pigs-rm

#! /bin/dash

# check if the pigs repository is initialized
if ! test -d ".pig"; then
    echo "pigs-rm: error: pigs repository directory .pig not found"
    exit 1
fi

# check if the number of arguments is correct
if test $# -eq 0; then
    echo "usage: pigs-rm [--force] [--cached] <filenames>"
    exit 1
fi

force=0
cached=0
files=""

# parse the arguments

for arg in "$@"; do
    case "$arg" in
    "--force")
        force=1
        ;;
    "--cached")
        cached=1
        ;;
    "-")
        echo "pigs-rm: error: invalid filename '$arg'"
        exit 1
        ;;
    -*)
        echo "usage: pigs-rm [--force] [--cached] <filenames>"
        exit 1
        ;;
    "")
        echo "usage: pigs-rm [--force] [--cached] <filenames>"
        exit 1
        ;;
    *)
        files="$files $arg"
        ;;
    esac
done

temp_log=$(mktemp)

index_temp=$(mktemp -d)
working_temp=$(mktemp -d)

trap 'rm "$temp_log"' INT HUP QUIT TERM EXIT
trap 'rm -rf "$index_temp" "$working_temp"' INT HUP QUIT TERM EXIT

current_branch=$(cat ".pig/active_branch")
branch_dir=".pig/branches/$current_branch"
index_dir="$branch_dir/index"
commit_history_dir="$branch_dir/commit_history"

commit_number=-1

# get the last commit number
if test -e ".pig/commit_total.log"; then
    commit_number=$(head -n 1 ".pig/commit_total.log" | sed -E -- 's/^([0-9]+) .*$/\1/')
fi

# if test -e "$branch_dir/commit_msg.log"; then
#     commit_number=$(head -n 1 "$branch_dir/commit_msg.log" | sed -E -- 's/^([0-9]+) .*$/\1/')
# fi

is_fail=0

for file in $files; do
    # check if the name of the file is valid
    if ! echo "$file" | grep -E -- '^[a-zA-Z0-9][a-zA-Z0-9.-_]*$' >/dev/null; then
        echo "pigs-rm: error: invalid filename '$file'"
        is_fail=1
        break
    fi

    # check if the file is in the index
    if ! test -e "$index_dir/$file"; then
        echo "pigs-rm: error: '$file' is not in the pigs repository"
        is_fail=1
        break
    fi

    if test "$force" -eq 0; then
        # check if the file is in the current directory
        if ! test -e "$file"; then
            cp "$index_dir/$file" "$index_temp/$file"
            rm "$index_dir/$file"
            echo "Removed $file from index" >>"$temp_log"
            # exit 0
        fi

        # check if it is the first commit
        if test "$commit_number" -eq -1; then
            echo "pigs-rm: error: '$file' has staged changes in the index"
            is_fail=1
            break
        fi

        # Check if index is different to both the current directory and the repository
        if ! diff "$file" "$index_dir/$file" >/dev/null &&
            ! diff "$index_dir/$file" "$commit_history_dir/commit_$commit_number/$file" >/dev/null; then
            echo "pigs-rm: error: '$file' in index is different to both the working file and the repository"
            is_fail=1
            break
        fi

        # check if the file in the current directory is different from the one in the index
        if ! diff "$file" "$index_dir/$file" >/dev/null &&
            test "$cached" -eq 0; then
            echo "pigs-rm: error: '$file' in the repository is different to the working file"
            is_fail=1
            break
        fi

        # check if the file has staged changes in the index
        if test -e "$index_dir/$file"; then
            # no --cached option is given
            if test "$cached" -eq 0; then
                # check if the file in the index exists in the last commit
                if test -e "$commit_history_dir/commit_$commit_number/$file"; then
                    # check if the file in the index is different from the one in the last commit
                    if ! diff "$index_dir/$file" "$commit_history_dir/commit_$commit_number/$file" >/dev/null; then
                        echo "pigs-rm: error: '$file' has staged changes in the index"
                        is_fail=1
                        break
                    fi
                else # if the file in the index does not exist in the last commit
                    echo "pigs-rm: error: '$file' has staged changes in the index"
                    is_fail=1
                    break
                fi
            fi
        fi
    fi

    cp "$index_dir/$file" "$index_temp/$file"
    rm "$index_dir/$file"
    echo "Removed $file from index" >>"$temp_log"
    if test "$cached" -eq 0 && test -e "$file"; then
        cp "$file" "$working_temp/$file"
        rm "$file"
        echo "Removed $file from working directory" >>"$temp_log"
    fi
done

# check if there is any error during the remove process
if test "$is_fail" -eq 1; then
    while read -r line; do
        filename=$(echo "$line" | sed -E -- 's/^Removed (.*) from .*$/\1/')
        action=$(echo "$line" | sed -E -- 's/^Removed .* from (.*)$/\1/')

        if test "$action" = "index"; then
            # restore the file to the index
            cp "$index_temp/$filename" "$index_dir/$filename"
        elif test "$action" = "working directory"; then
            cp "$working_temp/$filename" "$filename"
        fi
    done <"$temp_log"
fi