#!/usr/bin/env node

const fs = require("node:fs");
const path = require("node:path");
const { spawnSync } = require("node:child_process");

function usage(message) {
  if (message) {
    console.error(message);
  }
  console.error(
    "\nUsage: sherpa-onnx-tts [--runtime-dir <dir>] [--model-dir <dir>] [--model-file <file>] [--tokens-file <file>] [--data-dir <dir>] [--output <file>] \"text\"",
  );
  console.error("\nRequired env (or flags):\n  SHERPA_ONNX_RUNTIME_DIR\n  SHERPA_ONNX_MODEL_DIR");
  process.exit(1);
}

function resolveRuntimeDir(explicit) {
  const value = explicit || process.env.SHERPA_ONNX_RUNTIME_DIR || "";
  return value.trim();
}

function resolveModelDir(explicit) {
  const value = explicit || process.env.SHERPA_ONNX_MODEL_DIR || "";
  return value.trim();
}

function resolveModelFile(modelDir, explicitFlag) {
  const explicit = (explicitFlag || process.env.SHERPA_ONNX_MODEL_FILE || "").trim();
  if (explicit) return explicit;
  try {
    const candidates = fs
      .readdirSync(modelDir)
      .filter((entry) => entry.endsWith(".onnx"))
      .map((entry) => path.join(modelDir, entry));
    if (candidates.length === 1) return candidates[0];
  } catch {
    return "";
  }
  return "";
}

function resolveTokensFile(modelDir, explicitFlag) {
  const explicit = (explicitFlag || process.env.SHERPA_ONNX_TOKENS_FILE || "").trim();
  if (explicit) return explicit;
  const candidate = path.join(modelDir, "tokens.txt");
  return fs.existsSync(candidate) ? candidate : "";
}

function resolveDataDir(modelDir, explicitFlag) {
  const explicit = (explicitFlag || process.env.SHERPA_ONNX_DATA_DIR || "").trim();
  if (explicit) return explicit;
  const candidate = path.join(modelDir, "espeak-ng-data");
  return fs.existsSync(candidate) ? candidate : "";
}

function resolveBinary(runtimeDir) {
  const binName = process.platform === "win32" ? "sherpa-onnx-offline-tts.exe" : "sherpa-onnx-offline-tts";
  return path.join(runtimeDir, "bin", binName);
}

function prependEnvPath(current, next) {
  if (!next) return current;
  if (!current) return next;
  return `${next}${path.delimiter}${current}`;
}

const args = process.argv.slice(2);
let runtimeDir = "";
let modelDir = "";
let modelFile = "";
let tokensFile = "";
let dataDir = "";
let output = "tts.wav";
const textParts = [];

for (let i = 0; i < args.length; i += 1) {
  const arg = args[i];
  if (arg === "--runtime-dir") {
    runtimeDir = args[i + 1] || "";
    i += 1;
    continue;
  }
  if (arg === "--model-dir") {
    modelDir = args[i + 1] || "";
    i += 1;
    continue;
  }
  if (arg === "--model-file") {
    modelFile = args[i + 1] || "";
    i += 1;
    continue;
  }
  if (arg === "--tokens-file") {
    tokensFile = args[i + 1] || "";
    i += 1;
    continue;
  }
  if (arg === "--data-dir") {
    dataDir = args[i + 1] || "";
    i += 1;
    continue;
  }
  if (arg === "-o" || arg === "--output") {
    output = args[i + 1] || output;
    i += 1;
    continue;
  }
  if (arg === "--text") {
    textParts.push(args[i + 1] || "");
    i += 1;
    continue;
  }
  textParts.push(arg);
}

runtimeDir = resolveRuntimeDir(runtimeDir);
modelDir = resolveModelDir(modelDir);

if (!runtimeDir || !modelDir) {
  usage("Missing runtime/model directory.");
}

modelFile = resolveModelFile(modelDir, modelFile);
tokensFile = resolveTokensFile(modelDir, tokensFile);
dataDir = resolveDataDir(modelDir, dataDir);

if (!modelFile || !tokensFile || !dataDir) {
  usage(
    "Model directory is missing required files. Set SHERPA_ONNX_MODEL_FILE, SHERPA_ONNX_TOKENS_FILE, SHERPA_ONNX_DATA_DIR or pass --model-file/--tokens-file/--data-dir.",
  );
}

const text = textParts.join(" ").trim();
if (!text) {
  usage("Missing text.");
}

const bin = resolveBinary(runtimeDir);
if (!fs.existsSync(bin)) {
  usage(`TTS binary not found: ${bin}`);
}

const env = { ...process.env };
const libDir = path.join(runtimeDir, "lib");
if (process.platform === "darwin") {
  env.DYLD_LIBRARY_PATH = prependEnvPath(env.DYLD_LIBRARY_PATH || "", libDir);
} else if (process.platform === "win32") {
  env.PATH = prependEnvPath(env.PATH || "", [path.join(runtimeDir, "bin"), libDir].join(path.delimiter));
} else {
  env.LD_LIBRARY_PATH = prependEnvPath(env.LD_LIBRARY_PATH || "", libDir);
}

const outputPath = path.isAbsolute(output) ? output : path.join(process.cwd(), output);
fs.mkdirSync(path.dirname(outputPath), { recursive: true });

const child = spawnSync(
  bin,
  [
    `--vits-model=${modelFile}`,
    `--vits-tokens=${tokensFile}`,
    `--vits-data-dir=${dataDir}`,
    `--output-filename=${outputPath}`,
    text,
  ],
  {
    stdio: "inherit",
    env,
  },
);

if (typeof child.status === "number") {
  process.exit(child.status);
}
if (child.error) {
  console.error(child.error.message || String(child.error));
}
process.exit(1);