which is closed (by typing exit)

#exec 2>&3 3>&-
EOF

# create a modified .zshrc to produce a trace log
origzshrc=$(</tmp/ztrace/.zshrc.orig)
print "$tracetop\n$origzshrc\n$tracebot" >! "/tmp/ztrace/.zshrc"

# clean up the vars now that we are done with them.
unset origzshrc
unset tracetop
unset tracebot

print "\nSpawning zsh and producing trace...\n\n"
ZDOTDIR=/tmp/ztrace zsh -ic 'exit' 
print "Trace complete.\n"
print "Parsing logs to a nicer format; this may take some time..."

# this is ugly thing makes it pretty...
paste <( while read tim; do crt=000000000$((${tim//.}-10#0$last)); printf "%12.9f\n" ${crt:0:${#crt}-9}.${crt:${#crt}-9}; last=${tim//.}; done < /tmp/ztrace/sample-time.(*).tim; ) /tmp/ztrace/sample-time.(*).log > "/tmp/ztrace/ztrace.log" 
print "Parsing complete!"

# safe to remove old, unneeded environment files 
print "Tidying up before archive..."
rm -f /tmp/ztrace/sample-time.*
rm -rf /tmp/ztrace/.zim
rm -f /tmp/ztrace/.zshrc
mv /tmp/ztrace/.zshrc.orig /tmp/ztrace/.zshrc
rm -f /tmp/ztrace/.zhistory
rm -f /tmp/ztrace/.zcompdump.zwc

print "Archiving trace logs...\n"

tar -cf "/tmp/ztrace.tar.gz" "/tmp/ztrace/"

print "Archive complete!\n"

print "\nTrace by with execution time available at:"
print "\t/tmp/ztrace/ztrace.log"
print "\nArchive (for sharing/help) available at:"
print "\t/tmp/ztrace.tar.gz"