import { describe, it, expect, vi, beforeEach, afterEach, beforeAll, afterAll } from "vitest";
import * as fs from "fs";
import * as os from "os";
import * as path from "path";

/**
 * Unit tests for DIS-153: model selection per agent.
 *
 * cross-spawn is mocked so no real process is launched.
 * Each test inspects the args passed to spawn to verify --model is set correctly.
 */

// ---------------------------------------------------------------------------
// Spy on the args cross-spawn receives
// ---------------------------------------------------------------------------
let capturedArgs: string[] = [];

vi.mock("cross-spawn", () => {
  function makeMockChild(args: string[]) {
    capturedArgs = args;

    const stdoutListeners: Record<string, Array<(...a: unknown[]) => void>> = {};

    const stdoutStream = {
      setEncoding: () => {},
      on: (event: string, cb: (...a: unknown[]) => void) => {
        if (!stdoutListeners[event]) stdoutListeners[event] = [];
        stdoutListeners[event].push(cb);

        if (event === "data") {
          Promise.resolve().then(() => {
            for (const handler of stdoutListeners["data"] ?? []) {
              handler(JSON.stringify({ result: "ok" }));
            }
          });
        }
      },
    };

    const listeners: Record<string, Array<(...a: unknown[]) => void>> = {};
    const emit = (event: string, ...a: unknown[]) => {
      for (const cb of listeners[event] ?? []) cb(...a);
    };

    const child = {
      stdout: stdoutStream,
      stderr: { setEncoding: () => {}, on: () => {} },
      stdin: { end: () => {} },
      on: (event: string, cb: (...a: unknown[]) => void) => {
        if (!listeners[event]) listeners[event] = [];
        listeners[event].push(cb);

        if (event === "close") {
          Promise.resolve()
            .then(() => Promise.resolve())
            .then(() => emit("close", 0));
        }
      },
      kill: () => {},
    };

    return child;
  }

  return {
    default: (_cmd: string, args: string[]) => makeMockChild(args),
  };
});

import { runAgent, _resetSemaphore } from "../../src/agent/runner";
import { _resetResolveClaudeCache } from "../../src/runtime/resolve-claude";
import { AgentYamlSchema } from "../../src/agent/schema";

// ---------------------------------------------------------------------------
// Shared workspace fixture
// ---------------------------------------------------------------------------

describe("runner model selection (DIS-153)", () => {
  let workspaceDir: string;
  const originalEnv = { ...process.env };

  beforeAll(() => {
    workspaceDir = fs.mkdtempSync(path.join(os.tmpdir(), "disclaw-model-test-"));
    fs.writeFileSync(
      path.join(workspaceDir, "CLAUDE.md"),
      "# Model Test Agent\nYou are a test agent.\n",
      "utf-8"
    );
  });

  beforeEach(() => {
    capturedArgs = [];
    _resetResolveClaudeCache();
    _resetSemaphore(4);
    process.env.CLAUDE_PATH = "/fake/claude";
  });

  afterEach(() => {
    process.env = { ...originalEnv };
    _resetResolveClaudeCache();
  });

  afterAll(() => {
    try {
      fs.rmSync(workspaceDir, { recursive: true, force: true });
    } catch {
      // best-effort cleanup
    }
  });

  // -------------------------------------------------------------------------
  // Test 1: --model is passed when model is set in agent.yaml
  // -------------------------------------------------------------------------
  it("passes --model claude-sonnet-4-6 when model is set in agent.yaml", async () => {
    fs.writeFileSync(
      path.join(workspaceDir, "agent.yaml"),
      `name: model-agent\ndisplay_name: Model Agent\nrole: Testing\nchannel_id: "111"\nmodel: claude-sonnet-4-6\n`,
      "utf-8"
    );

    await runAgent({
      workspacePath: workspaceDir,
      channelName: "test",
      userMessage: "hello",
      conversationHistory: [],
    });

    const modelIdx = capturedArgs.indexOf("--model");
    expect(modelIdx).toBeGreaterThan(-1);
    expect(capturedArgs[modelIdx + 1]).toBe("claude-sonnet-4-6");
  });

  // -------------------------------------------------------------------------
  // Test 2: Default model is used when model field is absent from agent.yaml
  // -------------------------------------------------------------------------
  it("passes default model when model field is absent from agent.yaml", async () => {
    fs.writeFileSync(
      path.join(workspaceDir, "agent.yaml"),
      `name: model-agent\ndisplay_name: Model Agent\nrole: Testing\nchannel_id: "222"\n`,
      "utf-8"
    );

    await runAgent({
      workspacePath: workspaceDir,
      channelName: "test",
      userMessage: "hello",
      conversationHistory: [],
    });

    const modelIdx = capturedArgs.indexOf("--model");
    expect(modelIdx).toBeGreaterThan(-1);
    // DEFAULT_MODEL is claude-sonnet-4-6
    expect(capturedArgs[modelIdx + 1]).toBe("claude-sonnet-4-6");
  });

  // -------------------------------------------------------------------------
  // Test 3: Invalid model in agent.yaml → Zod validation throws
  // -------------------------------------------------------------------------
  it("throws when agent.yaml contains an invalid model value", () => {
    const rawYaml = `name: bad-model-agent\ndisplay_name: Bad\nrole: Testing\nchannel_id: "333"\nmodel: gpt-4-turbo\n`;
    const parsed = { name: "bad-model-agent", display_name: "Bad", role: "Testing", channel_id: "333", model: "gpt-4-turbo" };

    expect(() => AgentYamlSchema.parse(parsed)).toThrow();
  });
});