"""
Data model — unified internal representation for all coordinate data.
"""
from dataclasses import dataclass, field
from typing import Any


@dataclass
class CoordPoint:
    x: float
    y: float
    z: float | None = None
    attrs: dict[str, Any] = field(default_factory=dict)


@dataclass
class CoordData:
    """Unified container for all coordinate data regardless of source format."""
    points: list[CoordPoint] = field(default_factory=list)
    crs: str | None = None          # e.g. "EPSG:4326"
    columns: list[str] = field(default_factory=list)   # all column names
    geometry_type: str = "Point"    # Point / LineString / Polygon
    extra_meta: dict[str, Any] = field(default_factory=dict)

    @property
    def count(self) -> int:
        return len(self.points)

    def to_records(self) -> list[dict[str, Any]]:
        """Convert to list of flat dicts for DataFrame/Excel export."""
        records = []
        for pt in self.points:
            row = dict(pt.attrs)
            # Always put X, Y (and Z) at front
            row["X"] = pt.x
            row["Y"] = pt.y
            if pt.z is not None:
                row["Z"] = pt.z
            records.append(row)
        return records

    @classmethod
    def from_records(cls, records: list[dict], crs: str | None = None,
                     x_col: str = "X", y_col: str = "Y", z_col: str | None = "Z",
                     geometry_type: str = "Point") -> "CoordData":
        points = []
        for rec in records:
            pt = CoordPoint(
                x=float(rec[x_col]),
                y=float(rec[y_col]),
                z=float(rec[z_col]) if z_col and z_col in rec else None,
                attrs={k: v for k, v in rec.items()
                       if k not in (x_col, y_col, z_col)},
            )
            points.append(pt)
        cols = list(records[0].keys()) if records else []
        return cls(points=points, crs=crs, columns=cols, geometry_type=geometry_type)