import { expect, test, mock, spyOn, beforeEach, afterEach, describe } from "bun:test";
import * as fs from "node:fs";
import * as os from "node:os";
import multiModelTool from "./multi-model";

let originalBun$: typeof Bun.$;
let mockCommandResponses: Record<string, { ok: boolean; stdout: string; stderr: string }> = {};

function setupMockBun$() {
  const mockFn = mock((strings: TemplateStringsArray, ...values: any[]) => {
    const parts = values[0] as string[];
    const commandSignature = parts.join(" ");

    return {
      quiet: () => ({
        nothrow: async () => {
          const response = mockCommandResponses[commandSignature] ?? { ok: true, stdout: "", stderr: "" };
          return {
            exitCode: response.ok ? 0 : 1,
            stdout: { toString: () => response.stdout },
            stderr: { toString: () => response.stderr },
          };
        },
      }),
    };
  });

  (globalThis as any).Bun.$ = mockFn;
  return mockFn;
}

function restoreOriginalBun$() {
  (globalThis as any).Bun.$ = originalBun$;
}

describe("multi-model tool", () => {
  let existsSyncMock: ReturnType<typeof spyOn>;
  let bunMock: ReturnType<typeof setupMockBun$>;

  beforeEach(() => {
    spyOn(os, "homedir").mockReturnValue("/mock/home");
    existsSyncMock = spyOn(fs, "existsSync").mockReturnValue(false);
    bunMock = setupMockBun$();

    mockCommandResponses = {
      "git rev-parse --is-inside-work-tree": { ok: true, stdout: "true", stderr: "" },
      "command -v tmux": { ok: true, stdout: "/usr/bin/tmux", stderr: "" },
      "command -v opencode": { ok: true, stdout: "/usr/bin/opencode", stderr: "" },
      "opencode models": { ok: true, stdout: "openai/gpt-4o\nanthropic/claude-3-5-sonnet", stderr: "" },
      "tmux has-session -t test-session": { ok: false, stdout: "", stderr: "session not found" },
      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-4o": { ok: false, stdout: "", stderr: "" },
    };
  });

  afterEach(() => {
    restoreOriginalBun$();
  });

  test("fails if session name is empty", async () => {
    const result = await multiModelTool.execute(
      { sessionName: "", models: ["openai/gpt-4o"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Error: `sessionName` must not be empty.");
  });

  test("fails if no models are provided", async () => {
    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: [] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Error: Model names must not be empty.");
  });

  test("fails if duplicate models are provided", async () => {
    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: ["openai/gpt-4o", "openai/gpt-4o"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Duplicate model names are not allowed");
  });

  test("fails if not inside a git repository", async () => {
    mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: false, stdout: "", stderr: "not a git repo" };

    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: ["openai/gpt-4o"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Error: `multi-model` requires a git repository.");
  });

  test("fails if tmux is not installed", async () => {
    mockCommandResponses["command -v tmux"] = { ok: false, stdout: "", stderr: "" };

    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: ["openai/gpt-4o"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Error: `tmux` is not installed or not on `PATH`.");
  });

  test("fails if opencode is not installed", async () => {
    mockCommandResponses["command -v opencode"] = { ok: false, stdout: "", stderr: "" };

    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: ["openai/gpt-4o"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Error: `opencode` is not installed or not on `PATH`.");
  });

  test("fails if model name is not in allowlist", async () => {
    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: ["invalid/model"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Error: Model name 'invalid/model' not found");
  });

  test("fails if session already exists", async () => {
    mockCommandResponses["tmux has-session -t test-session"] = { ok: true, stdout: "", stderr: "" };

    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: ["openai/gpt-4o"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Error: Session already exists");
  });

  test("successfully plans and executes tmux launch with single model", async () => {
    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: ["openai/gpt-4o"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Use `tmux attach -t test-session` to join session");
  });

  test("successfully launches multiple models", async () => {
    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/claude-3-5-sonnet"] = { ok: false, stdout: "", stderr: "" };

    const result = await multiModelTool.execute(
      { sessionName: "test-session", models: ["openai/gpt-4o", "anthropic/claude-3-5-sonnet"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Use `tmux attach -t test-session` to join session");
  });

  test("sanitizes session name", async () => {
    mockCommandResponses["tmux has-session -t test session!"] = { ok: false, stdout: "", stderr: "" };

    const result = await multiModelTool.execute(
      { sessionName: "test session!", models: ["openai/gpt-4o"] },
      { metadata: mock() } as any
    );

    expect(result).toContain("Use `tmux attach -t test session!` to join session");
  });
});

describe("unit functions", () => {
  test("shellQuote escapes single quotes", () => {
    const value = "test'value";
    const quoted = "'" + value.replace(/'/g, `'"'"'`) + "'";
    expect(quoted).toBe("'test'\"'\"'value'");
  });

  test("normalizeModels trims and filters empty", () => {
    expect([" openai/gpt-4o ", ""].map(m => m.trim()).filter(Boolean)).toEqual(["openai/gpt-4o"]);
  });
});