const { AiProviderError, buildAiProvider, __testables } = require("../../../src/services/ai/provider");

describe("AI provider service", () => {
  const originalFetch = global.fetch;

  afterEach(() => {
    global.fetch = originalFetch;
    vi.restoreAllMocks();
  });

  it("preserves base path for openai-compatible chat completions endpoint", () => {
    expect(__testables.resolveChatCompletionsUrl("https://example.com/v1")).toBe(
      "https://example.com/v1/chat/completions",
    );
    expect(__testables.resolveChatCompletionsUrl("https://example.com/v1/")).toBe(
      "https://example.com/v1/chat/completions",
    );
    expect(__testables.resolveChatCompletionsUrl("https://example.com/chat/completions")).toBe(
      "https://example.com/chat/completions",
    );
  });

  it("returns deterministic mock suggestion payload", async () => {
    const provider = buildAiProvider({ aiProvider: "mock" });
    const result = await provider.generateSuggestion({
      targetType: "reimbursement",
      snapshot: {
        targetId: "r-1",
        formNumber: "BX-001",
        status: "reviewing",
        totalAmount: "123.00",
        itemCount: 2,
        budgetHint: { exceedsBudget: false, exceedsThreshold: true },
        invoiceSummary: { abnormalCount: 1 },
      },
      promptSpec: { systemPrompt: "system", userPrompt: "user" },
    });

    expect(result.provider).toBe("mock");
    expect(result.suggestion.summary).toContain("BX-001");
    expect(result.suggestion.riskHints.length).toBeGreaterThan(0);
  });

  it("maps http 4xx failures to upstream_4xx", async () => {
    global.fetch = vi.fn().mockResolvedValue({
      ok: false,
      status: 400,
      json: vi.fn().mockResolvedValue({ error: "bad_request" }),
    });

    const provider = buildAiProvider({
      aiProvider: "http",
      aiBaseUrl: "https://example.com/v1",
      aiModel: "gpt-test",
      aiTimeoutMs: 500,
    });

    await expect(
      provider.generateSuggestion({
        targetType: "reimbursement",
        snapshot: {},
        promptSpec: { systemPrompt: "system", userPrompt: "user" },
      }),
    ).rejects.toMatchObject({ code: "upstream_4xx" });
  });

  it("maps http 5xx failures to upstream_5xx", async () => {
    global.fetch = vi.fn().mockResolvedValue({
      ok: false,
      status: 503,
      json: vi.fn().mockResolvedValue({ error: "service_unavailable" }),
    });

    const provider = buildAiProvider({
      aiProvider: "http",
      aiBaseUrl: "https://example.com/v1",
      aiModel: "gpt-test",
      aiTimeoutMs: 500,
    });

    await expect(
      provider.generateSuggestion({
        targetType: "purchase_request",
        snapshot: {},
        promptSpec: { systemPrompt: "system", userPrompt: "user" },
      }),
    ).rejects.toMatchObject({ code: "upstream_5xx" });
  });

  it("maps aborted requests to timeout", async () => {
    global.fetch = vi.fn().mockRejectedValue({ name: "AbortError" });

    const provider = buildAiProvider({
      aiProvider: "http",
      aiBaseUrl: "https://example.com/v1",
      aiModel: "gpt-test",
      aiTimeoutMs: 500,
    });

    await expect(
      provider.generateSuggestion({
        targetType: "asset_card",
        snapshot: {},
        promptSpec: { systemPrompt: "system", userPrompt: "user" },
      }),
    ).rejects.toMatchObject({ code: "timeout" });
  });

  it("rejects invalid json payload from upstream", async () => {
    global.fetch = vi.fn().mockResolvedValue({
      ok: true,
      status: 200,
      json: vi.fn().mockResolvedValue({
        choices: [{ message: { content: "```json\nnot-valid-json\n```" } }],
        usage: {},
      }),
    });

    const provider = buildAiProvider({
      aiProvider: "http",
      aiBaseUrl: "https://example.com/v1",
      aiModel: "gpt-test",
      aiTimeoutMs: 500,
    });

    await expect(
      provider.generateSuggestion({
        targetType: "asset_card",
        snapshot: {},
        promptSpec: { systemPrompt: "system", userPrompt: "user" },
      }),
    ).rejects.toBeInstanceOf(AiProviderError);

    await expect(
      provider.generateSuggestion({
        targetType: "asset_card",
        snapshot: {},
        promptSpec: { systemPrompt: "system", userPrompt: "user" },
      }),
    ).rejects.toMatchObject({ code: "invalid_response" });
  });
});