"""Convert one EPRO2 SYMBOL Document → a KiCad ``(symbol ...)`` lib entry.

Phase-2 scope: render the SYMBOL primitives so KiCad's lib_symbols block can
provide a real graphical body for each placement (vs the Phase-1 red ``?``).

Coverage / fidelity:
  - PART        → outer (symbol "facere:<partId>" ...) wrapper + properties
  - PIN + ATTR  → (pin <type> line (at x y rot) (length L) (name ...) (number ...))
                  with ATTR(parent=pin, key="Pin Name"/"Pin Number"/"Pin Type")
                  pulled from sibling ATTR ops
  - RECT        → (rectangle (start ...) (end ...) ...)
  - POLY        → (polyline (pts (xy ...) ...) ...) with closed→fill
  - CIRCLE      → (circle (center ...) (radius ...) ...)
  - TEXT        → (text "..." (at ...) ...)
  - ATTR (no parent / on PART) → contributes to symbol-level Reference/Value/...
                                  (best-effort; mostly ignored at body level)

Coordinate convention:
  EPRO2 SYMBOL primitives use **mil** (same as schematic); we convert via
  ``MIL_TO_MM = 0.0254``. KiCad lib symbol coords are **Y-up** internally,
  but the placement of pins relative to body origin is what matters; for
  ESP-VoCat the empirical Y orientation is consistent (pins on left at -X,
  pins on right at +X), so we do not flip Y. If KiCad renders flipped, the
  fix is a per-axis sign in ``_pt`` here.
"""

from __future__ import annotations

from ..relations import Relations
from ..replay import Document
from .sch_writer import MIL_TO_MM
from .sexpr import Sym

# EPRO2 Pin Type -> KiCad electrical type. Empirical mapping; defaults to passive.
PIN_TYPE_MAP: dict[str, str] = {
    "IN": "input",
    "OUT": "output",
    "BIDIR": "bidirectional",
    "BIDIRECTIONAL": "bidirectional",
    "TRI_STATE": "tri_state",
    "TRISTATE": "tri_state",
    "PASSIVE": "passive",
    "POWER_IN": "power_in",
    "POWER_OUT": "power_out",
    "OPEN_COLLECTOR": "open_collector",
    "OPEN_EMITTER": "open_emitter",
    "NC": "no_connect",
    "NOT_CONNECTED": "no_connect",
    "UNSPECIFIED": "unspecified",
}


def _pt(v) -> float:
    """Coerce a mil number to mm. None → 0.0."""
    if v is None:
        return 0.0
    try:
        return float(v) * MIL_TO_MM
    except (TypeError, ValueError):
        return 0.0


def _stroke(width: float = 0.254) -> list:
    return [Sym("stroke"), [Sym("width"), width], [Sym("type"), Sym("default")]]


def _fill(kind: str = "none") -> list:
    return [Sym("fill"), [Sym("type"), Sym(kind)]]


def _font(size: float = 1.27) -> list:
    return [Sym("effects"), [Sym("font"), [Sym("size"), size, size]]]


def _hidden_font(size: float = 1.27) -> list:
    return [Sym("effects"), [Sym("font"), [Sym("size"), size, size]],
            [Sym("hide"), Sym("yes")]]


def _property(name: str, value: str, idx: int, *, hide: bool = False) -> list:
    return [
        Sym("property"), name, value,
        [Sym("at"), 0, 0, 0],
        _hidden_font() if hide else _font(),
    ]


def write_lib_symbol(doc: Document, *, lib_prefix: str = "facere") -> list | None:
    """Render a SYMBOL Document as a KiCad ``(symbol ...)`` block (S-expr list).

    Returns ``None`` if the doc has no PART (malformed lib doc). The caller
    embeds the returned list into a parent ``(lib_symbols ...)`` container.
    """
    if doc.doc_type != "SYMBOL":
        return None

    rel = Relations.build(doc)
    if not rel.parts:
        return None

    # Pick the first PART (ESP-VoCat probe shows 1 PART per SYMBOL doc).
    part_id, part = next(iter(rel.parts.items()))
    title = str(part.get("title") or part_id)

    # Body primitives: RECT, POLY, CIRCLE, TEXT, PIN.
    body: list = [Sym("symbol"), f"{part_id}_1_1"]
    for oid, obj in doc.objects.items():
        t = obj.get("_type")
        # Filter to primitives owned by this part (ignore stray objects)
        if obj.get("partId") != part_id:
            continue
        if t == "RECT":
            x1, y1 = _pt(obj.get("dotX1")), _pt(obj.get("dotY1"))
            x2, y2 = _pt(obj.get("dotX2")), _pt(obj.get("dotY2"))
            body.append([
                Sym("rectangle"),
                [Sym("start"), x1, y1],
                [Sym("end"), x2, y2],
                _stroke(),
                _fill(),
            ])
        elif t == "POLY":
            pts = obj.get("points") or []
            xy_list = [Sym("pts")] + [
                [Sym("xy"), _pt(p.get("x")), _pt(p.get("y"))] for p in pts
                if isinstance(p, dict)
            ]
            if len(xy_list) >= 3:  # at least 2 points + the "pts" tag
                body.append([
                    Sym("polyline"),
                    xy_list,
                    _stroke(),
                    _fill("outline" if obj.get("closed") else "none"),
                ])
        elif t == "CIRCLE":
            body.append([
                Sym("circle"),
                [Sym("center"), _pt(obj.get("centerX")), _pt(obj.get("centerY"))],
                [Sym("radius"), _pt(obj.get("radius"))],
                _stroke(),
                _fill(),
            ])
        elif t == "TEXT":
            val = str(obj.get("value") or "").strip()
            if not val:
                continue
            body.append([
                Sym("text"), val,
                [Sym("at"), _pt(obj.get("x")), _pt(obj.get("y")),
                            float(obj.get("rotation") or 0)],
                _font(),
            ])
        elif t == "PIN":
            attrs = rel.attrs_dict(oid)
            pin_number = str(attrs.get("Pin Number") or "")
            pin_name = str(attrs.get("Pin Name") or "")
            pin_type_raw = str(attrs.get("Pin Type") or "").upper()
            elec = PIN_TYPE_MAP.get(pin_type_raw, "passive")
            body.append([
                Sym("pin"), Sym(elec), Sym("line"),
                [Sym("at"), _pt(obj.get("x")), _pt(obj.get("y")),
                            float(obj.get("rotation") or 0)],
                [Sym("length"), _pt(obj.get("length"))],
                [Sym("name"), pin_name or "~", _font()],
                [Sym("number"), pin_number or "~", _font()],
            ])

    return [
        Sym("symbol"), f"{lib_prefix}:{part_id}",
        [Sym("pin_numbers"), [Sym("hide"), Sym("no")]],
        [Sym("pin_names"), [Sym("offset"), 1.016]],
        [Sym("in_bom"), Sym("yes")],
        [Sym("on_board"), Sym("yes")],
        _property("Reference", "U", 0),
        _property("Value", title, 1),
        _property("Footprint", "", 2, hide=True),
        _property("Datasheet", "", 3, hide=True),
        body,
    ]