const Graph = require('../src/graph');

describe('Graph', () => {
  test('should add reflection node and evaluate correctly', () => {
    const g = new Graph();
    g.addNode('A', 'reflection');
    const outputs = g.evaluate('A', 42);
    expect(outputs['A']).toBe(42);
  });

  test('should add rewrite node and evaluate correctly', () => {
    const g = new Graph();
    g.addNode('B', 'rewrite');
    const outputs = g.evaluate('B', 'hello');
    expect(outputs['B']).toBe('HELLO');
  });

  test('should propagate through connected nodes', () => {
    const g = new Graph();
    g.addNode('A', 'reflection');
    g.addNode('B', 'rewrite');
    g.addEdge('A', 'B');
    const outputs = g.evaluate('A', 'test');
    expect(outputs['A']).toBe('test');
    expect(outputs['B']).toBe('TEST');
  });

  test('should throw error on unknown node type', () => {
    const g = new Graph();
    expect(() => g.addNode('C', 'unknown')).toThrow();
  });

  test('should throw error on duplicate node name', () => {
    const g = new Graph();
    g.addNode('D', 'reflection');
    expect(() => g.addNode('D', 'rewrite')).toThrow();
  });

  test('should throw error on edge to non-existent node', () => {
    const g = new Graph();
    g.addNode('E', 'reflection');
    expect(() => g.addEdge('E', 'F')).toThrow();
  });

  test('should support custom transform function', () => {
    const g = new Graph();
    g.addNode('G', 'rewrite', { transform: (x) => x * 2 });
    const outputs = g.evaluate('G', 5);
    expect(outputs['G']).toBe(10);
  });

  test('should handle multiple outputs', () => {
    const g = new Graph();
    g.addNode('A', 'reflection');
    g.addNode('B', 'rewrite');
    g.addNode('C', 'rewrite');
    g.addEdge('A', 'B');
    g.addEdge('A', 'C');
    const outputs = g.evaluate('A', 'multi');
    expect(outputs['A']).toBe('multi');
    expect(outputs['B']).toBe('MULTI');
    expect(outputs['C']).toBe('MULTI');
  });
});