use basic_dsp::numbers::*;
use basic_dsp::*;
use num::complex::Complex32;
use rand::prelude::*;
use std::fmt::{Debug, Display};
use std::ops::Range;
use std::panic;

pub fn assert_vector_eq_with_reason<T>(left: &[T], right: &[T], reason: &str)
where
    T: RealNumber + Debug + Display,
{
    assert_vector_eq_with_reason_and_tolerance(left, right, T::from(1e-6).unwrap(), reason);
}

pub fn assert_vector_eq_with_reason_and_tolerance<T>(
    left: &[T],
    right: &[T],
    tolerance: T,
    reason: &str,
) where
    T: RealNumber + Debug + Display,
{
    let mut errors = Vec::new();
    if reason.len() > 0 {
        errors.push(format!("{}:\n", reason));
    }

    let size_assert_failed = left.len() != right.len();
    if size_assert_failed {
        errors.push(format!("Size difference {} != {}", left.len(), right.len()));
    }

    let len = if left.len() < right.len() {
        left.len()
    } else {
        right.len()
    };
    let mut differences = 0;
    for i in 0..len {
        if (left[i] - right[i]).abs() > tolerance {
            differences += 1;
            if differences <= 10 {
                errors.push(format!(
                    "Difference {} at index {}, left: {} != right: {}",
                    differences, i, left[i], right[i]
                ));
            }
        }
    }

    if differences > 0 {
        errors.push(format!(
            "Total number of differences: {}/{}={}%",
            differences,
            len,
            differences * 100 / len
        ));
    }

    if differences > 0 || size_assert_failed {
        let all_errors = errors.join("\n");
        let header = "-----------------------".to_owned();
        panic!("\n{}\n{}\n{}\n", header, all_errors, header);
    }
}

pub fn assert_vector_eq<T>(left: &[T], right: &[T])
where
    T: RealNumber + Debug + Display,
{
    assert_vector_eq_with_reason(left, right, "");
}

pub fn assert_close(left: f32, right: f32) {
    assert_in_tolerance(left, right, 1e-6);
}

pub fn assert_complex_close(left: Complex32, right: Complex32) {
    assert_complex_in_tolerance(left, right, 1e-6);
}

pub fn assert_in_tolerance(left: f32, right: f32, tol: f32) {
    let tol = tol.abs();
    if (left - right).abs() > tol {
        panic!("{} != {} (tol: {})", left, right, tol);
    }
}

pub fn assert_complex_in_tolerance(left: Complex32, right: Complex32, tol: f32) {
    let tol = tol.abs();
    if (left.re - right.re).abs() > tol || (left.im - right.im).abs() > tol {
        panic!("{} != {} (tol: {})", left, right, tol);
    }
}

pub fn create_data(seed: usize, iteration: usize, from: usize, to: usize) -> Vec<f32> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let len = if from == to {
        from
    } else {
        rng.gen_range(from, to)
    };
    create_data_with_len(seed, iteration, len)
}

pub fn create_data64(seed: usize, iteration: usize, from: usize, to: usize) -> Vec<f64> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let len = if from == to {
        from
    } else {
        rng.gen_range(from, to)
    };
    create_data_with_len64(seed, iteration, len)
}

pub fn create_data_even(seed: usize, iteration: usize, from: usize, to: usize) -> Vec<f32> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let len = rng.gen_range(from, to);
    let len = len + len % 2;
    create_data_with_len(seed, iteration, len)
}

pub fn create_data_with_len(seed: usize, iteration: usize, len: usize) -> Vec<f32> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let mut data = vec![0.0; len];
    for i in 0..len {
        data[i] = rng.gen_range(-10.0, 10.0);
    }
    data
}

pub fn create_data_with_len64(seed: usize, iteration: usize, len: usize) -> Vec<f64> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let mut data = vec![0.0; len];
    for i in 0..len {
        data[i] = rng.gen_range(-10.0, 10.0);
    }
    data
}

pub fn create_data_even_in_range(
    seed: usize,
    iteration: usize,
    from: usize,
    to: usize,
    range_start: f32,
    range_end: f32,
) -> Vec<f32> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let len = rng.gen_range(from, to);
    let len = len + len % 2;
    create_data_in_range_with_len(seed, iteration, len, range_start, range_end)
}

pub fn create_data_simd_len_in_range(
    seed: usize,
    iteration: usize,
    from: usize,
    to: usize,
) -> Vec<f32> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let len = rng.gen_range(from, to);
    let len = (len / 8 + 1) + 8; // Not exact but good enough
    let len = if len > to { to } else { len };
    create_data_with_len(seed, iteration, len)
}

pub fn create_data_in_range_with_len(
    seed: usize,
    iteration: usize,
    len: usize,
    range_start: f32,
    range_end: f32,
) -> Vec<f32> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let mut data = vec![0.0; len];
    for i in 0..len {
        data[i] = rng.gen_range(range_start, range_end);
    }
    data
}

pub fn create_delta(seed: usize, iteration: usize) -> f32 {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    rng.gen_range(-10.0, 10.0)
}

pub fn create_random_multitones(
    seed: usize,
    iteration: usize,
    from: usize,
    to: usize,
    number_of_tones: usize,
) -> Vec<f32> {
    let mut rng: StdRng = SeedableRng::seed_from_u64((seed + iteration) as u64);
    let len = 2 * rng.gen_range(from, to);
    let mut result = vec![0.0; len].to_real_time_vec();
    for _ in 0..number_of_tones {
        let mut arg = vec![0.0; len].to_real_time_vec();
        arg.map_inplace((), &|_, i, _| i as f32);
        let freq = rng.gen_range(0.24, 0.76);
        let phase = rng.gen_range(-1.0, 1.0);
        arg.scale(freq);
        arg.offset(phase);
        arg.cos();
        result.add(&arg).unwrap();
    }

    let (result, _) = result.get();
    result
}

use std::sync::{Arc, Mutex};

pub const RANGE_SINGLE_CORE: Range<usize> = Range {
    start: 10000,
    end: 100000,
};
pub const RANGE_MULTI_CORE: Range<usize> = Range {
    start: 100001,
    end: 200000,
};

pub fn parameterized_vector_test<F>(test_code: F)
where
    F: Fn(usize, Range<usize>) + Send + 'static + Sync,
{
    let mut test_errors = Vec::new();

    // I don't know if there is a good reason for this, but Rust
    // requires us to lock the test_code function,
    // does catch_panic spawn really a new thread?
    let test_code = Arc::new(Mutex::new(test_code));
    for iteration in 0..10 {
        if test_errors.len() > 0 {
            break; // Stop on the first error to speed up things
        }

        let small_range = RANGE_SINGLE_CORE;
        let test_code = test_code.clone();
        let safe_iteration = panic::AssertUnwindSafe(iteration);
        let small_range = panic::AssertUnwindSafe(small_range);
        let test_code = panic::AssertUnwindSafe(test_code);
        let result = panic::catch_unwind(move || {
            let test_code = test_code.lock().unwrap();
            test_code(*safe_iteration, (*small_range).clone());
        });

        match result {
            Ok(_) => (),
            Err(e) => {
                if let Some(e) = e.downcast_ref::<&'static str>() {
                    test_errors.push(format!(
                        "\nSingle threaded execution path failed on iteration \
                         {}\nFailure: {}",
                        iteration, e
                    ));
                } else if let Some(e) = e.downcast_ref::<String>() {
                    test_errors.push(format!(
                        "\nSingle threaded execution path failed on iteration \
                         {}\nFailure: {}",
                        iteration, e
                    ));
                } else {
                    test_errors.push(format!(
                        "\nSingle threaded execution path failed on iteration \
                         {}\nGot an unknown error: {:?}",
                        iteration, e
                    ));
                }
            }
        }
    }

    for iteration in 0..3 {
        if test_errors.len() > 0 {
            break; // Stop on the first error to speed up things
        }

        let large_range = RANGE_MULTI_CORE;
        let test_code = test_code.clone();
        let safe_iteration = panic::AssertUnwindSafe(iteration);
        let large_range = panic::AssertUnwindSafe(large_range);
        let test_code = panic::AssertUnwindSafe(test_code);
        let result = panic::catch_unwind(move || {
            let test_code = test_code.lock().unwrap();
            test_code(*safe_iteration, (*large_range).clone());
        });

        match result {
            Ok(_) => (),
            Err(e) => {
                if let Some(e) = e.downcast_ref::<&'static str>() {
                    test_errors.push(format!(
                        "\nMulti threaded execution path failed on \
                         iteration {}\nFailure: {}",
                        iteration, e
                    ));
                } else if let Some(e) = e.downcast_ref::<String>() {
                    test_errors.push(format!(
                        "\nMulti threaded execution path failed on \
                         iteration {}\nFailure: {}",
                        iteration, e
                    ));
                } else {
                    test_errors.push(format!(
                        "\nMulti threaded execution path failed on \
                         iteration {}\nGot an unknown error: {:?}",
                        iteration, e
                    ));
                }
            }
        }
    }

    if test_errors.len() > 0 {
        let error_messages = test_errors.join("\n");
        panic!("{}", error_messages);
    }
}