#!/usr/bin/env bash
set -e

scriptName=mark-broken # do not use the .wrapped name

die() {
    echo "$scriptName: error: $1" >&2
    exit 1
}

usage() {
    echo "Usage: $scriptName <attr> [--new-value=<new-value>]"
}

args=()

for arg in "$@"; do
    case $arg in
        --new-value=*)
            newValue="${arg#*=}"
        ;;
        --help)
            usage
            exit 0
        ;;
        --*)
            echo "$scriptName: Unknown argument: $arg"
            usage
            exit 1
        ;;
        *)
            args["${#args[*]}"]=$arg
        ;;
    esac
done

attr=${args[0]}

if (( "${#args[*]}" < 1 )); then
    echo "$scriptName: Too few arguments"
    usage
    exit 1
fi

if (( "${#args[*]}" > 1 )); then
    echo "$scriptName: Too many arguments"
    usage
    exit 1
fi

if [ -z $newValue ]; then
  newValue="true"
fi

nixFile=$(nix-instantiate --eval --json -E "with import ./. {}; (builtins.unsafeGetAttrPos \"description\" $attr.meta).file" | jq -r .)
if [[ ! -f "$nixFile" ]]; then
    die "Couldn't evaluate 'builtins.unsafeGetAttrPos \"description\" $attr.meta' to locate the .nix file!"
fi

# Insert broken attribute
sed -i.bak "$nixFile" -r \
  -e "/^\s*broken\s*=.*$/d" \
  -e "s/(\s*)meta\s*=.*\{/&\n\1  broken = $newValue;/"

if cmp -s "$nixFile" "$nixFile.bak"; then
    mv "$nixFile.bak" "$nixFile"
    die "Failed to mark the package as broken! Does it have a meta attribute?"
fi

if [[ "$newValue" == "true" ]]; then
    # broken should evaluate to true in any case now
    markedSuccessfully=$(nix-instantiate --eval -E "with import ./. {}; $attr.meta.broken" || true)
    if [[ ! "$markedSuccessfully" == "true" ]]; then
        mv "$nixFile.bak" "$nixFile"
        die "Couldn't verify the broken attribute to be set correctly, restoring backup!"
    fi
else
    # we can not check if broken evaluates to the correct value, but we can check that it does evaluate
    if ! nix-instantiate --eval -E "with import ./. {}; $attr.meta.broken" >/dev/null; then
        mv "$nixFile.bak" "$nixFile"
        die "Couldn't verify the broken attribute to be set correctly, restoring backup!"
    fi
fi

rm -f "$nixFile.bak"
rm -f "$attr.fetchlog"