import { describe, it, expect } from 'vitest';
import { stripUeMacros } from '../../src/core/ingestion/cpp-ue-preprocessor.js';

describe('stripUeMacros — detection guard', () => {
  it('returns input unchanged when no UE markers are present', () => {
    const src = `class Plain {\npublic:\n  int Get() const;\n};`;
    expect(stripUeMacros(src)).toBe(src);
  });

  it('returns input unchanged for STL-style code', () => {
    const src = `#include <vector>\nstd::vector<int> v;`;
    expect(stripUeMacros(src)).toBe(src);
  });
});

describe('stripUeMacros — length preservation', () => {
  const ueSamples: string[] = [
    `UCLASS()\nclass BRAWLUI_API UMyClass : public UObject { GENERATED_BODY() public: UFUNCTION() void Run(); };`,
    `UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Combat") int32 Health;`,
    `USTRUCT(BlueprintType)\nstruct ENGINE_API FMyData { GENERATED_BODY() float Value; };`,
    `DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FMyDelegate, int32, A, FString, B);`,
    `UE_DEPRECATED(5.0, "Use NewThing instead") void OldThing();`,
  ];

  for (const src of ueSamples) {
    it(`preserves byte length: ${src.slice(0, 40).replace(/\n/g, '\\n')}…`, () => {
      const out = stripUeMacros(src);
      expect(out.length).toBe(src.length);
    });

    it(`preserves newline positions: ${src.slice(0, 40).replace(/\n/g, '\\n')}…`, () => {
      const out = stripUeMacros(src);
      const inputNewlines: number[] = [];
      const outputNewlines: number[] = [];
      for (let i = 0; i < src.length; i++) {
        if (src.charCodeAt(i) === 0x0a) inputNewlines.push(i);
        if (out.charCodeAt(i) === 0x0a) outputNewlines.push(i);
      }
      expect(outputNewlines).toEqual(inputNewlines);
    });
  }
});

describe('stripUeMacros — macro removal', () => {
  it('elides UCLASS(...) with arguments', () => {
    const src = `UCLASS(BlueprintType, Category="Foo")\nclass UFoo {};`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('UCLASS');
    expect(out).not.toContain('BlueprintType');
    expect(out).toContain('class UFoo {};');
  });

  it('elides UCLASS() with empty parens', () => {
    const src = `UCLASS()\nclass UBar {};`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('UCLASS');
    expect(out).toContain('class UBar {};');
  });

  it('elides MODULE_API export macros (BRAWLUI_API style)', () => {
    const src = `class BRAWLUI_API UMyClass : public UObject {};`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('BRAWLUI_API');
    expect(out).toContain('class');
    expect(out).toContain('UMyClass');
    expect(out).toContain('public UObject');
  });

  it('elides multiple distinct *_API tokens in same file', () => {
    const src = `class CORE_API A {};\nclass UMG_API B : public A {};`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('CORE_API');
    expect(out).not.toContain('UMG_API');
    expect(out).toContain('class');
    expect(out).toContain('A {};');
  });

  it('elides GENERATED_BODY() inside class body', () => {
    const src = `class UThing { GENERATED_BODY() public: void Foo(); };`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('GENERATED_BODY');
    expect(out).toContain('public:');
    expect(out).toContain('void Foo();');
  });

  it('elides UFUNCTION(...) before method declarations', () => {
    const src = `class X { UFUNCTION(BlueprintCallable, Server, Reliable) void DoThing(); };`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('UFUNCTION');
    expect(out).not.toContain('BlueprintCallable');
    expect(out).toContain('void DoThing();');
  });

  it('elides UPROPERTY(...) before field declarations', () => {
    const src = `class X { UPROPERTY(EditAnywhere) int32 Health; };`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('UPROPERTY');
    expect(out).not.toContain('EditAnywhere');
    expect(out).toContain('int32 Health;');
  });

  it('elides DECLARE_DYNAMIC_MULTICAST_DELEGATE_*Params(...)', () => {
    const src = `DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FMyDelegate, int32, Value);\nclass X {};`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('DECLARE_DYNAMIC_MULTICAST_DELEGATE');
    expect(out).not.toContain('FMyDelegate');
    expect(out).toContain('class X {};');
  });

  it('elides UE_DEPRECATED(...) before function declarations', () => {
    const src = `UE_DEPRECATED(5.1, "Reason") void Old();`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('UE_DEPRECATED');
    expect(out).not.toContain('5.1');
    expect(out).toContain('void Old();');
  });
});

describe('stripUeMacros — false-positive guards', () => {
  it('does NOT strip identifiers that merely contain UCLASS as a substring', () => {
    const src = `void NotUCLASSAtAll(); int MyUCLASS = 0;`;
    const out = stripUeMacros(src);
    expect(out).toBe(src);
  });

  it('does NOT strip _API substrings inside larger identifiers', () => {
    const src = `class MY_APIName {};\nint not_my_API_thing = 0;`;
    const out = stripUeMacros(src);
    expect(out).toContain('MY_APIName');
    expect(out).toContain('not_my_API_thing');
  });

  it('does not eat parens balanced inside string literals', () => {
    const src = `UFUNCTION(meta=(DisplayName="Foo (Bar)")) void Z();`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('UFUNCTION');
    expect(out).not.toContain('DisplayName');
    expect(out).toContain('void Z();');
  });

  it('handles UCLASS with deeply nested parens in arguments', () => {
    const src = `UCLASS(meta=(Categories=("A.B", "C.D")), Within=Foo) class UDeep {};`;
    const out = stripUeMacros(src);
    expect(out).not.toContain('UCLASS');
    expect(out).not.toContain('Categories');
    expect(out).toContain('class UDeep {};');
  });

  it('leaves Qt macros alone (only UE markers stripped)', () => {
    const src = `class QFoo { Q_OBJECT public: void Bar(); };`;
    const out = stripUeMacros(src);
    expect(out).toContain('Q_OBJECT');
  });
});

describe('stripUeMacros — class-name extraction sanity', () => {
  it('after stripping, "class UMyClass" appears immediately after "class "', () => {
    const src = `UCLASS(BlueprintType)\nclass BRAWLUI_API UMyClass : public UObject\n{\n  GENERATED_BODY()\n};`;
    const out = stripUeMacros(src);
    const classIdx = out.indexOf('class ');
    expect(classIdx).toBeGreaterThanOrEqual(0);
    const tail = out.slice(classIdx + 'class '.length).trimStart();
    expect(tail.startsWith('UMyClass')).toBe(true);
  });
});