import Crypto from 'node:crypto';
import { afterEach } from 'node:test';
import { digest, generateSalt } from '@sd-jwt/crypto-nodejs';
import type { DisclosureFrame, Signer, Verifier } from '@sd-jwt/types';
import { HttpResponse, http } from 'msw';
import { setupServer } from 'msw/node';
import { afterAll, beforeAll, describe, expect, test, vitest } from 'vitest';
import { SDJwtVcInstance } from '..';
import type { SdJwtVcPayload } from '../sd-jwt-vc-payload';
import type { TypeMetadataFormat } from '../sd-jwt-vc-type-metadata-format';

const exampleVctm = {
  vct: 'http://example.com/example',
  name: 'ExampleCredentialType',
  description: 'An example credential type',
};

const baseVctm: TypeMetadataFormat = {
  vct: 'http://example.com/base',
  name: 'BaseCredentialType',
  description: 'A base credential type',
  claims: [
    {
      path: ['firstName'],
      display: [{ locale: 'en', label: 'First Name' }],
    },
  ],
  display: [
    {
      locale: 'en',
      name: 'Base Credential',
      description: 'Base description',
    },
  ],
};

const extendingVctm: TypeMetadataFormat = {
  vct: 'http://example.com/extending',
  name: 'ExtendingCredentialType',
  description: 'A credential type that extends the base',
  extends: 'http://example.com/base',
  claims: [
    {
      path: ['lastName'],
      display: [{ locale: 'en', label: 'Last Name' }],
    },
  ],
  display: [
    {
      locale: 'en',
      name: 'Extended Credential',
      description: 'Extended description',
    },
    {
      locale: 'de',
      name: 'Erweiterte Berechtigung',
      description: 'Erweiterte Beschreibung',
    },
  ],
};

const middleVctm: TypeMetadataFormat = {
  vct: 'http://example.com/middle',
  name: 'MiddleCredentialType',
  description: 'Middle type in chain',
  extends: 'http://example.com/extending',
  claims: [
    {
      path: ['age'],
      display: [{ locale: 'en', label: 'Age' }],
    },
  ],
};

const overridingVctm: TypeMetadataFormat = {
  vct: 'http://example.com/overriding',
  name: 'OverridingCredentialType',
  description: 'A credential type that overrides a claim from the base',
  extends: 'http://example.com/base',
  claims: [
    {
      path: ['firstName'],
      display: [{ locale: 'en', label: 'Given Name' }], // Override with different label
      sd: 'always' as const,
    },
    {
      path: ['middleName'],
      display: [{ locale: 'en', label: 'Middle Name' }],
    },
  ],
};

const circularVctm: TypeMetadataFormat = {
  vct: 'http://example.com/circular',
  name: 'CircularCredentialType',
  extends: 'http://example.com/circular',
};

const deepVctm: TypeMetadataFormat = {
  vct: 'http://example.com/deep',
  name: 'DeepCredentialType',
  extends: 'http://example.com/middle',
};

const baseWithSdAlways: TypeMetadataFormat = {
  vct: 'http://example.com/base-sd-always',
  name: 'BaseWithSdAlways',
  claims: [
    {
      path: ['sensitiveData'],
      sd: 'always' as const,
      display: [{ locale: 'en', label: 'Sensitive Data' }],
    },
  ],
};

const invalidExtendingSdChange: TypeMetadataFormat = {
  vct: 'http://example.com/invalid-sd-change',
  name: 'InvalidSdChange',
  extends: 'http://example.com/base-sd-always',
  claims: [
    {
      path: ['sensitiveData'],
      sd: 'never' as const, // Invalid: trying to change from 'always' to 'never'
      display: [{ locale: 'en', label: 'Sensitive Data' }],
    },
  ],
};

const validExtendingSdChange: TypeMetadataFormat = {
  vct: 'http://example.com/valid-sd-change',
  name: 'ValidSdChange',
  extends: 'http://example.com/base',
  claims: [
    {
      path: ['firstName'],
      sd: 'always' as const, // Valid: base doesn't have sd or has 'allowed'
      display: [{ locale: 'en', label: 'First Name' }],
    },
  ],
};

const vctWithCustomProperties: TypeMetadataFormat = {
  vct: 'http://example.com/custom-properties',
  name: 'CustomProperties',
  claims: [
    {
      path: ['firstName'],
      sd: 'always' as const, // Valid: base doesn't have sd or has 'allowed'
      display: [{ locale: 'en', label: 'First Name' }],
      anotherCustom: 'property',
    },
  ],
  test: 'something',
};

const restHandlers = [
  http.get('http://example.com/example', () => {
    const res: TypeMetadataFormat = exampleVctm;
    return HttpResponse.json(res);
  }),
  http.get('http://example.com/timeout', () => {
    return new Promise((resolve) => {
      setTimeout(() => {
        resolve(HttpResponse.json({}));
      }, 10000);
    });
  }),
  http.get('http://example.com/base', () => {
    return HttpResponse.json(baseVctm);
  }),
  http.get('http://example.com/extending', () => {
    return HttpResponse.json(extendingVctm);
  }),
  http.get('http://example.com/middle', () => {
    return HttpResponse.json(middleVctm);
  }),
  http.get('http://example.com/overriding', () => {
    return HttpResponse.json(overridingVctm);
  }),
  http.get('http://example.com/circular', () => {
    return HttpResponse.json(circularVctm);
  }),
  http.get('http://example.com/deep', () => {
    return HttpResponse.json(deepVctm);
  }),
  http.get('http://example.com/base-sd-always', () => {
    return HttpResponse.json(baseWithSdAlways);
  }),
  http.get('http://example.com/invalid-sd-change', () => {
    return HttpResponse.json(invalidExtendingSdChange);
  }),
  http.get('http://example.com/valid-sd-change', () => {
    return HttpResponse.json(validExtendingSdChange);
  }),
  http.get('http://example.com/custom-properties', () => {
    return HttpResponse.json(vctWithCustomProperties);
  }),
  http.get('http://example.com/invalid', () => {
    // Return invalid type metadata (missing required 'vct' field)
    return HttpResponse.json({
      name: 'InvalidCredentialType',
      description: 'Missing required vct field',
    });
  }),
];

//this value could be generated on demand to make it easier when changing the values
const vctIntegrity =
  'sha256-e8bf419e6b860595f385611fc6172f1e95c18de3c80eef57c865f49e03747637';

const server = setupServer(...restHandlers);

const iss = 'ExampleIssuer';
const vct = 'http://example.com/example';
const iat = Math.floor(Date.now() / 1000); // current time in seconds

const { privateKey, publicKey } = Crypto.generateKeyPairSync('ed25519');

const createSignerVerifier = () => {
  const signer: Signer = async (data: string) => {
    const sig = Crypto.sign(null, Buffer.from(data), privateKey);
    return Buffer.from(sig).toString('base64url');
  };
  const verifier: Verifier = async (data: string, sig: string) => {
    return Crypto.verify(
      null,
      Buffer.from(data),
      publicKey,
      Buffer.from(sig, 'base64url'),
    );
  };
  return { signer, verifier };
};

describe('App', () => {
  const { signer, verifier } = createSignerVerifier();

  const sdjwt = new SDJwtVcInstance({
    signer,
    signAlg: 'EdDSA',
    verifier,
    hasher: digest,
    hashAlg: 'sha-256',
    saltGenerator: generateSalt,
    loadTypeMetadataFormat: true,
    timeout: 1000,
  });

  const claims = {
    firstname: 'John',
  };
  const disclosureFrame = {
    _sd: ['firstname'],
  };

  beforeAll(() => server.listen({ onUnhandledRequest: 'warn' }));

  afterAll(() => server.close());

  afterEach(() => server.resetHandlers());

  test('VCT Validation', async () => {
    // The method is private, so TS complains, but you can use spies on private method just fine.
    // @ts-expect-error
    const validateIntegritySpy = vitest.spyOn(sdjwt, 'validateIntegrity');

    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct,
      'vct#integrity': vctIntegrity,
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    await sdjwt.verify(encodedSdjwt);

    // Ensure validateIntegrity method was called
    expect(validateIntegritySpy).toHaveBeenCalledWith(
      expect.any(Response),
      vct,
      vctIntegrity,
    );
  });

  test('VCT Validation with timeout', async () => {
    const vct = 'http://example.com/timeout';
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct,
      ...claims,
    };
    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    await expect(sdjwt.verify(encodedSdjwt)).rejects.toThrowError(
      `Request to ${vct} timed out`,
    );
  });

  test('VCT Metadata retrieval', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct,
      'vct#Integrity': vctIntegrity,
      ...claims,
    };
    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    const resolvedTypeMetadata = await sdjwt.getVct(encodedSdjwt);

    // Check mergedTypeMetadata
    expect(resolvedTypeMetadata?.mergedTypeMetadata).to.deep.eq({
      description: 'An example credential type',
      name: 'ExampleCredentialType',
      vct: 'http://example.com/example',
    });

    // Check typeMetadataChain - should have only one document (no extends)
    expect(resolvedTypeMetadata?.typeMetadataChain).toHaveLength(1);
    expect(resolvedTypeMetadata?.typeMetadataChain[0].vct).toBe(
      'http://example.com/example',
    );

    // Check vctValues - should have only one value
    expect(resolvedTypeMetadata?.vctValues).toHaveLength(1);
    expect(resolvedTypeMetadata?.vctValues[0]).toBe(
      'http://example.com/example',
    );
  });

  test('VCT with extends - simple chain', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/extending',
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    const resolvedTypeMetadata = await sdjwt.getVct(encodedSdjwt);

    // Check mergedTypeMetadata - should merge claims from both base and extending types
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims).toHaveLength(2);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[0].path).toEqual([
      'firstName',
    ]);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[1].path).toEqual([
      'lastName',
    ]);

    // Display from extending type completely replaces base display (section 8.2)
    expect(resolvedTypeMetadata?.mergedTypeMetadata.display).toHaveLength(2);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.display?.[0]).toEqual({
      locale: 'en',
      name: 'Extended Credential',
      description: 'Extended description',
    });
    expect(resolvedTypeMetadata?.mergedTypeMetadata.display?.[1]).toEqual({
      locale: 'de',
      name: 'Erweiterte Berechtigung',
      description: 'Erweiterte Beschreibung',
    });

    // Top-level properties should come from extending type
    expect(resolvedTypeMetadata?.mergedTypeMetadata.name).toBe(
      'ExtendingCredentialType',
    );
    expect(resolvedTypeMetadata?.mergedTypeMetadata.description).toBe(
      'A credential type that extends the base',
    );

    // Check typeMetadataChain - should have 2 documents in chain
    expect(resolvedTypeMetadata?.typeMetadataChain).toHaveLength(2);
    expect(resolvedTypeMetadata?.typeMetadataChain[0].vct).toBe(
      'http://example.com/extending',
    );
    expect(resolvedTypeMetadata?.typeMetadataChain[1].vct).toBe(
      'http://example.com/base',
    );

    // Check vctValues - should have 2 values
    expect(resolvedTypeMetadata?.vctValues).toHaveLength(2);
    expect(resolvedTypeMetadata?.vctValues[0]).toBe(
      'http://example.com/extending',
    );
    expect(resolvedTypeMetadata?.vctValues[1]).toBe('http://example.com/base');
  });

  test('VCT with extends - multi-level chain', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/middle',
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    const resolvedTypeMetadata = await sdjwt.getVct(encodedSdjwt);

    // Check mergedTypeMetadata - should merge claims from base -> extending -> middle
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims).toHaveLength(3);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[0].path).toEqual([
      'firstName',
    ]);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[1].path).toEqual([
      'lastName',
    ]);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[2].path).toEqual([
      'age',
    ]);

    // Top-level properties should come from the most derived type
    expect(resolvedTypeMetadata?.mergedTypeMetadata.name).toBe(
      'MiddleCredentialType',
    );
    expect(resolvedTypeMetadata?.mergedTypeMetadata.description).toBe(
      'Middle type in chain',
    );

    // Check typeMetadataChain - should have 3 documents in chain
    expect(resolvedTypeMetadata?.typeMetadataChain).toHaveLength(3);
    expect(resolvedTypeMetadata?.typeMetadataChain[0].vct).toBe(
      'http://example.com/middle',
    );
    expect(resolvedTypeMetadata?.typeMetadataChain[1].vct).toBe(
      'http://example.com/extending',
    );
    expect(resolvedTypeMetadata?.typeMetadataChain[2].vct).toBe(
      'http://example.com/base',
    );

    // Check vctValues - should have 3 values
    expect(resolvedTypeMetadata?.vctValues).toHaveLength(3);
    expect(resolvedTypeMetadata?.vctValues[0]).toBe(
      'http://example.com/middle',
    );
    expect(resolvedTypeMetadata?.vctValues[1]).toBe(
      'http://example.com/extending',
    );
    expect(resolvedTypeMetadata?.vctValues[2]).toBe('http://example.com/base');
  });

  test('VCT with circular dependency should throw error', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/circular',
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    await expect(sdjwt.getVct(encodedSdjwt)).rejects.toThrowError(
      'Circular dependency detected in VCT extends chain: http://example.com/circular',
    );
  });

  test('VCT with max depth exceeded should throw error', async () => {
    const sdjwtWithShallowDepth = new SDJwtVcInstance({
      signer,
      signAlg: 'EdDSA',
      verifier,
      hasher: digest,
      hashAlg: 'sha-256',
      saltGenerator: generateSalt,
      loadTypeMetadataFormat: true,
      timeout: 1000,
      maxVctExtendsDepth: 1, // Only allow 1 level of extends
    });

    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/middle', // This has 2 levels of extends
      ...claims,
    };

    const encodedSdjwt = await sdjwtWithShallowDepth.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    await expect(
      sdjwtWithShallowDepth.getVct(encodedSdjwt),
    ).rejects.toThrowError('Maximum VCT extends depth of 1 exceeded');
  });

  test('VCT extends chain should work in verify method', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/extending',
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    // Should not throw and should resolve the extends chain
    const result = await sdjwt.verify(encodedSdjwt);
    expect(result.payload.vct).toBe('http://example.com/extending');

    // Check that typeMetadata was populated with resolved chain
    expect(result.typeMetadata?.mergedTypeMetadata.claims).toHaveLength(2);
    expect(result.typeMetadata?.typeMetadataChain).toHaveLength(2);
    expect(result.typeMetadata?.vctValues).toHaveLength(2);
  });

  test('VCT with overriding claim metadata', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/overriding',
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    const resolvedTypeMetadata = await sdjwt.getVct(encodedSdjwt);

    // Check mergedTypeMetadata - should have 2 claims: overridden firstName and new middleName
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims).toHaveLength(2);

    // First claim should be the overridden firstName with new label and sd property
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[0].path).toEqual([
      'firstName',
    ]);
    expect(
      resolvedTypeMetadata?.mergedTypeMetadata.claims?.[0].display?.[0].label,
    ).toBe('Given Name');
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[0].sd).toBe(
      'always',
    );

    // Second claim should be the new middleName
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[1].path).toEqual([
      'middleName',
    ]);
    expect(
      resolvedTypeMetadata?.mergedTypeMetadata.claims?.[1].display?.[0].label,
    ).toBe('Middle Name');

    // Check typeMetadataChain - should have 2 documents
    expect(resolvedTypeMetadata?.typeMetadataChain).toHaveLength(2);
    expect(resolvedTypeMetadata?.typeMetadataChain[0].vct).toBe(
      'http://example.com/overriding',
    );
    expect(resolvedTypeMetadata?.typeMetadataChain[1].vct).toBe(
      'http://example.com/base',
    );

    // Check vctValues
    expect(resolvedTypeMetadata?.vctValues).toHaveLength(2);
    expect(resolvedTypeMetadata?.vctValues[0]).toBe(
      'http://example.com/overriding',
    );
    expect(resolvedTypeMetadata?.vctValues[1]).toBe('http://example.com/base');
  });

  test('VCT with valid sd property change (allowed to always)', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/valid-sd-change',
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    const resolvedTypeMetadata = await sdjwt.getVct(encodedSdjwt);

    // Check mergedTypeMetadata - should successfully merge - changing from undefined/allowed to always is valid
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims).toHaveLength(1);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[0].path).toEqual([
      'firstName',
    ]);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.claims?.[0].sd).toBe(
      'always',
    );

    // Check typeMetadataChain
    expect(resolvedTypeMetadata?.typeMetadataChain).toHaveLength(2);
    expect(resolvedTypeMetadata?.vctValues).toHaveLength(2);
  });

  test('VCT with invalid sd property change (always to never) should throw error', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/invalid-sd-change',
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    await expect(sdjwt.getVct(encodedSdjwt)).rejects.toThrowError(
      "Cannot change 'sd' property from 'always' to 'never' for claim at path [\"sensitiveData\"]",
    );
  });

  test('VCT extending type without display should inherit base display', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/middle', // middle doesn't define display
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    const resolvedTypeMetadata = await sdjwt.getVct(encodedSdjwt);

    // Check mergedTypeMetadata - since middle doesn't define display, it should inherit from extending which has display
    expect(resolvedTypeMetadata?.mergedTypeMetadata.display).toHaveLength(2);
    expect(resolvedTypeMetadata?.mergedTypeMetadata.display?.[0].locale).toBe(
      'en',
    );
    expect(resolvedTypeMetadata?.mergedTypeMetadata.display?.[1].locale).toBe(
      'de',
    );

    // Check typeMetadataChain - should have 3 documents
    expect(resolvedTypeMetadata?.typeMetadataChain).toHaveLength(3);
    expect(resolvedTypeMetadata?.vctValues).toHaveLength(3);
  });

  test('VCT with custom properties are kept', async () => {
    const expectedPayload: SdJwtVcPayload = {
      iat,
      iss,
      vct: 'http://example.com/custom-properties',
      ...claims,
    };

    const encodedSdjwt = await sdjwt.issue(
      expectedPayload,
      disclosureFrame as unknown as DisclosureFrame<SdJwtVcPayload>,
    );

    const resolvedTypeMetadata = await sdjwt.getVct(encodedSdjwt);

    expect(resolvedTypeMetadata?.mergedTypeMetadata).toEqual(
      vctWithCustomProperties,
    );
  });
});