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use super::JsoncFormatter;

pub struct PrettyFormatter {
    indent: usize,
}
impl PrettyFormatter {
    pub fn new() -> Self {
        Self { indent: 0 }
    }

    pub fn indent(&self) -> Vec<u8> {
        b"  ".repeat(self.indent)
    }

    pub fn should_write_trailing_comma(&self, index: usize, len: Option<usize>) -> bool {
        matches!(len.map(|l| index + 1 == l), Some(true))
    }
}
impl JsoncFormatter for PrettyFormatter {
    fn write_array_start<W: std::io::Write>(&mut self, write: &mut W) -> crate::Result<()> {
        let sup = self.write_array_start_super(write)?;
        self.indent += 1;
        write.write_all(b"\n")?;
        Ok(sup)
    }

    fn write_array_value_start<W: std::io::Write>(
        &mut self,
        write: &mut W,
        index: usize,
        len: Option<usize>,
    ) -> crate::Result<()> {
        write.write_all(&self.indent())?;
        let sup = self.write_array_value_start_super(write, index, len)?;
        Ok(sup)
    }

    fn write_array_value_end<W: std::io::Write>(
        &mut self,
        write: &mut W,
        index: usize,
        len: Option<usize>,
    ) -> crate::Result<()> {
        let sup = self.write_array_value_end_super(write, index, len)?;
        if self.should_write_trailing_comma(index, len) {
            write.write_all(b",\n")?;
        } else {
            write.write_all(b"\n")?;
        }
        Ok(sup)
    }

    fn write_array_end<W: std::io::Write>(&mut self, write: &mut W) -> crate::Result<()> {
        self.indent -= 1;
        write.write_all(&self.indent())?;
        let sup = self.write_array_end_super(write)?;
        Ok(sup)
    }

    fn write_object_start<W: std::io::Write>(&mut self, write: &mut W) -> crate::Result<()> {
        let sup = self.write_object_start_super(write)?;
        self.indent += 1;
        write.write_all(b"\n")?;
        Ok(sup)
    }

    fn write_object_key_start<W: std::io::Write>(
        &mut self,
        write: &mut W,
        index: usize,
        len: Option<usize>,
    ) -> crate::Result<()> {
        write.write_all(&self.indent())?;
        let sup = self.write_object_key_start_super(write, index, len)?;
        Ok(sup)
    }

    fn write_object_value_start<W: std::io::Write>(
        &mut self,
        write: &mut W,
        index: usize,
        len: Option<usize>,
    ) -> crate::Result<()> {
        write.write_all(b" ")?;
        let sup = self.write_object_value_start_super(write, index, len)?;
        Ok(sup)
    }

    fn write_object_value_end<W: std::io::Write>(
        &mut self,
        write: &mut W,
        index: usize,
        len: Option<usize>,
    ) -> crate::Result<()> {
        let sup = self.write_object_value_end_super(write, index, len)?;
        if self.should_write_trailing_comma(index, len) {
            write.write_all(b",\n")?;
        } else {
            write.write_all(b"\n")?;
        }
        Ok(sup)
    }

    fn write_object_end<W: std::io::Write>(&mut self, write: &mut W) -> crate::Result<()> {
        self.indent -= 1;
        write.write_all(&self.indent())?;
        let sup = self.write_object_end_super(write)?;
        Ok(sup)
    }
}