"""Pre-synthesise demo lines so the Gemini voice speaks instantly.

Cloud TTS costs a network round trip - roughly 4 s for a sentence, 8 s for a
paragraph. That is fine while rehearsing and painful in front of an audience.
This warms the on-disk cache ahead of time, so a warmed line plays with **no
delay at all**.

    python scripts/warm_voice.py "Good afternoon, welcome to our showroom."
    python scripts/warm_voice.py --file demo_lines.txt
    python scripts/warm_voice.py --stats
    python scripts/warm_voice.py --clear

Audio is saved in audio_library/ as ordinary .wav files with readable names, so
it survives restarts, plays in any media player, and needs no internet once
saved. The server reads the same folder - warm before you present.

Only relevant when MOCK_VOICE_ENGINE=gemini.
"""

from __future__ import annotations

import argparse
import sys
import time
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))


def _use_utf8_console() -> None:
    for stream in (sys.stdout, sys.stderr):
        try:
            if stream is not None and hasattr(stream, "reconfigure"):
                stream.reconfigure(encoding="utf-8", errors="replace")
        except Exception:
            pass


_use_utf8_console()

from backend.config.settings import get_settings  # noqa: E402
from backend.robot.gemini_voice import GeminiVoice  # noqa: E402


def build(settings) -> GeminiVoice:
    return GeminiVoice(
        api_key=settings.mock.gemini_api_key or "",
        model=settings.mock.gemini_model,
        voice=settings.mock.gemini_voice,
        style=settings.mock.gemini_style,
        chunk_chars=settings.mock.gemini_chunk_chars,
        fallback=None,
    )


def main() -> None:
    parser = argparse.ArgumentParser(description="Pre-synthesise lines for the Gemini voice.")
    parser.add_argument("lines", nargs="*", help="Lines to warm.")
    parser.add_argument("--file", help="Text file, one line per utterance.")
    parser.add_argument("--stats", action="store_true", help="Show library size and exit.")
    parser.add_argument("--clear", action="store_true", help="Delete all saved audio and exit.")
    args = parser.parse_args()

    settings = get_settings()
    if not settings.mock.gemini_api_key:
        print("\n  GEMINI_API_KEY is not set in .env - nothing to warm.\n")
        raise SystemExit(1)

    voice = build(settings)

    if args.clear:
        voice.clear_cache()
        print("\n  Cache cleared.\n")
        return

    if args.stats or not (args.lines or args.file):
        stats = voice.cache_stats()
        print("\n  Saved audio")
        print("  " + "-" * 52)
        print("  Entries : {0}".format(stats["entries"]))
        print("  Size    : {0:.1f} MB".format(stats["bytes"] / 1_048_576))
        print("  Location: {0}".format(stats["dir"]))
        print("  Voice   : {0} ({1})".format(settings.mock.gemini_voice, settings.mock.gemini_model))
        if not (args.lines or args.file):
            print("")
            print('  Warm a line:  python scripts/warm_voice.py "Welcome to our showroom."')
            print("  Warm a file:  python scripts/warm_voice.py --file demo_lines.txt")
        print("")
        return

    lines = list(args.lines)
    if args.file:
        path = Path(args.file)
        if not path.exists():
            print("\n  No such file: {0}\n".format(path))
            raise SystemExit(1)
        lines += [ln.strip() for ln in path.read_text(encoding="utf-8").splitlines() if ln.strip()]

    print("\n  Warming {0} line(s) with voice '{1}'...".format(len(lines), settings.mock.gemini_voice))
    print("  " + "-" * 60)
    total_new = 0
    started = time.time()
    for index, line in enumerate(lines, 1):
        t0 = time.time()
        try:
            fetched = voice.warm(line)
        except Exception as exc:
            print("  {0:>3}. FAILED  {1}".format(index, exc))
            continue
        total_new += fetched
        state = "cached already" if fetched == 0 else "fetched {0} chunk(s)".format(fetched)
        preview = line if len(line) <= 48 else line[:45] + "..."
        print("  {0:>3}. {1:<50} {2:>16}  {3:5.1f}s".format(
            index, preview, state, time.time() - t0))

    stats = voice.cache_stats()
    print("  " + "-" * 60)
    print("  {0} new clip(s) in {1:.1f}s. Library now holds {2} clips ({3:.1f} MB).".format(
        total_new, time.time() - started, stats["entries"], stats["bytes"] / 1_048_576))
    print("  These lines will now speak instantly.\n")
    voice.close()


if __name__ == "__main__":
    main()