#!/usr/bin/env bash

set -e
set -u

# 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: test/script/custom-linting-rules [--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"
    include_arg=''
    exclude_arg=''

    if [ $# -gt 2 ]; then
        include_arg="--include $3"
    fi

    if [ $# -gt 3 ]; then
        shift
        shift
        shift

        while (( "$#" )); do
          exclude_arg="$exclude_arg --exclude $1"
          shift
        done
    fi

    for directory in "${directories[@]}"; do
        # shellcheck disable=SC2086
        while read -r; do
            RETURN_CODE=1
            echo "$REPLY $message"
        done < <(grep -H -n "$regex" $include_arg $exclude_arg "$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
        # Improving type checks.
        sed -i $'s/\\(==.\\?\\|is\\) type([\'"]\+)/is v:t_string/g' "$directory"/**/*.vim
        sed -i 's/\(==.\?\|is\) type([0-9]\+)/is v:t_number/g' "$directory"/**/*.vim
        sed -i 's/\(==.\?\|is\) type(\[\])/is v:t_list/g' "$directory"/**/*.vim
        sed -i 's/\(==.\?\|is\) type({})/is v:t_dict/g' "$directory"/**/*.vim
        sed -i 's/\(==.\?\|is\) type(function([^)]\+))/is v:t_func/g' "$directory"/**/*.vim
        sed -i $'s/\\(!=.\\?\\|isnot\\) type([\'"]\+)/isnot v:t_string/g' "$directory"/**/*.vim
        sed -i 's/\(!=.\?\|isnot\) type([0-9]\+)/isnot v:t_number/g' "$directory"/**/*.vim
        sed -i 's/\(!=.\?\|isnot\) type(\[\])/isnot v:t_list/g' "$directory"/**/*.vim
        sed -i 's/\(!=.\?\|isnot\) type({})/isnot v:t_dict/g' "$directory"/**/*.vim
        sed -i 's/\(!=.\?\|isnot\) type(function([^)]\+))/isnot v:t_func/g' "$directory"/**/*.vim
    done
fi

# The arguments are: regex, explanation, [filename_filter], [list, of, exclusions]
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 'tempname(' 'Use ale#util#Tempname instead of tempname'
check_errors 'getcurpos(' "Use getpos('.') instead of getcurpos() if you don't need curswant, to avoid a bug that changes curswant"
check_errors "expand(['\"]%" "Use expand('#' . a:buffer . '...') instead. You might get a filename for the wrong buffer."
check_errors 'getcwd()' "Do not use getcwd(), as it could run from the wrong buffer. Use expand('#' . a:buffer . ':p:h') instead."
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"
check_errors '^ *:\?echo\>' "Stray echo line. Use \`execute echo\` if you want to echo something"
check_errors '^ *:\?redir' 'User execute() instead of redir'
# Exclusions for grandfathered-in exceptions
exclusions="clojure/clj_kondo.vim elixir/elixir_ls.vim go/golangci_lint.vim swift/swiftformat.vim"
# shellcheck disable=SC2086
check_errors $'name.:.*\'[a-z_]*[^a-z_0-9][a-z_0-9]*\',$' 'Use snake_case names for linters' '*/ale_linters/*' $exclusions
# Checks for improving type checks.
check_errors $'\\(==.\\?\\|is\\) type([\'"]\+)' "Use 'is v:t_string' instead"
check_errors '\(==.\?\|is\) type([0-9]\+)' "Use 'is v:t_number' instead"
check_errors '\(==.\?\|is\) type(\[\])' "Use 'is v:t_list' instead"
check_errors '\(==.\?\|is\) type({})' "Use 'is v:t_dict' instead"
check_errors '\(==.\?\|is\) type(function([^)]\+))' "Use 'is v:t_func' instead"
check_errors $'\\(!=.\\?\\|isnot\\) type([\'"]\+)' "Use 'isnot v:t_string' instead"
check_errors '\(!=.\?\|isnot\) type([0-9]\+)' "Use 'isnot v:t_number' instead"
check_errors '\(!=.\?\|isnot\) type(\[\])' "Use 'isnot v:t_list' instead"
check_errors '\(!=.\?\|isnot\) type({})' "Use 'isnot v:t_dict' instead"
check_errors '\(!=.\?\|isnot\) type(function([^)]\+))' "Use 'isnot v:t_func' instead"

# Run a Python script to find lines that require padding around them.  For
# users without Python installed, we'll skip these checks. GitHub Actions will
# run the script.
if command -v python > /dev/null; then
    if ! test/script/block-padding-checker "$directory"/**/*.vim; then
        RETURN_CODE=1
    fi
fi

exit $RETURN_CODE