use std::ops::Range;
use unicode_segmentation::UnicodeSegmentation;
use crate::{
sequence::SequenceState,
unicode::{
diff::NormalizationDiff,
text::{NormalizationForm, TextAnalysis},
},
viewport::ListViewport,
};
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum NormalizationMove {
Previous,
Next,
First,
Last,
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct TextMetrics {
pub code_points: usize,
pub bytes: usize,
pub graphemes: usize,
}
impl TextMetrics {
pub fn original(analysis: &TextAnalysis) -> Self {
Self {
code_points: analysis.code_points().len(),
bytes: analysis.byte_count(),
graphemes: analysis.graphemes().len(),
}
}
}
#[derive(Debug, Clone)]
pub struct NormalizationComparison {
pub result: SequenceState,
pub diff: NormalizationDiff,
original_viewport: ListViewport,
}
impl NormalizationComparison {
pub fn original_selection(&self, original: &TextAnalysis) -> Range<usize> {
let index = self.result.code_points()[self.result.selected_index()].grapheme_index();
let Some(range) = self
.diff
.original_graphemes(index)
.filter(|range| !range.is_empty())
else {
return 0..0;
};
original.graphemes()[range.start].code_point_range().start
..original.graphemes()[range.end - 1].code_point_range().end
}
pub fn original_visible_range(&self, original: &TextAnalysis) -> Range<usize> {
self.original_viewport
.visible_range(original.code_points().len())
}
pub fn follow_selection(&mut self, original: &TextAnalysis) {
let selected = self.original_selection(original);
if !selected.is_empty() {
self.original_viewport
.ensure_visible(selected.end - 1, original.code_points().len());
self.original_viewport
.ensure_visible(selected.start, original.code_points().len());
}
}
pub fn resize_original_viewport(&mut self, original: &TextAnalysis, height: usize) {
let selected = self.original_selection(original);
self.original_viewport
.resize(height, selected.start, original.code_points().len());
self.follow_selection(original);
}
}
#[derive(Debug, Clone)]
pub struct NormalizationState {
selected: usize,
metrics: [TextMetrics; 4],
comparisons: [Option<NormalizationComparison>; 4],
}
impl NormalizationState {
pub fn new(original: &TextAnalysis) -> Self {
let metrics = NormalizationForm::ALL.map(|form| {
let text = original.normalized_text(form);
TextMetrics {
code_points: original.normalization().get(form).code_point_count(),
bytes: text.len(),
graphemes: text.graphemes(true).count(),
}
});
let mut state = Self {
selected: 0,
metrics,
comparisons: std::array::from_fn(|_| None),
};
state.prepare_result(original);
state
}
pub fn form(&self) -> NormalizationForm {
NormalizationForm::ALL[self.selected]
}
pub fn metrics(&self, form: NormalizationForm) -> TextMetrics {
self.metrics[form as usize]
}
pub fn comparison(&self) -> &NormalizationComparison {
self.comparisons[self.selected]
.as_ref()
.expect("the selected comparison is prepared")
}
pub fn comparison_mut(&mut self) -> &mut NormalizationComparison {
self.comparisons[self.selected]
.as_mut()
.expect("the selected comparison is prepared")
}
pub fn move_selection(&mut self, movement: NormalizationMove, original: &TextAnalysis) {
self.selected = match movement {
NormalizationMove::Previous => self.selected.saturating_sub(1),
NormalizationMove::Next => (self.selected + 1).min(3),
NormalizationMove::First => 0,
NormalizationMove::Last => 3,
};
self.prepare_result(original);
}
fn prepare_result(&mut self, original: &TextAnalysis) {
let form = self.form();
self.comparisons[self.selected].get_or_insert_with(|| {
let result = SequenceState::new(original.normalized_text(form).to_owned());
let diff = NormalizationDiff::new(original, result.analysis(), form);
NormalizationComparison {
result,
diff,
original_viewport: ListViewport::default(),
}
});
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn reference_tracks_expanded_scalars_and_adjacent_changes_separately() {
let original = TextAnalysis::new("ffi①".to_owned());
let mut state = NormalizationState::new(&original);
state.move_selection(NormalizationMove::Next, &original);
state.move_selection(NormalizationMove::Next, &original);
let comparison = state.comparison_mut();
for expected in [0..1, 0..1, 0..1, 1..2] {
assert_eq!(comparison.original_selection(&original), expected);
comparison
.result
.move_selection(crate::sequence::SequenceMove::Next);
}
}
#[test]
fn lazily_prepares_forms_and_preserves_the_original() {
let original = TextAnalysis::new("A\u{0301} ①👩💻".to_owned());
let saved = original.clone();
let mut state = NormalizationState::new(&original);
assert_eq!(state.form(), NormalizationForm::Nfc);
assert_eq!(state.comparison().result.analysis().source(), "Á ①👩💻");
assert_eq!(
state
.comparisons
.iter()
.filter(|value| value.is_some())
.count(),
1
);
state.move_selection(NormalizationMove::Last, &original);
assert_eq!(state.form(), NormalizationForm::Nfkd);
assert_eq!(
state.metrics(NormalizationForm::Nfkc),
TextMetrics {
code_points: 6,
bytes: 15,
graphemes: 4
}
);
assert_eq!(
state
.comparisons
.iter()
.filter(|value| value.is_some())
.count(),
2
);
assert_eq!(original, saved);
state.move_selection(NormalizationMove::Next, &original);
assert_eq!(state.form(), NormalizationForm::Nfkd);
state.move_selection(NormalizationMove::First, &original);
state.move_selection(NormalizationMove::Previous, &original);
assert_eq!(state.form(), NormalizationForm::Nfc);
}
}