// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Used because we use `futures::select!`.
//
// From https://docs.rs/futures/0.3.1/futures/macro.select.html:
//   Note that select! relies on proc-macro-hack, and may require to set the compiler's
//   recursion limit very high, e.g. #![recursion_limit="1024"].
#![recursion_limit = "512"]

use {
    fidl_fuchsia_test::Invocation,
    fidl_fuchsia_test_manager::HarnessProxy,
    fuchsia_async as fasync,
    futures::{channel::mpsc, prelude::*},
    std::collections::HashSet,
    std::fmt,
    std::io::{self, Write},
    test_executor::{TestEvent, TestRunOptions},
};

pub use test_executor::DisabledTestHandling;

#[derive(PartialEq, Debug)]
pub enum Outcome {
    Passed,
    Failed,
    Inconclusive,
    Timedout,
    Error,
}

impl fmt::Display for Outcome {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Outcome::Passed => write!(f, "PASSED"),
            Outcome::Failed => write!(f, "FAILED"),
            Outcome::Inconclusive => write!(f, "INCONCLUSIVE"),
            Outcome::Timedout => write!(f, "TIMED OUT"),
            Outcome::Error => write!(f, "ERROR"),
        }
    }
}

#[derive(PartialEq, Debug)]
pub struct RunResult {
    /// Test outcome.
    pub outcome: Outcome,

    /// All tests which were executed.
    pub executed: Vec<String>,

    /// All tests which passed.
    pub passed: Vec<String>,

    /// Suite protocol completed without error.
    pub successful_completion: bool,
}

// Parameters for test.
pub struct TestParams {
    /// Test URL.
    pub test_url: String,

    /// |timeout|: Test timeout.should be more than zero.
    pub timeout: Option<std::num::NonZeroU32>,

    /// Filter tests based on this glob pattern.
    pub test_filter: Option<String>,

    // Run disabled tests.
    pub also_run_disabled_tests: bool,

    /// Test concurrency count.
    pub parallel: Option<u16>,

    /// Arguments to pass to test using command line.
    pub test_args: Option<Vec<String>>,

    /// HarnessProxy that manages running the tests.
    pub harness: HarnessProxy,
}

impl TestParams {
    fn disabled_tests(&self) -> DisabledTestHandling {
        return match self.also_run_disabled_tests {
            true => DisabledTestHandling::Include,
            false => DisabledTestHandling::Exclude,
        };
    }
}

async fn run_test_for_invocations<W: Write>(
    suite_instance: &test_executor::SuiteInstance,
    invocations: Vec<Invocation>,
    run_options: TestRunOptions,
    timeout: Option<std::num::NonZeroU32>,
    writer: &mut W,
) -> Result<RunResult, anyhow::Error> {
    let mut timeout = match timeout {
        Some(timeout) => futures::future::Either::Left(
            fasync::Timer::new(std::time::Duration::from_secs(timeout.get().into()))
                .map(|()| Err(())),
        ),
        None => futures::future::Either::Right(futures::future::ready(Ok(()))),
    }
    .fuse();

    let (sender, mut recv) = mpsc::channel(1);
    let mut outcome = Outcome::Passed;

    let mut test_cases_in_progress = HashSet::new();
    let mut test_cases_executed = HashSet::new();
    let mut test_cases_passed = HashSet::new();
    let mut successful_completion = false;

    let test_fut = suite_instance
        .run_and_collect_results_for_invocations(sender, invocations, run_options)
        .fuse();
    futures::pin_mut!(test_fut);

    loop {
        futures::select! {
            timeout_res = timeout => {
                match timeout_res {
                    Ok(()) => {}, // No timeout specified.
                    Err(()) => {
                        outcome = Outcome::Timedout;
                        break
                    },
                }
            },
            test_res = test_fut => {
                let () = test_res?;
            },
            test_event = recv.next() => {
                if let Some(test_event) = test_event {
                    match test_event {
                        TestEvent::TestCaseStarted { test_case_name } => {
                            if test_cases_executed.contains(&test_case_name) {
                                return Err(anyhow::anyhow!("test case: '{}' started twice", test_case_name));
                            }
                            writeln!(writer, "[RUNNING]\t{}", test_case_name).expect("Cannot write logs");
                            test_cases_in_progress.insert(test_case_name.clone());
                            test_cases_executed.insert(test_case_name);
                        }
                        TestEvent::TestCaseFinished { test_case_name, result } => {
                            if !test_cases_in_progress.contains(&test_case_name) {
                                return Err(anyhow::anyhow!(
                                    "test case: '{}' was never started, still got a finish event",
                                    test_case_name
                                ));
                            }
                            test_cases_in_progress.remove(&test_case_name);
                            let result_str = match result {
                                test_executor::TestResult::Passed => {
                                    test_cases_passed.insert(test_case_name.clone());
                                    "PASSED"
                                }
                                test_executor::TestResult::Failed => {
                                    if outcome == Outcome::Passed {
                                        outcome = Outcome::Failed;
                                    }
                                    "FAILED"
                                }
                                test_executor::TestResult::Skipped => "SKIPPED",
                                test_executor::TestResult::Error => {
                                    outcome = Outcome::Error;
                                    "ERROR"
                                }
                            };
                            writeln!(writer, "[{}]\t{}", result_str, test_case_name)
                                .expect("Cannot write logs");
                        }
                        TestEvent::LogMessage { test_case_name, mut msg } => {
                            if !test_cases_executed.contains(&test_case_name) {
                                return Err(anyhow::anyhow!(
                                    "test case: '{}' was never started, still got a log",
                                    test_case_name
                                ));
                            }
                            // check if last byte is newline and remove it as we are already
                            // printing a newline.
                            if msg.ends_with("\n") {
                                msg.truncate(msg.len()-1)
                            }
                            // TODO(anmittal): buffer by newline or something else.
                            writeln!(writer, "[output - {}]:\n{}", test_case_name, msg).expect("Cannot write logs");

                        }
                        TestEvent::Finish => {
                            successful_completion = true;
                            break;
                        }
                    }
                }
            },
            complete => { break },
        }
    }

    let mut test_cases_in_progress: Vec<String> = test_cases_in_progress.into_iter().collect();
    test_cases_in_progress.sort();

    if test_cases_in_progress.len() != 0 {
        match outcome {
            Outcome::Passed | Outcome::Failed => {
                outcome = Outcome::Inconclusive;
            }
            _ => {}
        }
        writeln!(writer, "\nThe following test(s) never completed:").expect("Cannot write logs");
        for t in test_cases_in_progress {
            writeln!(writer, "{}", t).expect("Cannot write logs");
        }
    }

    let mut test_cases_executed: Vec<String> = test_cases_executed.into_iter().collect();
    let mut test_cases_passed: Vec<String> = test_cases_passed.into_iter().collect();

    test_cases_executed.sort();
    test_cases_passed.sort();

    Ok(RunResult {
        outcome,
        executed: test_cases_executed,
        passed: test_cases_passed,
        successful_completion,
    })
}

/// Runs the test `count` number of times, and writes logs to writer.
pub async fn run_test<'a, W: Write>(
    test_params: TestParams,
    count: u16,
    writer: &'a mut W,
) -> impl Stream<Item = Result<RunResult, anyhow::Error>> + 'a {
    let run_options = TestRunOptions {
        disabled_tests: test_params.disabled_tests(),
        parallel: test_params.parallel,
        arguments: test_params.test_args.clone(),
    };

    struct FoldArgs<'a, W: Write> {
        current_count: u16,
        count: u16,
        suite_instance: Option<test_executor::SuiteInstance>,
        invocations: Option<Vec<fidl_fuchsia_test::Invocation>>,
        test_params: TestParams,
        run_options: TestRunOptions,
        writer: &'a mut W,
    }

    let args = FoldArgs {
        current_count: 0,
        count,
        suite_instance: None,
        invocations: None,
        test_params,
        run_options,
        writer,
    };

    stream::try_unfold(args, |mut args| async move {
        if args.current_count >= args.count {
            return Ok(None);
        }
        let suite_instance = match args.suite_instance {
            Some(s) => s,
            None => {
                test_executor::SuiteInstance::new(
                    &args.test_params.harness,
                    &args.test_params.test_url,
                )
                .await?
            }
        };

        let invocations = match args.invocations {
            Some(i) => i,
            None => {
                suite_instance
                    .enumerate_tests(&args.test_params.test_filter.as_ref().map(String::as_str))
                    .await?
            }
        };

        let mut next_count = args.current_count + 1;
        let result = run_test_for_invocations(
            &suite_instance,
            invocations.clone(),
            args.run_options.clone(),
            args.test_params.timeout,
            args.writer,
        )
        .await?;
        if result.outcome == Outcome::Timedout || result.outcome == Outcome::Error {
            // don't run test again
            next_count = args.count;
        }

        args.suite_instance = Some(suite_instance);
        args.invocations = Some(invocations);
        args.current_count = next_count;
        Ok(Some((result, args)))
    })
}

/// Runs the test and writes logs to stdout.
/// |count|: Number of times to run this test.
pub async fn run_tests_and_get_outcome(
    test_params: TestParams,
    count: std::num::NonZeroU16,
) -> Outcome {
    let test_url = test_params.test_url.clone();
    println!("\nRunning test '{}'", &test_url);

    let mut stdout = io::stdout();

    let mut final_outcome = Outcome::Passed;

    let stream = run_test(test_params, count.get(), &mut stdout).await;
    futures::pin_mut!(stream);
    let mut i: u16 = 1;

    loop {
        match stream.try_next().await {
            Err(e) => {
                println!("Test suite encountered error trying to run tests: {:?}", e);
                return Outcome::Error;
            }
            Ok(Some(RunResult { outcome, executed, passed, successful_completion })) => {
                if count.get() > 1 {
                    println!("\nTest run count {}/{}", i, count);
                }
                println!("{} out of {} tests passed...", passed.len(), executed.len());
                println!("{} completed with result: {}", &test_url, outcome);

                if !successful_completion {
                    println!("{} did not complete successfully.", &test_url);
                }
                i = i + 1;
                if count.get() > 1 {
                    if outcome != Outcome::Passed {
                        final_outcome = Outcome::Failed;
                    }
                } else {
                    final_outcome = outcome;
                }
            }
            Ok(None) => {
                break;
            }
        }
    }

    if count.get() > 1 && final_outcome != Outcome::Passed {
        println!("One or more test runs failed.");
    }

    final_outcome
}