"""
模型路径配置（共享配置文件）
用于 Docker 构建阶段预下载和运行时加载
"""

# 默认模型（供 run.py 帮助信息等轻量场景使用，避免导入 torch/transformers）
DEFAULT_BASE_MODEL = "qwen3-0.6b"
DEFAULT_INSTRUCT_MODEL = "qwen3-0.6b-instruct"

# Base 槽位（--base_model）
MODEL_PATHS = {
    # 标准模型（FP16/BF16）
    'qwen2.5-0.5b': 'Qwen/Qwen2.5-0.5B',
    # qwen3 base
    'qwen3-0.6b': 'Qwen/Qwen3-0.6B-Base',
    'qwen3-1.7b': 'Qwen/Qwen3-1.7B-Base',
    'qwen3-4b': 'Qwen/Qwen3-4B-Base',
    'qwen3-8b': 'Qwen/Qwen3-8B-Base',
    'qwen3-14b': 'Qwen/Qwen3-14B-Base',
    # qwen3.5
    'qwen3.5-0.8b': 'Qwen/Qwen3.5-0.8B-Base',
    'qwen3.5-2b': 'Qwen/Qwen3.5-2B-Base',
    'qwen3.5-4b': 'Qwen/Qwen3.5-4B-Base',
}

# Instruct 槽位（--instruct_model；chat template 与指令理解）
INSTRUCT_MODEL_PATHS = {
    "qwen3-0.6b-instruct": "Qwen/Qwen3-0.6B",
    "qwen3-1.7b-instruct": "Qwen/Qwen3-1.7B",
    "qwen3-4b-instruct": "Qwen/Qwen3-4B-Instruct-2507",
    "qwen3-8b-instruct": "Qwen/Qwen3-8B",
    # qwen3.5，目前只支持CPU。MPS上有反向传播不支持fp16问题，CUDA上有transformers 5.x版本报错问题。
    "qwen3.5-0.8b-instruct": "Qwen/Qwen3.5-0.8B",
    "qwen3.5-2b-instruct": "Qwen/Qwen3.5-2B",
    "qwen3.5-4b-instruct": "Qwen/Qwen3.5-4B"
}

# run.py 帮助：两槽位 id 列表（先 base 后 instruct）
CLI_MODEL_IDS = tuple(MODEL_PATHS.keys()) + tuple(INSTRUCT_MODEL_PATHS.keys())
BASE_MODEL_IDS = frozenset(MODEL_PATHS.keys())
INSTRUCT_MODEL_IDS = frozenset(INSTRUCT_MODEL_PATHS.keys())


def _normalize_cli_id(cli_id: str) -> str:
    raw = cli_id.strip()
    if not raw:
        raise ValueError("model id must be non-empty")
    return raw


def validate_base_model_id(cli_id: str) -> str:
    """校验 --base_model；返回规范化后的 id（保留原始大小写键）。"""
    raw = _normalize_cli_id(cli_id)
    lk = raw.lower()
    if lk not in MODEL_PATHS:
        known = ", ".join(sorted(MODEL_PATHS.keys()))
        raise ValueError(f"unknown base_model {raw!r}; known base ids: {known}")
    for key in MODEL_PATHS:
        if key.lower() == lk:
            return key
    return raw  # unreachable


def validate_instruct_model_id(cli_id: str) -> str:
    """校验 --instruct_model；返回规范化后的 id。"""
    raw = _normalize_cli_id(cli_id)
    lk = raw.lower()
    if lk not in INSTRUCT_MODEL_PATHS:
        known = ", ".join(sorted(INSTRUCT_MODEL_PATHS.keys()))
        raise ValueError(f"unknown instruct_model {raw!r}; known instruct ids: {known}")
    for key in INSTRUCT_MODEL_PATHS:
        if key.lower() == lk:
            return key
    return raw


def resolve_hf_path(cli_id: str) -> str:
    """
    将 CLI 模型 id 解析为 HuggingFace 仓库 id（或本地路径字符串）。
    查找顺序：MODEL_PATHS → INSTRUCT_MODEL_PATHS（键不区分大小写）→ 未命中则原样返回（视为 HF id）。
    """
    raw = _normalize_cli_id(cli_id)
    lk = raw.lower()
    return MODEL_PATHS.get(lk) or INSTRUCT_MODEL_PATHS.get(lk) or raw