"""
本地 GPU 音色库（ChatTTS，无需云端 API）
- custom：用户在「音色锁定」克隆的 speaker_emb.pt
- preset_*：ChatTTS sample_random_speaker 生成的内置说话人（scripts/generate_voice_presets.sh）
"""

from __future__ import annotations

import json
import logging
from pathlib import Path
from typing import Any, Dict, List, Optional, Tuple

import torch

from config import BASE_DIR, SPEAKER_EMB_PATH

logger = logging.getLogger(__name__)

VOICES_DIR = Path(BASE_DIR) / "voices"
PRESETS_DIR = VOICES_DIR / "presets"
MANIFEST_PATH = VOICES_DIR / "manifest.json"

CUSTOM_VOICE_ID = "custom"

# 生成脚本写入的预设元数据（.pt 文件不入 Git）
DEFAULT_MANIFEST = {
    "presets": [
        {"id": "preset_01", "label": "预设·沉稳男声", "file": "presets/preset_01.pt"},
        {"id": "preset_02", "label": "预设·青年男声", "file": "presets/preset_02.pt"},
        {"id": "preset_03", "label": "预设·温柔女声", "file": "presets/preset_03.pt"},
        {"id": "preset_04", "label": "预设·活泼女声", "file": "presets/preset_04.pt"},
        {"id": "preset_05", "label": "预设·中性旁白", "file": "presets/preset_05.pt"},
        {"id": "preset_06", "label": "预设·纪录片风", "file": "presets/preset_06.pt"},
    ]
}


def ensure_manifest() -> None:
    VOICES_DIR.mkdir(parents=True, exist_ok=True)
    PRESETS_DIR.mkdir(parents=True, exist_ok=True)
    if not MANIFEST_PATH.is_file():
        MANIFEST_PATH.write_text(
            json.dumps(DEFAULT_MANIFEST, ensure_ascii=False, indent=2),
            encoding="utf-8",
        )


def _read_manifest() -> Dict[str, Any]:
    ensure_manifest()
    try:
        return json.loads(MANIFEST_PATH.read_text(encoding="utf-8"))
    except Exception as exc:
        logger.warning("读取 manifest 失败: %s", exc)
        return DEFAULT_MANIFEST


def list_voice_choices() -> List[Tuple[str, str]]:
    """
    返回 Gradio Dropdown 选项：(显示名, voice_id)。
  仅列出磁盘上已存在的音色。
    """
    choices: List[Tuple[str, str]] = []

    if SPEAKER_EMB_PATH.is_file():
        choices.append(("我的锁定音色（声音克隆）", CUSTOM_VOICE_ID))

    for preset in _read_manifest().get("presets", []):
        pid = preset.get("id", "")
        label = preset.get("label", pid)
        rel = preset.get("file", "")
        if pid and rel and (VOICES_DIR / rel).is_file():
            choices.append((label, pid))

    if not choices:
        choices.append(
            (
                "（请先在「音色锁定」上传人声，或运行 generate_voice_presets.sh）",
                CUSTOM_VOICE_ID,
            )
        )
    return choices


def default_voice_id() -> str:
    choices = list_voice_choices()
    if not choices:
        return CUSTOM_VOICE_ID
    for _label, vid in choices:
        if vid == CUSTOM_VOICE_ID:
            return CUSTOM_VOICE_ID
    return choices[0][1]


def voice_choice_labels() -> List[str]:
    return [c[0] for c in list_voice_choices()]


def label_to_voice_id(label: str) -> str:
    for lbl, vid in list_voice_choices():
        if lbl == label:
            return vid
    return default_voice_id()


def load_voice_payload(voice_id: str) -> Tuple[Optional[Dict[str, Any]], Optional[str]]:
    """按 voice_id 加载 ChatTTS 说话人数据。"""
    if voice_id == CUSTOM_VOICE_ID or not voice_id:
        if not SPEAKER_EMB_PATH.is_file():
            return None, (
                "未找到锁定音色。请在「音色锁定」上传参考人声，"
                "或选择下方「预设」音色（需先运行 scripts/generate_voice_presets.sh）。"
            )
        return _load_payload_file(SPEAKER_EMB_PATH)

    for preset in _read_manifest().get("presets", []):
        if preset.get("id") != voice_id:
            continue
        path = VOICES_DIR / preset.get("file", "")
        if not path.is_file():
            return None, (
                f"预设音色「{preset.get('label', voice_id)}」尚未生成。\n"
                f"请在服务器执行: bash scripts/generate_voice_presets.sh"
            )
        return _load_payload_file(path)

    return None, f"未知音色 ID: {voice_id}"


def _load_payload_file(path: Path) -> Tuple[Optional[Dict[str, Any]], Optional[str]]:
    try:
        payload = torch.load(path, map_location="cpu", weights_only=False)
        if isinstance(payload, torch.Tensor):
            return {"spk_emb": payload, "spk_smp": None, "txt_smp": ""}, None
        if isinstance(payload, dict):
            return payload, None
        return None, f"音色文件格式无效: {path.name}"
    except Exception as exc:
        return None, f"读取音色文件失败 ({path.name}): {exc}"