use std::{io, io::prelude::Write};

use super::OutputFormatter;
use crate::{
    bench::fmt_bench_samples,
    console::{ConsoleTestDiscoveryState, ConsoleTestState, OutputLocation},
    term,
    test_result::TestResult,
    time,
    types::NamePadding,
    types::TestDesc,
};

// 当输出在安静模式下达到 100 列时，我们插入一个 '\n'。
// 88 个测试结果字符为 " 11704/12853" 等进度计数留下 12 个字符。
const QUIET_MODE_MAX_COLUMN: usize = 88;

pub(crate) struct TerseFormatter<T> {
    out: OutputLocation<T>,
    use_color: bool,
    is_multithreaded: bool,
    /// 对齐名称时要填充的列数
    max_name_len: usize,

    test_count: usize,
    total_test_count: usize,
}

impl<T: Write> TerseFormatter<T> {
    pub fn new(
        out: OutputLocation<T>,
        use_color: bool,
        max_name_len: usize,
        is_multithreaded: bool,
    ) -> Self {
        TerseFormatter {
            out,
            use_color,
            max_name_len,
            is_multithreaded,
            test_count: 0,
            total_test_count: 0, // 稍后在调用 write_run_start 时初始化
        }
    }

    pub fn write_ok(&mut self) -> io::Result<()> {
        self.write_short_result(".", term::color::GREEN)
    }

    pub fn write_failed(&mut self) -> io::Result<()> {
        self.write_short_result("F", term::color::RED)
    }

    pub fn write_ignored(&mut self) -> io::Result<()> {
        self.write_short_result("i", term::color::YELLOW)
    }

    pub fn write_bench(&mut self) -> io::Result<()> {
        self.write_pretty("bench", term::color::CYAN)
    }

    pub fn write_short_result(
        &mut self,
        result: &str,
        color: term::color::Color,
    ) -> io::Result<()> {
        self.write_pretty(result, color)?;
        if self.test_count % QUIET_MODE_MAX_COLUMN == QUIET_MODE_MAX_COLUMN - 1 {
            // 在处理行缓冲输出 (例如，rust CI 中的 `stamp` 管道) 时，我们会定期插入新行以刷新屏幕。
            //
            //
            let out = format!(" {}/{}\n", self.test_count + 1, self.total_test_count);
            self.write_plain(out)?;
        }

        self.test_count += 1;
        Ok(())
    }

    pub fn write_pretty(&mut self, word: &str, color: term::color::Color) -> io::Result<()> {
        match self.out {
            OutputLocation::Pretty(ref mut term) => {
                if self.use_color {
                    term.fg(color)?;
                }
                term.write_all(word.as_bytes())?;
                if self.use_color {
                    term.reset()?;
                }
                term.flush()
            }
            OutputLocation::Raw(ref mut stdout) => {
                stdout.write_all(word.as_bytes())?;
                stdout.flush()
            }
        }
    }

    pub fn write_plain<S: AsRef<str>>(&mut self, s: S) -> io::Result<()> {
        let s = s.as_ref();
        self.out.write_all(s.as_bytes())?;
        self.out.flush()
    }

    pub fn write_outputs(&mut self, state: &ConsoleTestState) -> io::Result<()> {
        self.write_plain("\nsuccesses:\n")?;
        let mut successes = Vec::new();
        let mut stdouts = String::new();
        for (f, stdout) in &state.not_failures {
            successes.push(f.name.to_string());
            if !stdout.is_empty() {
                stdouts.push_str(&format!("---- {} stdout ----\n", f.name));
                let output = String::from_utf8_lossy(stdout);
                stdouts.push_str(&output);
                stdouts.push('\n');
            }
        }
        if !stdouts.is_empty() {
            self.write_plain("\n")?;
            self.write_plain(&stdouts)?;
        }

        self.write_plain("\nsuccesses:\n")?;
        successes.sort();
        for name in &successes {
            self.write_plain(&format!("    {name}\n"))?;
        }
        Ok(())
    }

    pub fn write_failures(&mut self, state: &ConsoleTestState) -> io::Result<()> {
        self.write_plain("\nfailures:\n")?;
        let mut failures = Vec::new();
        let mut fail_out = String::new();
        for (f, stdout) in &state.failures {
            failures.push(f.name.to_string());
            if !stdout.is_empty() {
                fail_out.push_str(&format!("---- {} stdout ----\n", f.name));
                let output = String::from_utf8_lossy(stdout);
                fail_out.push_str(&output);
                fail_out.push('\n');
            }
        }
        if !fail_out.is_empty() {
            self.write_plain("\n")?;
            self.write_plain(&fail_out)?;
        }

        self.write_plain("\nfailures:\n")?;
        failures.sort();
        for name in &failures {
            self.write_plain(&format!("    {name}\n"))?;
        }
        Ok(())
    }

    fn write_test_name(&mut self, desc: &TestDesc) -> io::Result<()> {
        let name = desc.padded_name(self.max_name_len, desc.name.padding());
        if let Some(test_mode) = desc.test_mode() {
            self.write_plain(format!("test {name} - {test_mode} ... "))?;
        } else {
            self.write_plain(format!("test {name} ... "))?;
        }

        Ok(())
    }
}

impl<T: Write> OutputFormatter for TerseFormatter<T> {
    fn write_discovery_start(&mut self) -> io::Result<()> {
        Ok(())
    }

    fn write_test_discovered(&mut self, desc: &TestDesc, test_type: &str) -> io::Result<()> {
        self.write_plain(format!("{}: {test_type}\n", desc.name))
    }

    fn write_discovery_finish(&mut self, _state: &ConsoleTestDiscoveryState) -> io::Result<()> {
        Ok(())
    }

    fn write_run_start(&mut self, test_count: usize, shuffle_seed: Option<u64>) -> io::Result<()> {
        self.total_test_count = test_count;
        let noun = if test_count != 1 { "tests" } else { "test" };
        let shuffle_seed_msg = if let Some(shuffle_seed) = shuffle_seed {
            format!(" (shuffle seed: {shuffle_seed})")
        } else {
            String::new()
        };
        self.write_plain(format!("\nrunning {test_count} {noun}{shuffle_seed_msg}\n"))
    }

    fn write_test_start(&mut self, desc: &TestDesc) -> io::Result<()> {
        // 旧 libtest 代码的残余部分，这些代码使用填充值来指示基准。
        // 在运行基准测试时，简洁模式仍应打印其名称，就像它是 Pretty 格式化程序一样。
        //
        //
        if !self.is_multithreaded && desc.name.padding() == NamePadding::PadOnRight {
            self.write_test_name(desc)?;
        }

        Ok(())
    }

    fn write_result(
        &mut self,
        desc: &TestDesc,
        result: &TestResult,
        _: Option<&time::TestExecTime>,
        _: &[u8],
        _: &ConsoleTestState,
    ) -> io::Result<()> {
        match *result {
            TestResult::TrOk => self.write_ok(),
            TestResult::TrFailed | TestResult::TrFailedMsg(_) | TestResult::TrTimedFail => {
                self.write_failed()
            }
            TestResult::TrIgnored => self.write_ignored(),
            TestResult::TrBench(ref bs) => {
                if self.is_multithreaded {
                    self.write_test_name(desc)?;
                }
                self.write_bench()?;
                self.write_plain(format!(": {}\n", fmt_bench_samples(bs)))
            }
        }
    }

    fn write_timeout(&mut self, desc: &TestDesc) -> io::Result<()> {
        self.write_plain(format!(
            "test {} has been running for over {} seconds\n",
            desc.name,
            time::TEST_WARN_TIMEOUT_S
        ))
    }

    fn write_run_finish(&mut self, state: &ConsoleTestState) -> io::Result<bool> {
        if state.options.display_output {
            self.write_outputs(state)?;
        }
        let success = state.failed == 0;
        if !success {
            self.write_failures(state)?;
        }

        self.write_plain("\ntest result: ")?;

        if success {
            // 此时没有并行性，因此使用颜色是安全的
            self.write_pretty("ok", term::color::GREEN)?;
        } else {
            self.write_pretty("FAILED", term::color::RED)?;
        }

        let s = format!(
            ". {} passed; {} failed; {} ignored; {} measured; {} filtered out",
            state.passed, state.failed, state.ignored, state.measured, state.filtered_out
        );

        self.write_plain(s)?;

        if let Some(ref exec_time) = state.exec_time {
            let time_str = format!("; finished in {exec_time}");
            self.write_plain(time_str)?;
        }

        self.write_plain("\n\n")?;

        // 自定义处理只有 1 个测试要执行且该测试被忽略的情况。
        // 我们希望显示更详细的 information(为什么这个测试被忽略了) 以供调查之用。
        if self.total_test_count == 1 && state.ignores.len() == 1 {
            let test_desc = &state.ignores[0].0;
            if let Some(im) = test_desc.ignore_message {
                self.write_plain(format!("test: {}, ignore_message: {}\n\n", test_desc.name, im))?;
            }
        }

        Ok(success)
    }
}