AppFlowy/frontend/rust-lib/flowy-client-sync/src/client_document/extensions/helper.rs

use crate::util::find_newline;
use lib_ot::core::AttributeEntry;
use lib_ot::text_delta::{
  empty_attributes, AttributeScope, DeltaTextOperation, DeltaTextOperations,
};

pub(crate) fn line_break(
  op: &DeltaTextOperation,
  attribute: &AttributeEntry,
  scope: AttributeScope,
) -> DeltaTextOperations {
  let mut new_delta = DeltaTextOperations::new();
  let mut start = 0;
  let end = op.len();
  let mut s = op.get_data();

  while let Some(line_break) = find_newline(s) {
    match scope {
      AttributeScope::Inline => {
        new_delta.retain(line_break - start, attribute.clone().into());
        new_delta.retain(1, empty_attributes());
      },
      AttributeScope::Block => {
        new_delta.retain(line_break - start, empty_attributes());
        new_delta.retain(1, attribute.clone().into());
      },
      _ => {
        tracing::error!("Unsupported parser line break for {:?}", scope);
      },
    }

    start = line_break + 1;
    s = &s[start..s.len()];
  }

  if start < end {
    match scope {
      AttributeScope::Inline => new_delta.retain(end - start, attribute.clone().into()),
      AttributeScope::Block => new_delta.retain(end - start, empty_attributes()),
      _ => tracing::error!("Unsupported parser line break for {:?}", scope),
    }
  }
  new_delta
}