import { GPUConst } from '../../../../constants.js';
import { isPowerOfTwo } from '../../../../util/math.js';

import {
  kMinimumLimitBaseParams,
  makeLimitTestGroup,
  MinimumLimitValueTest,
  MinimumTestValue,
} from './limit_utils.js';

function getDeviceLimitToRequest(
  limitValueTest: MinimumLimitValueTest,
  defaultLimit: number,
  minimumLimit: number
) {
  switch (limitValueTest) {
    case 'atDefault':
      return defaultLimit;
    case 'overDefault':
      return 2 ** (Math.log2(defaultLimit) + 1);
    case 'betweenDefaultAndMinimum':
      return 2 ** (((Math.log2(defaultLimit) + Math.log2(minimumLimit)) / 2) | 0);
    case 'atMinimum':
      return minimumLimit;
    case 'underMinimum':
      return 2 ** (Math.log2(minimumLimit) - 1);
  }
}

function getTestValue(testValueName: MinimumTestValue, requestedLimit: number) {
  switch (testValueName) {
    case 'atLimit':
      return requestedLimit;
    case 'underLimit':
      return 2 ** (Math.log2(requestedLimit) - 1);
  }
}

function getDeviceLimitToRequestAndValueToTest(
  limitValueTest: MinimumLimitValueTest,
  testValueName: MinimumTestValue,
  defaultLimit: number,
  maximumLimit: number
) {
  const requestedLimit = getDeviceLimitToRequest(limitValueTest, defaultLimit, maximumLimit);
  return {
    requestedLimit,
    testValue: getTestValue(testValueName, requestedLimit),
  };
}

const limit = 'minStorageBufferOffsetAlignment';
export const { g, description } = makeLimitTestGroup(limit);

g.test('createBindGroup,at_over')
  .desc(`Test using createBindGroup at and over ${limit} limit`)
  .params(kMinimumLimitBaseParams)
  .fn(async t => {
    const { limitTest, testValueName } = t.params;
    // note: LimitTest.maximum is the adapter.limits[limit] value
    const { defaultLimit, adapterLimit: minimumLimit } = t;
    const { requestedLimit, testValue } = getDeviceLimitToRequestAndValueToTest(
      limitTest,
      testValueName,
      defaultLimit,
      minimumLimit
    );

    await t.testDeviceWithSpecificLimits(
      requestedLimit,
      testValue,
      async ({ device, testValue, shouldError }) => {
        const storageBuffer = t.createBufferTracked({
          size: testValue * 2,
          usage: GPUBufferUsage.STORAGE,
        });

        const layout = device.createBindGroupLayout({
          entries: [
            {
              binding: 0,
              visibility: GPUShaderStage.COMPUTE,
              buffer: { type: 'storage' },
            },
          ],
        });

        await t.expectValidationError(() => {
          device.createBindGroup({
            layout,
            entries: [
              {
                binding: 0,
                resource: {
                  buffer: storageBuffer,
                  offset: testValue,
                },
              },
            ],
          });
        }, shouldError);
      }
    );
  });

g.test('setBindGroup,at_over')
  .desc(`Test using setBindGroup at and over ${limit} limit`)
  .params(kMinimumLimitBaseParams)
  .fn(async t => {
    const { limitTest, testValueName } = t.params;
    // note: LimitTest.maximum is the adapter.limits[limit] value
    const { defaultLimit, adapterLimit: minimumLimit } = t;
    const { requestedLimit, testValue } = getDeviceLimitToRequestAndValueToTest(
      limitTest,
      testValueName,
      defaultLimit,
      minimumLimit
    );

    await t.testDeviceWithSpecificLimits(
      requestedLimit,
      testValue,
      async ({ device, testValue, shouldError }) => {
        const buffer = t.createBufferTracked({
          size: testValue * 2,
          usage: GPUBufferUsage.STORAGE,
        });

        const layout = device.createBindGroupLayout({
          entries: [
            {
              binding: 0,
              visibility: GPUConst.ShaderStage.COMPUTE,
              buffer: {
                type: 'storage',
                hasDynamicOffset: true,
              },
            },
          ],
        });

        const bindGroup = device.createBindGroup({
          layout,
          entries: [
            {
              binding: 0,
              resource: {
                buffer,
                size: testValue / 2,
              },
            },
          ],
        });

        const encoder = device.createCommandEncoder();
        const pass = encoder.beginComputePass();
        pass.setBindGroup(0, bindGroup, [testValue]);
        pass.end();

        await t.expectValidationError(() => {
          encoder.finish();
        }, shouldError);

        buffer.destroy();
      }
    );
  });

g.test('validate,powerOf2')
  .desc('Verify that ${limit} is power of 2')
  .fn(t => {
    t.expect(isPowerOfTwo(t.defaultLimit));
    t.expect(isPowerOfTwo(t.adapterLimit));
  });

g.test('validate,greaterThanOrEqualTo32')
  .desc('Verify that ${limit} is >= 32')
  .fn(t => {
    t.expect(t.defaultLimit >= 32);
    t.expect(t.adapterLimit >= 32);
  });
