use regex::Regex;
use std::ops::Deref;
use std::sync::LazyLock;

/// XLS WorkSheet data.
pub struct WorkSheet {
    pub data: calamine::Range<calamine::Data>,
    pub merges: Vec<calamine::Dimensions>,
}

impl Deref for WorkSheet {
    type Target = calamine::Range<calamine::Data>;

    fn deref(&self) -> &Self::Target {
        &self.data
    }
}

impl WorkSheet {
    /// Getting a line from the required cell.
    pub fn get_string_from_cell(&self, row: u32, col: u32) -> Option<String> {
        let cell_data = if let Some(data) = self.get((row as usize, col as usize)) {
            data.to_string()
        } else {
            return None;
        };

        if cell_data.trim().is_empty() {
            return None;
        }

        static NL_RE: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"[\n\r]+").unwrap());
        static SP_RE: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"\s+").unwrap());

        let trimmed_data = SP_RE
            .replace_all(&NL_RE.replace_all(&cell_data, " "), " ")
            .trim()
            .to_string();

        if trimmed_data.is_empty() {
            None
        } else {
            Some(trimmed_data)
        }
    }

    /// Obtaining the boundaries of the cell along its upper left coordinate.
    pub fn get_merge_from_start(&self, row: u32, column: u32) -> ((u32, u32), (u32, u32)) {
        match self
            .merges
            .iter()
            .find(|merge| merge.start.0 == row && merge.start.1 == column)
        {
            Some(merge) => (merge.start, (merge.end.0 + 1, merge.end.1 + 1)),
            None => ((row, column), (row + 1, column + 1)),
        }
    }
}