import { Agent } from '../sdk/agent';
import type { ExecutionOptions, RunOptions } from '../types';

type WithPrivates = {
	mergeWithDefaults: (
		options?: RunOptions & ExecutionOptions,
	) => (RunOptions & ExecutionOptions) | undefined;
};

describe('Agent.configuration()', () => {
	it('is chainable', () => {
		const agent = new Agent('test');
		expect(agent.configuration({ maxIterations: 5 })).toBe(agent);
	});

	it('returns undefined when no defaults and no per-call options are given', () => {
		const agent = new Agent('test');
		const result = (agent as unknown as WithPrivates).mergeWithDefaults();
		expect(result).toBeUndefined();
	});

	it('returns per-call options unchanged when no defaults are set', () => {
		const agent = new Agent('test');
		const options = { maxIterations: 10 };
		const result = (agent as unknown as WithPrivates).mergeWithDefaults(options);
		expect(result).toBe(options);
	});

	it('returns defaults when no per-call options are provided', () => {
		const agent = new Agent('test');
		agent.configuration({ maxIterations: 5 });
		const result = (agent as unknown as WithPrivates).mergeWithDefaults();
		expect(result).toEqual({ maxIterations: 5 });
	});

	it('per-call options override defaults', () => {
		const agent = new Agent('test');
		agent.configuration({ maxIterations: 5 });
		const result = (agent as unknown as WithPrivates).mergeWithDefaults({ maxIterations: 10 });
		expect(result?.maxIterations).toBe(10);
	});

	it('preserves default fields not present in the per-call options', () => {
		const controller = new AbortController();
		const agent = new Agent('test');
		agent.configuration({ maxIterations: 5, abortSignal: controller.signal });
		const result = (agent as unknown as WithPrivates).mergeWithDefaults({ maxIterations: 10 });
		expect(result?.maxIterations).toBe(10);
		expect(result?.abortSignal).toBe(controller.signal);
	});

	it('last call to configuration() replaces the previous defaults', () => {
		const agent = new Agent('test');
		agent.configuration({ maxIterations: 5 });
		agent.configuration({ maxIterations: 20 });
		const result = (agent as unknown as WithPrivates).mergeWithDefaults();
		expect(result?.maxIterations).toBe(20);
	});
});