// This file is part of ICU4X. For terms of use, please see the file

// called LICENSE at the top level of the ICU4X source tree

// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).

use crate::*;

use alloc::string::String;

use alloc::vec::Vec;

pub(crate) struct TestWriter {

    pub(crate) string: String,

    pub(crate) parts: Vec<(usize, usize, Part)>,

}

impl TestWriter {

    pub(crate) fn finish(mut self) -> (String, Vec<(usize, usize, Part)>) {

        // Sort by first open and last closed

        self.parts

            .sort_unstable_by_key(|(begin, end, _)| (*begin, end.wrapping_neg()));

        (self.string, self.parts)

    }

}

impl fmt::Write for TestWriter {

    fn write_str(&mut self, s: &str) -> fmt::Result {

        self.string.write_str(s)

    }

    fn write_char(&mut self, c: char) -> fmt::Result {

        self.string.write_char(c)

    }

}

impl PartsWrite for TestWriter {

    type SubPartsWrite = Self;

    fn with_part(

        &mut self,

        part: Part,

        mut f: impl FnMut(&mut Self::SubPartsWrite) -> fmt::Result,

    ) -> fmt::Result {

        let start = self.string.len();

        f(self)?;

        let end = self.string.len();

        if start < end {

            self.parts.push((start, end, part));

        }

        Ok(())

    }

}

#[allow(clippy::type_complexity)]

pub fn writeable_to_parts_for_test<W: Writeable>(

    writeable: &W,

) -> (String, Vec<(usize, usize, Part)>) {

    let mut writer = TestWriter {

        string: alloc::string::String::new(),

        parts: Vec::new(),

    };

    #[allow(clippy::expect_used)] // for test code

    writeable

        .write_to_parts(&mut writer)

        .expect("String writer infallible");

    writer.finish()

}

#[allow(clippy::type_complexity)]

pub fn try_writeable_to_parts_for_test<W: TryWriteable>(

    writeable: &W,

) -> (String, Vec<(usize, usize, Part)>, Option<W::Error>) {

    let mut writer = TestWriter {

        string: alloc::string::String::new(),

        parts: Vec::new(),

    };

    #[allow(clippy::expect_used)] // for test code

    let result = writeable

        .try_write_to_parts(&mut writer)

        .expect("String writer infallible");

    let (actual_str, actual_parts) = writer.finish();

    (actual_str, actual_parts, result.err())

}