import { existsSync, mkdirSync, readFileSync, rmSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { afterEach, beforeEach, describe, expect, test } from "vitest";
import { AuthStorage } from "../src/core/auth-storage.js";
import { clearApiKeyCache, ModelRegistry } from "../src/core/model-registry.js";

describe("ModelRegistry", () => {
	let tempDir: string;
	let modelsJsonPath: string;
	let authStorage: AuthStorage;

	beforeEach(() => {
		tempDir = join(tmpdir(), `pi-test-model-registry-${Date.now()}-${Math.random().toString(36).slice(2)}`);
		mkdirSync(tempDir, { recursive: true });
		modelsJsonPath = join(tempDir, "models.json");
		authStorage = new AuthStorage(join(tempDir, "auth.json"));
	});

	afterEach(() => {
		if (tempDir && existsSync(tempDir)) {
			rmSync(tempDir, { recursive: true });
		}
		clearApiKeyCache();
	});

	/** Create minimal provider config  */
	function providerConfig(
		baseUrl: string,
		models: Array<{ id: string; name?: string }>,
		api: string = "anthropic-messages",
	) {
		return {
			baseUrl,
			apiKey: "TEST_KEY",
			api,
			models: models.map((m) => ({
				id: m.id,
				name: m.name ?? m.id,
				reasoning: false,
				input: ["text"],
				cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
				contextWindow: 100000,
				maxTokens: 8000,
			})),
		};
	}

	function writeModelsJson(providers: Record<string, ReturnType<typeof providerConfig>>) {
		writeFileSync(modelsJsonPath, JSON.stringify({ providers }));
	}

	function getModelsForProvider(registry: ModelRegistry, provider: string) {
		return registry.getAll().filter((m) => m.provider === provider);
	}

	/** Create a baseUrl-only override (no custom models) */
	function overrideConfig(baseUrl: string, headers?: Record<string, string>) {
		return { baseUrl, ...(headers && { headers }) };
	}

	/** Write raw providers config (for mixed override/replacement scenarios) */
	function writeRawModelsJson(providers: Record<string, unknown>) {
		writeFileSync(modelsJsonPath, JSON.stringify({ providers }));
	}

	describe("baseUrl override (no custom models)", () => {
		test("overriding baseUrl keeps all built-in models", () => {
			writeRawModelsJson({
				anthropic: overrideConfig("https://my-proxy.example.com/v1"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const anthropicModels = getModelsForProvider(registry, "anthropic");

			// Should have multiple built-in models, not just one
			expect(anthropicModels.length).toBeGreaterThan(1);
			expect(anthropicModels.some((m) => m.id.includes("claude"))).toBe(true);
		});

		test("overriding baseUrl changes URL on all built-in models", () => {
			writeRawModelsJson({
				anthropic: overrideConfig("https://my-proxy.example.com/v1"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const anthropicModels = getModelsForProvider(registry, "anthropic");

			// All models should have the new baseUrl
			for (const model of anthropicModels) {
				expect(model.baseUrl).toBe("https://my-proxy.example.com/v1");
			}
		});

		test("overriding headers merges with model headers", () => {
			writeRawModelsJson({
				anthropic: overrideConfig("https://my-proxy.example.com/v1", {
					"X-Custom-Header": "custom-value",
				}),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const anthropicModels = getModelsForProvider(registry, "anthropic");

			for (const model of anthropicModels) {
				expect(model.headers?.["X-Custom-Header"]).toBe("custom-value");
			}
		});

		test("baseUrl-only override does not affect other providers", () => {
			writeRawModelsJson({
				anthropic: overrideConfig("https://my-proxy.example.com/v1"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const googleModels = getModelsForProvider(registry, "google");

			// Google models should still have their original baseUrl
			expect(googleModels.length).toBeGreaterThan(0);
			expect(googleModels[0].baseUrl).not.toBe("https://my-proxy.example.com/v1");
		});

		test("can mix baseUrl override and full replacement", () => {
			writeRawModelsJson({
				// baseUrl-only for anthropic
				anthropic: overrideConfig("https://anthropic-proxy.example.com/v1"),
				// Full replacement for google
				google: providerConfig(
					"https://google-proxy.example.com/v1",
					[{ id: "gemini-custom" }],
					"google-generative-ai",
				),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);

			// Anthropic: multiple built-in models with new baseUrl
			const anthropicModels = getModelsForProvider(registry, "anthropic");
			expect(anthropicModels.length).toBeGreaterThan(1);
			expect(anthropicModels[0].baseUrl).toBe("https://anthropic-proxy.example.com/v1");

			// Google: single custom model
			const googleModels = getModelsForProvider(registry, "google");
			expect(googleModels).toHaveLength(1);
			expect(googleModels[0].id).toBe("gemini-custom");
		});

		test("refresh() picks up baseUrl override changes", () => {
			writeRawModelsJson({
				anthropic: overrideConfig("https://first-proxy.example.com/v1"),
			});
			const registry = new ModelRegistry(authStorage, modelsJsonPath);

			expect(getModelsForProvider(registry, "anthropic")[0].baseUrl).toBe("https://first-proxy.example.com/v1");

			// Update and refresh
			writeRawModelsJson({
				anthropic: overrideConfig("https://second-proxy.example.com/v1"),
			});
			registry.refresh();

			expect(getModelsForProvider(registry, "anthropic")[0].baseUrl).toBe("https://second-proxy.example.com/v1");
		});
	});

	describe("provider replacement (with custom models)", () => {
		test("custom provider with same name as built-in replaces built-in models", () => {
			writeModelsJson({
				anthropic: providerConfig("https://my-proxy.example.com/v1", [{ id: "claude-custom" }]),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const anthropicModels = getModelsForProvider(registry, "anthropic");

			expect(anthropicModels).toHaveLength(1);
			expect(anthropicModels[0].id).toBe("claude-custom");
			expect(anthropicModels[0].baseUrl).toBe("https://my-proxy.example.com/v1");
		});

		test("custom provider with same name as built-in does not affect other built-in providers", () => {
			writeModelsJson({
				anthropic: providerConfig("https://my-proxy.example.com/v1", [{ id: "claude-custom" }]),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);

			expect(getModelsForProvider(registry, "google").length).toBeGreaterThan(0);
			expect(getModelsForProvider(registry, "openai").length).toBeGreaterThan(0);
		});

		test("multiple built-in providers can be overridden", () => {
			writeModelsJson({
				anthropic: providerConfig("https://anthropic-proxy.example.com/v1", [{ id: "claude-proxy" }]),
				google: providerConfig(
					"https://google-proxy.example.com/v1",
					[{ id: "gemini-proxy" }],
					"google-generative-ai",
				),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const anthropicModels = getModelsForProvider(registry, "anthropic");
			const googleModels = getModelsForProvider(registry, "google");

			expect(anthropicModels).toHaveLength(1);
			expect(anthropicModels[0].id).toBe("claude-proxy");
			expect(anthropicModels[0].baseUrl).toBe("https://anthropic-proxy.example.com/v1");

			expect(googleModels).toHaveLength(1);
			expect(googleModels[0].id).toBe("gemini-proxy");
			expect(googleModels[0].baseUrl).toBe("https://google-proxy.example.com/v1");
		});

		test("refresh() reloads overrides from disk", () => {
			writeModelsJson({
				anthropic: providerConfig("https://first-proxy.example.com/v1", [{ id: "claude-first" }]),
			});
			const registry = new ModelRegistry(authStorage, modelsJsonPath);

			expect(getModelsForProvider(registry, "anthropic")[0].id).toBe("claude-first");

			// Update and refresh
			writeModelsJson({
				anthropic: providerConfig("https://second-proxy.example.com/v1", [{ id: "claude-second" }]),
			});
			registry.refresh();

			const anthropicModels = getModelsForProvider(registry, "anthropic");
			expect(anthropicModels[0].id).toBe("claude-second");
			expect(anthropicModels[0].baseUrl).toBe("https://second-proxy.example.com/v1");
		});

		test("removing override from models.json restores built-in provider", () => {
			writeModelsJson({
				anthropic: providerConfig("https://proxy.example.com/v1", [{ id: "claude-custom" }]),
			});
			const registry = new ModelRegistry(authStorage, modelsJsonPath);

			expect(getModelsForProvider(registry, "anthropic")).toHaveLength(1);

			// Remove override and refresh
			writeModelsJson({});
			registry.refresh();

			const anthropicModels = getModelsForProvider(registry, "anthropic");
			expect(anthropicModels.length).toBeGreaterThan(1);
			expect(anthropicModels.some((m) => m.id.includes("claude"))).toBe(true);
		});
	});

	describe("API key resolution", () => {
		/** Create provider config with custom apiKey */
		function providerWithApiKey(apiKey: string) {
			return {
				baseUrl: "https://example.com/v1",
				apiKey,
				api: "anthropic-messages",
				models: [
					{
						id: "test-model",
						name: "Test Model",
						reasoning: false,
						input: ["text"],
						cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
						contextWindow: 100000,
						maxTokens: 8000,
					},
				],
			};
		}

		test("apiKey with ! prefix executes command and uses stdout", async () => {
			writeRawModelsJson({
				"custom-provider": providerWithApiKey("!echo test-api-key-from-command"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const apiKey = await registry.getApiKeyForProvider("custom-provider");

			expect(apiKey).toBe("test-api-key-from-command");
		});

		test("apiKey with ! prefix trims whitespace from command output", async () => {
			writeRawModelsJson({
				"custom-provider": providerWithApiKey("!echo '  spaced-key  '"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const apiKey = await registry.getApiKeyForProvider("custom-provider");

			expect(apiKey).toBe("spaced-key");
		});

		test("apiKey with ! prefix handles multiline output (uses trimmed result)", async () => {
			writeRawModelsJson({
				"custom-provider": providerWithApiKey("!printf 'line1\\nline2'"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const apiKey = await registry.getApiKeyForProvider("custom-provider");

			expect(apiKey).toBe("line1\nline2");
		});

		test("apiKey with ! prefix returns undefined on command failure", async () => {
			writeRawModelsJson({
				"custom-provider": providerWithApiKey("!exit 1"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const apiKey = await registry.getApiKeyForProvider("custom-provider");

			expect(apiKey).toBeUndefined();
		});

		test("apiKey with ! prefix returns undefined on nonexistent command", async () => {
			writeRawModelsJson({
				"custom-provider": providerWithApiKey("!nonexistent-command-12345"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const apiKey = await registry.getApiKeyForProvider("custom-provider");

			expect(apiKey).toBeUndefined();
		});

		test("apiKey with ! prefix returns undefined on empty output", async () => {
			writeRawModelsJson({
				"custom-provider": providerWithApiKey("!printf ''"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const apiKey = await registry.getApiKeyForProvider("custom-provider");

			expect(apiKey).toBeUndefined();
		});

		test("apiKey as environment variable name resolves to env value", async () => {
			const originalEnv = process.env.TEST_API_KEY_12345;
			process.env.TEST_API_KEY_12345 = "env-api-key-value";

			try {
				writeRawModelsJson({
					"custom-provider": providerWithApiKey("TEST_API_KEY_12345"),
				});

				const registry = new ModelRegistry(authStorage, modelsJsonPath);
				const apiKey = await registry.getApiKeyForProvider("custom-provider");

				expect(apiKey).toBe("env-api-key-value");
			} finally {
				if (originalEnv === undefined) {
					delete process.env.TEST_API_KEY_12345;
				} else {
					process.env.TEST_API_KEY_12345 = originalEnv;
				}
			}
		});

		test("apiKey as literal value is used directly when not an env var", async () => {
			// Make sure this isn't an env var
			delete process.env.literal_api_key_value;

			writeRawModelsJson({
				"custom-provider": providerWithApiKey("literal_api_key_value"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const apiKey = await registry.getApiKeyForProvider("custom-provider");

			expect(apiKey).toBe("literal_api_key_value");
		});

		test("apiKey command can use shell features like pipes", async () => {
			writeRawModelsJson({
				"custom-provider": providerWithApiKey("!echo 'hello world' | tr ' ' '-'"),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const apiKey = await registry.getApiKeyForProvider("custom-provider");

			expect(apiKey).toBe("hello-world");
		});

		describe("caching", () => {
			test("command is only executed once per process", async () => {
				// Use a command that writes to a file to count invocations
				const counterFile = join(tempDir, "counter");
				writeFileSync(counterFile, "0");

				const command = `!sh -c 'count=$(cat ${counterFile}); echo $((count + 1)) > ${counterFile}; echo "key-value"'`;
				writeRawModelsJson({
					"custom-provider": providerWithApiKey(command),
				});

				const registry = new ModelRegistry(authStorage, modelsJsonPath);

				// Call multiple times
				await registry.getApiKeyForProvider("custom-provider");
				await registry.getApiKeyForProvider("custom-provider");
				await registry.getApiKeyForProvider("custom-provider");

				// Command should have only run once
				const count = parseInt(readFileSync(counterFile, "utf-8").trim(), 10);
				expect(count).toBe(1);
			});

			test("cache persists across registry instances", async () => {
				const counterFile = join(tempDir, "counter");
				writeFileSync(counterFile, "0");

				const command = `!sh -c 'count=$(cat ${counterFile}); echo $((count + 1)) > ${counterFile}; echo "key-value"'`;
				writeRawModelsJson({
					"custom-provider": providerWithApiKey(command),
				});

				// Create multiple registry instances
				const registry1 = new ModelRegistry(authStorage, modelsJsonPath);
				await registry1.getApiKeyForProvider("custom-provider");

				const registry2 = new ModelRegistry(authStorage, modelsJsonPath);
				await registry2.getApiKeyForProvider("custom-provider");

				// Command should still have only run once
				const count = parseInt(readFileSync(counterFile, "utf-8").trim(), 10);
				expect(count).toBe(1);
			});

			test("clearApiKeyCache allows command to run again", async () => {
				const counterFile = join(tempDir, "counter");
				writeFileSync(counterFile, "0");

				const command = `!sh -c 'count=$(cat ${counterFile}); echo $((count + 1)) > ${counterFile}; echo "key-value"'`;
				writeRawModelsJson({
					"custom-provider": providerWithApiKey(command),
				});

				const registry = new ModelRegistry(authStorage, modelsJsonPath);
				await registry.getApiKeyForProvider("custom-provider");

				// Clear cache and call again
				clearApiKeyCache();
				await registry.getApiKeyForProvider("custom-provider");

				// Command should have run twice
				const count = parseInt(readFileSync(counterFile, "utf-8").trim(), 10);
				expect(count).toBe(2);
			});

			test("different commands are cached separately", async () => {
				writeRawModelsJson({
					"provider-a": providerWithApiKey("!echo key-a"),
					"provider-b": providerWithApiKey("!echo key-b"),
				});

				const registry = new ModelRegistry(authStorage, modelsJsonPath);

				const keyA = await registry.getApiKeyForProvider("provider-a");
				const keyB = await registry.getApiKeyForProvider("provider-b");

				expect(keyA).toBe("key-a");
				expect(keyB).toBe("key-b");
			});

			test("failed commands are cached (not retried)", async () => {
				const counterFile = join(tempDir, "counter");
				writeFileSync(counterFile, "0");

				const command = `!sh -c 'count=$(cat ${counterFile}); echo $((count + 1)) > ${counterFile}; exit 1'`;
				writeRawModelsJson({
					"custom-provider": providerWithApiKey(command),
				});

				const registry = new ModelRegistry(authStorage, modelsJsonPath);

				// Call multiple times - all should return undefined
				const key1 = await registry.getApiKeyForProvider("custom-provider");
				const key2 = await registry.getApiKeyForProvider("custom-provider");

				expect(key1).toBeUndefined();
				expect(key2).toBeUndefined();

				// Command should have only run once despite failures
				const count = parseInt(readFileSync(counterFile, "utf-8").trim(), 10);
				expect(count).toBe(1);
			});

			test("environment variables are not cached (changes are picked up)", async () => {
				const envVarName = "TEST_API_KEY_CACHE_TEST_98765";
				const originalEnv = process.env[envVarName];

				try {
					process.env[envVarName] = "first-value";

					writeRawModelsJson({
						"custom-provider": providerWithApiKey(envVarName),
					});

					const registry = new ModelRegistry(authStorage, modelsJsonPath);

					const key1 = await registry.getApiKeyForProvider("custom-provider");
					expect(key1).toBe("first-value");

					// Change env var
					process.env[envVarName] = "second-value";

					const key2 = await registry.getApiKeyForProvider("custom-provider");
					expect(key2).toBe("second-value");
				} finally {
					if (originalEnv === undefined) {
						delete process.env[envVarName];
					} else {
						process.env[envVarName] = originalEnv;
					}
				}
			});
		});
	});
});