excel_reader 2.0.2

use std::io::Read;
use anyhow::bail;
use quick_xml::events::{BytesStart, Event};

use crate::{common_types::Dimension, excel::XmlReader};

/// https://learn.microsoft.com/en-us/dotnet/api/documentformat.openxml.spreadsheet.mergecells?view=openxml-3.0.1
///
/// This collection expresses all the merged cells in the sheet.
///
/// Example:
/// ```
/// <mergeCells>
///   <mergeCell ref="C2:F2"/>
///   <mergeCell ref="B19:C20"/>
///   <mergeCell ref="E19:G19"/>
/// </mergeCells>
/// ```
pub type XlsxMergeCells = Vec<XlsxMergeCell>;

pub(crate) fn load_merge_cells(reader: &mut XmlReader<impl Read>) -> anyhow::Result<XlsxMergeCells> {
    let mut cells: XlsxMergeCells = vec![];

    let mut buf = Vec::new();
    loop {
        buf.clear();

        match reader.read_event_into(&mut buf) {
            Ok(Event::Start(ref e)) if e.local_name().as_ref() == b"mergeCell" => {
                if let Some(cell) = load_merge_cell(e)? {
                    cells.push(cell);
                }
            }
            Ok(Event::End(ref e)) if e.local_name().as_ref() == b"mergeCells" => break,
            Ok(Event::Eof) => bail!("unexpected end of file."),
            Err(e) => bail!(e.to_string()),
            _ => (),
        }
    }

    Ok(cells)
}

/// https://learn.microsoft.com/en-us/dotnet/api/documentformat.openxml.spreadsheet.mergecell?view=openxml-3.0.1
///
/// A single merged cell
///
/// Example
/// ```
/// <mergeCell ref="A1:B1" />
/// ```
pub type XlsxMergeCell = Dimension;

pub(crate) fn load_merge_cell(e: &BytesStart) -> anyhow::Result<Option<XlsxMergeCell>> {
    let attributes = e.attributes();

    for a in attributes {
        match a {
            Ok(a) => match a.key.local_name().as_ref() {
                b"ref" => {
                    let value = a.value.as_ref();
                    return Ok(XlsxMergeCell::from_a1(value));
                }
                _ => {}
            },
            Err(error) => {
                bail!(error.to_string())
            }
        }
    }
    Ok(None)
}