#!/bin/bash -eu

# This Bash script implements custom sanity checks for scripts beyond what
# Vint covers, which are easy to check with regex.

# A flag for automatically fixing some errors.
FIX_ERRORS=0
RETURN_CODE=0

function print_help() {
    echo "Usage: ./custom-checks [--fix] [DIRECTORY]" 1>&2
    echo 1>&2
    echo "  -h, --help    Print this help text" 1>&2
    echo "      --fix     Automatically fix some errors" 1>&2
    exit 1
}

while [ $# -ne 0 ]; do
    case $1 in
    -h) ;& --help)
        print_help
    ;;
    --fix)
        FIX_ERRORS=1
        shift
    ;;
    --)
        shift
        break
    ;;
    -?*)
        echo "Invalid argument: $1" 1>&2
        exit 1
    ;;
    *)
        break
    ;;
    esac
done

if [ $# -eq 0 ] || [ -z "$1" ]; then
    print_help
fi

shopt -s globstar

directories=("$@")

check_errors() {
    regex="$1"
    message="$2"

    for directory in "${directories[@]}"; do
        while IFS= read -r match; do
            RETURN_CODE=1
            echo "$match $message"
        done < <(grep -n "$regex" "$directory"/**/*.vim \
            | grep -v 'no-custom-checks' \
            | grep -o '^[^:]\+:[0-9]\+' \
            | sed 's:^\./::')
    done
}

if (( FIX_ERRORS )); then
    for directory in "${directories[@]}"; do
        sed -i "s/^\(function.*)\) *$/\1 abort/" "$directory"/**/*.vim
        sed -i "s/shellescape(/ale#Escape(/" "$directory"/**/*.vim
        sed -i 's/==#/is#/g' "$directory"/**/*.vim
        sed -i 's/==?/is?/g' "$directory"/**/*.vim
        sed -i 's/!=#/isnot#/g' "$directory"/**/*.vim
        sed -i 's/!=?/isnot?/g' "$directory"/**/*.vim
    done
fi

check_errors \
    '^function.*) *$' \
    'Function without abort keyword (See :help except-compat)'
check_errors '^function[^!]' 'function without !'
check_errors ' \+$' 'Trailing whitespace'
check_errors '^ * end\?i\? *$' 'Write endif, not en, end, or endi'
check_errors '^  [^ ]' 'Use four spaces, not two spaces'
check_errors $'\t' 'Use four spaces, not tabs'
# This check should prevent people from using a particular inconsistent name.
check_errors 'let g:ale_\w\+_\w\+_args =' 'Name your option g:ale_<filetype>_<lintername>_options instead'
check_errors 'shellescape(' 'Use ale#Escape instead of shellescape'
check_errors 'simplify(' 'Use ale#path#Simplify instead of simplify'
check_errors "expand(['\"]%" "Use expand('#' . a:buffer . '...') instead. You might get a filename for the wrong buffer."
check_errors '==#' "Use 'is#' instead of '==#'. 0 ==# 'foobar' is true"
check_errors '==?' "Use 'is?' instead of '==?'. 0 ==? 'foobar' is true"
check_errors '!=#' "Use 'isnot#' instead of '!=#'. 0 !=# 'foobar' is false"
check_errors '!=?' "Use 'isnot?' instead of '!=?'. 0 !=? 'foobar' is false"

exit $RETURN_CODE