export const description = `Validation tests for entry point built-in variables`;

import { makeTestGroup } from '../../../../common/framework/test_group.js';
import { keysOf } from '../../../../common/util/data_tables.js';
import { WGSLLanguageFeature } from '../../../capability_info.js';
import { ShaderValidationTest } from '../shader_validation_test.js';

import { generateShader } from './util.js';

export const g = makeTestGroup(ShaderValidationTest);

interface Builtin {
  name: string;
  stage: 'vertex' | 'fragment' | 'compute';
  io: 'in' | 'out';
  type: string;
  enable?: string;
  requires?: WGSLLanguageFeature;
}

// List of all built-in variables and their stage, in|out usage, and type.
// Taken from table in Section 15:
// https://www.w3.org/TR/WGSL/#builtin-inputs-outputs
export const kBuiltins: readonly Builtin[] = [
  { name: 'vertex_index', stage: 'vertex', io: 'in', type: 'u32' },
  { name: 'instance_index', stage: 'vertex', io: 'in', type: 'u32' },
  { name: 'position', stage: 'vertex', io: 'out', type: 'vec4<f32>' },
  { name: 'position', stage: 'fragment', io: 'in', type: 'vec4<f32>' },
  { name: 'front_facing', stage: 'fragment', io: 'in', type: 'bool' },
  { name: 'frag_depth', stage: 'fragment', io: 'out', type: 'f32' },
  { name: 'local_invocation_id', stage: 'compute', io: 'in', type: 'vec3<u32>' },
  { name: 'local_invocation_index', stage: 'compute', io: 'in', type: 'u32' },
  { name: 'global_invocation_id', stage: 'compute', io: 'in', type: 'vec3<u32>' },
  { name: 'workgroup_id', stage: 'compute', io: 'in', type: 'vec3<u32>' },
  { name: 'num_workgroups', stage: 'compute', io: 'in', type: 'vec3<u32>' },
  { name: 'sample_index', stage: 'fragment', io: 'in', type: 'u32' },
  { name: 'sample_mask', stage: 'fragment', io: 'in', type: 'u32' },
  { name: 'sample_mask', stage: 'fragment', io: 'out', type: 'u32' },
  { name: 'subgroup_invocation_id', stage: 'compute', io: 'in', type: 'u32', enable: 'subgroups' },
  { name: 'subgroup_size', stage: 'compute', io: 'in', type: 'u32', enable: 'subgroups' },
  { name: 'subgroup_invocation_id', stage: 'fragment', io: 'in', type: 'u32', enable: 'subgroups' },
  { name: 'subgroup_size', stage: 'fragment', io: 'in', type: 'u32', enable: 'subgroups' },
  {
    name: 'clip_distances',
    stage: 'vertex',
    io: 'out',
    type: 'array<f32,1>',
    enable: 'clip_distances',
  },
  {
    name: 'clip_distances',
    stage: 'vertex',
    io: 'out',
    type: 'array<f32,2>',
    enable: 'clip_distances',
  },
  {
    name: 'clip_distances',
    stage: 'vertex',
    io: 'out',
    type: 'array<f32,3>',
    enable: 'clip_distances',
  },
  {
    name: 'clip_distances',
    stage: 'vertex',
    io: 'out',
    type: 'array<f32,4>',
    enable: 'clip_distances',
  },
  {
    name: 'clip_distances',
    stage: 'vertex',
    io: 'out',
    type: 'array<f32,5>',
    enable: 'clip_distances',
  },
  {
    name: 'clip_distances',
    stage: 'vertex',
    io: 'out',
    type: 'array<f32,6>',
    enable: 'clip_distances',
  },
  {
    name: 'clip_distances',
    stage: 'vertex',
    io: 'out',
    type: 'array<f32,7>',
    enable: 'clip_distances',
  },
  {
    name: 'clip_distances',
    stage: 'vertex',
    io: 'out',
    type: 'array<f32,8>',
    enable: 'clip_distances',
  },
  {
    name: 'primitive_id',
    stage: 'fragment',
    io: 'in',
    type: 'u32',
    enable: 'chromium_experimental_primitive_id',
  },
  {
    name: 'subgroup_id',
    stage: 'compute',
    io: 'in',
    type: 'u32',
    enable: 'subgroups',
    requires: 'subgroup_id',
  },
  {
    name: 'num_subgroups',
    stage: 'compute',
    io: 'in',
    type: 'u32',
    enable: 'subgroups',
    requires: 'subgroup_id',
  },
  {
    name: 'workgroup_index',
    stage: 'compute',
    io: 'in',
    type: 'u32',
    requires: 'linear_indexing',
  },
  {
    name: 'global_invocation_index',
    stage: 'compute',
    io: 'in',
    type: 'u32',
    requires: 'linear_indexing',
  },
] as const;

// List of types to test against.
const kTestTypes = [
  'bool',
  'u32',
  'i32',
  'f32',
  'vec2<bool>',
  'vec2<u32>',
  'vec2<i32>',
  'vec2<f32>',
  'vec3<bool>',
  'vec3<u32>',
  'vec3<i32>',
  'vec3<f32>',
  'vec4<bool>',
  'vec4<u32>',
  'vec4<i32>',
  'vec4<f32>',
  'mat2x2<f32>',
  'mat2x3<f32>',
  'mat2x4<f32>',
  'mat3x2<f32>',
  'mat3x3<f32>',
  'mat3x4<f32>',
  'mat4x2<f32>',
  'mat4x3<f32>',
  'mat4x4<f32>',
  'atomic<u32>',
  'atomic<i32>',
  'array<bool,4>',
  'array<u32,4>',
  'array<i32,4>',
  'array<f32,1>',
  'array<f32,2>',
  'array<f32,3>',
  'array<f32,4>',
  'array<f32,5>',
  'array<f32,6>',
  'array<f32,7>',
  'array<f32,8>',
  'array<f32,9>',
  'MyStruct',
] as const;

g.test('stage_inout')
  .desc(
    `Test that each @builtin attribute is validated against the required stage and in/out usage for that built-in variable.`
  )
  .params(u =>
    u
      .combineWithParams(kBuiltins)
      .combine('use_struct', [true, false] as const)
      .combine('target_stage', ['', 'vertex', 'fragment', 'compute'] as const)
      .combine('target_io', ['in', 'out'] as const)
      .beginSubcases()
  )
  .beforeAllSubcases(t => {
    t.skipIf(
      t.isCompatibility && ['sample_index', 'sample_mask'].includes(t.params.name),
      'compatibility mode does not support sample_index or sample_mask'
    );
    t.skipIf(
      t.params.name !== 'position' &&
        t.params.target_stage === 'vertex' &&
        t.params.target_io === 'out' &&
        !t.params.use_struct,
      'missing @builtin(position) in the vertex output when the vertex output is not a struct'
    );
  })
  .fn(t => {
    const code = generateShader({
      attribute: `@builtin(${t.params.name})`,
      type: t.params.type,
      stage: t.params.target_stage,
      io: t.params.target_io,
      use_struct: t.params.use_struct,
      enable: t.params.enable,
    });

    // Expect to pass iff the built-in table contains an entry that matches.
    const expectation = kBuiltins.some(
      x =>
        x.name === t.params.name &&
        (x.stage === t.params.target_stage ||
          (t.params.use_struct && t.params.target_stage === '')) &&
        (x.io === t.params.target_io || t.params.target_stage === '') &&
        x.type === t.params.type &&
        (x.requires === undefined || t.hasLanguageFeature(x.requires))
    );
    t.expectCompileResult(expectation, code);
  });

g.test('type')
  .desc(
    `Test that each @builtin attribute is validated against the required type of that built-in variable.`
  )
  .params(u =>
    u
      .combineWithParams(kBuiltins)
      .combine('use_struct', [true, false] as const)
      .beginSubcases()
      .combine('target_type', kTestTypes)
  )
  .beforeAllSubcases(t => {
    t.skipIf(
      t.isCompatibility && ['sample_index', 'sample_mask'].includes(t.params.name),
      'compatibility mode does not support sample_index or sample_mask'
    );
    t.skipIf(
      t.params.name !== 'position' &&
        t.params.stage === 'vertex' &&
        t.params.io === 'out' &&
        !t.params.use_struct,
      'missing @builtin(position) in the vertex output'
    );
  })
  .fn(t => {
    let code = '';

    if (t.params.target_type === 'MyStruct') {
      // Generate a struct that contains the correct built-in type.
      code += 'struct MyStruct {\n';
      code += `  value : ${t.params.type}\n`;
      code += '};\n\n';
    }

    code += generateShader({
      attribute: `@builtin(${t.params.name})`,
      type: t.params.target_type,
      stage: t.params.stage,
      io: t.params.io,
      use_struct: t.params.use_struct,
      enable: t.params.enable,
    });

    // Expect to pass iff the built-in table contains an entry that matches.
    const expectation = kBuiltins.some(
      x =>
        x.name === t.params.name &&
        x.stage === t.params.stage &&
        x.io === t.params.io &&
        x.type === t.params.target_type &&
        (x.requires === undefined || t.hasLanguageFeature(x.requires))
    );
    t.expectCompileResult(expectation, code);
  });

g.test('nesting')
  .desc(`Test validation of nested built-in variables`)
  .params(u =>
    u
      .combine('target_stage', ['fragment', ''] as const)
      .combine('target_io', ['in', 'out'] as const)
      .beginSubcases()
  )
  .fn(t => {
    // Generate a struct that contains a frag_depth builtin, nested inside another struct.
    let code = `
    struct Inner {
      @builtin(frag_depth) value : f32
    };
    struct Outer {
      inner : Inner
    };`;

    code += generateShader({
      attribute: '',
      type: 'Outer',
      stage: t.params.target_stage,
      io: t.params.target_io,
      use_struct: false,
    });

    // Expect to pass only if the struct is not used for entry point IO.
    t.expectCompileResult(t.params.target_stage === '', code);
  });

g.test('duplicates')
  .desc(`Test that duplicated built-in variables are validated.`)
  .params(u =>
    u
      // Place two @builtin(sample_mask) attributes onto the entry point function.
      // We use `sample_mask` as it is valid as both an input and output for the same entry point.
      // The function:
      // - has two non-struct parameters (`p1` and `p2`)
      // - has two struct parameters each with two members (`s1{a,b}` and `s2{a,b}`)
      // - returns a struct with two members (`ra` and `rb`)
      // By default, all of these variables will have unique @location() attributes.
      .combine('first', ['p1', 's1a', 's2a', 'ra'] as const)
      .combine('second', ['p2', 's1b', 's2b', 'rb'] as const)
      .beginSubcases()
  )
  .beforeAllSubcases(t => {
    t.skipIf(t.isCompatibility, 'compatibility mode does not support sample_mask');
  })
  .fn(t => {
    const p1 =
      t.params.first === 'p1' ? '@builtin(sample_mask)' : '@location(1) @interpolate(flat, either)';
    const p2 =
      t.params.second === 'p2'
        ? '@builtin(sample_mask)'
        : '@location(2) @interpolate(flat, either)';
    const s1a =
      t.params.first === 's1a'
        ? '@builtin(sample_mask)'
        : '@location(3) @interpolate(flat, either)';
    const s1b =
      t.params.second === 's1b'
        ? '@builtin(sample_mask)'
        : '@location(4) @interpolate(flat, either)';
    const s2a =
      t.params.first === 's2a'
        ? '@builtin(sample_mask)'
        : '@location(5) @interpolate(flat, either)';
    const s2b =
      t.params.second === 's2b'
        ? '@builtin(sample_mask)'
        : '@location(6) @interpolate(flat, either)';
    const ra =
      t.params.first === 'ra' ? '@builtin(sample_mask)' : '@location(1) @interpolate(flat, either)';
    const rb =
      t.params.second === 'rb'
        ? '@builtin(sample_mask)'
        : '@location(2) @interpolate(flat, either)';
    const code = `
    struct S1 {
      ${s1a} a : u32,
      ${s1b} b : u32,
    };
    struct S2 {
      ${s2a} a : u32,
      ${s2b} b : u32,
    };
    struct R {
      ${ra} a : u32,
      ${rb} b : u32,
    };
    @fragment
    fn main(${p1} p1 : u32,
            ${p2} p2 : u32,
            s1 : S1,
            s2 : S2,
            ) -> R {
      return R();
    }
    `;

    // The test should fail if both @builtin(sample_mask) attributes are on the input parameters
    // or structures, or it they are both on the output struct. Otherwise it should pass.
    const firstIsRet = t.params.first === 'ra';
    const secondIsRet = t.params.second === 'rb';
    const expectation = firstIsRet !== secondIsRet;
    t.expectCompileResult(expectation, code);
  });

g.test('missing_vertex_position')
  .desc(`Test that vertex shaders are required to output @builtin(position).`)
  .params(u =>
    u
      .combine('use_struct', [true, false] as const)
      .combine('attribute', ['@builtin(position)', '@location(0)'] as const)
      .beginSubcases()
  )
  .fn(t => {
    const code = `
    struct S {
      ${t.params.attribute} value : vec4<f32>
    };

    @vertex
    fn main() -> ${t.params.use_struct ? 'S' : `${t.params.attribute} vec4<f32>`} {
      return ${t.params.use_struct ? 'S' : 'vec4<f32>'}();
    }
    `;

    // Expect to pass only when using @builtin(position).
    t.expectCompileResult(t.params.attribute === '@builtin(position)', code);
  });

g.test('reuse_builtin_name')
  .desc(`Test that a builtin name can be used in different contexts`)
  .params(u =>
    u
      .combineWithParams(kBuiltins)
      .combine('use', ['alias', 'struct', 'function', 'module-var', 'function-var'])
  )
  .fn(t => {
    let code = '';
    if (t.params.use === 'alias') {
      code += `alias ${t.params.name} = i32;`;
    } else if (t.params.use === `struct`) {
      code += `struct ${t.params.name} { i: f32, }`;
    } else if (t.params.use === `function`) {
      code += `fn ${t.params.name}() {}`;
    } else if (t.params.use === `module-var`) {
      code += `const ${t.params.name} = 1;`;
    } else if (t.params.use === `function-var`) {
      code += `fn test() { let ${t.params.name} = 1; }`;
    }
    t.expectCompileResult(true, code);
  });

const kBuiltinTests = {
  pos: {
    src: `@builtin(position)`,
    pass: true,
  },
  trailing_comma: {
    src: `@builtin(position,)`,
    pass: true,
  },
  newline_in_attr: {
    src: `@ \n builtin(position)`,
    pass: true,
  },
  whitespace_in_attr: {
    src: `@/* comment */builtin/* comment */\n\n(\t/*comment*/position/*comment*/)`,
    pass: true,
  },
  invalid_name: {
    src: `@abuiltin(position)`,
    pass: false,
  },
  no_params: {
    src: `@builtin`,
    pass: false,
  },
  missing_param: {
    src: `@builtin()`,
    pass: false,
  },
  missing_parens: {
    src: `@builtin position`,
    pass: false,
  },
  missing_lparen: {
    src: `@builtin position)`,
    pass: false,
  },
  missing_rparen: {
    src: `@builtin(position`,
    pass: false,
  },
  multiple_params: {
    src: `@builtin(position, frag_depth)`,
    pass: false,
  },
  ident_param: {
    src: `@builtin(identifier)`,
    pass: false,
  },
  number_param: {
    src: `@builtin(2)`,
    pass: false,
  },
  duplicate: {
    src: `@builtin(position) @builtin(position)`,
    pass: false,
  },
};

g.test('parse_builtin')
  .desc(`Test that @builtin is parsed correctly.`)
  .params(u => u.combine('builtin', keysOf(kBuiltinTests)))
  .fn(t => {
    const src = kBuiltinTests[t.params.builtin].src;
    const code = `
@vertex
fn main() -> ${src} vec4<f32> {
  return vec4<f32>(.4, .2, .3, .1);
}`;
    t.expectCompileResult(kBuiltinTests[t.params.builtin].pass, code);
  });

g.test('placement')
  .desc('Tests the locations @builtin is allowed to appear')
  .params(u =>
    u
      .combine('scope', [
        // The fn-param and fn-ret are part of the shader_io/builtins tests
        'private-var',
        'storage-var',
        'struct-member',
        'non-ep-param',
        'non-ep-ret',
        'fn-decl',
        'fn-var',
        'while-stmt',
        undefined,
      ] as const)
      .combine('attribute', [
        {
          'private-var': false,
          'storage-var': false,
          'struct-member': true,
          'non-ep-param': false,
          'non-ep-ret': false,
          'fn-decl': false,
          'fn-var': false,
          'fn-return': false,
          'while-stmt': false,
        },
      ])
      .beginSubcases()
  )
  .fn(t => {
    const scope = t.params.scope;

    const attr = '@builtin(vertex_index)';
    const code = `
      ${scope === 'private-var' ? attr : ''}
      var<private> priv_var : u32;

      ${scope === 'storage-var' ? attr : ''}
      @group(0) @binding(0)
      var<storage> stor_var : u32;

      struct A {
        ${scope === 'struct-member' ? attr : ''}
        a : u32,
      }

      fn v(${scope === 'non-ep-param' ? attr : ''} i : u32) ->
            ${scope === 'non-ep-ret' ? attr : ''} u32 { return 1; }

      @vertex
      ${scope === 'fn-decl' ? attr : ''}
      fn f(
        @location(0) b : u32,
      ) -> @builtin(position) vec4f {
        ${scope === 'fn-var' ? attr : ''}
        var<function> func_v : u32;

        ${scope === 'while-stmt' ? attr : ''}
        while false {}

        return vec4(1, 1, 1, 1);
      }
    `;

    t.expectCompileResult(scope === undefined || t.params.attribute[scope], code);
  });

const kFragDepthTests = {
  unset: {
    src: `@builtin(frag_depth)`,
    pass: true,
    requires_feature: false,
  },
  less: {
    src: `@builtin(frag_depth, less)`,
    pass: true,
    requires_feature: true,
  },
  greater: {
    src: `@builtin(frag_depth, greater)`,
    pass: true,
    requires_feature: true,
  },
  trailing_comma: {
    src: `@builtin(frag_depth, less,)`,
    pass: true,
    requires_feature: true,
  },
  missing_enum: {
    src: `@builtin(frag_depth,)`,
    pass: true,
    requires_feature: false,
  },
  invalid_enum: {
    src: `@builtin(frag_depth, any)`,
    pass: false,
    requires_feature: false,
  },
  missing_comma: {
    src: `@builtin(frag_depth greater)`,
    pass: false,
    requires_feature: false,
  },
};

g.test('parse_frag_depth')
  .desc(`Test that @builtin is parsed correctly.`)
  .params(u => u.combine('builtin', keysOf(kFragDepthTests)))
  .fn(t => {
    const data = kFragDepthTests[t.params.builtin];

    if (data.requires_feature) {
      t.skipIfLanguageFeatureNotSupported('fragment_depth');
    }

    const code = `
@fragment
fn main() -> ${data.src} f32 {
  return .5;
}`;
    t.expectCompileResult(data.pass, code);
  });