#!/bin/bash
set -e
fixers="
lib2to3.fixes.fix_apply
lib2to3.fixes.fix_except
lib2to3.fixes.fix_exitfunc
lib2to3.fixes.fix_funcattrs
lib2to3.fixes.fix_has_key
lib2to3.fixes.fix_idioms
lib2to3.fixes.fix_intern
lib2to3.fixes.fix_isinstance
lib2to3.fixes.fix_methodattrs
lib2to3.fixes.fix_ne
lib2to3.fixes.fix_numliterals
lib2to3.fixes.fix_paren
lib2to3.fixes.fix_reduce
lib2to3.fixes.fix_renames
lib2to3.fixes.fix_repr
lib2to3.fixes.fix_standarderror
lib2to3.fixes.fix_sys_exc
lib2to3.fixes.fix_throw
lib2to3.fixes.fix_tuple_params
lib2to3.fixes.fix_types
lib2to3.fixes.fix_ws_comma
lib2to3.fixes.fix_xreadlines
libfuturize.fixes.fix_absolute_import
libfuturize.fixes.fix_future_standard_library_urllib
libfuturize.fixes.fix_next_call
libfuturize.fixes.fix_print_with_import
libfuturize.fixes.fix_raise
libmodernize.fixes.fix_basestring
libfuturize.fixes.fix_division_safe
libmodernize.fixes.fix_file
libmodernize.fixes.fix_filter
libmodernize.fixes.fix_imports_six
libmodernize.fixes.fix_input_six
libmodernize.fixes.fix_int_long_tuple
libmodernize.fixes.fix_map
libmodernize.fixes.fix_raise_six
libmodernize.fixes.fix_xrange_six
libmodernize.fixes.fix_zip
libmodernize.fixes.fix_unicode_type
libpasteurize.fixes.fix_newstyle
"

echo; echo "Testing for additions of Python 2 patterns we've removed as part of moving towards Python 3 compatibility."; echo

if [ -n "$(git status --porcelain)" ]; then
    echo "The repository is not clean. check-py3 can only be run if the repository is clean."
    echo "Displaying output from 'git status --porcelain' to help debug"
    git status --porcelain
    exit 1
fi

script_dir=$(dirname "$0")
lister_path="$script_dir/lister.py"
python_files="$($lister_path -f py)"

if [ -z "$python_files" ]; then
    echo "There are no python files to check in the current directory."
    exit 0
fi

quick=1
if [ "$1" == "--find-fixers" ]; then
    quick=0
fi

fixer_options=""
for fixer in $fixers; do
    fixer_options+="-f $fixer "
done

failed=0
# run quick check
echo "Running quick Python 3 compatibility test"
echo "$python_files" | xargs futurize $fixer_options -j4 -n -w >/dev/null 2>/dev/null
if ! git diff --exit-code; then
    # Clear the output from this one
    git reset --hard >/dev/null
    failed=1
fi

# run slow check
if [ "$failed" = "1" -a "$quick" == "0" ]; then
    echo "Running each fixer separately to find out which fixers need to be applied"
    for fixer in $fixers; do
        echo "Running Python 3 compatibility test $fixer"
        echo "$python_files" | xargs futurize -f $fixer -j4 -n -w >/dev/null 2>/dev/null
        if ! git diff --exit-code; then
            # Clear the output from this one
            git reset --hard >/dev/null
        fi
    done
fi

# The dict fixer tries to add list() even in for loops over an
# iterator where it's just counterproductive.  To address this, we run
# the fixer but check for lines which don't include code that works
# with iterators (currently for, join, and from_iterable).
fixer="libmodernize.fixes.fix_dict_six"
echo "Running python 3 compatability test $fixer"
echo "$python_files" | xargs python-modernize -f $fixer -j4 -n -w >/dev/null 2>/dev/null
if git --no-pager diff | grep "^+ " | grep -v '[ ]*for' | grep -v [.]join | grep -v from_iterable; then
    echo
    echo "Error: the above are changes suggested by python-modernize "
    echo "to handle the list=>iterator transition in Python 3."
    echo "Because 'python-modernize -f libmodernize.fixes.fix_dict_six' is spammy "
    echo "and also changes places where an iterator works fine, this output "
    echo "does not display the full context; you can find the diff with context by "
    echo "searching through the (unfortunately very spammy) full output below:"
    echo
    git --no-pager diff
    echo
    echo "That was a lot of text!  Read this output from the top for more readable details."
    failed=1
fi
# Clear the output
git reset --hard >/dev/null

if git grep -q '\(^\W*import StringIO\|^\W*from StringIO\)'; then
    echo "ERROR: StringIO imports not compatible with python 2+3:"
    git grep '\(^\W*import StringIO\|^\W*from StringIO\)'
    echo "Please use 'from six.moves import cStringIO as StringIO'"
    failed=1
fi

echo
if [ "$failed" == "0" ]; then
    echo "No issues detected!"
else
    echo "Python 3 compatibility error(s) detected!  See diffs above for what you need to change."
    exit 1
fi