import { afterEach, beforeEach, describe, expect, it } from 'vitest';

import { IdentityDB } from '../src/core/identity-db';
import type { FactExtractor } from '../src/ingestion/types';
import type { EmbeddingProvider } from '../src/types/api';

class FakeEmbeddingProvider implements EmbeddingProvider {
  model = 'fake-semantic-v1';
  dimensions = 3;

  async embed(input: string): Promise<number[]> {
    return embeddingFor(input);
  }

  async embedMany(inputs: string[]): Promise<number[][]> {
    return Promise.all(inputs.map((input) => this.embed(input)));
  }
}

function embeddingFor(input: string): number[] {
  const normalized = input.toLowerCase();

  if (normalized.includes('bun') && normalized.includes('typescript')) {
    return [1, 0, 0];
  }

  if (normalized.includes('tooling') || normalized.includes('runtime')) {
    return [0.98, 0.02, 0];
  }

  if (normalized.includes('typescript')) {
    return [0.9, 0.1, 0];
  }

  if (normalized.includes('python')) {
    return [0, 1, 0];
  }

  if (normalized.includes('database')) {
    return [0, 0.2, 0.8];
  }

  return [0.1, 0.1, 0.1];
}

describe('IdentityDB semantic search', () => {
  let db: IdentityDB;
  let provider: FakeEmbeddingProvider;

  beforeEach(async () => {
    provider = new FakeEmbeddingProvider();
    db = await IdentityDB.connect({ client: 'sqlite', filename: ':memory:' });
    await db.initialize();

    await db.addFact({
      statement: 'Bun runs TypeScript tooling quickly.',
      topics: [
        { name: 'Bun', category: 'entity', granularity: 'concrete' },
        { name: 'TypeScript', category: 'entity', granularity: 'concrete' },
      ],
    });

    await db.addFact({
      statement: 'TypeScript compiles to JavaScript.',
      topics: [
        { name: 'TypeScript', category: 'entity', granularity: 'concrete' },
        { name: 'JavaScript', category: 'entity', granularity: 'concrete' },
      ],
    });

    await db.addFact({
      statement: 'Python uses indentation syntax.',
      topics: [
        { name: 'Python', category: 'entity', granularity: 'concrete' },
      ],
    });
  });

  afterEach(async () => {
    await db.close();
  });

  it('indexes facts and returns semantic search matches ordered by score', async () => {
    await db.indexFactEmbeddings({ provider });

    const matches = await db.searchFacts({
      query: 'TypeScript runtime tooling',
      provider,
      limit: 2,
    });

    expect(matches).toHaveLength(2);
    expect(matches[0]?.statement).toBe('Bun runs TypeScript tooling quickly.');
    expect(matches[1]?.statement).toBe('TypeScript compiles to JavaScript.');
    expect(matches[0]!.score).toBeGreaterThan(matches[1]!.score);
  });

  it('filters semantic search candidates by topic names', async () => {
    await db.indexFactEmbeddings({ provider });

    const matches = await db.searchFacts({
      query: 'TypeScript runtime tooling',
      provider,
      topicNames: ['Python'],
      limit: 5,
    });

    expect(matches.map((match) => match.statement)).toEqual(['Python uses indentation syntax.']);
  });

  it('finds similar facts from an input statement', async () => {
    await db.indexFactEmbeddings({ provider });

    const matches = await db.findSimilarFacts({
      statement: 'Bun makes TypeScript tooling fast.',
      provider,
      limit: 2,
    });

    expect(matches[0]?.statement).toBe('Bun runs TypeScript tooling quickly.');
    expect(matches[0]!.score).toBeGreaterThan(matches[1]!.score);
  });
});

describe('IdentityDB dedup-aware ingestion', () => {
  let db: IdentityDB;
  let provider: FakeEmbeddingProvider;
  let extractor: FactExtractor;

  beforeEach(async () => {
    provider = new FakeEmbeddingProvider();
    extractor = {
      async extract(input) {
        return {
          statement: input,
          topics: [
            { name: 'Bun', category: 'entity', granularity: 'concrete' },
            { name: 'TypeScript', category: 'entity', granularity: 'concrete' },
          ],
        };
      },
    };

    db = await IdentityDB.connect({ client: 'sqlite', filename: ':memory:' });
    await db.initialize();
  });

  afterEach(async () => {
    await db.close();
  });

  it('returns the existing fact when ingestion detects a semantic duplicate', async () => {
    const first = await db.ingestStatement('Bun runs TypeScript tooling quickly.', {
      extractor,
      embeddingProvider: provider,
    });

    const second = await db.ingestStatement('Bun makes TypeScript tooling fast.', {
      extractor,
      embeddingProvider: provider,
      duplicateThreshold: 0.95,
    });

    const facts = await db.getTopicFacts('TypeScript');

    expect(second.id).toBe(first.id);
    expect(facts).toHaveLength(1);
    expect(facts[0]?.statement).toBe('Bun runs TypeScript tooling quickly.');
  });
});