import { expect, test, mock, spyOn, beforeEach, afterEach, describe } from "bun:test";
import * as fs from "node:fs";
import * as os from "node:os";
import { openMultiModel } from "../src/core/open";
import {
  shellQuote,
  normalizeModels,
  findDuplicates,
  createWindowBaseName,
  createWindowPlans,
  levenshtein,
  suggestModels,
  formatInvalidModelError,
  sanitizeName,
  runCommand,
  getWorktreePath,
  getSessionPath,
  undoWorktree,
  launchModelInWindow,
  getWorktreesForSession,
  getBinaryName,
} from "../src/core/utils";

let originalBun$: typeof Bun.$ = (globalThis as any).Bun?.$;
let mockCommandResponses: Record<string, { ok: boolean; stdout: string; stderr: string }> = {};
let executedCommands: string[] = [];

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

    executedCommands.push(commandSignature);

    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 launch", () => {
  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$();
    executedCommands = [];

    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-5.2\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-5-2": { ok: false, stdout: "", stderr: "" },
    };
  });

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

  test("fails if session name is empty", async () => {
    const result = await openMultiModel({
      sessionName: "",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Error: `sessionName` must not be empty.");
    expect(executedCommands).toEqual([]);
  });

  test("fails if no models are provided", async () => {
    const result = await openMultiModel({
      sessionName: "test-session",
      models: [],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Error: Model names must not be empty.");
    expect(executedCommands).toEqual([]);
  });

  test("fails if duplicate models are provided", async () => {
    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2", "openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Duplicate model names are not allowed");
    expect(executedCommands).toEqual([]);
  });

  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 openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Error: `multi-model` requires a git repository.");
    expect(executedCommands).toEqual(["git rev-parse --is-inside-work-tree"]);
  });

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

    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Error: `tmux` is not installed or not on `PATH`.");
    expect(executedCommands).toEqual([
      "git rev-parse --is-inside-work-tree",
      "command -v tmux",
    ]);
  });

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

    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Error: `opencode` is not installed or not on `PATH`.");
    expect(executedCommands).toEqual([
      "git rev-parse --is-inside-work-tree",
      "command -v tmux",
      "command -v opencode",
    ]);
  });

  test("fails if model name is not in allowlist", async () => {
    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["invalid/model"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Error: Model name 'invalid/model' not found");
    expect(executedCommands).toEqual([
      "git rev-parse --is-inside-work-tree",
      "command -v tmux",
      "command -v opencode",
      "opencode models",
    ]);
  });

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

    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Error: Session already exists");
    expect(executedCommands).toEqual([
      "git rev-parse --is-inside-work-tree",
      "command -v tmux",
      "command -v opencode",
      "opencode models",
      "tmux has-session -t test-session",
    ]);
  });

  test("successfully plans and executes tmux launch with single model", async () => {
    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(true);
    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
    expect(executedCommands.some(c => c.startsWith("tmux send-keys -t test-session:gpt-5-2"))).toBe(true);
  });

  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 openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2", "anthropic/claude-3-5-sonnet"],
    });

    expect(result.success).toBe(true);
    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
    expect(executedCommands.some(c => c.startsWith("tmux new-window -d -t test-session -n claude-3-5-sonnet"))).toBe(true);
  });

  test("sanitizes session name", async () => {
    mockCommandResponses["tmux has-session -t test session!"] = { ok: false, stdout: "", stderr: "" };
    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "" };

    const result = await openMultiModel({
      sessionName: "test session!",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(true);
    expect(result.instructions).toContain("Use `tmux attach -t test session!` to join session");
    expect(executedCommands.some(c => c.startsWith("git worktree add -b opencode/test-session/gpt-5-2"))).toBe(true);
  });

  test("fails if tmux new-session fails for the first model and triggers undo", async () => {
    mockCommandResponses["tmux new-session -d -s test-session -n gpt-5-2 -c /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "tmux error" };
    mockCommandResponses["git worktree remove -f /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };
    mockCommandResponses["git branch -D opencode/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };

    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Failed to create tmux session");
    expect(executedCommands).toEqual([
      "git rev-parse --is-inside-work-tree",
      "command -v tmux",
      "command -v opencode",
      "opencode models",
      "tmux has-session -t test-session",
      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2",
      "git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
      "tmux new-session -d -s test-session -n gpt-5-2 -c /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
      "git worktree remove -f /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
      "git branch -D opencode/test-session/gpt-5-2",
    ]);
  });

  test("fails if worktree path exists for first model", async () => {
    existsSyncMock.mockImplementation((path: string) => {
      return path.includes("test-session/gpt-5-2");
    });

    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Worktree path already exists");
    expect(executedCommands).toEqual([
      "git rev-parse --is-inside-work-tree",
      "command -v tmux",
      "command -v opencode",
      "opencode models",
      "tmux has-session -t test-session",
    ]);
  });

  test("fails if git branch exists for first model", async () => {
    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };

    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Branch 'opencode/test-session/gpt-5-2' already exists");
    expect(executedCommands).toEqual([
      "git rev-parse --is-inside-work-tree",
      "command -v tmux",
      "command -v opencode",
      "opencode models",
      "tmux has-session -t test-session",
      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2",
    ]);
  });

  test("fails if git worktree add fails for first model", async () => {
    mockCommandResponses["git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "git error" };

    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2"],
    });

    expect(result.success).toBe(false);
    expect(result.error).toContain("Failed to create worktree");
    expect(executedCommands).toEqual([
      "git rev-parse --is-inside-work-tree",
      "command -v tmux",
      "command -v opencode",
      "opencode models",
      "tmux has-session -t test-session",
      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2",
      "git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
    ]);
  });

  test("model name collision creates unique window names", async () => {
    mockCommandResponses["opencode models"] = { ok: true, stdout: "openai/gpt-5.2\nanthropic/gpt-5.2", stderr: "" };
    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "" };
    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2-2"] = { ok: false, stdout: "", stderr: "" };

    const result = await openMultiModel({
      sessionName: "test-session",
      models: ["openai/gpt-5.2", "anthropic/gpt-5.2"],
    });

    expect(result.success).toBe(true);
    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
    expect(executedCommands.some(c => c.startsWith("tmux new-window -d -t test-session -n gpt-5-2-2"))).toBe(true);
  });

  test("long model name is truncated in window name", async () => {
    const longModel = "verylongmodelfrontexampleprovider";
    mockCommandResponses["opencode models"] = { ok: true, stdout: longModel, stderr: "" };
    mockCommandResponses[`git show-ref --verify --quiet refs/heads/opencode/test-session/${longModel.slice(0, 24)}`] = { ok: false, stdout: "", stderr: "" };

    const result = await openMultiModel({
      sessionName: "test-session",
      models: [longModel],
    });

    expect(result.success).toBe(true);
    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
    const windowName = executedCommands.find(c => c.includes("tmux new-session"))?.match(/-n (\S+)/)?.[1];
    expect(windowName?.length).toBeLessThanOrEqual(24);
  });
});

// ----------
// Core utils tests remain in a separate file.