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, { __testing_helpers } from "./tools/multi-model";

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 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$();
    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-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.");
    expect(executedCommands).toEqual([]);
  });

  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.");
    expect(executedCommands).toEqual([]);
  });

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

    expect(result).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 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`.");
    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 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`.");
    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 multiModelTool.execute(
      { sessionName: "test-session", models: ["invalid/model"] },
      { metadata: mock() } as any
    );

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

    expect(result).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 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");
    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-4o"))).toBe(true);
    expect(executedCommands.some(c => c.startsWith("tmux send-keys -t test-session:gpt-4o"))).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 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");
    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-4o"))).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-4o"] = { 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");
    expect(executedCommands.some(c => c.startsWith("git worktree add -b opencode/test-session/gpt-4o"))).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-4o -c /mock/home/.local/share/opencode/multi-model/test-session/gpt-4o"] = { ok: false, stdout: "", stderr: "tmux error" };
    mockCommandResponses["git worktree remove -f /mock/home/.local/share/opencode/multi-model/test-session/gpt-4o"] = { ok: true, stdout: "", stderr: "" };
    mockCommandResponses["git branch -D opencode/test-session/gpt-4o"] = { ok: true, stdout: "", stderr: "" };

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

    expect(result).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-4o",
      "git worktree add -b opencode/test-session/gpt-4o /mock/home/.local/share/opencode/multi-model/test-session/gpt-4o",
      "tmux new-session -d -s test-session -n gpt-4o -c /mock/home/.local/share/opencode/multi-model/test-session/gpt-4o",
      "git worktree remove -f /mock/home/.local/share/opencode/multi-model/test-session/gpt-4o",
      "git branch -D opencode/test-session/gpt-4o"
    ]);
  });

  test("fails if worktree path exists for first model", async () => {
    existsSyncMock.mockImplementation((path: string) => {
      return path.includes("test-session/gpt-4o");
    });

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

    expect(result).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-4o"] = { ok: true, stdout: "", stderr: "" };

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

    expect(result).toContain("Branch 'opencode/test-session/gpt-4o' 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-4o"
    ]);
  });

  test("fails if git worktree add fails for first model", async () => {
    mockCommandResponses["git worktree add -b opencode/test-session/gpt-4o /mock/home/.local/share/opencode/multi-model/test-session/gpt-4o"] = { ok: false, stdout: "", stderr: "git error" };

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

    expect(result).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-4o",
      "git worktree add -b opencode/test-session/gpt-4o /mock/home/.local/share/opencode/multi-model/test-session/gpt-4o"
    ]);
  });

  test("model name collision creates unique window names", async () => {
    mockCommandResponses["opencode models"] = { ok: true, stdout: "openai/gpt-4o\nanthropic/gpt-4o", stderr: "" };
    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-4o"] = { ok: false, stdout: "", stderr: "" };
    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-4o-2"] = { ok: false, stdout: "", stderr: "" };

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

    expect(result).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-4o"))).toBe(true);
    expect(executedCommands.some(c => c.startsWith("tmux new-window -d -t test-session -n gpt-4o-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 multiModelTool.execute(
      { sessionName: "test-session", models: [longModel] },
      { metadata: mock() } as any
    );

    expect(result).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);
  });
});

describe("__testing_helpers", () => {
  describe("shellQuote", () => {
    test("normal string without special characters", () => {
      expect(__testing_helpers.shellQuote("test")).toBe("'test'");
    });

    test("string with spaces", () => {
      expect(__testing_helpers.shellQuote("test value")).toBe("'test value'");
    });

    test("string with single quotes", () => {
      expect(__testing_helpers.shellQuote("test'value")).toBe("'test'\"'\"'value'");
    });

    test("string with multiple single quotes", () => {
      expect(__testing_helpers.shellQuote("te's't'v'alue")).toBe("'te'\"'\"'s'\"'\"'t'\"'\"'v'\"'\"'alue'");
    });

    test("empty string", () => {
      expect(__testing_helpers.shellQuote("")).toBe("''");
    });
  });

  describe("normalizeModels", () => {
    test("empty array", () => {
      expect(__testing_helpers.normalizeModels([])).toEqual([]);
    });

    test("undefined input", () => {
      expect(__testing_helpers.normalizeModels(undefined)).toEqual([]);
    });

    test("array with whitespace-only strings", () => {
      expect(__testing_helpers.normalizeModels(["   ", "  "])).toEqual([]);
    });

    test("array with mixed valid models, padded models, and empty strings", () => {
      expect(__testing_helpers.normalizeModels([" openai/gpt-4o ", "", " anthropic/claude "])).toEqual(["openai/gpt-4o", "anthropic/claude"]);
    });
  });

  describe("findDuplicates", () => {
    test("array with no duplicates", () => {
      expect(__testing_helpers.findDuplicates(["a", "b", "c"])).toEqual([]);
    });

    test("array with one duplicate pair", () => {
      expect(__testing_helpers.findDuplicates(["a", "b", "a"])).toEqual(["a"]);
    });

    test("array with multiple different duplicates", () => {
      expect(__testing_helpers.findDuplicates(["a", "b", "a", "c", "b"])).toEqual(["a", "b"]);
    });

    test("array with a single value repeated more than twice", () => {
      expect(__testing_helpers.findDuplicates(["a", "a", "a"])).toEqual(["a"]);
    });

    test("verifying first-repeated-occurrence order", () => {
      expect(__testing_helpers.findDuplicates(["x", "a", "b", "a", "x", "b"])).toEqual(["a", "x", "b"]);
    });
  });

  describe("createWindowBaseName", () => {
    test("normal model name without slashes", () => {
      expect(__testing_helpers.createWindowBaseName("gpt-4o")).toBe("gpt-4o");
    });

    test("model with slashes", () => {
      expect(__testing_helpers.createWindowBaseName("vendor/namespace/model")).toBe("model");
    });

    test("model exceeding WINDOW_NAME_LIMIT", () => {
      const longName = "a".repeat(30);
      expect(__testing_helpers.createWindowBaseName(longName)).toBe("aaaaaaaaaaaaaaaaaaaaaaaa");
    });

    test("model with special characters", () => {
      expect(__testing_helpers.createWindowBaseName("OpenAI/GPT_4.0!")).toBe("gpt-4-0");
    });

    test("model made entirely of special characters", () => {
      expect(__testing_helpers.createWindowBaseName("!@#$%^&*()")).toBe("model");
    });
  });

  describe("createWindowPlans", () => {
    test("single model", () => {
      expect(__testing_helpers.createWindowPlans(["openai/gpt-4o"])).toEqual([{ model: "openai/gpt-4o", windowName: "gpt-4o" }]);
    });

    test("two models with the same base name", () => {
      expect(__testing_helpers.createWindowPlans(["openai/gpt-4o", "anthropic/gpt-4o"])).toEqual([
        { model: "openai/gpt-4o", windowName: "gpt-4o" },
        { model: "anthropic/gpt-4o", windowName: "gpt-4o-2" }
      ]);
    });

    test("multiple collisions", () => {
      const result = __testing_helpers.createWindowPlans(["a", "b", "c", "a", "b", "a"]);
      expect(result[0]?.windowName).toBe("a");
      expect(result[3]?.windowName).toBe("a-2");
      expect(result[5]?.windowName).toBe("a-3");
    });

    test("truncation to accommodate suffix", () => {
      const longBase = "a".repeat(23);
      const result = __testing_helpers.createWindowPlans([longBase, "b"]);
      expect(result[1]?.windowName.length).toBeLessThanOrEqual(24);
    });
  });

  describe("levenshtein", () => {
    test("identical strings", () => {
      expect(__testing_helpers.levenshtein("test", "test")).toBe(0);
    });

    test("one substitution", () => {
      expect(__testing_helpers.levenshtein("test", "tent")).toBe(1);
    });

    test("one insertion", () => {
      expect(__testing_helpers.levenshtein("test", "tests")).toBe(1);
    });

    test("one deletion", () => {
      expect(__testing_helpers.levenshtein("tests", "test")).toBe(1);
    });

    test("completely different strings", () => {
      expect(__testing_helpers.levenshtein("abc", "xyz")).toBe(3);
    });

    test("one empty string", () => {
      expect(__testing_helpers.levenshtein("", "test")).toBe(4);
    });

    test("both empty strings", () => {
      expect(__testing_helpers.levenshtein("", "")).toBe(0);
    });
  });

  describe("suggestModels", () => {
    test("exact match", () => {
      const result = __testing_helpers.suggestModels("gpt-4o", ["gpt-4o", "gpt-4o-mini"]);
      expect(result[0]).toBe("gpt-4o");
    });

    test("fuzzy match/typo", () => {
      expect(__testing_helpers.suggestModels("gpt5.4", ["gpt-5.4"])).toEqual(["gpt-5.4"]);
    });

    test("fuzzy match with contains boost", () => {
      const suggestions = __testing_helpers.suggestModels("gpt4o", ["gpt-4o", "gpt-4o-mini"]);
      expect(suggestions[0]).toBe("gpt-4o");
    });

    test("maximum of 3 suggestions", () => {
      const allowlist = ["gpt-4o", "gpt-4o-mini", "gpt-4o-pro", "gpt-4o-ultra"];
      expect(__testing_helpers.suggestModels("gpt4o", allowlist).length).toBe(3);
    });

    test("sorting logic", () => {
      const suggestions = __testing_helpers.suggestModels("abc", ["abc", "abd", "abe"]);
      expect(suggestions).toEqual(["abc", "abd", "abe"]);
    });
  });

  describe("formatInvalidModelError", () => {
    test("single invalid model with available suggestions", () => {
      const error = __testing_helpers.formatInvalidModelError(["gpt5.4"], ["gpt-5.4", "gpt-4o"]);
      expect(error).toContain("Model name 'gpt5.4' not found");
      expect(error).toContain("Did you mean");
    });

    test("single invalid model without close matches", () => {
      const error = __testing_helpers.formatInvalidModelError(["xyz"], ["abc", "def"]);
      expect(error).toContain("Model name 'xyz' not found");
      expect(error).toContain("Did you mean");
    });

    test("multiple invalid models", () => {
      const error = __testing_helpers.formatInvalidModelError(["xyz", "abc"], ["def"]);
      expect(error).toContain("Model names not found");
      expect(error).toContain("'xyz'");
      expect(error).toContain("'abc'");
    });
  });

  describe("sanitizeName", () => {
    test("normal alphanumeric name", () => {
      expect(__testing_helpers.sanitizeName("test-session")).toBe("test-session");
    });

    test("name with spaces and special chars", () => {
      expect(__testing_helpers.sanitizeName("test session!")).toBe("test-session");
    });

    test("name with consecutive hyphens", () => {
      expect(__testing_helpers.sanitizeName("test--session")).toBe("test-session");
    });

    test("name with leading/trailing hyphens", () => {
      expect(__testing_helpers.sanitizeName("-test-session-")).toBe("test-session");
    });
  });
});