import { describe, it } from "vitest";
import fc from "fast-check";
import { GeminiBackend } from "../../src/backends/gemini-backend.js";
import type { BackendAdapterConfig } from "../../src/backends/types.js";

// Feature: multi-cli-backend, Property 3: Gemini backend required flags
// **Validates: Requirements 4.2, 4.3, 4.4**

/**
 * Arbitrary for non-empty strings that won't break CLI arg parsing.
 */
const nonEmptyString = fc.string({ minLength: 1, maxLength: 200 });

function createBackend(): GeminiBackend {
  const config: BackendAdapterConfig = {
    cliPath: "gemini",
    workingDir: "/workspace",
    queryTimeoutMs: 60000,
    allowedTools: [],
    maxTurns: 25,
  };
  return new GeminiBackend(config);
}

describe("Property 3: Gemini backend required flags", () => {
  it("generated args always contain the prompt as a positional argument", () => {
    fc.assert(
      fc.property(
        nonEmptyString,
        (prompt) => {
          const backend = createBackend();
          const args = backend.buildArgs(prompt);

          // The prompt (or a string containing the prompt) must appear
          // as a positional arg (not preceded by a flag)
          return args.some((arg) => arg.includes(prompt));
        },
      ),
      { numRuns: 100 },
    );
  });

  it("generated args always contain --output-format json", () => {
    fc.assert(
      fc.property(
        nonEmptyString,
        (prompt) => {
          const backend = createBackend();
          const args = backend.buildArgs(prompt);

          const idx = args.indexOf("--output-format");
          return idx !== -1 && args[idx + 1] === "json";
        },
      ),
      { numRuns: 100 },
    );
  });

  it("generated args always contain --approval-mode yolo", () => {
    fc.assert(
      fc.property(
        nonEmptyString,
        (prompt) => {
          const backend = createBackend();
          const args = backend.buildArgs(prompt);

          const idx = args.indexOf("--approval-mode");
          return idx !== -1 && args[idx + 1] === "yolo";
        },
      ),
      { numRuns: 100 },
    );
  });
});