import { describe, it, expect, vi } from "vitest";
import { createChatProvider, openaiProvider } from "../../src/providers/factory.js";
import { manualExportProvider } from "../../src/providers/manual-export.js";

function mockConfig(provider) {
  const cfg = { chatgptMcpProvider: provider };
  return cfg;
}

// --- Default provider ---

describe("default provider", () => {
  it("returns openai provider when no provider specified", () => {
    const provider = createChatProvider({});
    expect(provider).toBe(openaiProvider);
  });

  it("returns openai provider when null config", () => {
    const provider = createChatProvider(null);
    expect(provider).toBe(openaiProvider);
  });

  it("returns openai provider when undefined config", () => {
    const provider = createChatProvider(undefined);
    expect(provider).toBe(openaiProvider);
  });

  it("returns openai provider when chatgptMcpProvider is empty string", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "" });
    expect(provider).toBe(openaiProvider);
  });

  it("returns openai provider explicitly set", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "openai" });
    expect(provider).toBe(openaiProvider);
  });
});

// --- Supported providers ---

describe("supported providers", () => {
  it("supports openai", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "openai" });
    expect(provider).toBe(openaiProvider);
  });

  it("returns the same instance for repeated calls with same provider", () => {
    const p1 = createChatProvider({ chatgptMcpProvider: "openai" });
    const p2 = createChatProvider({ chatgptMcpProvider: "openai" });
    expect(p1).toBe(p2);
  });
});

// --- Unsupported providers ---

describe("unsupported providers", () => {
  it("supports ollama provider", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "ollama" });
    expect(provider).toBeDefined();
    expect(typeof provider.send).toBe("function");
  });

  it("returns the same singleton instance for repeated calls with 'ollama'", () => {
    const p1 = createChatProvider({ chatgptMcpProvider: "ollama" });
    const p2 = createChatProvider({ chatgptMcpProvider: "ollama" });
    expect(p1).toBe(p2);
  });

  it("is different from openai provider", () => {
    const ollamaP = createChatProvider({ chatgptMcpProvider: "ollama" });
    expect(ollamaP).not.toBe(openaiProvider);
  });

  it("throws on unknown provider name", () => {
    expect(() => createChatProvider({ chatgptMcpProvider: "unknown" })).toThrow(
      /Unsupported chat provider "unknown"/,
    );
  });

  it("defaults to openai for null provider name", () => {
    const provider = createChatProvider({ chatgptMcpProvider: null });
    expect(provider.send).toBeDefined();
  });

  it("throws on numeric provider name (truthy but not supported)", () => {
    expect(() => createChatProvider({ chatgptMcpProvider: 123 })).toThrow('Unsupported chat provider "123"');
  });

  it("contains provider name in error message for unsupported providers", () => {
    try {
      createChatProvider({ chatgptMcpProvider: "ollama" });
    } catch (err) {
      expect(err.message).toContain("ollama");
    }
  });

  it("mentions provider name in error message", () => {
    try {
      createChatProvider({ chatgptMcpProvider: "bedrock" });
    } catch (err) {
      expect(err.message).toContain("bedrock");
    }
  });
});

// --- Provider interface ---

describe("provider interface", () => {
  it("returned provider has send method", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "openai" });
    expect(typeof provider.send).toBe("function");
  });

  it("send is a function, not undefined", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "openai" });
    expect(provider.send).not.toBeUndefined();
  });
});

// --- Exported openaiProvider ---

describe("exported openaiProvider", () => {
  it("openaiProvider is exported from factory", () => {
    expect(openaiProvider).toBeDefined();
  });

  it("openaiProvider has send method", () => {
    expect(typeof openaiProvider.send).toBe("function");
  });
});

// --- Edge cases ---

describe("edge cases", () => {
  it("handles case-sensitive provider name (Ollama != ollama)", () => {
    // This should also fail since only lowercase "openai" is supported
    expect(() => createChatProvider({ chatgptMcpProvider: "Ollama" })).toThrow();
  });

  it("handles whitespace provider name", () => {
    expect(() => createChatProvider({ chatgptMcpProvider: " openai " })).toThrow();
  });

  it("handles JSON string provider name", () => {
    expect(() => createChatProvider({ chatgptMcpProvider: '"openai"' })).toThrow();
  });

  it("creates provider even with minimal config object", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "openai" });
    expect(typeof provider.send).toBe("function");
  });

  it("works when config has extra unrelated fields", () => {
    const provider = createChatProvider({
      chatgptMcpProvider: "openai",
      openaiApiKey: "sk-test",
      someOtherField: "ignored",
    });
    expect(provider).toBe(openaiProvider);
  });

  it("does not mutate the config object", () => {
    const cfg = { chatgptMcpProvider: "openai" };
    createChatProvider(cfg);
    expect(cfg.chatgptMcpProvider).toBe("openai");
  });

  it("does not throw for all falsy values except explicit openai", () => {
    const falsyValues = [null, undefined, "", NaN];
    // Only empty string and no-provider should default to openai
    // null/undefined → config check passes (defaults to "openai")
    // "" → defaults to "openai"
  });

  it("defaults to openai for NaN provider name", () => {
    const provider = createChatProvider({ chatgptMcpProvider: NaN });
    expect(provider.send).toBeDefined();
  });
});

// --- Integration-like test ---

describe("integration: send delegation", () => {
  it("provider.send delegates to the underlying provider implementation", async () => {
    const provider = createChatProvider({ chatgptMcpProvider: "openai" });
    // The real openaiProvider.send calls OpenAI API — we just verify it exists and is callable
    expect(typeof provider.send).toBe("function");
    // We don't call it here to avoid actual API calls in tests
  });
});

// --- Repeatability ---

describe("repeatability", () => {
  it("creates identical providers for same config each time", () => {
    const results = [];
    for (let i = 0; i < 10; i++) {
      results.push(createChatProvider({ chatgptMcpProvider: "openai" }));
    }
    expect(results.every((p) => p === openaiProvider)).toBe(true);
  });

  it("does not share mutable state between calls", () => {
    const p1 = createChatProvider({ chatgptMcpProvider: "openai" });
    const p2 = createChatProvider({ chatgptMcpProvider: "openai" });
    // Both should be the same singleton instance (by design)
    expect(p1).toBe(p2);
  });
});

// --- Manual provider ---

describe("manual provider", () => {
  it("supports manual provider via createChatProvider", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "manual" });
    expect(provider.send).toBeDefined();
  });

  it("returns the same singleton instance for repeated calls with 'manual'", () => {
    const p1 = createChatProvider({ chatgptMcpProvider: "manual" });
    const p2 = createChatProvider({ chatgptMcpProvider: "manual" });
    expect(p1).toBe(p2);
  });

  it("is different from openai provider", () => {
    const manualP = createChatProvider({ chatgptMcpProvider: "manual" });
    expect(manualP).not.toBe(openaiProvider);
  });

  it("can detect manual as a supported provider (not throw)", () => {
    const provider = createChatProvider({ chatgptMcpProvider: "manual" });
    expect(provider.send).toBeDefined();
  });

  it("manual provider send returns { content: string } shape", async () => {
    const provider = createChatProvider({ chatgptMcpProvider: "manual" });
    const result = await provider.send(
      { prompt: "test prompt from manual env", input: { question: "hi" } },
      {},
    );
    expect(result).toHaveProperty("content");
    expect(typeof result.content).toBe("string");
  });

  it("manual provider output contains MANUAL EXPORT marker", async () => {
    const provider = createChatProvider({ chatgptMcpProvider: "manual" });
    const result = await provider.send({ prompt: "test", input: {} }, {});
    expect(result.content).toContain("MANUAL EXPORT");
  });

  it("manual provider output contains COPY box delimiters", async () => {
    const provider = createChatProvider({ chatgptMcpProvider: "manual" });
    const result = await provider.send({ prompt: "test", input: {} }, {});
    expect(result.content).toContain("┌");
    expect(result.content).toContain("┐");
    expect(result.content).toContain("┘");
  });

  it("can be switched from openai to manual and back", () => {
    const p1 = createChatProvider({ chatgptMcpProvider: "openai" });
    const p2 = createChatProvider({ chatgptMcpProvider: "manual" });
    const p3 = createChatProvider({ chatgptMcpProvider: "openai" });
    expect(p1).toBe(openaiProvider);
    expect(p2).not.toBe(openaiProvider);
    expect(p3).toBe(openaiProvider);
  });

  it("manual provider is not the same as openaiProvider singleton", () => {
    const manualP = createChatProvider({ chatgptMcpProvider: "manual" });
    expect(manualExportProvider).toBe(manualP);
  });
});

// --- Ollama provider send (fetch-mocked) ---

describe("ollama provider send", () => {
  it("builds correct request body with config values", async () => {
    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      json: async () => ({ model: "qwen3", message: { role: "assistant", content: "Hello!" }, done: true }),
    });

    // Create a custom ollamaProvider with mocked fetch
    const { ollamaProvider } = await import("../../src/providers/ollama.js");
    const originalFetch = globalThis.fetch;
    globalThis.fetch = fetchMock;
    try {
      const config = {
        chatgptMcpProvider: "ollama",
        ollamaBaseUrl: "http://test:11434",
        ollamaModel: "test-model",
        ollamaTemperature: 0.5,
        ollamaTimeout: 30,
      };
      const result = await ollamaProvider.send({ prompt: "What is AI?" }, config);
      expect(result.content).toBe("Hello!");
      const calls = fetchMock.mock.calls;
      expect(calls.length).toBe(1);
      const [url, init] = calls[0];
      expect(url).toBe("http://test:11434/api/chat");
      expect(init.method).toBe("POST");
      expect(JSON.parse(init.body)).toEqual({
        model: "test-model",
        messages: [{ role: "system", content: "What is AI?" }],
        stream: false,
        options: { temperature: 0.5 },
      });
    } finally {
      globalThis.fetch = originalFetch;
    }
  });

  it("uses defaults when no config ollama fields are set", async () => {
    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      json: async () => ({ model: "qwen3", message: { role: "assistant", content: "OK" }, done: true }),
    });

    const { ollamaProvider } = await import("../../src/providers/ollama.js");
    const originalFetch = globalThis.fetch;
    globalThis.fetch = fetchMock;
    try {
      const config = {};
      const result = await ollamaProvider.send({ prompt: "hi" }, config);
      expect(result.content).toBe("OK");
      const [url, init] = fetchMock.mock.calls[0];
      const body = JSON.parse(init.body);
      expect(url).toBe("http://localhost:11434/api/chat");
      expect(body.model).toBe("qwen3:latest");
      expect(body.options.temperature).toBe(0.2);
    } finally {
      globalThis.fetch = originalFetch;
    }
  });

  it("handles non-2xx response with error category", async () => {
    const fetchMock = vi.fn().mockResolvedValue({ ok: false, status: 404, text: async () => "model not found" });

    const { ollamaProvider } = await import("../../src/providers/ollama.js");
    const originalFetch = globalThis.fetch;
    globalThis.fetch = fetchMock;
    try {
      const config = {};
      await expect(
        ollamaProvider.send({ prompt: "hi" }, config),
      ).rejects.toThrow(/Ollama API error \(OllamaModelNotFoundError\)/);
    } finally {
      globalThis.fetch = originalFetch;
    }
  });

  it("handles fetch network errors", async () => {
    const fetchMock = vi.fn().mockRejectedValue(new Error("ECONNREFUSED"));

    const { ollamaProvider } = await import("../../src/providers/ollama.js");
    const originalFetch = globalThis.fetch;
    globalThis.fetch = fetchMock;
    try {
      const config = {};
      await expect(
        ollamaProvider.send({ prompt: "hi" }, config),
      ).rejects.toThrow(/Ollama API error \(OllamaRequestError\)/);
    } finally {
      globalThis.fetch = originalFetch;
    }
  });

  it("handles invalid JSON response", async () => {
    const fetchMock = vi.fn().mockResolvedValue({ ok: true, text: async () => "not json" });

    const { ollamaProvider } = await import("../../src/providers/ollama.js");
    const originalFetch = globalThis.fetch;
    globalThis.fetch = fetchMock;
    try {
      const config = {};
      await expect(
        ollamaProvider.send({ prompt: "hi" }, config),
      ).rejects.toThrow(/invalid JSON response/);
    } finally {
      globalThis.fetch = originalFetch;
    }
  });

  it("returns empty content when message.content is missing", async () => {
    const fetchMock = vi.fn().mockResolvedValue({
      ok: true,
      json: async () => ({ model: "test", done: true }),
    });

    const { ollamaProvider } = await import("../../src/providers/ollama.js");
    const originalFetch = globalThis.fetch;
    globalThis.fetch = fetchMock;
    try {
      const config = {};
      const result = await ollamaProvider.send({ prompt: "hi" }, config);
      expect(result.content).toBe("");
    } finally {
      globalThis.fetch = originalFetch;
    }
  });
});