From 7bac48f8fc4655a72cdd44ba8317799f22bd4c4b Mon Sep 17 00:00:00 2001
From: n08i40k <nhomcencko1@gmail.com>
Date: Fri, 10 Oct 2025 01:27:05 +0400
Subject: [PATCH] feat(error): add more intuitive CellPos formatting and get
 rid of ErrorCell

---
 .../src/parser/error.rs                       | 22 ++-------------
 .../src/parser/mod.rs                         |  6 ++--
 .../src/parser/worksheet.rs                   | 28 +++++++++++++++++--
 3 files changed, 30 insertions(+), 26 deletions(-)

diff --git a/providers/provider-engels-polytechnic/src/parser/error.rs b/providers/provider-engels-polytechnic/src/parser/error.rs
index 0635bd9..2b8df5c 100644
--- a/providers/provider-engels-polytechnic/src/parser/error.rs
+++ b/providers/provider-engels-polytechnic/src/parser/error.rs
@@ -1,21 +1,5 @@
-use derive_more::{Display, Error, From};
 use crate::parser::worksheet::CellPos;
-
-#[derive(Clone, Debug, Display, Error)]
-#[display("'{data}' at {pos}")]
-pub struct ErrorCell {
-    pub pos: CellPos,
-    pub data: String,
-}
-
-impl ErrorCell {
-    pub fn new(row: u32, column: u32, data: &str) -> Self {
-        Self {
-            pos: CellPos { row, column },
-            data: data.to_string(),
-        }
-    }
-}
+use derive_more::{Display, Error, From};
 
 #[derive(Debug, Display, Error, From)]
 pub enum Error {
@@ -28,8 +12,8 @@ pub enum Error {
     #[display("There is no data on work sheet boundaries.")]
     UnknownWorkSheetRange,
 
-    #[display("Failed to read lesson start and end from {_0}.")]
-    NoLessonBoundaries(ErrorCell),
+    #[display("Failed to read lesson start and end of lesson at {_0}.")]
+    NoLessonBoundaries(CellPos),
 
     #[display("No start and end times matching the lesson (at {_0}) was found.")]
     LessonTimeNotFound(CellPos),
diff --git a/providers/provider-engels-polytechnic/src/parser/mod.rs b/providers/provider-engels-polytechnic/src/parser/mod.rs
index 0ac915f..a40312e 100644
--- a/providers/provider-engels-polytechnic/src/parser/mod.rs
+++ b/providers/provider-engels-polytechnic/src/parser/mod.rs
@@ -1,6 +1,5 @@
 pub use self::error::{Error, Result};
 use crate::or_continue;
-use crate::parser::error::ErrorCell;
 use crate::parser::worksheet::{CellPos, CellRange, WorkSheet};
 use crate::parser::LessonParseResult::{Lessons, Street};
 use base::LessonType::Break;
@@ -548,9 +547,8 @@ fn parse_day_boundaries(
             continue;
         };
 
-        let lesson_time = parse_lesson_boundaries_cell(&time_cell, date).ok_or(
-            Error::NoLessonBoundaries(ErrorCell::new(row, column, &time_cell)),
-        )?;
+        let lesson_time = parse_lesson_boundaries_cell(&time_cell, date)
+            .ok_or(Error::NoLessonBoundaries(CellPos::new(row, column)))?;
 
         // type
         let lesson_type = if time_cell.contains("пара") {
diff --git a/providers/provider-engels-polytechnic/src/parser/worksheet.rs b/providers/provider-engels-polytechnic/src/parser/worksheet.rs
index adc70b6..0ad5573 100644
--- a/providers/provider-engels-polytechnic/src/parser/worksheet.rs
+++ b/providers/provider-engels-polytechnic/src/parser/worksheet.rs
@@ -1,5 +1,5 @@
-use derive_more::Display;
 use regex::Regex;
+use std::fmt::{Display, Formatter};
 use std::ops::Deref;
 use std::sync::LazyLock;
 
@@ -9,13 +9,35 @@ pub struct WorkSheet {
     pub merges: Vec<calamine::Dimensions>,
 }
 
-#[derive(Clone, Debug, Display, derive_more::Error)]
-#[display("row {row}, column {column}")]
+#[derive(Clone, Debug, derive_more::Error)]
 pub struct CellPos {
     pub row: u32,
     pub column: u32,
 }
 
+fn format_column_index(index: u32) -> String {
+    // https://stackoverflow.com/a/297214
+    let quotient = index / 26;
+
+    let char = char::from((65 + (index % 26)) as u8);
+
+    if quotient > 0 {
+        return format!("{}{}", format_column_index(quotient - 1), char);
+    }
+
+    return char.to_string();
+}
+
+impl Display for CellPos {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.write_fmt(format_args!(
+            "column {}, row {}",
+            format_column_index(self.column),
+            self.row + 1,
+        ))
+    }
+}
+
 pub struct CellRange {
     pub start: CellPos,
     pub end: CellPos,