from __future__ import annotations

import json
import os
from pathlib import Path
from typing import Any, Dict, List


def _safe_int(v: Any, default: int) -> int:
    try:
        return int(v)
    except Exception:
        return int(default)


def _safe_float(v: Any, default: float) -> float:
    try:
        return float(v)
    except Exception:
        return float(default)


def _resolve_path(base_dir: Path, value: str | None) -> Path:
    raw = (value or "").strip()
    p = Path(raw).expanduser()
    if p.is_absolute():
        return p
    return (base_dir / p).resolve()


def run_startup_self_check(cfg: Dict[str, Any], base_dir: Path | None = None) -> Dict[str, Any]:
    """
    Validate runtime-critical config and paths.
    Returns a report dict suitable for GUI popup / worker status.
    """
    if base_dir is None:
        base_dir = Path(__file__).resolve().parent
    base = Path(base_dir).resolve()

    errors: List[str] = []
    warnings: List[str] = []
    info: List[str] = []

    app_cfg = cfg.get("app", {}) or {}
    livox_cfg = cfg.get("livox", {}) or {}
    map_cfg = cfg.get("map", {}) or {}
    loc_cfg = cfg.get("localization", {}) or {}
    nav_cfg = cfg.get("navigation_export", {}) or {}
    nav_rt_cfg = cfg.get("navigation_runtime", {}) or {}
    loop_cfg = cfg.get("loop_closure", {}) or {}
    autosave_cfg = cfg.get("autosave", {}) or {}

    maps_dir = _resolve_path(base, str(app_cfg.get("maps_dir", "DataMap")))
    livox_file = _resolve_path(base, str(livox_cfg.get("config_file", "mid360_config.json")))

    try:
        maps_dir.mkdir(parents=True, exist_ok=True)
    except Exception as e:
        errors.append(f"maps_dir is not creatable: {maps_dir} ({e})")
    else:
        if not maps_dir.is_dir():
            errors.append(f"maps_dir is not a directory: {maps_dir}")
        else:
            if not maps_dir.exists():
                errors.append(f"maps_dir missing: {maps_dir}")
            if not os.access(maps_dir, os.W_OK):
                warnings.append(f"maps_dir is not writable: {maps_dir}")
            info.append(f"maps_dir: {maps_dir}")

    if not livox_file.exists():
        errors.append(f"livox.config_file missing: {livox_file}")
    else:
        info.append(f"livox config: {livox_file.name}")
        try:
            livox_data = json.loads(livox_file.read_text())
            lidar_cfgs = livox_data.get("lidar_configs", []) or []
            ext = {}
            if lidar_cfgs and isinstance(lidar_cfgs[0], dict):
                ext = lidar_cfgs[0].get("extrinsic_parameter", {}) or {}
            ext_vals = [
                _safe_float(ext.get("roll", 0.0), 0.0),
                _safe_float(ext.get("pitch", 0.0), 0.0),
                _safe_float(ext.get("yaw", 0.0), 0.0),
                _safe_float(ext.get("x", 0.0), 0.0),
                _safe_float(ext.get("y", 0.0), 0.0),
                _safe_float(ext.get("z", 0.0), 0.0),
            ]
            if all(abs(v) <= 1e-6 for v in ext_vals):
                warnings.append(
                    "MID360 extrinsics are all zero in mid360_config.json; "
                    "verify G1 upside-down mounting correction before trusting localization."
                )
            else:
                info.append(
                    "MID360 extrinsics: "
                    f"rpy=({ext_vals[0]:.2f}, {ext_vals[1]:.2f}, {ext_vals[2]:.2f}) "
                    f"xyz=({ext_vals[3]:.3f}, {ext_vals[4]:.3f}, {ext_vals[5]:.3f})"
                )
        except Exception as e:
            warnings.append(f"Could not parse MID360 extrinsics from {livox_file.name}: {e}")

    min_map = _safe_int(map_cfg.get("min_points_to_save", 0), 0)
    min_loc = _safe_int(loc_cfg.get("min_points_for_localize", 0), 0)
    min_nav = _safe_int(nav_cfg.get("min_points", 0), 0)
    if min_map <= 0 or min_loc <= 0 or min_nav <= 0:
        errors.append("min points must be > 0 for map/localization/navigation.")
    if not (min_map == min_loc == min_nav):
        warnings.append(
            f"min points mismatch (map/localize/nav): {min_map}/{min_loc}/{min_nav}. "
            "This can confuse export/localization behavior."
        )
    else:
        info.append(f"min points unified: {min_map}")

    z_min = _safe_float(nav_cfg.get("z_min_m", -0.4), -0.4)
    z_max = _safe_float(nav_cfg.get("z_max_m", 1.2), 1.2)
    if z_min >= z_max:
        errors.append(f"navigation_export z range invalid: z_min({z_min}) >= z_max({z_max})")

    rt_z_min = _safe_float(nav_rt_cfg.get("z_min_m", z_min), z_min)
    rt_z_max = _safe_float(nav_rt_cfg.get("z_max_m", z_max), z_max)
    if rt_z_min >= rt_z_max:
        errors.append(f"navigation_runtime z range invalid: z_min({rt_z_min}) >= z_max({rt_z_max})")

    loc_use_p2pl = bool(loc_cfg.get("use_point_to_plane", False))
    loc_unsafe = bool(loc_cfg.get("allow_point_to_plane_unsafe", False))
    if loc_use_p2pl and not loc_unsafe:
        warnings.append(
            "localization.use_point_to_plane=true but allow_point_to_plane_unsafe=false. "
            "Worker will use point-to-point for stability."
        )

    if bool(loop_cfg.get("enabled", False)):
        max_corr_t = _safe_float(loop_cfg.get("max_correction_translation_m", 2.0), 2.0)
        max_corr_r = _safe_float(loop_cfg.get("max_correction_rotation_deg", 20.0), 20.0)
        if max_corr_t <= 0.0 or max_corr_r <= 0.0:
            warnings.append("loop_closure enabled but safe correction limits are non-positive.")
        else:
            info.append(f"loop safe limits: {max_corr_t:.2f}m / {max_corr_r:.1f}deg")

    if bool(autosave_cfg.get("enabled", False)):
        iv = _safe_float(autosave_cfg.get("interval_sec", 90.0), 90.0)
        if iv < 5.0:
            warnings.append(f"autosave interval is very low ({iv:.1f}s).")

    status = "ok"
    if errors:
        status = "error"
    elif warnings:
        status = "warn"
    return {
        "status": status,
        "errors": errors,
        "warnings": warnings,
        "info": info,
    }