import { afterEach, beforeEach, describe, expect, test } from "bun:test";
import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";
import type { OpenAICompat } from "@oh-my-pi/pi-ai";
import { kNoAuth, MODEL_ROLES, ModelRegistry } from "@oh-my-pi/pi-coding-agent/config/model-registry";
import { AuthStorage } from "@oh-my-pi/pi-coding-agent/session/auth-storage";
import { Snowflake } from "@oh-my-pi/pi-utils";

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

	test("commit role includes a visible badge tag", () => {
		expect(MODEL_ROLES.commit.tag).toBe("COMMIT");
		expect(MODEL_ROLES.commit.color).toBe("dim");
	});

	beforeEach(async () => {
		tempDir = path.join(os.tmpdir(), `pi-test-model-registry-${Snowflake.next()}`);
		fs.mkdirSync(tempDir, { recursive: true });
		modelsJsonPath = path.join(tempDir, "models.json");
		authStorage = await AuthStorage.create(path.join(tempDir, "testauth.db"));
	});

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

	type ProviderConfig = {
		baseUrl: string;
		apiKey: string;
		api: string;
		models: Array<{
			id: string;
			name: string;
			reasoning: boolean;
			input: string[];
			cost: { input: number; output: number; cacheRead: number; cacheWrite: number };
			contextWindow: number;
			maxTokens: number;
		}>;
	};

	/** 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, ProviderConfig>) {
		fs.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>) {
		fs.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 models merge", () => {
			writeRawModelsJson({
				// baseUrl-only for anthropic
				anthropic: overrideConfig("https://anthropic-proxy.example.com/v1"),
				// Add custom model for google (merged with built-ins)
				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: built-ins plus custom model
			const googleModels = getModelsForProvider(registry, "google");
			expect(googleModels.length).toBeGreaterThan(1);
			expect(googleModels.some(m => m.id === "gemini-custom")).toBe(true);
		});

		test("refresh() picks up baseUrl override changes", async () => {
			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"),
			});
			await registry.refresh();

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

	describe("custom models merge behavior", () => {
		test("custom provider with same name as built-in merges with 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");

			// Built-in models still present, custom model merged in
			expect(anthropicModels.length).toBeGreaterThan(1);
			const custom = anthropicModels.find(m => m.id === "claude-custom");
			expect(custom).toBeDefined();
			expect(custom!.baseUrl).toBe("https://my-proxy.example.com/v1");
		});

		test("custom model with same id replaces built-in model by id", () => {
			writeModelsJson({
				openrouter: providerConfig(
					"https://my-proxy.example.com/v1",
					[{ id: "anthropic/claude-sonnet-4" }],
					"openai-completions",
				),
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");
			const sonnetModels = models.filter(m => m.id === "anthropic/claude-sonnet-4");

			expect(sonnetModels).toHaveLength(1);
			expect(sonnetModels[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("provider-level baseUrl applies to both built-in and custom models", () => {
			writeModelsJson({
				anthropic: providerConfig("https://merged-proxy.example.com/v1", [{ id: "claude-custom" }]),
			});

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

			for (const model of anthropicModels) {
				expect(model.baseUrl).toBe("https://merged-proxy.example.com/v1");
			}
		});

		test("modelOverrides still apply when provider also defines models", () => {
			writeRawModelsJson({
				openrouter: {
					baseUrl: "https://my-proxy.example.com/v1",
					apiKey: "OPENROUTER_API_KEY",
					api: "openai-completions",
					models: [
						{
							id: "custom/openrouter-model",
							name: "Custom OpenRouter Model",
							reasoning: false,
							input: ["text"],
							cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
							contextWindow: 128000,
							maxTokens: 16384,
						},
					],
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							name: "Overridden Built-in Sonnet",
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");

			expect(models.some(m => m.id === "custom/openrouter-model")).toBe(true);
			expect(models.some(m => m.id === "anthropic/claude-sonnet-4" && m.name === "Overridden Built-in Sonnet")).toBe(
				true,
			);
		});

		test("refresh() reloads merged custom models from disk", async () => {
			writeModelsJson({
				anthropic: providerConfig("https://first-proxy.example.com/v1", [{ id: "claude-custom" }]),
			});
			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			expect(getModelsForProvider(registry, "anthropic").some(m => m.id === "claude-custom")).toBe(true);

			// Update and refresh
			writeModelsJson({
				anthropic: providerConfig("https://second-proxy.example.com/v1", [{ id: "claude-custom-2" }]),
			});
			await registry.refresh();

			const anthropicModels = getModelsForProvider(registry, "anthropic");
			expect(anthropicModels.some(m => m.id === "claude-custom")).toBe(false);
			expect(anthropicModels.some(m => m.id === "claude-custom-2")).toBe(true);
			expect(anthropicModels.some(m => m.id.includes("claude"))).toBe(true);
		});

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

			expect(getModelsForProvider(registry, "anthropic").some(m => m.id === "claude-custom")).toBe(true);

			// Remove custom models and refresh
			writeModelsJson({});
			await registry.refresh();

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

	describe("modelOverrides (per-model customization)", () => {
		test("model override applies to a single built-in model", () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							name: "Custom Sonnet Name",
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");

			const sonnet = models.find(m => m.id === "anthropic/claude-sonnet-4");
			expect(sonnet?.name).toBe("Custom Sonnet Name");

			// Other models should be unchanged
			const opus = models.find(m => m.id === "anthropic/claude-opus-4");
			expect(opus?.name).not.toBe("Custom Sonnet Name");
		});

		test("model override with compat.openRouterRouting", () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							compat: {
								openRouterRouting: { only: ["amazon-bedrock"] },
							},
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");

			const sonnet = models.find(m => m.id === "anthropic/claude-sonnet-4");
			const compat = sonnet?.compat as OpenAICompat | undefined;
			expect(compat?.openRouterRouting).toEqual({ only: ["amazon-bedrock"] });
		});

		test("model override deep merges compat settings", () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							compat: {
								openRouterRouting: { order: ["anthropic", "together"] },
							},
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");
			const sonnet = models.find(m => m.id === "anthropic/claude-sonnet-4");

			const compat = sonnet?.compat as OpenAICompat | undefined;
			expect(compat?.openRouterRouting).toEqual({ order: ["anthropic", "together"] });
		});

		test("multiple model overrides on same provider", () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							compat: { openRouterRouting: { only: ["amazon-bedrock"] } },
						},
						"anthropic/claude-opus-4": {
							compat: { openRouterRouting: { only: ["anthropic"] } },
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");

			const sonnet = models.find(m => m.id === "anthropic/claude-sonnet-4");
			const opus = models.find(m => m.id === "anthropic/claude-opus-4");

			const sonnetCompat = sonnet?.compat as OpenAICompat | undefined;
			const opusCompat = opus?.compat as OpenAICompat | undefined;
			expect(sonnetCompat?.openRouterRouting).toEqual({ only: ["amazon-bedrock"] });
			expect(opusCompat?.openRouterRouting).toEqual({ only: ["anthropic"] });
		});

		test("model override combined with baseUrl override", () => {
			writeRawModelsJson({
				openrouter: {
					baseUrl: "https://my-proxy.example.com/v1",
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							name: "Proxied Sonnet",
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");
			const sonnet = models.find(m => m.id === "anthropic/claude-sonnet-4");

			// Both overrides should apply
			expect(sonnet?.baseUrl).toBe("https://my-proxy.example.com/v1");
			expect(sonnet?.name).toBe("Proxied Sonnet");

			// Other models should have the baseUrl but not the name override
			const opus = models.find(m => m.id === "anthropic/claude-opus-4");
			expect(opus?.baseUrl).toBe("https://my-proxy.example.com/v1");
			expect(opus?.name).not.toBe("Proxied Sonnet");
		});

		test("model override for non-existent model ID is ignored", () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"nonexistent/model-id": {
							name: "This should not appear",
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");

			// Should not create a new model
			expect(models.find(m => m.id === "nonexistent/model-id")).toBeUndefined();
			// Should not crash or show error
			expect(registry.getError()).toBeUndefined();
		});

		test("model override can change cost fields partially", () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							cost: { input: 99 },
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");
			const sonnet = models.find(m => m.id === "anthropic/claude-sonnet-4");

			// Input cost should be overridden
			expect(sonnet?.cost.input).toBe(99);
			// Other cost fields should be preserved from built-in
			expect(sonnet?.cost.output).toBeGreaterThan(0);
		});

		test("model override can add headers", () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							headers: { "X-Custom-Model-Header": "value" },
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const models = getModelsForProvider(registry, "openrouter");
			const sonnet = models.find(m => m.id === "anthropic/claude-sonnet-4");

			expect(sonnet?.headers?.["X-Custom-Model-Header"]).toBe("value");
		});

		test("refresh() picks up model override changes", async () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							name: "First Name",
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			expect(
				getModelsForProvider(registry, "openrouter").find(m => m.id === "anthropic/claude-sonnet-4")?.name,
			).toBe("First Name");

			// Update and refresh
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							name: "Second Name",
						},
					},
				},
			});
			await registry.refresh();

			expect(
				getModelsForProvider(registry, "openrouter").find(m => m.id === "anthropic/claude-sonnet-4")?.name,
			).toBe("Second Name");
		});

		test("removing model override restores built-in values", async () => {
			writeRawModelsJson({
				openrouter: {
					modelOverrides: {
						"anthropic/claude-sonnet-4": {
							name: "Custom Name",
						},
					},
				},
			});

			const registry = new ModelRegistry(authStorage, modelsJsonPath);
			const customName = getModelsForProvider(registry, "openrouter").find(
				m => m.id === "anthropic/claude-sonnet-4",
			)?.name;
			expect(customName).toBe("Custom Name");

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

			const restoredName = getModelsForProvider(registry, "openrouter").find(
				m => m.id === "anthropic/claude-sonnet-4",
			)?.name;
			expect(restoredName).not.toBe("Custom Name");
		});
	});

	describe("runtime discovery", () => {
		test("auto-discovers ollama models without provider config", async () => {
			const originalFetch = globalThis.fetch;
			globalThis.fetch = (async (input: string | URL | Request) => {
				expect(String(input)).toBe("http://127.0.0.1:11434/api/tags");
				return new Response(JSON.stringify({ models: [{ name: "phi4-mini" }] }), {
					status: 200,
					headers: { "Content-Type": "application/json" },
				});
			}) as unknown as typeof fetch;

			try {
				const registry = new ModelRegistry(authStorage, modelsJsonPath);
				await registry.refresh();
				const ollamaModels = getModelsForProvider(registry, "ollama");
				expect(ollamaModels.some(m => m.id === "phi4-mini")).toBe(true);
				expect(registry.getAvailable().some(m => m.provider === "ollama" && m.id === "phi4-mini")).toBe(true);
				expect(await registry.getApiKey(ollamaModels[0])).toBe(kNoAuth);
			} finally {
				globalThis.fetch = originalFetch;
			}
		});

		test("discovers ollama models at runtime and treats auth:none providers as available", async () => {
			writeRawModelsJson({
				ollama: {
					baseUrl: "http://127.0.0.1:11434/v1",
					api: "openai-completions",
					auth: "none",
					discovery: { type: "ollama" },
				},
			});

			const originalFetch = globalThis.fetch;
			globalThis.fetch = (async (input: string | URL | Request) => {
				expect(String(input)).toBe("http://127.0.0.1:11434/api/tags");
				return new Response(
					JSON.stringify({
						models: [{ name: "qwen2.5-coder:7b" }, { model: "llama3.2:3b", name: "llama3.2:3b" }],
					}),
					{ status: 200, headers: { "Content-Type": "application/json" } },
				);
			}) as unknown as typeof fetch;

			try {
				const registry = new ModelRegistry(authStorage, modelsJsonPath);
				await registry.refresh();

				const ollamaModels = getModelsForProvider(registry, "ollama");
				expect(ollamaModels.some(m => m.id === "qwen2.5-coder:7b")).toBe(true);
				expect(ollamaModels.some(m => m.id === "llama3.2:3b")).toBe(true);

				const available = registry.getAvailable().filter(m => m.provider === "ollama");
				expect(available.length).toBe(2);
				expect(await registry.getApiKey(available[0])).toBe(kNoAuth);
			} finally {
				globalThis.fetch = originalFetch;
			}
		});

		test("discovery failure does not fail model registry refresh", async () => {
			writeRawModelsJson({
				ollama: {
					baseUrl: "http://127.0.0.1:11434",
					api: "openai-completions",
					auth: "none",
					discovery: { type: "ollama" },
				},
			});

			const originalFetch = globalThis.fetch;
			globalThis.fetch = (async () => {
				throw new Error("connection refused");
			}) as unknown as typeof fetch;

			try {
				const registry = new ModelRegistry(authStorage, modelsJsonPath);
				await registry.refresh();
				expect(getModelsForProvider(registry, "ollama")).toHaveLength(0);
				expect(registry.getError()).toBeUndefined();
			} finally {
				globalThis.fetch = originalFetch;
			}
		});
	});
});