/**
 * Test totalTokens field across all providers.
 *
 * totalTokens represents the total number of tokens processed by the LLM,
 * including input (with cache) and output (with thinking). This is the
 * base for calculating context size for the next request.
 *
 * - OpenAI Completions: Uses native total_tokens field
 * - OpenAI Responses: Uses native total_tokens field
 * - Google: Uses native totalTokenCount field
 * - Anthropic: Computed as input + output + cacheRead + cacheWrite
 * - Other OpenAI-compatible providers: Uses native total_tokens field
 */

import { describe, expect, it } from "vitest";
import { getModel } from "../src/models.js";
import { complete } from "../src/stream.js";
import type { Api, Context, Model, OptionsForApi, Usage } from "../src/types.js";

// Generate a long system prompt to trigger caching (>2k bytes for most providers)
const LONG_SYSTEM_PROMPT = `You are a helpful assistant. Be concise in your responses.

Here is some additional context that makes this system prompt long enough to trigger caching:

${Array(50)
	.fill(
		"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.",
	)
	.join("\n\n")}

Remember: Always be helpful and concise.`;

async function testTotalTokensWithCache<TApi extends Api>(
	llm: Model<TApi>,
	options: OptionsForApi<TApi> = {} as OptionsForApi<TApi>,
): Promise<{ first: Usage; second: Usage }> {
	// First request - no cache
	const context1: Context = {
		systemPrompt: LONG_SYSTEM_PROMPT,
		messages: [
			{
				role: "user",
				content: "What is 2 + 2? Reply with just the number.",
				timestamp: Date.now(),
			},
		],
	};

	const response1 = await complete(llm, context1, options);
	expect(response1.stopReason).toBe("stop");

	// Second request - should trigger cache read (same system prompt, add conversation)
	const context2: Context = {
		systemPrompt: LONG_SYSTEM_PROMPT,
		messages: [
			...context1.messages,
			response1, // Include previous assistant response
			{
				role: "user",
				content: "What is 3 + 3? Reply with just the number.",
				timestamp: Date.now(),
			},
		],
	};

	const response2 = await complete(llm, context2, options);
	expect(response2.stopReason).toBe("stop");

	return { first: response1.usage, second: response2.usage };
}

function logUsage(label: string, usage: Usage) {
	const computed = usage.input + usage.output + usage.cacheRead + usage.cacheWrite;
	console.log(`  ${label}:`);
	console.log(
		`    input: ${usage.input}, output: ${usage.output}, cacheRead: ${usage.cacheRead}, cacheWrite: ${usage.cacheWrite}`,
	);
	console.log(`    totalTokens: ${usage.totalTokens}, computed: ${computed}`);
}

function assertTotalTokensEqualsComponents(usage: Usage) {
	const computed = usage.input + usage.output + usage.cacheRead + usage.cacheWrite;
	expect(usage.totalTokens).toBe(computed);
}

describe("totalTokens field", () => {
	// =========================================================================
	// Anthropic
	// =========================================================================

	describe.skipIf(!process.env.ANTHROPIC_API_KEY)("Anthropic (API Key)", () => {
		it("claude-3-5-haiku - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("anthropic", "claude-3-5-haiku-20241022");

			console.log(`\nAnthropic / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.ANTHROPIC_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);

			// Anthropic should have cache activity
			const hasCache = second.cacheRead > 0 || second.cacheWrite > 0 || first.cacheWrite > 0;
			expect(hasCache).toBe(true);
		}, 60000);
	});

	describe.skipIf(!process.env.ANTHROPIC_OAUTH_TOKEN)("Anthropic (OAuth)", () => {
		it("claude-sonnet-4 - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("anthropic", "claude-sonnet-4-20250514");

			console.log(`\nAnthropic OAuth / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.ANTHROPIC_OAUTH_TOKEN });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);

			// Anthropic should have cache activity
			const hasCache = second.cacheRead > 0 || second.cacheWrite > 0 || first.cacheWrite > 0;
			expect(hasCache).toBe(true);
		}, 60000);
	});

	// =========================================================================
	// OpenAI
	// =========================================================================

	describe.skipIf(!process.env.OPENAI_API_KEY)("OpenAI Completions", () => {
		it("gpt-4o-mini - should return totalTokens equal to sum of components", async () => {
			const llm: Model<"openai-completions"> = {
				...getModel("openai", "gpt-4o-mini")!,
				api: "openai-completions",
			};

			console.log(`\nOpenAI Completions / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm);

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});

	describe.skipIf(!process.env.OPENAI_API_KEY)("OpenAI Responses", () => {
		it("gpt-4o - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("openai", "gpt-4o");

			console.log(`\nOpenAI Responses / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm);

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});

	// =========================================================================
	// Google
	// =========================================================================

	describe.skipIf(!process.env.GEMINI_API_KEY)("Google", () => {
		it("gemini-2.0-flash - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("google", "gemini-2.0-flash");

			console.log(`\nGoogle / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm);

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});

	// =========================================================================
	// xAI
	// =========================================================================

	describe.skipIf(!process.env.XAI_API_KEY)("xAI", () => {
		it("grok-3-fast - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("xai", "grok-3-fast");

			console.log(`\nxAI / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.XAI_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});

	// =========================================================================
	// Groq
	// =========================================================================

	describe.skipIf(!process.env.GROQ_API_KEY)("Groq", () => {
		it("openai/gpt-oss-120b - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("groq", "openai/gpt-oss-120b");

			console.log(`\nGroq / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.GROQ_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});

	// =========================================================================
	// Cerebras
	// =========================================================================

	describe.skipIf(!process.env.CEREBRAS_API_KEY)("Cerebras", () => {
		it("gpt-oss-120b - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("cerebras", "gpt-oss-120b");

			console.log(`\nCerebras / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.CEREBRAS_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});

	// =========================================================================
	// z.ai
	// =========================================================================

	describe.skipIf(!process.env.ZAI_API_KEY)("z.ai", () => {
		it("glm-4.5-flash - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("zai", "glm-4.5-flash");

			console.log(`\nz.ai / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.ZAI_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});

	// =========================================================================
	// Mistral
	// =========================================================================

	describe.skipIf(!process.env.MISTRAL_API_KEY)("Mistral", () => {
		it("devstral-medium-latest - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("mistral", "devstral-medium-latest");

			console.log(`\nMistral / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.MISTRAL_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});

	// =========================================================================
	// OpenRouter - Multiple backend providers
	// =========================================================================

	describe.skipIf(!process.env.OPENROUTER_API_KEY)("OpenRouter", () => {
		it("anthropic/claude-sonnet-4 - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("openrouter", "anthropic/claude-sonnet-4");

			console.log(`\nOpenRouter / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.OPENROUTER_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);

		it("deepseek/deepseek-chat - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("openrouter", "deepseek/deepseek-chat");

			console.log(`\nOpenRouter / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.OPENROUTER_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);

		it("mistralai/mistral-small-3.1-24b-instruct - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("openrouter", "mistralai/mistral-small-3.1-24b-instruct");

			console.log(`\nOpenRouter / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.OPENROUTER_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);

		it("google/gemini-2.0-flash-001 - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("openrouter", "google/gemini-2.0-flash-001");

			console.log(`\nOpenRouter / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.OPENROUTER_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);

		it("meta-llama/llama-4-maverick - should return totalTokens equal to sum of components", async () => {
			const llm = getModel("openrouter", "meta-llama/llama-4-maverick");

			console.log(`\nOpenRouter / ${llm.id}:`);
			const { first, second } = await testTotalTokensWithCache(llm, { apiKey: process.env.OPENROUTER_API_KEY });

			logUsage("First request", first);
			logUsage("Second request", second);

			assertTotalTokensEqualsComponents(first);
			assertTotalTokensEqualsComponents(second);
		}, 60000);
	});
});