use std::ops::Range;

#[derive(Debug, Clone, Eq, PartialEq)]
pub struct StrRange<'src_buf> {
   src: &'src_buf str,
   range: Range<usize>,
}

impl<'src_buf> StrRange<'src_buf> {
   pub fn new(src: &'src_buf str, start: usize, length: usize) -> Self {
      Self {
         src,
         range: start..(start + length),
      }
   }

   pub fn src(&self) -> &'src_buf str {
      self.src
   }

   pub fn increase_length(&mut self, add_len: usize) {
      self.range = self.range.start..self.range.end + add_len;
   }

   pub fn as_str(&self) -> &'src_buf str {
      &self.src[self.range.clone()]
   }

   pub fn len(&self) -> usize {
      self.range.len()
   }

   pub fn is_empty(&self) -> bool {
      self.range.is_empty()
   }

   // pub fn offset_range(&self, range: Range<usize>) -> Self {
   //    Self {
   //       range: (self.range.start + range.start)..(self.range.start + range.end),
   //       src: self.src,
   //    }
   // }

   pub fn start(&self) -> usize {
      self.range.start
   }
}

impl<'src_buf> core::fmt::Display for StrRange<'src_buf> {
   fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> core::fmt::Result {
      write![f, "{}", self.as_str()]
   }
}