from __future__ import annotations

import os
from pathlib import Path
from typing import Any

import yaml

_PROJECT_ROOT = Path(__file__).resolve().parent.parent

_ENV_MAP = {
    "POSEFIT_WS_HOST": ("server", "host"),
    "POSEFIT_WS_PORT": ("server", "port", int),
    "POSEFIT_WS_MAX_SIZE": ("server", "max_ws_size", int),
    "POSEFIT_PROCESS_EVERY_N_FRAMES": ("video", "process_every_n_frames", int),
    "POSEFIT_MODEL_PATH": ("model", "path"),
    "POSEFIT_PREFER_GPU": ("model", "prefer_gpu", lambda v: v not in ("0", "false", "False")),
    "POSEFIT_VISIBILITY_THRESHOLD": ("dead_bug", "visibility_threshold", float),
    "POSEFIT_EXTENSION_CONFIRM_FRAMES": ("dead_bug", "extension_confirm_frames", int),
    "POSEFIT_RESET_CONFIRM_FRAMES": ("dead_bug", "reset_confirm_frames", int),
    "POSEFIT_REP_ANNOUNCER_ENABLED": ("audio", "rep_announcer_enabled", lambda v: v not in ("0", "false", "False")),
    "POSEFIT_REP_ANNOUNCER_RATE": ("audio", "rep_announcer_rate", int),
    "POSEFIT_REP_ANNOUNCER_VOLUME": ("audio", "rep_announcer_volume", float),
    "POSEFIT_LOG_ROTATION": ("logging", "rotation"),
    "POSEFIT_LOG_RETENTION": ("logging", "retention"),
    "POSEFIT_LOG_DIR": ("logging", "dir"),
}


def _load_yaml() -> dict[str, Any]:
    config_path = _PROJECT_ROOT / "config.yaml"
    if config_path.exists():
        with open(config_path, encoding="utf-8") as f:
            return yaml.safe_load(f) or {}
    return {}


def _apply_env_overrides(config: dict) -> None:
    for env_var, (section, key, *rest) in _ENV_MAP.items():
        value = os.getenv(env_var)
        if value is None:
            continue
        if rest:
            value = rest[0](value)
        config.setdefault(section, {})[key] = value


_cfg = _load_yaml()
_apply_env_overrides(_cfg)


def _get(section: str, key: str, default: Any = None) -> Any:
    return _cfg.get(section, {}).get(key, default)


# ── Server ──────────────────────────────────────────────────────────────────
WS_HOST = _get("server", "host", "0.0.0.0")
WS_PORT = _get("server", "port", 8765)
WS_MAX_SIZE = _get("server", "max_ws_size", 10485760)

# ── Video processing ────────────────────────────────────────────────────────
PROCESS_EVERY_N_FRAMES = max(1, _get("video", "process_every_n_frames", 1))

# ── Model ───────────────────────────────────────────────────────────────────
MODEL_DIR: Path = _PROJECT_ROOT / "pose_models"
_model_path = _get("model", "path", "")
MODEL_PATH = _model_path if _model_path else str(MODEL_DIR / "pose_landmarker_full.task")
PREFER_GPU = bool(_get("model", "prefer_gpu", True))

# ── Dead bug exercise ───────────────────────────────────────────────────────
VISIBILITY_THRESHOLD = float(_get("dead_bug", "visibility_threshold", 0.45))
EXTENSION_CONFIRM_FRAMES = int(_get("dead_bug", "extension_confirm_frames", 4))
RESET_CONFIRM_FRAMES = int(_get("dead_bug", "reset_confirm_frames", 3))

# ── Audio ───────────────────────────────────────────────────────────────────
REP_ANNOUNCER_ENABLED = bool(_get("audio", "rep_announcer_enabled", True))
REP_ANNOUNCER_RATE = int(_get("audio", "rep_announcer_rate", 185))
REP_ANNOUNCER_VOLUME = float(_get("audio", "rep_announcer_volume", 1.0))

# ── Logging ─────────────────────────────────────────────────────────────────
LOG_DIR: Path = _PROJECT_ROOT / _get("logging", "dir", "logs")
LOG_ROTATION = _get("logging", "rotation", "20 MB")
LOG_RETENTION = _get("logging", "retention", "14 days")