import { GeminiHandler } from "../gemini"
import { Anthropic } from "@anthropic-ai/sdk"
import { GoogleGenerativeAI } from "@google/generative-ai"

// Mock the Google Generative AI SDK
jest.mock("@google/generative-ai", () => ({
	GoogleGenerativeAI: jest.fn().mockImplementation(() => ({
		getGenerativeModel: jest.fn().mockReturnValue({
			generateContentStream: jest.fn(),
			generateContent: jest.fn().mockResolvedValue({
				response: {
					text: () => "Test response",
				},
			}),
		}),
	})),
}))

describe("GeminiHandler", () => {
	let handler: GeminiHandler

	beforeEach(() => {
		handler = new GeminiHandler({
			apiKey: "test-key",
			apiModelId: "gemini-2.0-flash-thinking-exp-1219",
			geminiApiKey: "test-key",
		})
	})

	describe("constructor", () => {
		it("should initialize with provided config", () => {
			expect(handler["options"].geminiApiKey).toBe("test-key")
			expect(handler["options"].apiModelId).toBe("gemini-2.0-flash-thinking-exp-1219")
		})

		it("should throw if API key is missing", () => {
			expect(() => {
				new GeminiHandler({
					apiModelId: "gemini-2.0-flash-thinking-exp-1219",
					geminiApiKey: "",
				})
			}).toThrow("API key is required for Google Gemini")
		})
	})

	describe("createMessage", () => {
		const mockMessages: Anthropic.Messages.MessageParam[] = [
			{
				role: "user",
				content: "Hello",
			},
			{
				role: "assistant",
				content: "Hi there!",
			},
		]

		const systemPrompt = "You are a helpful assistant"

		it("should handle text messages correctly", async () => {
			// Mock the stream response
			const mockStream = {
				stream: [{ text: () => "Hello" }, { text: () => " world!" }],
				response: {
					usageMetadata: {
						promptTokenCount: 10,
						candidatesTokenCount: 5,
					},
				},
			}

			// Setup the mock implementation
			const mockGenerateContentStream = jest.fn().mockResolvedValue(mockStream)
			const mockGetGenerativeModel = jest.fn().mockReturnValue({
				generateContentStream: mockGenerateContentStream,
			})

			;(handler["client"] as any).getGenerativeModel = mockGetGenerativeModel

			const stream = handler.createMessage(systemPrompt, mockMessages)
			const chunks = []

			for await (const chunk of stream) {
				chunks.push(chunk)
			}

			// Should have 3 chunks: 'Hello', ' world!', and usage info
			expect(chunks.length).toBe(3)
			expect(chunks[0]).toEqual({
				type: "text",
				text: "Hello",
			})
			expect(chunks[1]).toEqual({
				type: "text",
				text: " world!",
			})
			expect(chunks[2]).toEqual({
				type: "usage",
				inputTokens: 10,
				outputTokens: 5,
			})

			// Verify the model configuration
			expect(mockGetGenerativeModel).toHaveBeenCalledWith({
				model: "gemini-2.0-flash-thinking-exp-1219",
				systemInstruction: systemPrompt,
			})

			// Verify generation config
			expect(mockGenerateContentStream).toHaveBeenCalledWith(
				expect.objectContaining({
					generationConfig: {
						temperature: 0,
					},
				}),
			)
		})

		it("should handle API errors", async () => {
			const mockError = new Error("Gemini API error")
			const mockGenerateContentStream = jest.fn().mockRejectedValue(mockError)
			const mockGetGenerativeModel = jest.fn().mockReturnValue({
				generateContentStream: mockGenerateContentStream,
			})

			;(handler["client"] as any).getGenerativeModel = mockGetGenerativeModel

			const stream = handler.createMessage(systemPrompt, mockMessages)

			await expect(async () => {
				for await (const chunk of stream) {
					// Should throw before yielding any chunks
				}
			}).rejects.toThrow("Gemini API error")
		})
	})

	describe("completePrompt", () => {
		it("should complete prompt successfully", async () => {
			const mockGenerateContent = jest.fn().mockResolvedValue({
				response: {
					text: () => "Test response",
				},
			})
			const mockGetGenerativeModel = jest.fn().mockReturnValue({
				generateContent: mockGenerateContent,
			})
			;(handler["client"] as any).getGenerativeModel = mockGetGenerativeModel

			const result = await handler.completePrompt("Test prompt")
			expect(result).toBe("Test response")
			expect(mockGetGenerativeModel).toHaveBeenCalledWith({
				model: "gemini-2.0-flash-thinking-exp-1219",
			})
			expect(mockGenerateContent).toHaveBeenCalledWith({
				contents: [{ role: "user", parts: [{ text: "Test prompt" }] }],
				generationConfig: {
					temperature: 0,
				},
			})
		})

		it("should handle API errors", async () => {
			const mockError = new Error("Gemini API error")
			const mockGenerateContent = jest.fn().mockRejectedValue(mockError)
			const mockGetGenerativeModel = jest.fn().mockReturnValue({
				generateContent: mockGenerateContent,
			})
			;(handler["client"] as any).getGenerativeModel = mockGetGenerativeModel

			await expect(handler.completePrompt("Test prompt")).rejects.toThrow(
				"Gemini completion error: Gemini API error",
			)
		})

		it("should handle empty response", async () => {
			const mockGenerateContent = jest.fn().mockResolvedValue({
				response: {
					text: () => "",
				},
			})
			const mockGetGenerativeModel = jest.fn().mockReturnValue({
				generateContent: mockGenerateContent,
			})
			;(handler["client"] as any).getGenerativeModel = mockGetGenerativeModel

			const result = await handler.completePrompt("Test prompt")
			expect(result).toBe("")
		})
	})

	describe("getModel", () => {
		it("should return correct model info", () => {
			const modelInfo = handler.getModel()
			expect(modelInfo.id).toBe("gemini-2.0-flash-thinking-exp-1219")
			expect(modelInfo.info).toBeDefined()
			expect(modelInfo.info.maxTokens).toBe(8192)
			expect(modelInfo.info.contextWindow).toBe(32_767)
		})

		it("should return default model if invalid model specified", () => {
			const invalidHandler = new GeminiHandler({
				apiModelId: "invalid-model",
				geminiApiKey: "test-key",
			})
			const modelInfo = invalidHandler.getModel()
			expect(modelInfo.id).toBe("gemini-2.0-flash-thinking-exp-01-21") // Default model
		})
	})
})