fixed_source_ext_test.mbt

// Copyright 2026 International Digital Economy Academy
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

///|
struct ExternalFixedSource {
  samples : Array[Sample]
  cursor : Ref[Int]
  channels : ChannelCount
  sample_rate : SampleRate
}

///|
fn ExternalFixedSource::new(
  channels : ChannelCount,
  sample_rate : SampleRate,
  samples : Array[Sample],
) -> ExternalFixedSource {
  { samples, cursor: @ref.new(0), channels, sample_rate }
}

///|
impl FixedSource for ExternalFixedSource with fn next(
  self : ExternalFixedSource,
) {
  if self.cursor.val >= self.samples.length() {
    None
  } else {
    let sample = self.samples[self.cursor.val]
    self.cursor.val += 1
    Some(sample)
  }
}

///|
impl FixedSource for ExternalFixedSource with fn channels(
  self : ExternalFixedSource,
) {
  self.channels
}

///|
impl FixedSource for ExternalFixedSource with fn sample_rate(
  self : ExternalFixedSource,
) {
  self.sample_rate
}

///|
impl FixedSource for ExternalFixedSource with fn total_duration(
  _self : ExternalFixedSource,
) {
  None
}

///|
test "rodio::fixed_source::adapter_from_samples_buffer" {
  let adapted = FixedSourceAdapter::new(
    FixedSamplesBuffer::new(1, 48_000, [1.0, 2.0, 3.0]),
  )
  @debug.assert_eq(adapted.channels(), 1)
  @debug.assert_eq(adapted.sample_rate(), 48_000)
  @debug.assert_eq(adapted.next(), Some(1.0))
  @debug.assert_eq(adapted.next(), Some(2.0))
  @debug.assert_eq(adapted.next(), Some(3.0))
  @debug.assert_eq(adapted.next(), None)
}

///|
test "rodio::fixed_source::adapter_uses_inner_duration" {
  let adapted = FixedSourceAdapter::new(
    FixedSamplesBuffer::new(2, 2, [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]),
  )
  let d = adapted.total_duration().unwrap()
  @debug.assert_eq(d.secs, (1 : UInt64))
  @debug.assert_eq(d.nanos, 500_000_000)
}

///|
test "rodio::fixed_source::adapter_seek_not_supported" {
  let adapted = FixedSourceAdapter::new(
    FixedSamplesBuffer::new(1, 44_100, [1.0]),
  )
  let got_not_supported = try {
    adapted.try_seek(@moon_cpal.Duration::from_secs((0 : UInt64)))
    false
  } catch {
    NotSupported => true
  }
  assert_true(got_not_supported)
}

///|
test "rodio::fixed_source::open_trait_impl_external_type" {
  let adapted = FixedSourceAdapter::new(
    ExternalFixedSource::new(1, 48_000, [7.0, 8.0]),
  )
  @debug.assert_eq(adapted.channels(), 1)
  @debug.assert_eq(adapted.sample_rate(), 48_000)
  @debug.assert_eq(adapted.next(), Some(7.0))
  @debug.assert_eq(adapted.next(), Some(8.0))
  @debug.assert_eq(adapted.next(), None)
}