import json
import logging

logger = logging.getLogger(__name__)

DEFAULT_CONFIG = {
    "output_format": "PNG",   # PNG or JPG
    "output_quality": 95,     # JPG quality 1-95
    "output_dir": "",         # empty = use app output/ dir
    "last_garment_dir": "",
    "last_print_dir": "",
    "last_template": "",       # name of the last-selected template
    "last_batch_mode": "full_combo",  # BatchMode value of the last-used mode
    "update_source": "",       # HTTP(S) manifest source (empty = no update check)
    "update_user": "",         # HTTP Basic Auth user (empty = anonymous)
    "update_pass": "",         # HTTP Basic Auth password (empty = anonymous)
    # AI 穿搭（docs/11 §11）：上次路径与批量设置并入 app_config（密钥不在此，见 ai_models.json）
    "outfit_excel": "",
    "outfit_output_dir": "",
    "outfit_model": "",            # last-selected model name
    "outfit_concurrency": 1,
    "outfit_request_interval": 2.0,
    "outfit_task_cooldown": 1.0,
    "outfit_retry_count": 2,
    "outfit_resolution": "1K",
    "outfit_quality": "均衡",
    "outfit_retry_failed": False,
}

_CONFIG_FILENAME = "app_config.json"
_AI_MODELS_FILENAME = "ai_models.json"
_OUTFIT_PROMPT_FILENAME = "outfit_prompt.txt"

# Default outfit prompt (docs/11 §7). Persisted to outfit_prompt.txt on first save.
DEFAULT_OUTFIT_PROMPT = (
    "为商品「{title}」生成人物上身实穿效果图：真人模特正面穿着这件衣服，"
    "完整保留款式、版型、颜色与印花图案，自然光、纯色棚拍背景，"
    "电商主图风格，不加文字与促销标签。"
)


def load_config():
    """
    从 JSON 文件加载应用配置。

    返回默认配置与文件配置的合并字典。如果配置文件不存在、损坏或无法读取，
    函数不会抛出异常，而是记录日志并返回默认配置。

    Returns:
        dict: 合并后的配置字典
    """
    from services.file_service import get_config_path
    config_file = get_config_path(_CONFIG_FILENAME)

    if not config_file.exists():
        logger.info("Config file not found, using defaults: %s", config_file)
        return dict(DEFAULT_CONFIG)

    try:
        with open(str(config_file), encoding="utf-8") as f:
            data = json.load(f)
        if not isinstance(data, dict):
            raise ValueError("Config root is not a JSON object")
        merged = dict(DEFAULT_CONFIG)
        merged.update(data)
        logger.info("Config loaded from %s", config_file)
        return merged
    except (json.JSONDecodeError, ValueError) as exc:
        logger.warning("Config file damaged (%s), using defaults: %s", exc, config_file)
        return dict(DEFAULT_CONFIG)
    except OSError as exc:
        logger.warning("Config file unreadable (%s), using defaults: %s", exc, config_file)
        return dict(DEFAULT_CONFIG)


def save_config(data):
    """Save config dict to JSON. Logs error on failure, does not raise."""
    from services.file_service import get_config_path
    config_file = get_config_path(_CONFIG_FILENAME)

    try:
        config_file.parent.mkdir(parents=True, exist_ok=True)
        with open(str(config_file), "w", encoding="utf-8") as f:
            json.dump(data, f, ensure_ascii=False, indent=2)
        logger.info("Config saved to %s", config_file)
    except OSError as exc:
        logger.error("Failed to save config to %s: %s", config_file, exc)


def load_ai_models():
    """Load AI model configs from ai_models.json.

    Returns a list of dicts (each with a ``name`` plus AiModelConfig fields).
    Missing/corrupt file → empty list (the UI then prompts the admin to add one).
    Keys live only in ~/.cmbot and are never committed (docs/11 §11).
    """
    from services.file_service import get_config_path
    models_file = get_config_path(_AI_MODELS_FILENAME)
    if not models_file.exists():
        logger.info("AI models file not found: %s", models_file)
        return []
    try:
        with open(str(models_file), encoding="utf-8-sig") as f:
            data = json.load(f)
    except (json.JSONDecodeError, ValueError, OSError) as exc:
        logger.warning("AI models file unreadable (%s): %s", exc, models_file)
        return []

    models = data.get("models") if isinstance(data, dict) else data
    if not isinstance(models, list):
        logger.warning("AI models file has no model list: %s", models_file)
        return []
    return [m for m in models if isinstance(m, dict)]


def load_outfit_prompt():
    """Return the saved outfit prompt template, or the built-in default."""
    from services.file_service import get_config_path
    prompt_file = get_config_path(_OUTFIT_PROMPT_FILENAME)
    if not prompt_file.exists():
        return DEFAULT_OUTFIT_PROMPT
    try:
        with open(str(prompt_file), encoding="utf-8-sig") as f:
            return f.read()
    except OSError as exc:
        logger.warning("Outfit prompt unreadable (%s): %s", exc, prompt_file)
        return DEFAULT_OUTFIT_PROMPT


def save_outfit_prompt(text):
    """Persist the outfit prompt template (utf-8, no BOM). Does not raise."""
    from services.file_service import get_config_path
    prompt_file = get_config_path(_OUTFIT_PROMPT_FILENAME)
    try:
        prompt_file.parent.mkdir(parents=True, exist_ok=True)
        with open(str(prompt_file), "w", encoding="utf-8") as f:
            f.write(text)
        logger.info("Outfit prompt saved to %s", prompt_file)
    except OSError as exc:
        logger.error("Failed to save outfit prompt to %s: %s", prompt_file, exc)