// This file is part of the 64k demo project.
// It tests the Effect/Sequence/MainSequence lifecycle using headless rendering.
// Verifies effect initialization, activation, and basic rendering.

#include "effect_test_helpers.h"
#include "offscreen_render_target.h"
#include "webgpu_test_fixture.h"
#include "gpu/demo_effects.h"
#include "gpu/effect.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();
  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 FlashEffect (simple post-process effect)
  auto effect = std::make_shared<FlashEffect>(
      fixture.ctx());

  assert(!effect->is_initialized && "Effect should not be initialized yet");

  fprintf(stdout, "  ✓ FlashEffect constructed (not initialized)\n");
}

// Test 4: Effect initialization via Sequence
static void test_effect_initialization() {
  fprintf(stdout, "Testing effect initialization...\n");

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

  // Create MainSequence (use init_test for test environment)
  MainSequence main_seq;
  main_seq.init_test(fixture.ctx());

  // Create FlashEffect
  auto effect = std::make_shared<FlashEffect>(
      fixture.ctx());

  assert(!effect->is_initialized && "Effect should not be initialized yet");

  // Add effect to sequence
  auto seq = std::make_shared<Sequence>();
  seq->add_effect(effect, 0.0f, 10.0f, 0);

  // Initialize sequence (this sets effect->is_initialized)
  seq->init(&main_seq);

  assert(effect->is_initialized && "Effect should be initialized after Sequence::init()");

  fprintf(stdout, "  ✓ FlashEffect initialized via Sequence::init()\n");
}

// Test 5: Sequence add_effect
static void test_sequence_add_effect() {
  fprintf(stdout, "Testing Sequence::add_effect...\n");

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

  MainSequence main_seq;
  main_seq.init_test(fixture.ctx());

  // Create sequence
  auto seq = std::make_shared<Sequence>();

  // Create effect
  auto effect = std::make_shared<FlashEffect>(
      fixture.ctx());

  assert(!effect->is_initialized && "Effect should not be initialized before Sequence::init()");

  // Add effect to sequence (time range: 0.0 - 10.0, priority 0)
  seq->add_effect(effect, 0.0f, 10.0f, 0);

  // Initialize sequence (this should initialize the effect)
  seq->init(&main_seq);

  assert(effect->is_initialized && "Effect should be initialized after Sequence::init()");

  fprintf(stdout, "  ✓ Effect added to sequence and initialized (time=0.0-10.0, priority=0)\n");
}

// Test 6: Sequence activation logic
static void test_sequence_activation() {
  fprintf(stdout, "Testing sequence activation logic...\n");

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

  MainSequence main_seq;
  main_seq.init_test(fixture.ctx());

  auto seq = std::make_shared<Sequence>();
  auto effect = std::make_shared<FlashEffect>(
      fixture.ctx());

  // Effect active from 5.0 to 10.0 seconds
  seq->add_effect(effect, 5.0f, 10.0f, 0);
  seq->init(&main_seq);

  // Before start time: should not be active
  seq->update_active_list(-1.0f);
  std::vector<SequenceItem*> scene_before, post_before;
  seq->collect_active_effects(scene_before, post_before);
  assert(scene_before.empty() && post_before.empty() &&
         "Effect should not be active before start time");

  fprintf(stdout, "  ✓ Effect not active before start time (t=-1.0)\n");

  // At start time: should be active
  seq->update_active_list(5.0f);
  std::vector<SequenceItem*> scene_at_start, post_at_start;
  seq->collect_active_effects(scene_at_start, post_at_start);
  const size_t active_at_start = scene_at_start.size() + post_at_start.size();
  assert(active_at_start == 1 && "Effect should be active at start time");

  fprintf(stdout, "  ✓ Effect active at start time (t=5.0)\n");

  // During active period: should remain active
  seq->update_active_list(7.5f);
  std::vector<SequenceItem*> scene_during, post_during;
  seq->collect_active_effects(scene_during, post_during);
  const size_t active_during = scene_during.size() + post_during.size();
  assert(active_during == 1 && "Effect should be active during period");

  fprintf(stdout, "  ✓ Effect active during period (t=7.5)\n");

  // After end time: should not be active
  seq->update_active_list(11.0f);
  std::vector<SequenceItem*> scene_after, post_after;
  seq->collect_active_effects(scene_after, post_after);
  assert(scene_after.empty() && post_after.empty() &&
         "Effect should not be active after end time");

  fprintf(stdout, "  ✓ Effect not active after end time (t=11.0)\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");

  test_webgpu_fixture();
  test_offscreen_render_target();
  test_effect_construction();
  test_effect_initialization();
  test_sequence_add_effect();
  test_sequence_activation();
  test_pixel_helpers();

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