import { describe, it, expect, vi } from "vitest";

// Module-level mock capture for buildDebugIssuePrompt integration testing.
const buildDebugIssuePromptCalls = [];

vi.mock("../../src/prompts/debug-issue.js", async () => ({
  buildDebugIssuePrompt: vi.fn((input) => {
    buildDebugIssuePromptCalls.push(input);
    return "mocked debug issue prompt";
  }),
}));

// Import after the mock is registered (hoisted by vitest).
const { handleDebugIssue } = await import("../../src/tools/debug-issue.js");

const mockConfig = {
  openaiApiKey: "sk-test-key",
  openaiModel: "gpt-5.1",
  temperature: 0.2,
  maxOutputTokens: 2000,
  logLevel: "info",
  enableFileContext: false,
  contextDir: "./context",
  maxInputChars: 30000,
  maxFileChars: 12000,
  maxFiles: 5,
  maxLogChars: 10000,
  redactSecrets: true,
};

function makeValidInput(question) {
  return { question };
}

// --- Success path ---

describe("success path", () => {
  it("returns ok:true with answer on full happy flow", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn(async () => ({ content: "OK" }));

    const result = await handleDebugIssue(makeValidInput("Debug my issue"), {
      loadConfig, createOpenAIClient, sendOpenAIResponse,
    });

    expect(result.ok).toBe(true);
    expect(result.answer).toBe("OK");
    expect(result.warnings).toEqual([]);
  });

  it("propagates budget warnings through to success result", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const trimmedBudget = { ...mockConfig, maxInputChars: 50 };
    const loadConfig = vi.fn(() => trimmedBudget);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn(async () => ({ content: "OK" }));

    const result = await handleDebugIssue(makeValidInput("hi"), {
      loadConfig, createOpenAIClient, sendOpenAIResponse,
    });

    expect(result.ok).toBe(true);
    expect(Array.isArray(result.warnings)).toBe(true);
  });
});

// --- Validation failure (short-circuit before config) ---

describe("validation failure", () => {
  it("returns structured error when question is missing", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn();
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue({}, { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(typeof result.error).toBe("string");
    expect(result.warnings).toEqual([]);
  });

  it("short-circuits — no other deps called", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn();
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    await handleDebugIssue({ foo: "bar" }, { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(loadConfig).not.toHaveBeenCalled();
    expect(createOpenAIClient).not.toHaveBeenCalled();
    expect(sendOpenAIResponse).not.toHaveBeenCalled();
  });

  it("returns structured error when question is empty string", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn();
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue({ question: "" }, { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(typeof result.error).toBe("string");
    expect(result.warnings).toEqual([]);
  });

  it("returns structured error when question is wrong type", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn();
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue({ question: 123 }, { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(typeof result.error).toBe("string");
    expect(result.warnings).toEqual([]);
  });
});

// --- Config failure ---

describe("config failure", () => {
  it("returns structured error when loadConfig throws", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => { throw new Error("OPENAI_API_KEY is missing."); });
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(result.error).toContain("OPENAI_API_KEY is missing");
  });

  it("short-circuits — no client or response calls after config failure", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => { throw new Error("No key."); });
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(createOpenAIClient).not.toHaveBeenCalled();
    expect(sendOpenAIResponse).not.toHaveBeenCalled();
  });

  it("passes original error message", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => { throw new Error("OPENAI_API_KEY is missing."); });
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.error).toBe("Error: OPENAI_API_KEY is missing.");
  });
});

// --- Budget failure (short-circuit before prompt/client) ---

describe("budget failure", () => {
  it("returns structured error with budget warnings when input exceeds budget", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const tinyBudget = { ...mockConfig, maxInputChars: 0 };
    const loadConfig = vi.fn(() => tinyBudget);
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(typeof result.error).toBe("string");
    expect(Array.isArray(result.warnings)).toBe(true);
  });

  it("short-circuits — no prompt built, no client created, no response sent", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const tinyBudget = { ...mockConfig, maxInputChars: 0 };
    const loadConfig = vi.fn(() => tinyBudget);
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(createOpenAIClient).not.toHaveBeenCalled();
    expect(sendOpenAIResponse).not.toHaveBeenCalled();
  });

  it("passes budget warnings through to the error result", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const tinyBudget = { ...mockConfig, maxInputChars: 0 };
    const loadConfig = vi.fn(() => tinyBudget);
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(
      { question: "x", context: "a".repeat(20) },
      { loadConfig, createOpenAIClient, sendOpenAIResponse },
    );

    expect(result.ok).toBe(false);
    expect(Array.isArray(result.warnings)).toBe(true);
  });
});

// --- Client creation failure ---

describe("client creation failure", () => {
  it("returns structured error when createOpenAIClient throws", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => { throw new Error("Invalid config."); });
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(typeof result.error).toBe("string");
    expect(result.warnings).toEqual([]);
  });

  it("short-circuits — no response sent after client failure", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => { throw new Error("Invalid config."); });
    const sendOpenAIResponse = vi.fn();

    await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(sendOpenAIResponse).not.toHaveBeenCalled();
  });

  it("passes original error message unchanged", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => { throw new Error("Invalid config."); });
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.error).toBe("Error: Invalid config.");
  });
});

// --- OpenAI failure (pass-through) ---

describe("OpenAI failure", () => {
  it("passes through err.message unchanged", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn().mockRejectedValue(new Error("API key invalid."));

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(result.error).toBe("Error: API key invalid.");
    expect(result.warnings).toEqual([]);
  });

  it("short-circuits — no extra processing after API failure", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn().mockRejectedValue(new Error("rate limit"));

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(result.error).toBe("Error: rate limit");
  });

  it("does not wrap or reformat the error", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn().mockRejectedValue(new Error("429 Too Many Requests"));

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.error).toBe("Error: 429 Too Many Requests");
  });
});

// --- Dependency call order ---

describe("dependency call order", () => {
  it("calls deps in correct order: config -> client -> response", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const callLog = [];
    const loadConfig = vi.fn(() => { callLog.push("config"); return mockConfig; });
    const createOpenAIClient = vi.fn(() => { callLog.push("client"); return { responses: { create: vi.fn() } }; });
    const sendOpenAIResponse = vi.fn(async () => { callLog.push("response"); return { content: "OK" }; });

    await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(callLog).toEqual(["config", "client", "response"]);
  });
});

// --- buildDebugIssuePrompt integration ---

describe("buildDebugIssuePrompt integration", () => {
  it("calls buildDebugIssuePrompt and receives budget.input as argument", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn(async () => ({ content: "OK" }));

    await handleDebugIssue(makeValidInput("test question"), {
      loadConfig, createOpenAIClient, sendOpenAIResponse,
    });

    // Verify buildDebugIssuePrompt was called (once) with the trimmed input from checkContextBudget.
    expect(buildDebugIssuePromptCalls.length).toBe(1);
    const captured = buildDebugIssuePromptCalls[0];
    expect(typeof captured).toBe("object");
    expect(captured.question).toBe("test question");
  });
});

// --- No throws escaping ---

describe("no throws escaping", () => {
  it("returns structured result when sendOpenAIResponse throws null", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn().mockRejectedValue(null);

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(typeof result.error).toBe("string");
  });

  it("returns structured result when loadConfig throws non-Error", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => { throw "string error"; });
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(typeof result.error).toBe("string");
  });
});

// --- Warning propagation ---

describe("warning propagation", () => {
  it("includes budget warnings in success result when budget passes with warnings", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const trimmedBudget = { ...mockConfig, maxInputChars: 50 };
    const loadConfig = vi.fn(() => trimmedBudget);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn(async () => ({ content: "OK" }));

    const result = await handleDebugIssue(
      { question: "hi", context: "x".repeat(49) },
      { loadConfig, createOpenAIClient, sendOpenAIResponse },
    );

    expect(result.ok).toBe(true);
    expect(Array.isArray(result.warnings)).toBe(true);
  });

  it("includes budget warnings in failure result when budget fails", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const emptyBudget = { ...mockConfig, maxInputChars: 0 };
    const loadConfig = vi.fn(() => emptyBudget);
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(result.ok).toBe(false);
    expect(Array.isArray(result.warnings)).toBe(true);
  });
});

// --- Result shape ---

describe("result shape", () => {
  it("returns exactly { ok, answer, warnings } on success", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn(async () => ({ content: "OK" }));

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(Object.keys(result).sort()).toEqual(["answer", "ok", "warnings"]);
    expect(result.ok).toBe(true);
    expect(typeof result.answer).toBe("string");
    expect(Array.isArray(result.warnings)).toBe(true);
  });

  it("returns exactly { ok, error, warnings } on failure", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => { throw new Error("fail"); });
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    const result = await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(Object.keys(result).sort()).toEqual(["error", "ok", "warnings"]);
    expect(result.ok).toBe(false);
    expect(typeof result.error).toBe("string");
    expect(Array.isArray(result.warnings)).toBe(true);
  });
});

// --- Short-circuit behavior ---

describe("short-circuit behavior", () => {
  it("stops at first failure without calling downstream deps", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => mockConfig);
    const createOpenAIClient = vi.fn(() => ({ responses: { create: vi.fn() } }));
    const sendOpenAIResponse = vi.fn().mockRejectedValue(new Error("boom"));

    await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(loadConfig).toHaveBeenCalledTimes(1);
    expect(createOpenAIClient).toHaveBeenCalledTimes(1);
    expect(sendOpenAIResponse).toHaveBeenCalledTimes(1);
  });

  it("stops at config failure without calling downstream deps", async () => {
    buildDebugIssuePromptCalls.length = 0;

    const loadConfig = vi.fn(() => { throw new Error("fail"); });
    const createOpenAIClient = vi.fn();
    const sendOpenAIResponse = vi.fn();

    await handleDebugIssue(makeValidInput("hi"), { loadConfig, createOpenAIClient, sendOpenAIResponse });
    expect(loadConfig).toHaveBeenCalledTimes(1);
    expect(createOpenAIClient).not.toHaveBeenCalled();
    expect(sendOpenAIResponse).not.toHaveBeenCalled();
  });
});