#!/usr/bin/env bash

# For code formatting we have clang-format.
#
# But it's not sane to apply clang-format for whole code base,
#  because it sometimes makes worse for properly formatted files.
#
# It's only reasonable to blindly apply clang-format only in cases
#  when the code is likely to be out of style.
#
# For this purpose we have a script that will use very primitive heuristics
#  (simple regexps) to check if the code is likely to have basic style violations.
#  and then to run formatter only for the specified files.

LC_ALL="en_US.UTF-8"
ROOT_PATH=$(git rev-parse --show-toplevel)
EXCLUDE_DIRS='build/|integration/|widechar_width/|glibc-compatibility/|poco/|memcpy/|consistent-hashing|benchmark|tests/.*.cpp|utils/keeper-bench/example.yaml'

# From [1]:
#     But since array_to_string_internal() in array.c still loops over array
#     elements and concatenates them into a string, it's probably not more
#     efficient than the looping solutions proposed, but it's more readable.
#
#  [1]: https://stackoverflow.com/a/15394738/328260
function in_array()
{
    local IFS="|"
    local value=$1 && shift

    [[ "${IFS}${*}${IFS}" =~ "${IFS}${value}${IFS}" ]]
}

find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' 2>/dev/null |
    grep -vP $EXCLUDE_DIRS |
    xargs grep $@ -P '((class|struct|namespace|enum|if|for|while|else|throw|switch).*|\)(\s*const)?(\s*override)?\s*)\{$|\s$|^ {1,3}[^\* ]\S|\t|^\s*(if|else if|if constexpr|else if constexpr|for|while|catch|switch)\(|\( [^\s\\]|\S \)' |
# a curly brace not in a new line, but not for the case of C++11 init or agg. initialization | trailing whitespace | number of ws not a multiple of 4, but not in the case of comment continuation | missing whitespace after for/if/while... before opening brace | whitespaces inside braces
    grep -v -P '(//|:\s+\*|\$\(\()| \)"'
# single-line comment | continuation of a multiline comment | a typical piece of embedded shell code | something like ending of raw string literal

# Tabs
find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' 2>/dev/null |
    grep -vP $EXCLUDE_DIRS |
    xargs grep $@ -F $'\t'

# // namespace comments are unneeded
find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' 2>/dev/null |
    grep -vP $EXCLUDE_DIRS |
    xargs grep $@ -P '}\s*//+\s*namespace\s*'

# Broken symlinks
find -L $ROOT_PATH -type l 2>/dev/null | grep -v contrib && echo "^ Broken symlinks found"

# Double whitespaces
find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' 2>/dev/null |
    grep -vP $EXCLUDE_DIRS |
    while read i; do $ROOT_PATH/utils/check-style/double-whitespaces.pl < $i || echo -e "^ File $i contains double whitespaces\n"; done

# Unused/Undefined/Duplicates ErrorCodes/ProfileEvents/CurrentMetrics
declare -A EXTERN_TYPES
EXTERN_TYPES[ErrorCodes]=int
EXTERN_TYPES[ProfileEvents]=Event
EXTERN_TYPES[CurrentMetrics]=Metric

EXTERN_TYPES_EXCLUDES=(
    ProfileEvents::global_counters
    ProfileEvents::Event
    ProfileEvents::Count
    ProfileEvents::Counters
    ProfileEvents::end
    ProfileEvents::increment
    ProfileEvents::incrementForLogMessage
    ProfileEvents::getName
    ProfileEvents::Type
    ProfileEvents::TypeEnum
    ProfileEvents::dumpToMapColumn
    ProfileEvents::getProfileEvents
    ProfileEvents::ThreadIdToCountersSnapshot
    ProfileEvents::LOCAL_NAME
    ProfileEvents::CountersIncrement

    CurrentMetrics::add
    CurrentMetrics::sub
    CurrentMetrics::get
    CurrentMetrics::set
    CurrentMetrics::end
    CurrentMetrics::Increment
    CurrentMetrics::Metric
    CurrentMetrics::values
    CurrentMetrics::Value

    ErrorCodes::ErrorCode
    ErrorCodes::getName
    ErrorCodes::increment
    ErrorCodes::end
    ErrorCodes::values
    ErrorCodes::values[i]
    ErrorCodes::getErrorCodeByName
)
for extern_type in ${!EXTERN_TYPES[@]}; do
    type_of_extern=${EXTERN_TYPES[$extern_type]}
    allowed_chars='[_A-Za-z]+'

    # Unused
    # NOTE: to fix automatically, replace echo with:
    # sed -i "/extern const $type_of_extern $val/d" $file
    find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' | {
        # NOTE: the check is pretty dumb and distinguish only by the type_of_extern,
        # and this matches with zkutil::CreateMode
        grep -v 'src/Common/ZooKeeper/Types.h'
    } | {
        grep -vP $EXCLUDE_DIRS | xargs grep -l -P "extern const $type_of_extern $allowed_chars"
    } | while read file; do
        grep -P "extern const $type_of_extern $allowed_chars;" $file | sed -r -e "s/^.*?extern const $type_of_extern ($allowed_chars);.*?$/\1/" | while read val; do
            if ! grep -q "$extern_type::$val" $file; then
                # Excludes for SOFTWARE_EVENT/HARDWARE_EVENT/CACHE_EVENT in ThreadProfileEvents.cpp
                if [[ ! $extern_type::$val =~ ProfileEvents::Perf.* ]]; then
                    echo "$extern_type::$val is defined but not used in file $file"
                fi
            fi
        done
    done

    # Undefined
    # NOTE: to fix automatically, replace echo with:
    # ( grep -q -F 'namespace $extern_type' $file && \
    #   sed -i -r "0,/(\s*)extern const $type_of_extern [$allowed_chars]+/s//\1extern const $type_of_extern $val;\n&/" $file || \
    #     awk '{ print; if (ns == 1) { ns = 2 }; if (ns == 2) { ns = 0; print "namespace $extern_type\n{\n    extern const $type_of_extern '$val';\n}" } }; /namespace DB/ { ns = 1; };' < $file > ${file}.tmp && mv ${file}.tmp $file )
    find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' | {
        grep -vP $EXCLUDE_DIRS | xargs grep -l -P "$extern_type::$allowed_chars"
    } | while read file; do
        grep -P "$extern_type::$allowed_chars" $file | grep -P -v '^\s*//' | sed -r -e "s/^.*?$extern_type::($allowed_chars).*?$/\1/" | while read val; do
            if ! grep -q "extern const $type_of_extern $val" $file; then
                if ! in_array "$extern_type::$val" "${EXTERN_TYPES_EXCLUDES[@]}"; then
                    echo "$extern_type::$val is used in file $file but not defined"
                fi
            fi
        done
    done

    # Duplicates
    find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' | {
        grep -vP $EXCLUDE_DIRS | xargs grep -l -P "$extern_type::$allowed_chars"
    } | while read file; do
        grep -P "extern const $type_of_extern $allowed_chars;" $file | sort | uniq -c | grep -v -P ' +1 ' && echo "Duplicate $extern_type in file $file"
    done
done

# Three or more consecutive empty lines
find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' |
    grep -vP $EXCLUDE_DIRS |
    while read file; do awk '/^$/ { ++i; if (i > 2) { print "More than two consecutive empty lines in file '$file'" } } /./ { i = 0 }' $file; done

# Broken XML files (requires libxml2-utils)
find $ROOT_PATH/{src,base,programs,utils} -name '*.xml' |
    grep -vP $EXCLUDE_DIRS |
    xargs xmllint --noout --nonet

# FIXME: for now only clickhouse-test
pylint --rcfile=$ROOT_PATH/.pylintrc --persistent=no --score=n $ROOT_PATH/tests/clickhouse-test $ROOT_PATH/tests/ci/*.py

find $ROOT_PATH -not -path $ROOT_PATH'/contrib*' \( -name '*.yaml' -or -name '*.yml' \) -type f |
    grep -vP $EXCLUDE_DIRS |
    xargs yamllint --config-file=$ROOT_PATH/.yamllint

# Tests should not be named with "fail" in their names. It makes looking at the results less convenient.
find $ROOT_PATH/tests/queries -iname '*fail*' |
    grep . && echo 'Tests should not be named with "fail" in their names. It makes looking at the results less convenient when you search for "fail" substring in browser.'

# Queries to system.query_log/system.query_thread_log should have current_database = currentDatabase() condition
# NOTE: it is not that accurate, but at least something.
tests_with_query_log=( $(
    find $ROOT_PATH/tests/queries -iname '*.sql' -or -iname '*.sh' -or -iname '*.py' -or -iname '*.j2' |
        xargs grep --with-filename -e system.query_log -e system.query_thread_log | cut -d: -f1 | sort -u
) )
for test_case in "${tests_with_query_log[@]}"; do
    grep -qE current_database.*currentDatabase "$test_case" || {
        grep -qE 'current_database.*\$CLICKHOUSE_DATABASE' "$test_case"
    } || echo "Queries to system.query_log/system.query_thread_log does not have current_database = currentDatabase() condition in $test_case"
done

# There shouldn't be large jumps between test numbers (since they should be consecutive)
max_diff=$(
    find $ROOT_PATH/tests/queries -iname '*.sql' -or -iname '*.sh' -or -iname '*.py' -or -iname '*.j2' |
          grep -oP '\d+\D+\K\d+' | sort -n -u | awk 's{print ($0-s) " diff " s " and " $0 }{s=$0}' | sort -n | tail -n 1
)
max_diff_value=( $(echo $max_diff) )
if [[ $max_diff_value -ge 100 ]];
then
    echo "Too big of a difference between test numbers: $max_diff"
fi

# Queries to:
tables_with_database_column=(
    system.tables
    system.parts
    system.detached_parts
    system.parts_columns
    system.columns
    system.projection_parts
    system.mutations
)
# should have database = currentDatabase() condition
#
# NOTE: it is not that accuate, but at least something.
tests_with_database_column=( $(
    find $ROOT_PATH/tests/queries -iname '*.sql' -or -iname '*.sh' -or -iname '*.py' -or -iname '*.j2' |
        xargs grep --with-filename $(printf -- "-e %s " "${tables_with_database_column[@]}") |
        grep -v -e ':--' -e ':#' |
        cut -d: -f1 | sort -u
) )
for test_case in "${tests_with_database_column[@]}"; do
    grep -qE database.*currentDatabase "$test_case" || {
        grep -qE 'database.*\$CLICKHOUSE_DATABASE' "$test_case"
    } || {
        # explicit database
        grep -qE "database[ ]*=[ ]*'" "$test_case"
    } || {
        echo "Queries to ${tables_with_database_column[*]} does not have database = currentDatabase()/\$CLICKHOUSE_DATABASE condition in $test_case"
    }
done

# Queries with ReplicatedMergeTree
# NOTE: it is not that accuate, but at least something.
tests_with_replicated_merge_tree=( $(
    find $ROOT_PATH/tests/queries -iname '*.sql' -or -iname '*.sh' -or -iname '*.py' -or -iname '*.j2' |
        xargs grep --with-filename -e "Replicated.*MergeTree[ ]*(.*" | cut -d: -f1 | sort -u
) )
for test_case in "${tests_with_replicated_merge_tree[@]}"; do
    case "$test_case" in
        *.gen.*)
            ;;
        *.sh)
            test_case_zk_prefix="\(\$CLICKHOUSE_TEST_ZOOKEEPER_PREFIX\|{database}\)"
            grep -q -e "Replicated.*MergeTree[ ]*(.*$test_case_zk_prefix" "$test_case" || echo "Replicated.*MergeTree should contain '$test_case_zk_prefix' in zookeeper path to avoid overlaps ($test_case)"
            ;;
        *.sql|*.sql.j2)
            test_case_zk_prefix="\({database}\|currentDatabase()\|{uuid}\|{default_path_test}\)"
            grep -q -e "Replicated.*MergeTree[ ]*(.*$test_case_zk_prefix" "$test_case" || echo "Replicated.*MergeTree should contain '$test_case_zk_prefix' in zookeeper path to avoid overlaps ($test_case)"
            ;;
        *.py)
            # Right now there is not such tests anyway
            echo "No ReplicatedMergeTree style check for *.py ($test_case)"
            ;;
    esac
done

# All the submodules should be from https://github.com/
find $ROOT_PATH -name '.gitmodules' | while read i; do grep -F 'url = ' $i | grep -v -F 'https://github.com/' && echo 'All the submodules should be from https://github.com/'; done

# There shouldn't be any code snippets under GPL or LGPL
find $ROOT_PATH/{src,base,programs} -name '*.h' -or -name '*.cpp' 2>/dev/null | xargs grep -i -F 'General Public License' && echo "There shouldn't be any code snippets under GPL or LGPL"

# There shouldn't be any docker containers outside docker directory
find $ROOT_PATH -not -path $ROOT_PATH'/tests/ci*' -not -path $ROOT_PATH'/docker*' -not -path $ROOT_PATH'/contrib*' -name Dockerfile -type f 2>/dev/null | xargs --no-run-if-empty -n1 echo "Please move Dockerfile to docker directory:"

# There shouldn't be any docker compose files outside docker directory
find $ROOT_PATH -name '*compose*.yml' -type f -not -path $ROOT_PATH'/docker' -not -path $ROOT_PATH'/tests/integration*' -not -path $ROOT_PATH'/docker*' -not -path $ROOT_PATH'/contrib*' 2>/dev/null | grep -vP $EXCLUDE_DIRS | xargs --no-run-if-empty grep -l "version:" | xargs --no-run-if-empty -n1 echo "Please move docker compose to the 'docker' or 'tests' directory:"

# Check that every header file has #pragma once in first line
find $ROOT_PATH/{src,programs,utils} -name '*.h' |
    grep -vP $EXCLUDE_DIRS |
    while read file; do [[ $(head -n1 $file) != '#pragma once' ]] && echo "File $file must have '#pragma once' in first line"; done

# Check for executable bit on non-executable files
find $ROOT_PATH/{src,base,programs,utils,tests,docs,cmake} '(' -name '*.cpp' -or -name '*.h' -or -name '*.sql' -or -name '*.j2' -or -name '*.xml' -or -name '*.reference' -or -name '*.txt' -or -name '*.md' ')' -and -executable | grep -P '.' && echo "These files should not be executable."

# Check for BOM
find $ROOT_PATH/{src,base,programs,utils,tests,docs,cmake} -name '*.md' -or -name '*.cpp' -or -name '*.h' | xargs grep -l -F $'\xEF\xBB\xBF' | grep -P '.' && echo "Files should not have UTF-8 BOM"
find $ROOT_PATH/{src,base,programs,utils,tests,docs,cmake} -name '*.md' -or -name '*.cpp' -or -name '*.h' | xargs grep -l -F $'\xFF\xFE' | grep -P '.' && echo "Files should not have UTF-16LE BOM"
find $ROOT_PATH/{src,base,programs,utils,tests,docs,cmake} -name '*.md' -or -name '*.cpp' -or -name '*.h' | xargs grep -l -F $'\xFE\xFF' | grep -P '.' && echo "Files should not have UTF-16BE BOM"

# Too many exclamation marks
find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' |
    grep -vP $EXCLUDE_DIRS |
    xargs grep -F '!!!' | grep -P '.' && echo "Too many exclamation marks (looks dirty, unconfident)."

# Trailing whitespaces
find $ROOT_PATH/{src,base,programs,utils} -name '*.h' -or -name '*.cpp' |
    grep -vP $EXCLUDE_DIRS |
    xargs grep -n -P ' $' | grep -n -P '.' && echo "^ Trailing whitespaces."

# Forbid stringstream because it's easy to use them incorrectly and hard to debug possible issues
find $ROOT_PATH/{src,programs,utils} -name '*.h' -or -name '*.cpp' |
    grep -vP $EXCLUDE_DIRS |
    xargs grep -P 'std::[io]?stringstream' | grep -v "STYLE_CHECK_ALLOW_STD_STRING_STREAM" && echo "Use WriteBufferFromOwnString or ReadBufferFromString instead of std::stringstream"

# Forbid std::cerr/std::cout in src (fine in programs/utils)
std_cerr_cout_excludes=(
    /examples/
    /tests/
    _fuzzer
    # DUMP()
    base/base/iostream_debug_helpers.h
    # OK
    src/Common/ProgressIndication.cpp
    # only under #ifdef DBMS_HASH_MAP_DEBUG_RESIZES, that is used only in tests
    src/Common/HashTable/HashTable.h
    # SensitiveDataMasker::printStats()
    src/Common/SensitiveDataMasker.cpp
    # StreamStatistics::print()
    src/Compression/LZ4_decompress_faster.cpp
    # ContextSharedPart with subsequent std::terminate()
    src/Interpreters/Context.cpp
    # IProcessor::dump()
    src/Processors/IProcessor.cpp
    src/Client/ClientBase.cpp
    src/Client/LineReader.cpp
    src/Client/QueryFuzzer.cpp
    src/Client/Suggest.cpp
    src/Bridge/IBridge.cpp
    src/Daemon/BaseDaemon.cpp
    src/Loggers/Loggers.cpp
)
sources_with_std_cerr_cout=( $(
    find $ROOT_PATH/{src,base} -name '*.h' -or -name '*.cpp' | \
        grep -vP $EXCLUDE_DIRS | \
        grep -F -v $(printf -- "-e %s " "${std_cerr_cout_excludes[@]}") | \
        xargs grep -F --with-filename -e std::cerr -e std::cout | cut -d: -f1 | sort -u
) )
# Exclude comments
for src in "${sources_with_std_cerr_cout[@]}"; do
    # suppress stderr, since it may contain warning for #pargma once in headers
    if gcc -fpreprocessed -dD -E "$src" 2>/dev/null | grep -F -q -e std::cerr -e std::cout; then
        echo "$src: uses std::cerr/std::cout"
    fi
done

# Queries with event_date should have yesterday() not today()
#
# NOTE: it is not that accuate, but at least something.
tests_with_event_time_date=( $(
    find $ROOT_PATH/tests/queries -iname '*.sql' -or -iname '*.sh' -or -iname '*.py' -or -iname '*.j2' |
        grep -vP $EXCLUDE_DIRS |
        xargs grep --with-filename -e event_time -e event_date | cut -d: -f1 | sort -u
) )
for test_case in "${tests_with_event_time_date[@]}"; do
    cat "$test_case" | tr '\n' ' ' | grep -q -i -e 'WHERE.*event_date[ ]*=[ ]*today()' -e 'WHERE.*event_date[ ]*=[ ]*today()' && {
        echo "event_time/event_date should be filtered using >=yesterday() in $test_case (to avoid flakiness)"
    }
done

expect_tests=( $(find $ROOT_PATH/tests/queries -name '*.expect') )
for test_case in "${expect_tests[@]}"; do
    pattern="^exp_internal -f \$env(CLICKHOUSE_TMP)/\$basename.debuglog 0$"
    grep -q "$pattern" "$test_case" || echo "Missing '$pattern' in '$test_case'"

    if grep -q "^spawn.*CLICKHOUSE_CLIENT_BINARY$" "$test_case"; then
        pattern="^spawn.*CLICKHOUSE_CLIENT_BINARY.*--history_file$"
        grep -q "$pattern" "$test_case" || echo "Missing '$pattern' in '$test_case'"
    fi

    # Otherwise expect_after/expect_before will not bail without stdin attached
    # (and actually this is a hack anyway, correct way is to use $any_spawn_id)
    pattern="-i \$any_spawn_id timeout"
    grep -q -- "$pattern" "$test_case" || echo "Missing '$pattern' in '$test_case'"
    pattern="-i \$any_spawn_id eof"
    grep -q -- "$pattern" "$test_case" || echo "Missing '$pattern' in '$test_case'"
done

# Conflict markers
find $ROOT_PATH/{src,base,programs,utils,tests,docs,cmake} -name '*.md' -or -name '*.cpp' -or -name '*.h' |
    xargs grep -P '^(<<<<<<<|=======|>>>>>>>)$' | grep -P '.' && echo "Conflict markers are found in files"

# Forbid subprocess.check_call(...) in integration tests because it does not provide enough information on errors
find $ROOT_PATH'/tests/integration' -name '*.py' |
    xargs grep -F 'subprocess.check_call' | grep -v "STYLE_CHECK_ALLOW_SUBPROCESS_CHECK_CALL" && echo "Use helpers.cluster.run_and_check or subprocess.run instead of subprocess.check_call to print detailed info on error"

# Forbid non-unique error codes
if [[ "$(grep -Po "M\([0-9]*," $ROOT_PATH/src/Common/ErrorCodes.cpp | wc -l)" != "$(grep -Po "M\([0-9]*," $ROOT_PATH/src/Common/ErrorCodes.cpp | sort | uniq | wc -l)" ]]
then
    echo "ErrorCodes.cpp contains non-unique error codes"
fi

# Check that there is no system-wide libraries/headers in use.
#
# NOTE: it is better to override find_path/find_library in cmake, but right now
# it is not possible, see [1] for the reference.
#
#   [1]: git grep --recurse-submodules -e find_library -e find_path contrib
if git grep -e find_path -e find_library -- :**CMakeLists.txt; then
    echo "There is find_path/find_library usage. ClickHouse should use everything bundled. Consider adding one more contrib module."
fi

# Forbid files that differ only by character case
find $ROOT_PATH | sort -f | uniq -i -c | awk '{ if ($1 > 1) print }'

# Forbid std::filesystem::is_symlink and std::filesystem::read_symlink, because it's easy to use them incorrectly
find $ROOT_PATH/{src,programs,utils} -name '*.h' -or -name '*.cpp' |
    grep -vP $EXCLUDE_DIRS |
    xargs grep -P '::(is|read)_symlink' | grep -v "STYLE_CHECK_ALLOW_STD_FS_SYMLINK" && echo "Use DB::FS::isSymlink and DB::FS::readSymlink instead"

# Forbid __builtin_unreachable(), because it's hard to debug when it becomes reachable
find $ROOT_PATH/{src,programs,utils} -name '*.h' -or -name '*.cpp' |
    grep -vP $EXCLUDE_DIRS |
    xargs grep -P '__builtin_unreachable' && echo "Use UNREACHABLE() from defines.h instead"

# Require checking return value of close(),
# since it can hide fd misuse and break other places.
find $ROOT_PATH/{src,programs,utils} -name '*.h' -or -name '*.cpp' |
    grep -vP $EXCLUDE_DIRS |
    xargs grep -e ' close(.*fd' -e ' ::close(' | grep -v = && echo "Return value of close() should be checked"

# Check for existence of __init__.py files
for i in "${ROOT_PATH}"/tests/integration/test_*; do FILE="${i}/__init__.py"; [ ! -f "${FILE}" ] && echo "${FILE} should exist for every integration test"; done

# A small typo can lead to debug code in release builds, see https://github.com/ClickHouse/ClickHouse/pull/47647
find $ROOT_PATH/{src,programs,utils} -name '*.h' -or -name '*.cpp' | xargs grep -l -F '#ifdef NDEBUG' | xargs -I@FILE awk '/#ifdef NDEBUG/ { inside = 1; dirty = 1 } /#endif/ { if (inside && dirty) { print "File @FILE has suspicious #ifdef NDEBUG, possibly confused with #ifndef NDEBUG" }; inside = 0 } /#else/ { dirty = 0 }' @FILE

# If a user is doing dynamic or typeid cast with a pointer, and immediately dereferencing it, it is unsafe.
find $ROOT_PATH/{src,programs,utils} -name '*.h' -or -name '*.cpp' | xargs grep --line-number -P '(dynamic|typeid)_cast<[^>]+\*>\([^\(\)]+\)->' | grep -P '.' && echo "It's suspicious when you are doing a dynamic_cast or typeid_cast with a pointer and immediately dereferencing it. Use references instead of pointers or check a pointer to nullptr."

# The stateful directory should only contain the tests that depend on the test dataset (hits or visits).
find $ROOT_PATH/tests/queries/1_stateful -name '*.sql' -or -name '*.sh' | grep -v '00076_system_columns_bytes' | xargs -I{} bash -c 'grep -q -P "hits|visits" "{}" || echo "The test {} does not depend on the test dataset (hits or visits table) and should be located in the 0_stateless directory. You can also add an exception to the check-style script."'

# Check for bad punctuation: whitespace before comma.
find $ROOT_PATH/{src,programs,utils} -name '*.h' -or -name '*.cpp' | xargs grep -P --line-number '\w ,' | grep -v 'bad punctuation is ok here' && echo "^ There is bad punctuation: whitespace before comma. You should write it like this: 'Hello, world!'"

# Cyrillic characters hiding inside Latin.
find $ROOT_PATH/{src,programs,utils} -name '*.h' -or -name '*.cpp' | xargs grep -P --line-number '[a-zA-Z][а-яА-ЯёЁ]|[а-яА-ЯёЁ][a-zA-Z]' && echo "^ Cyrillic characters found in unexpected place."