"""Convert one EPRO2 PCB Document → an EasyEDA Std-format PCB JSON.

Std PCB format (probed on `data/raw/oshwhub/3e2f893d.../25931ddab8.json`):

  {
    "success": true, "code": 0,
    "result": {
      "uuid": <doc_uuid>, "puuid": <project_uuid>, "title": "...",
      "docType": 3,
      "components": {<lib_uuid>: <ref_count>, ...},
      "dataStr": {
        "head": {"docType":"3","editorVersion":"...","x":...,"y":...},
        "canvas": "CA~<w>~<h>~<bg>~...",
        "shape": ["TRACK~...", "PAD~...", "LIB~...#@$PAD~...#@$TEXT~...", ...],
        "layers": ["1~TopLayer~#FF0000~true~true~true~", ...],
        "objects": [], "BBox": {...}
      }
    }
  }

Each shape verb is a tilde-delimited string. LIB shapes nest inner PAD/TEXT
via the ``#@$`` separator so a footprint placement is one outer LIB string
plus its body.

Phase-1 scope (mirrors the KiCad PCB writer): TRACK / VIA / COPPERAREA /
RECT / CIRCLE / SOLIDREGION / LIB(+PAD+TEXT). Skipped: SVGNODE bitmaps,
manual FILL on copper (rare), TEARDROP fillets (cosmetic).
"""

from __future__ import annotations

import json
import math
import uuid as _uuid
from dataclasses import dataclass, field
from typing import TYPE_CHECKING

from ..relations import Relations
from ..replay import Document

if TYPE_CHECKING:
    from ..project_relations import ProjectRelations


# -- EPRO2 layer id → Std layer id --------------------------------------
#
# Std uses a different numbering than EPRO2. Probed from a Std PCB file's
# `layers` block; mismatches in the 5/6/7/8 (mask/paste) range are real.
EPRO_TO_STD_LAYER: dict[int, int] = {
    1: 1,    # TOP_LAYER
    2: 2,    # BOTTOM_LAYER
    3: 3,    # TOP_SILK
    4: 4,    # BOT_SILK
    5: 7,    # TOP_SOLDER_MASK (Std 7, EPRO2 5 — flipped vs PASTE)
    6: 8,    # BOT_SOLDER_MASK
    7: 5,    # TOP_PASTE_MASK (Std 5, EPRO2 7)
    8: 6,    # BOT_PASTE_MASK
    9: 13,   # TOP_ASSEMBLY
    10: 14,  # BOT_ASSEMBLY
    11: 10,  # OUTLINE → BoardOutLine
    12: 11,  # MULTI → Multi-Layer
    13: 12,  # DOCUMENT
    14: 15,  # MECHANICAL
}
# EPRO2 SIGNAL inner layers 15..46 → Std Inner1..Inner30 = layer ids 21..50.

# Default Std layer block — we emit the standard ones plus any inner layers
# the board actually uses. Matches the "layers" format `id~name~color~visible
# ~active~locked~clearance/type`.
_DEFAULT_STD_LAYERS: list[str] = [
    "1~TopLayer~#FF0000~true~true~true~",
    "2~BottomLayer~#0000FF~true~false~true~",
    "3~TopSilkLayer~#FFCC00~true~false~true~",
    "4~BottomSilkLayer~#66CC33~true~false~true~",
    "5~TopPasteMaskLayer~#808080~true~false~true~",
    "6~BottomPasteMaskLayer~#800000~true~false~true~",
    "7~TopSolderMaskLayer~#800080~true~false~true~0.3",
    "8~BottomSolderMaskLayer~#AA00FF~true~false~true~0.3",
    "9~Ratlines~#6464FF~true~false~true~",
    "10~BoardOutLine~#FF00FF~true~false~true~",
    "11~Multi-Layer~#C0C0C0~true~false~true~",
    "12~Document~#FFFFFF~true~false~true~",
    "13~TopAssembly~#33CC99~false~false~false~",
    "14~BottomAssembly~#5555FF~false~false~false~",
    "15~Mechanical~#F022F0~false~false~false~",
]


@dataclass
class WriteStats:
    tracks: int = 0
    vias: int = 0
    copperareas: int = 0
    rects: int = 0
    circles: int = 0
    solidregions: int = 0
    libs: int = 0
    libs_unresolved: int = 0
    pads: int = 0
    texts: int = 0
    holes: int = 0
    skipped: int = 0


def _gge() -> str:
    """Std prefixes ids with `gge<8 hex>`. We use uuid4 hex slice for
    uniqueness; downstream tools accept any unique opaque string here."""
    return "gge" + _uuid.uuid4().hex[:8]


def _num(v) -> str:
    """Format a number like Std does (no trailing .0, but keep precision)."""
    if v is None:
        return "0"
    try:
        f = float(v)
    except (TypeError, ValueError):
        return "0"
    if math.isclose(f, int(f), abs_tol=1e-9):
        return str(int(f))
    return f"{f:.4f}".rstrip("0").rstrip(".")


def _layer(epro_layer_id, signal_inner_map: dict[int, int]) -> str:
    if epro_layer_id is None:
        return "0"
    try:
        lid = int(epro_layer_id)
    except (TypeError, ValueError):
        return "0"
    if lid in EPRO_TO_STD_LAYER:
        return str(EPRO_TO_STD_LAYER[lid])
    if lid in signal_inner_map:
        return str(signal_inner_map[lid])
    return str(lid)


def _build_signal_inner_map(doc: Document) -> dict[int, int]:
    """EPRO2 SIGNAL inner layer ids (15+) → Std inner ids (21..50)."""
    inner_ids: list[int] = []
    for oid, obj in doc.objects.items():
        if obj.get("_type") != "LAYER":
            continue
        if obj.get("layerType") != "SIGNAL":
            continue
        if oid.startswith('["LAYER",'):
            try:
                cid = json.loads(oid)
                lid = int(cid[1])
                if obj.get("use") and lid >= 15:
                    inner_ids.append(lid)
            except (ValueError, IndexError, TypeError):
                continue
    inner_ids.sort()
    return {lid: 21 + i for i, lid in enumerate(inner_ids)}


def _track(line: dict, signal_inner_map: dict[int, int]) -> str | None:
    layer = _layer(line.get("layerId"), signal_inner_map)
    width = _num(line.get("width") or 6)
    net = str(line.get("netName") or "")
    pts = (
        f"{_num(line.get('startX'))} {_num(line.get('startY'))} "
        f"{_num(line.get('endX'))} {_num(line.get('endY'))}"
    )
    return f"TRACK~{width}~{layer}~{net}~{pts}~{_gge()}~0"


def _via(via: dict) -> str:
    cx = _num(via.get("centerX"))
    cy = _num(via.get("centerY"))
    outer = _num(via.get("viaDiameter"))
    inner = _num(via.get("holeDiameter"))
    net = str(via.get("netName") or "")
    return f"VIA~{cx}~{cy}~{outer}~{net}~{inner}~{_gge()}~0"


def _path_to_svg(path) -> str:
    """EPRO2 path tokens → SVG-ish 'M x y L x y ...' string used by Std
    COPPERAREA / SOLIDREGION shapes. ARC tokens collapse to chord
    segments (Phase-1 same call as the KiCad writer). Numbers are
    formatted via ``_num`` (no trailing ``.0`` on integers) so the
    output matches Std's typographic conventions exactly."""
    if not isinstance(path, list) or not path:
        return ""
    if isinstance(path[0], list):
        # path is wrapped in an extra outer list, like POUR.path = [[...]]
        path = path[0]
    head = path[0] if path else None
    if isinstance(head, str) and head.upper() == "R" and len(path) >= 5:
        try:
            x = float(path[1]); y = float(path[2])
            w = float(path[3]); h = float(path[4])
            return (
                f"M {_num(x)} {_num(y)} L {_num(x + w)} {_num(y)} "
                f"L {_num(x + w)} {_num(y + h)} L {_num(x)} {_num(y + h)} Z"
            )
        except (TypeError, ValueError):
            pass
    if isinstance(head, str) and head.upper() == "CIRCLE" and len(path) >= 4:
        try:
            cx = float(path[1]); cy = float(path[2]); r = float(path[3])
            pts = []
            for i in range(24):
                a = 2 * math.pi * i / 24
                pts.append((cx + r * math.cos(a), cy + r * math.sin(a)))
            return "M " + " L ".join(f"{_num(x)} {_num(y)}" for x, y in pts) + " Z"
        except (TypeError, ValueError):
            pass
    out: list[str] = []
    i = 0
    started = False
    while i < len(path):
        tok = path[i]
        if isinstance(tok, str):
            if tok.upper() == "ARC":
                try:
                    ex = float(path[i + 2]); ey = float(path[i + 3])
                    out.append(f"L {_num(ex)} {_num(ey)}")
                except (TypeError, ValueError, IndexError):
                    pass
                i += 4
                continue
            i += 1
            continue
        try:
            x = float(path[i]); y = float(path[i + 1])
            out.append(("M" if not started else "L") + f" {_num(x)} {_num(y)}")
            started = True
            i += 2
        except (TypeError, ValueError, IndexError):
            i += 1
    return " ".join(out)


def _copperarea(pour: dict, signal_inner_map: dict[int, int]) -> str | None:
    layer = _layer(pour.get("layerId"), signal_inner_map)
    net = str(pour.get("netName") or "")
    svg = _path_to_svg(pour.get("path"))
    if not svg:
        return None
    width = _num(pour.get("width") or 1)
    # COPPERAREA~clearance~layer~net~svgPath~strokeWidth~~~~~~~uuid?
    return f"COPPERAREA~1~{layer}~{net}~{svg}~{width}~~~~~~~{_gge()}~0"


def _circle(obj: dict, signal_inner_map: dict[int, int]) -> str | None:
    """Used for non-copper graphic POLYs whose path is `['CIRCLE', cx, cy, r]`."""
    path = obj.get("path") or []
    head = path[0] if path else None
    if isinstance(head, list):
        head = head[0] if head else None
    if not (isinstance(head, str) and head.upper() == "CIRCLE"):
        return None
    inner = path[0] if isinstance(path[0], list) else path
    try:
        cx = _num(inner[1]); cy = _num(inner[2]); r = _num(inner[3])
    except (TypeError, IndexError, ValueError):
        return None
    layer = _layer(obj.get("layerId"), signal_inner_map)
    width = _num(obj.get("width") or 1)
    return f"CIRCLE~{cx}~{cy}~{r}~{width}~{layer}~{_gge()}~0~~"


def _solidregion(obj: dict) -> str | None:
    """EPRO2 FILL → Std SOLIDREGION."""
    svg = _path_to_svg(obj.get("path"))
    if not svg:
        return None
    return f"SOLIDREGION~99~~{svg}~solid~{_gge()}~~~~0"


def _pad_for_lib(pad: dict, comp_id: str, pcb_rel: Relations,
                 signal_inner_map: dict[int, int]) -> str | None:
    """Std nested PAD inside a LIB, format:
       PAD~shape~x~y~width~height~layer~net~num~drillSize~~rot~uuid~~~plated~?~?~clearance~paste"""
    default_pad = pad.get("defaultPad") or {}
    shape_map = {"RECT": "RECT", "ELLIPSE": "ELLIPSE", "OVAL": "OVAL", "POLYGON": "POLYGON"}
    shape = shape_map.get(default_pad.get("padType"))
    if shape is None:
        return None
    cx = _num(pad.get("centerX"))
    cy = _num(pad.get("centerY"))
    w = _num(default_pad.get("width"))
    h = _num(default_pad.get("height"))
    layer = _layer(pad.get("layerId"), signal_inner_map)
    rot = _num(pad.get("padAngle") or 0)
    pin_num = str(pad.get("num") or "")

    # Net via PCB-level PAD_NET (cross-doc, like in footprint_writer)
    net_name = ""
    pad_id = next(
        (pid for pid in pcb_rel.pads if pcb_rel.pads[pid] is pad),  # rare path; usually pad_id is the dict key
        None,
    )
    # The standard path: walk pad_nets_by_pad keyed by the pad's id.
    # We don't have the id here; caller passes it via outer loop.
    net_name = ""

    # Hole
    hole = pad.get("hole")
    drill = "0"
    if hole:
        drill = _num(hole.get("width") or 0)

    # Phase-1 leaves the trailing free-form metadata empty but keeps the
    # field count; downstream Std parsers can tolerate empties but balk
    # at missing positional fields.
    return (
        f"PAD~{shape}~{cx}~{cy}~{w}~{h}~{layer}~{net_name}~{pin_num}~{drill}~~"
        f"{rot}~{_gge()}~0~~Y~0~0~0.2~{cx},{cy}"
    )


def _lib(comp_id: str, comp: dict, attrs: dict, fp_doc: Document,
         pcb_rel: Relations, signal_inner_map: dict[int, int]) -> tuple[str, int]:
    """Build a Std LIB shape with nested PAD / TEXT children separated by `#@$`.

    Returns ``(lib_string, pad_count_for_stats)``.
    """
    px = _num(comp.get("x"))
    py = _num(comp.get("y"))
    rot = _num(comp.get("angle") or 0)
    designator = str(attrs.get("Designator") or "")
    fp_title = (fp_doc.objects.get("META") or {}).get("title") or fp_doc.doc_uuid[:8]
    package = f"{fp_title}`"  # Std emits a trailing backtick after package name

    # Outer LIB: x, y, package_name, rotation, ?, uuid, display, ?, ?, locked,
    #           ?, yes, ?
    outer = (
        f"LIB~{px}~{py}~{package}~{rot}~~{_gge()}~1~~~0~~yes~~"
    )

    # Build inner PAD blocks per FOOTPRINT.PAD with its abs (footprint-local)
    # coords offset to the placement origin. Std stores pad coords as
    # absolute board coords; we therefore translate from footprint-local
    # to PCB absolute here.
    rel_fp = Relations.build(fp_doc)
    inners: list[str] = []
    pad_count = 0
    px_f = float(comp.get("x") or 0)
    py_f = float(comp.get("y") or 0)
    rot_f = math.radians(float(comp.get("angle") or 0))
    cos_a, sin_a = math.cos(rot_f), math.sin(rot_f)
    for pad_id, pad in rel_fp.pads.items():
        local_x = float(pad.get("centerX") or 0)
        local_y = float(pad.get("centerY") or 0)
        # Apply placement rotation to the local (x, y) then translate.
        abs_x = px_f + local_x * cos_a - local_y * sin_a
        abs_y = py_f + local_x * sin_a + local_y * cos_a

        default_pad = pad.get("defaultPad") or {}
        shape_kind = default_pad.get("padType") or "RECT"
        w = _num(default_pad.get("width"))
        h = _num(default_pad.get("height"))
        layer = _layer(pad.get("layerId"), signal_inner_map)
        pad_rot = _num((float(pad.get("padAngle") or 0) + float(comp.get("angle") or 0)) % 360)
        pin_num = str(pad.get("num") or "")
        # Net resolution via PCB PAD_NET (cross-doc)
        net_name = ""
        for record in pcb_rel.pad_nets_by_pad.get(pad_id, []):
            if record.get("comp") == comp_id:
                net_name = record.get("net_name") or ""
                break
        hole = pad.get("hole")
        drill = _num(hole.get("width")) if hole else "0"
        inners.append(
            f"PAD~{shape_kind}~{_num(abs_x)}~{_num(abs_y)}~{w}~{h}~{layer}~"
            f"{net_name}~{pin_num}~{drill}~~{pad_rot}~{_gge()}~0~~Y~0~0~0.2~"
            f"{_num(abs_x)},{_num(abs_y)}"
        )
        pad_count += 1

    # Designator text (Std treats it as P=property)
    if designator:
        inners.append(
            f"TEXT~P~{px}~{py}~0.7~0~0~3~~4.5~{designator}~~~"
        )

    body = "#@$".join([outer] + inners)
    return body, pad_count


def write_pcb_std(
    doc: Document,
    *,
    project_relations: "ProjectRelations" | None = None,
) -> dict:
    """EPRO2 PCB Document → Std-format JSON dict (ready for json.dump)."""
    if doc.doc_type != "PCB":
        raise ValueError(f"expected PCB doc, got {doc.doc_type!r}")

    rel = Relations.build(doc)
    signal_inner_map = _build_signal_inner_map(doc)
    stats = WriteStats()
    shape: list[str] = []

    # Tracks
    for oid, obj in doc.objects.items():
        if obj.get("_type") != "LINE":
            continue
        # Std TRACK is for any layer (copper or silk), unlike KiCad which
        # splits copper→segment / silk→gr_line. Std uses the same verb,
        # disambiguated by layer id.
        track = _track(obj, signal_inner_map)
        if track:
            shape.append(track)
            stats.tracks += 1

    # Vias
    for oid, obj in doc.objects.items():
        if obj.get("_type") == "VIA":
            shape.append(_via(obj))
            stats.vias += 1

    # Copper pours
    for oid, obj in doc.objects.items():
        if obj.get("_type") != "POUR":
            continue
        s = _copperarea(obj, signal_inner_map)
        if s:
            shape.append(s)
            stats.copperareas += 1
        else:
            stats.skipped += 1

    # POLY graphics: circles vs polygons → CIRCLE / SOLIDREGION
    for oid, obj in doc.objects.items():
        if obj.get("_type") != "POLY":
            continue
        c = _circle(obj, signal_inner_map)
        if c:
            shape.append(c)
            stats.circles += 1
            continue
        s = _solidregion(obj)
        if s:
            shape.append(s)
            stats.solidregions += 1

    # FILL (manual filled regions) → SOLIDREGION
    for oid, obj in doc.objects.items():
        if obj.get("_type") != "FILL":
            continue
        s = _solidregion(obj)
        if s:
            shape.append(s)
            stats.solidregions += 1

    # Footprint placements (LIB with nested PAD/TEXT)
    components_dict: dict[str, int] = {}
    if project_relations is not None:
        for cid, comp in rel.components.items():
            fp_uuid = project_relations.resolve_footprint_doc(doc.doc_uuid, cid)
            if not fp_uuid or fp_uuid not in project_relations.project.documents:
                stats.libs_unresolved += 1
                continue
            fp_doc = project_relations.project.documents[fp_uuid]
            attrs = rel.attrs_dict(cid)
            try:
                lib_str, pad_count = _lib(cid, comp, attrs, fp_doc, rel, signal_inner_map)
            except Exception:
                stats.skipped += 1
                continue
            shape.append(lib_str)
            stats.libs += 1
            stats.pads += pad_count
            components_dict[fp_uuid] = components_dict.get(fp_uuid, 0) + 1

    # ---- envelope ----
    title = (doc.objects.get("META") or {}).get("title") or doc.doc_uuid[:12]
    canvas_x = "4000"
    canvas_y = "3000"
    canvas = (
        f"CA~1000~1000~#000000~yes~#FFFFFF~0.1~1000~1000~line~0.1~mm~"
        f"4.499991~45~visible~0.1~{canvas_x}~{canvas_y}~0~yes"
    )
    # Add inner SIGNAL layers Std actually saw on this board
    layers = list(_DEFAULT_STD_LAYERS)
    for i, std_id in enumerate(sorted(signal_inner_map.values())):
        layers.append(f"{std_id}~Inner{i+1}~#999966~true~false~true~0~Signal")

    result = {
        "uuid": doc.doc_uuid,
        "puuid": "",  # filled in by caller if known
        "title": title,
        "description": "",
        "docType": 3,
        "components": components_dict,
        "dataStr": {
            "head": {
                "docType": "3",
                "editorVersion": "facere-epro2/0.1",
                "newgId": True,
                "c_para": [],
                "x": canvas_x,
                "y": canvas_y,
                "hasIdFlag": True,
                "importFlag": 0,
                "transformList": "",
            },
            "canvas": canvas,
            "shape": shape,
            "layers": layers,
            "objects": [],
            "BBox": {"x": 0, "y": 0, "width": 0, "height": 0},
            "preference": {},
            "DRCRULE": {},
            "netColors": [],
        },
    }
    write_pcb_std.last_stats = stats  # type: ignore[attr-defined]
    return {"success": True, "code": 0, "result": result}