import { joinPath } from "../../platform/paths";
import {
  defaultVoiceForLang,
  removeIfExists,
  resolveExecutable,
  writeTempTextFile,
} from "../../platform/executable";
import { runCommand } from "../../platform/subprocess";
import type { TtsProvider, TtsSynthesizeOptions, TtsResult } from "../types";
import { TtsError } from "../types";
import { getPref } from "../../../../../utils/prefs";

async function estimateWavDurationMs(path: string): Promise<number> {
  try {
    const stat = await IOUtils.stat(path);
    return Math.max(1000, Math.floor((stat.size / 32000) * 1000));
  } catch {
    return 0;
  }
}

export function createWindowsSapiProvider(): TtsProvider {
  return {
    id: "system-win",
    label: "Windows SAPI",
    kind: "local",
    supportsTimestamps: false,
    async synthesize(options: TtsSynthesizeOptions): Promise<TtsResult> {
      const powershell = await resolveExecutable("powershell");
      const voice =
        options.voice ||
        (getPref("ttsVoice") as string) ||
        defaultVoiceForLang(options.lang);

      const outWav = options.outputPath.endsWith(".wav")
        ? options.outputPath
        : options.outputPath.replace(/\.\w+$/, ".wav");

      const textPath = await writeTempTextFile(options.text, "sapi-text");
      const scriptPath = joinPath(
        PathUtils.tempDir,
        `chatpapers-sapi-${Date.now()}.ps1`,
      );

      const psScript = [
        "Add-Type -AssemblyName System.Speech",
        "$text = Get-Content -LiteralPath $args[0] -Raw -Encoding UTF8",
        "$out = $args[1]",
        "$voice = $args[2]",
        "$synth = New-Object System.Speech.Synthesis.SpeechSynthesizer",
        "if ($voice) { try { $synth.SelectVoice($voice) } catch {} }",
        "$synth.SetOutputToWaveFile($out)",
        "$synth.Speak($text)",
        "$synth.Dispose()",
      ].join("\n");

      await IOUtils.writeUTF8(scriptPath, psScript);

      try {
        const result = await runCommand(powershell, [
          "-NoProfile",
          "-ExecutionPolicy",
          "Bypass",
          "-File",
          scriptPath,
          textPath,
          outWav,
          voice,
        ]);

        if (result.exitCode !== 0) {
          throw new TtsError(
            `PowerShell SAPI 退出码 ${result.exitCode}`,
            "runtime",
          );
        }
        if (!(await IOUtils.exists(outWav))) {
          throw new TtsError("SAPI 未生成音频文件", "runtime");
        }

        return {
          audioPath: outWav,
          timestamps: [],
          durationMs: await estimateWavDurationMs(outWav),
          format: "wav",
        };
      } finally {
        await removeIfExists(textPath);
        await removeIfExists(scriptPath);
      }
    },
  };
}