2 files changed, 145 insertions, 0 deletions

diff --git a/bin/src/fix/all.rs b/bin/src/fix/all.rs
new file mode 100644
index 0000000..8c0770d
--- /dev/null
+++ b/bin/src/fix/all.rs
@@ -0,0 +1,86 @@
+use std::borrow::Cow;
+
+use lib::{Report, LINTS};
+use rnix::{parser::ParseError as RnixParseErr, WalkEvent};
+
+use crate::fix::{Fixed, FixResult};
+
+fn collect_fixes(source: &str) -> Result<Vec<Report>, RnixParseErr> {
+    let parsed = rnix::parse(source).as_result()?;
+
+    Ok(parsed
+        .node()
+        .preorder_with_tokens()
+        .filter_map(|event| match event {
+            WalkEvent::Enter(child) => LINTS.get(&child.kind()).map(|rules| {
+                rules
+                    .iter()
+                    .filter_map(|rule| rule.validate(&child))
+                    .filter(|report| report.total_suggestion_range().is_some())
+                    .collect::<Vec<_>>()
+            }),
+            _ => None,
+        })
+        .flatten()
+        .collect())
+}
+
+fn reorder(mut reports: Vec<Report>) -> Vec<Report> {
+    use std::collections::VecDeque;
+
+    reports.sort_by(|a, b| {
+        let a_range = a.range();
+        let b_range = b.range();
+        a_range.end().partial_cmp(&b_range.end()).unwrap()
+    });
+
+    reports
+        .into_iter()
+        .fold(VecDeque::new(), |mut deque: VecDeque<Report>, new_elem| {
+            let front = deque.front();
+            let new_range = new_elem.range();
+            if let Some(front_range) = front.map(|f| f.range()) {
+                if new_range.start() > front_range.end() {
+                    deque.push_front(new_elem);
+                }
+            } else {
+                deque.push_front(new_elem);
+            }
+            deque
+        })
+        .into()
+}
+
+impl<'a> Iterator for FixResult<'a> {
+    type Item = FixResult<'a>;
+    fn next(&mut self) -> Option<Self::Item> {
+        let all_reports = collect_fixes(&self.src).ok()?;
+        if all_reports.is_empty() {
+            return None;
+        }
+
+        let reordered = reorder(all_reports);
+        let fixed = reordered
+            .iter()
+            .map(|r| Fixed {
+                at: r.range(),
+                code: r.code,
+            })
+            .collect::<Vec<_>>();
+        for report in reordered {
+            report.apply(self.src.to_mut());
+        }
+
+        Some(FixResult {
+            src: self.src.clone(),
+            fixed
+        })
+    }
+}
+
+pub fn all(src: &str) -> Option<FixResult> {
+    let src = Cow::from(src);
+    let _ = rnix::parse(&src).as_result().ok()?;
+    let initial = FixResult::empty(src);
+    initial.into_iter().last()
+}
diff --git a/bin/src/fix/single.rs b/bin/src/fix/single.rs
new file mode 100644
index 0000000..d430693
--- /dev/null
+++ b/bin/src/fix/single.rs
@@ -0,0 +1,59 @@
+use std::{borrow::Cow, convert::TryFrom};
+
+use lib::{Report, LINTS};
+use rnix::{TextRange, TextSize};
+
+use crate::err::SingleFixErr;
+use crate::fix::Source;
+
+pub struct SingleFixResult<'δ> {
+    pub src: Source<'δ>,
+}
+
+fn pos_to_byte(line: usize, col: usize, src: &str) -> Result<TextSize, SingleFixErr> {
+    let mut byte: TextSize = TextSize::of("");
+    for (_, l) in src.lines().enumerate().take_while(|(i, _)| i <= &line) {
+        byte += TextSize::of(l);
+    }
+    byte += TextSize::try_from(col).map_err(|_| SingleFixErr::Conversion(col))?;
+
+    if usize::from(byte) >= src.len() {
+        Err(SingleFixErr::OutOfBounds(line, col))
+    } else {
+        Ok(byte)
+    }
+}
+
+fn find(offset: TextSize, src: &str) -> Result<Report, SingleFixErr> {
+    // we don't really need the source to form a completely parsed tree
+    let parsed = rnix::parse(src);
+
+    let elem_at = parsed
+        .node()
+        .child_or_token_at_range(TextRange::empty(offset))
+        .ok_or(SingleFixErr::NoOp)?;
+
+    LINTS
+        .get(&elem_at.kind())
+        .map(|rules| {
+            rules
+                .iter()
+                .filter_map(|rule| rule.validate(&elem_at))
+                .filter(|report| report.total_suggestion_range().is_some())
+                .next()
+        })
+        .flatten()
+        .ok_or(SingleFixErr::NoOp)
+}
+
+pub fn single(line: usize, col: usize, src: &str) -> Result<SingleFixResult, SingleFixErr> {
+    let mut src = Cow::from(src);
+    let offset = pos_to_byte(line, col, &*src)?;
+    let report = find(offset, &*src)?;
+
+    report.apply(src.to_mut());
+
+    Ok(SingleFixResult {
+        src
+    })
+}