/**
 * Coverage for `FirstLineCache`, the on-disk cache of pre-synthesized first
 * TTS sentences plus its voice-revision fingerprint/invalidation helpers.
 * Exercises the real filesystem against a temp directory.
 */
import { mkdtempSync, rmSync, statSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import path from "node:path";
import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { FIRST_SENTENCE_SNIP_VERSION } from "@elizaos/shared";
import {
	_resetVoiceRevisionMemoForTesting,
	computeLocalVoiceRevision,
	fingerprintVoiceSettings,
	FirstLineCache,
	type FirstLineCacheKey,
	hashCacheKey,
} from "../src/services/voice/first-line-cache";

let tmpRoot: string;
const openCaches: FirstLineCache[] = [];

function makeCache(opts: Partial<ConstructorParameters<typeof FirstLineCache>[0]> = {}) {
	const cache = new FirstLineCache({ rootDir: tmpRoot, ...opts });
	openCaches.push(cache);
	return cache;
}

function makeKey(over: Partial<FirstLineCacheKey> = {}): FirstLineCacheKey {
	return {
		algoVersion: FIRST_SENTENCE_SNIP_VERSION,
		provider: "elevenlabs",
		voiceId: "EXAVITQu4vr4xnSDxMaL",
		voiceRevision: "rev-aaaa",
		sampleRate: 44100,
		codec: "mp3",
		voiceSettingsFingerprint: fingerprintVoiceSettings({}),
		normalizedText: "got it",
		...over,
	};
}

function makeBytes(len = 32, fill = 0x42): Uint8Array {
	const b = new Uint8Array(len);
	b.fill(fill);
	return b;
}

beforeEach(() => {
	tmpRoot = mkdtempSync(path.join(tmpdir(), "fl-cache-"));
});
afterEach(() => {
	// Close every cache before removing its dir: an open SQLite (WAL) handle
	// blocks rmSync on Windows (EBUSY/EPERM); POSIX tolerates open handles.
	// close() is idempotent, so double-closing an already-closed cache is safe.
	for (const cache of openCaches.splice(0)) cache.close();
	rmSync(tmpRoot, { recursive: true, force: true, maxRetries: 5, retryDelay: 50 });
});

describe("hashCacheKey", () => {
	it("is deterministic across calls", () => {
		const k = makeKey();
		expect(hashCacheKey(k)).toBe(hashCacheKey(k));
	});
	it("changes when any key field changes", () => {
		const base = makeKey();
		const baseHash = hashCacheKey(base);
		expect(hashCacheKey({ ...base, voiceId: "other" })).not.toBe(baseHash);
		expect(hashCacheKey({ ...base, voiceRevision: "rev-bbbb" })).not.toBe(baseHash);
		expect(hashCacheKey({ ...base, normalizedText: "sure thing" })).not.toBe(baseHash);
		expect(hashCacheKey({ ...base, sampleRate: 24000 })).not.toBe(baseHash);
		expect(hashCacheKey({ ...base, codec: "opus" })).not.toBe(baseHash);
		expect(hashCacheKey({ ...base, provider: "kokoro" })).not.toBe(baseHash);
		expect(
			hashCacheKey({
				...base,
				voiceSettingsFingerprint: fingerprintVoiceSettings({ stability: 0.2 }),
			}),
		).not.toBe(baseHash);
	});
});

describe("fingerprintVoiceSettings", () => {
	it("is order-independent", () => {
		expect(
			fingerprintVoiceSettings({ stability: 0.5, style: 0.3 }),
		).toBe(fingerprintVoiceSettings({ style: 0.3, stability: 0.5 }));
	});
	it("differs when values differ", () => {
		expect(fingerprintVoiceSettings({ stability: 0.5 })).not.toBe(
			fingerprintVoiceSettings({ stability: 0.6 }),
		);
	});
});

describe("computeLocalVoiceRevision", () => {
	it("hashes the file contents", async () => {
		_resetVoiceRevisionMemoForTesting();
		const fA = path.join(tmpRoot, "a.bin");
		const fB = path.join(tmpRoot, "b.bin");
		writeFileSync(fA, "voice-pack-bytes");
		writeFileSync(fB, "model-bytes");
		const rev = await computeLocalVoiceRevision([fA, fB]);
		expect(rev).toMatch(/^[0-9a-f]{64}$/);

		writeFileSync(fA, "voice-pack-bytes-v2");
		_resetVoiceRevisionMemoForTesting();
		const rev2 = await computeLocalVoiceRevision([fA, fB]);
		expect(rev2).not.toBe(rev);
	});
	it("memoises by file list", async () => {
		_resetVoiceRevisionMemoForTesting();
		const fA = path.join(tmpRoot, "a.bin");
		writeFileSync(fA, "x");
		const rev1 = await computeLocalVoiceRevision([fA]);
		// Mutate file but expect the memoized result.
		writeFileSync(fA, "y");
		const rev2 = await computeLocalVoiceRevision([fA]);
		expect(rev2).toBe(rev1);
		_resetVoiceRevisionMemoForTesting();
		const rev3 = await computeLocalVoiceRevision([fA]);
		expect(rev3).not.toBe(rev1);
	});
});

describe("FirstLineCache — basics", () => {
	it("returns null on miss", () => {
		const cache = makeCache();
		expect(cache.get(makeKey())).toBeNull();
	});

	it("put then get round-trip", () => {
		const cache = makeCache();
		const ok = cache.put({
			...makeKey(),
			bytes: makeBytes(64),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 500,
		});
		expect(ok).toBe(true);
		const got = cache.get(makeKey());
		expect(got).not.toBeNull();
		expect(got?.bytes.length).toBe(64);
		expect(got?.rawText).toBe("Got it.");
		expect(got?.contentType).toBe("audio/mpeg");
		expect(got?.durationMs).toBe(500);
		expect(got?.hitCount).toBe(1);
	});

	it("has() reflects put/delete", () => {
		const cache = makeCache();
		expect(cache.has(makeKey())).toBe(false);
		cache.put({
			...makeKey(),
			bytes: makeBytes(),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		expect(cache.has(makeKey())).toBe(true);
		cache.delete(makeKey());
		expect(cache.has(makeKey())).toBe(false);
	});
});

describe("FirstLineCache — F3 voice-swap safety", () => {
	it("Kokoro entry does NOT resolve under an ElevenLabs key", () => {
		const cache = makeCache();
		const kokoroKey = makeKey({
			provider: "kokoro",
			voiceId: "af_bella",
			voiceRevision: "kokoro-rev-1",
			sampleRate: 24000,
			codec: "opus",
		});
		cache.put({
			...kokoroKey,
			bytes: makeBytes(48, 0xaa),
			rawText: "Got it.",
			contentType: "audio/opus",
			durationMs: 0,
		});
		// Same normalized text but different provider/voice/revision → miss.
		const elevenLookup = makeKey({
			provider: "elevenlabs",
			voiceId: "EXAVITQu4vr4xnSDxMaL",
			voiceRevision: "eleven-rev-1",
		});
		expect(cache.get(elevenLookup)).toBeNull();
	});

	it("different voiceRevision invalidates the cache (re-published voice pack)", () => {
		const cache = makeCache();
		const k1 = makeKey({ voiceRevision: "rev-1" });
		const k2 = makeKey({ voiceRevision: "rev-2" });
		cache.put({
			...k1,
			bytes: makeBytes(48),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		expect(cache.has(k1)).toBe(true);
		expect(cache.has(k2)).toBe(false);
	});

	it("different voiceSettingsFingerprint produces miss", () => {
		const cache = makeCache();
		const neutral = fingerprintVoiceSettings({});
		const stylised = fingerprintVoiceSettings({ stability: 0.2 });
		cache.put({
			...makeKey({ voiceSettingsFingerprint: neutral }),
			bytes: makeBytes(48),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		expect(cache.get(makeKey({ voiceSettingsFingerprint: stylised }))).toBeNull();
	});
});

describe("FirstLineCache — safety rejections", () => {
	it("rejects empty voiceRevision on put + on lookup", () => {
		const cache = makeCache();
		const ok = cache.put({
			...makeKey({ voiceRevision: "" }),
			bytes: makeBytes(48),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		expect(ok).toBe(false);
		expect(cache.get(makeKey({ voiceRevision: "" }))).toBeNull();
	});

	it("rejects empty bytes", () => {
		const cache = makeCache();
		const ok = cache.put({
			...makeKey(),
			bytes: new Uint8Array(0),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		expect(ok).toBe(false);
	});

	it("rejects entries larger than maxBytesPerEntry", () => {
		const cache = makeCache({ maxBytesPerEntry: 1024 });
		const ok = cache.put({
			...makeKey(),
			bytes: makeBytes(2048),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		expect(ok).toBe(false);
	});

	it("rejects > 10-word phrases via implicit wordCount", () => {
		const cache = makeCache();
		const ok = cache.put({
			...makeKey({
				normalizedText: "one two three four five six seven eight nine ten eleven",
			}),
			bytes: makeBytes(48),
			rawText: "One two three four five six seven eight nine ten eleven.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		expect(ok).toBe(false);
	});

	it("noops when disabled", () => {
		const cache = makeCache({ disabled: true });
		expect(cache.isEnabled).toBe(false);
		expect(
			cache.put({
				...makeKey(),
				bytes: makeBytes(48),
				rawText: "Got it.",
				contentType: "audio/mpeg",
				durationMs: 0,
			}),
		).toBe(false);
		expect(cache.get(makeKey())).toBeNull();
	});
});

describe("FirstLineCache — LRU eviction", () => {
	it("evicts oldest entries when over byte budget", () => {
		// 5 entries × 64 bytes = 320; budget 200 → must evict at least 2.
		const cache = makeCache({ maxBytes: 200, maxBytesPerEntry: 1024 });
		const baseKey = makeKey();
		const variants = [
			{ ...baseKey, normalizedText: "okay" },
			{ ...baseKey, normalizedText: "sure" },
			{ ...baseKey, normalizedText: "right" },
			{ ...baseKey, normalizedText: "got it" },
			{ ...baseKey, normalizedText: "one sec" },
		];
		for (const v of variants) {
			cache.put({
				...v,
				bytes: makeBytes(64),
				rawText: v.normalizedText,
				contentType: "audio/mpeg",
				durationMs: 0,
			});
		}
		const stats = cache.stats();
		expect(stats.bytes).toBeLessThanOrEqual(200);
		expect(stats.entries).toBeLessThanOrEqual(3);
	});
});

describe("FirstLineCache — persistence across reopen", () => {
	it("survives closing and re-opening the index", () => {
		const cache1 = makeCache();
		cache1.put({
			...makeKey(),
			bytes: makeBytes(48),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		cache1.close();
		const cache2 = makeCache();
		const got = cache2.get(makeKey());
		expect(got).not.toBeNull();
		expect(got?.bytes.length).toBe(48);
	});

	it("drops orphan rows when the blob file is missing", () => {
		const cache1 = makeCache();
		cache1.put({
			...makeKey(),
			bytes: makeBytes(48),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		const blobs = path.join(tmpRoot, "blobs");
		// Find and unlink any .mp3 blob recursively (one entry).
		const { readdirSync, unlinkSync } = require("node:fs") as typeof import("node:fs");
		function purge(dir: string) {
			for (const ent of readdirSync(dir, { withFileTypes: true })) {
				const f = path.join(dir, ent.name);
				if (ent.isDirectory()) purge(f);
				else if (f.endsWith(".mp3")) unlinkSync(f);
			}
		}
		purge(blobs);

		const got = cache1.get(makeKey());
		expect(got).toBeNull();
	});
});

describe("FirstLineCache — TTL sweep", () => {
	it("removes entries older than ttlDays", () => {
		const cache = makeCache({ ttlDays: 1 });
		cache.put({
			...makeKey(),
			bytes: makeBytes(48),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		expect(cache.has(makeKey())).toBe(true);
		// Sweep with a "now" 2 days in the future → entry past TTL.
		const removed = cache.sweep(Date.now() + 2 * 86_400_000);
		expect(removed).toBe(1);
		expect(cache.has(makeKey())).toBe(false);
	});
});

describe("FirstLineCache — blob layout", () => {
	it("writes blobs under <root>/blobs/<provider>/<voiceId>/<voiceRevision>/", () => {
		const cache = makeCache();
		cache.put({
			...makeKey({
				provider: "elevenlabs",
				voiceId: "EXAVITQu4vr4xnSDxMaL",
				voiceRevision: "rev-aaaa",
			}),
			bytes: makeBytes(48),
			rawText: "Got it.",
			contentType: "audio/mpeg",
			durationMs: 0,
		});
		const expectedDir = path.join(
			tmpRoot,
			"blobs",
			"elevenlabs",
			"EXAVITQu4vr4xnSDxMaL",
			"rev-aaaa",
		);
		expect(statSync(expectedDir).isDirectory()).toBe(true);
	});
});