// This file is part of the 64k demo project.
// It tests the EffectV2/SequenceV2 lifecycle using headless rendering.
// Verifies effect initialization and basic rendering.

#include "../common/effect_test_helpers.h"
#include "../common/offscreen_render_target.h"
#include "../common/webgpu_test_fixture.h"
#include "effects/passthrough_effect_v2.h"
#include "gpu/effect_v2.h"
#include "gpu/sequence_v2.h"
#include <cassert>
#include <cstdio>
#include <memory>

// Test 1: WebGPU fixture initialization
static void test_webgpu_fixture() {
  fprintf(stdout, "Testing WebGPU fixture...\n");

  WebGPUTestFixture fixture;
  const bool init_success = fixture.init();

  if (!init_success) {
    fprintf(stdout, "  ⚠ WebGPU unavailable - skipping test\n");
    return;
  }

  assert(fixture.is_initialized() && "Fixture should be initialized");
  assert(fixture.device() != nullptr && "Device should be valid");
  assert(fixture.queue() != nullptr && "Queue should be valid");

  fprintf(stdout, "  ✓ WebGPU fixture initialized successfully\n");

  fixture.shutdown();
  assert(!fixture.is_initialized() && "Fixture should be shutdown");

  fprintf(stdout, "  ✓ WebGPU fixture shutdown successfully\n");
}

// Test 2: Offscreen render target creation
static void test_offscreen_render_target() {
  fprintf(stdout, "Testing offscreen render target...\n");

  WebGPUTestFixture fixture;
  if (!fixture.init()) {
    fprintf(stdout, "  ⚠ WebGPU unavailable - skipping test\n");
    return;
  }

  OffscreenRenderTarget target(fixture.instance(), fixture.device(), 256, 256);

  assert(target.texture() != nullptr && "Texture should be valid");
  assert(target.view() != nullptr && "Texture view should be valid");
  assert(target.width() == 256 && "Width should be 256");
  assert(target.height() == 256 && "Height should be 256");

  fprintf(stdout, "  ✓ Offscreen render target created (256x256)\n");

  // Test pixel readback (should initially be all zeros or uninitialized)
  const std::vector<uint8_t> pixels = target.read_pixels();

  // Note: Buffer mapping may fail on some systems (WebGPU driver issue)
  // Don't fail the test if readback returns empty buffer
  if (pixels.empty()) {
    fprintf(stdout,
            "  ⚠ Pixel readback skipped (buffer mapping unavailable)\n");
  } else {
    assert(pixels.size() == 256 * 256 * 4 && "Pixel buffer size should match");
    fprintf(stdout, "  ✓ Pixel readback succeeded (%zu bytes)\n",
            pixels.size());
  }
}

// Test 3: Effect construction
static void test_effect_construction() {
  fprintf(stdout, "Testing effect construction...\n");

  WebGPUTestFixture fixture;
  if (!fixture.init()) {
    fprintf(stdout, "  ⚠ WebGPU unavailable - skipping test\n");
    return;
  }

  // Create PassthroughEffectV2 (simple effect)
  auto effect = std::make_shared<PassthroughEffectV2>(
      fixture.ctx(), std::vector<std::string>{"source"},
      std::vector<std::string>{"sink"});

  assert(effect != nullptr && "Effect should be constructed");

  fprintf(stdout, "  ✓ PassthroughEffectV2 constructed\n");
}

// Test 4: Effect added to sequence DAG
static void test_effect_in_sequence() {
  fprintf(stdout, "Testing effect in SequenceV2 DAG...\n");

  WebGPUTestFixture fixture;
  if (!fixture.init()) {
    fprintf(stdout, "  ⚠ WebGPU unavailable - skipping test\n");
    return;
  }

  // Create minimal sequence with one effect
  class TestSequence : public SequenceV2 {
  public:
    TestSequence(const GpuContext& ctx, int w, int h) : SequenceV2(ctx, w, h) {
      auto effect = std::make_shared<PassthroughEffectV2>(
          ctx, std::vector<std::string>{"source"},
          std::vector<std::string>{"sink"});

      effect_dag_.push_back({effect, {"source"}, {"sink"}, 0});
      init_effect_nodes();
    }
  };

  auto seq = std::make_unique<TestSequence>(fixture.ctx(), 256, 256);

  assert(seq->get_effect_dag().size() == 1 && "Should have one effect");
  assert(seq->get_effect_dag()[0].effect != nullptr && "Effect should exist");

  fprintf(stdout, "  ✓ Effect added to DAG and initialized\n");
}

// Test 5: Sequence rendering (smoke test)
static void test_sequence_render() {
  fprintf(stdout, "Testing sequence render...\n");

  WebGPUTestFixture fixture;
  if (!fixture.init()) {
    fprintf(stdout, "  ⚠ WebGPU unavailable - skipping test\n");
    return;
  }

  OffscreenRenderTarget target(fixture.instance(), fixture.device(), 256, 256);

  class TestSequence : public SequenceV2 {
  public:
    TestSequence(const GpuContext& ctx, int w, int h) : SequenceV2(ctx, w, h) {
      auto effect = std::make_shared<PassthroughEffectV2>(
          ctx, std::vector<std::string>{"source"},
          std::vector<std::string>{"sink"});

      effect_dag_.push_back({effect, {"source"}, {"sink"}, 0});
      init_effect_nodes();
    }
  };

  auto seq = std::make_unique<TestSequence>(fixture.ctx(), 256, 256);
  seq->set_sink_view(target.view());
  seq->set_source_view(target.view());

  // Create encoder and attempt render
  WGPUCommandEncoder encoder = wgpuDeviceCreateCommandEncoder(
      fixture.device(), nullptr);

  seq->render_effects(encoder);

  WGPUCommandBuffer commands = wgpuCommandEncoderFinish(encoder, nullptr);
  wgpuQueueSubmit(fixture.queue(), 1, &commands);
  wgpuCommandBufferRelease(commands);

  fprintf(stdout, "  ✓ Sequence rendered without error\n");
}

// Test 6: Sequence time-based parameters
static void test_sequence_time_params() {
  fprintf(stdout, "Testing sequence time parameters...\n");

  WebGPUTestFixture fixture;
  if (!fixture.init()) {
    fprintf(stdout, "  ⚠ WebGPU unavailable - skipping test\n");
    return;
  }

  class TestSequence : public SequenceV2 {
  public:
    TestSequence(const GpuContext& ctx, int w, int h) : SequenceV2(ctx, w, h) {
      init_effect_nodes();
    }

    void preprocess(float seq_time, float beat_time, float beat_phase,
                    float audio_intensity) override {
      SequenceV2::preprocess(seq_time, beat_time, beat_phase, audio_intensity);
      last_time = seq_time;
    }

    float last_time = -1.0f;
  };

  auto seq = std::make_unique<TestSequence>(fixture.ctx(), 256, 256);

  // Test different time values
  seq->preprocess(0.0f, 0.0f, 0.0f, 0.0f);
  assert(seq->last_time == 0.0f && "Time at t=0");

  seq->preprocess(5.5f, 10.0f, 0.5f, 0.8f);
  assert(seq->last_time == 5.5f && "Time at t=5.5");

  fprintf(stdout, "  ✓ Sequence time parameters updated correctly\n");
}

// Test 7: Pixel validation helpers
static void test_pixel_helpers() {
  fprintf(stdout, "Testing pixel validation helpers...\n");

  // Test has_rendered_content (should detect non-black pixels)
  std::vector<uint8_t> black_frame(256 * 256 * 4, 0);
  assert(!has_rendered_content(black_frame, 256, 256) &&
         "Black frame should have no content");

  std::vector<uint8_t> colored_frame(256 * 256 * 4, 0);
  colored_frame[0] = 255; // Set one red pixel
  assert(has_rendered_content(colored_frame, 256, 256) &&
         "Colored frame should have content");

  fprintf(stdout, "  ✓ has_rendered_content() works correctly\n");

  // Test all_pixels_match_color
  std::vector<uint8_t> red_frame(256 * 256 * 4, 0);
  for (size_t i = 0; i < 256 * 256; ++i) {
    red_frame[i * 4 + 2] = 255; // BGRA: Red in position 2
  }
  assert(all_pixels_match_color(red_frame, 256, 256, 255, 0, 0, 5) &&
         "Red frame should match red color");

  fprintf(stdout, "  ✓ all_pixels_match_color() works correctly\n");

  // Test hash_pixels
  const uint64_t hash1 = hash_pixels(black_frame);
  const uint64_t hash2 = hash_pixels(colored_frame);
  assert(hash1 != hash2 && "Different frames should have different hashes");

  fprintf(stdout, "  ✓ hash_pixels() produces unique hashes\n");
}

int main() {
  fprintf(stdout, "=== Effect Base Tests ===\n");

  extern void InitShaderComposer();
  InitShaderComposer();

  test_webgpu_fixture();
  test_offscreen_render_target();
  test_effect_construction();
  test_effect_in_sequence();
  test_sequence_render();
  test_sequence_time_params();
  test_pixel_helpers();

  fprintf(stdout, "=== All Effect Base Tests Passed ===\n");
  return 0;
}