"""Component → pin → net → block hierarchy (usable inventory, not a platform)."""

from __future__ import annotations

from pydantic import BaseModel

from backend.periscopex.functional_groups import FunctionalGroupsReport
from backend.periscopex.models import DesignGraph, Finding


class HierarchyPin(BaseModel):
    number: str
    net: str = ""


class HierarchyComponent(BaseModel):
    ref: str
    component_type: str
    pins: list[HierarchyPin] = []
    nets: list[str] = []
    block_id: str | None = None


class HierarchyNet(BaseModel):
    name: str
    net_type: str
    components: list[str] = []
    block_id: str | None = None


class HierarchyBlock(BaseModel):
    block_id: str
    kind: str  # domain | group | rail
    ic_refs: list[str] = []
    nets: list[str] = []


class HierarchyReport(BaseModel):
    components: list[HierarchyComponent] = []
    nets: list[HierarchyNet] = []
    blocks: list[HierarchyBlock] = []


def build_hierarchy(
    graph: DesignGraph,
    plan: FunctionalGroupsReport | None = None,
) -> HierarchyReport:
    """Walk component.pins → nets, then group into domains / rail blocks."""
    ref_block: dict[str, str] = {}
    blocks: list[HierarchyBlock] = []
    if plan is not None:
        for d in plan.domains:
            blocks.append(HierarchyBlock(
                block_id=d.domain_id,
                kind="domain",
                ic_refs=list(d.ic_refs),
                nets=list(d.power_nets),
            ))
            for ref in d.ic_refs:
                ref_block[ref] = d.domain_id
        for g in plan.groups:
            bid = ref_block.get(g.ref) or f"group:{g.ref}"
            if g.ref not in ref_block:
                blocks.append(HierarchyBlock(
                    block_id=bid, kind="group", ic_refs=[g.ref], nets=[],
                ))
                ref_block[g.ref] = bid
    else:
        for net in graph.nets.values():
            if net.net_type.value != "power":
                continue
            ics = [
                p.component_ref for p in net.pins
                if (graph.components.get(p.component_ref)
                    and graph.components[p.component_ref].component_type.value == "ic")
            ]
            if not ics:
                continue
            bid = f"rail:{net.name}"
            blocks.append(HierarchyBlock(
                block_id=bid, kind="rail", ic_refs=sorted(set(ics)), nets=[net.name],
            ))
            for ref in ics:
                ref_block.setdefault(ref, bid)

    net_block: dict[str, str] = {}
    for b in blocks:
        for n in b.nets:
            net_block[n] = b.block_id

    comps: list[HierarchyComponent] = []
    for ref, comp in sorted(graph.components.items()):
        pins = [
            HierarchyPin(number=str(num), net=n or "")
            for num, n in sorted(comp.pins.items(), key=lambda x: str(x[0]))
        ]
        nets = sorted({p.net for p in pins if p.net})
        bid = ref_block.get(ref)
        if bid is None and nets:
            for n in nets:
                if n in net_block:
                    bid = net_block[n]
                    break
        comps.append(HierarchyComponent(
            ref=ref,
            component_type=comp.component_type.value,
            pins=pins,
            nets=nets,
            block_id=bid,
        ))

    hnets: list[HierarchyNet] = []
    for name, net in sorted(graph.nets.items()):
        refs = sorted({p.component_ref for p in net.pins})
        bid = net_block.get(name)
        if bid is None:
            for r in refs:
                if r in ref_block:
                    bid = ref_block[r]
                    break
        hnets.append(HierarchyNet(
            name=name,
            net_type=net.net_type.value,
            components=refs,
            block_id=bid,
        ))
    return HierarchyReport(components=comps, nets=hnets, blocks=blocks)


def check_hierarchy(graph: DesignGraph, plan: FunctionalGroupsReport | None = None) -> list[Finding]:
    """FACT: IC pin with an empty net. Skip unnamed power-flags."""
    out: list[Finding] = []
    for ref, comp in sorted(graph.components.items()):
        if comp.component_type.value != "ic":
            continue
        dangling = [str(n) for n, net in comp.pins.items() if not (net or "").strip()]
        if not dangling:
            continue
        rec = f"Connect {ref} pin(s) {', '.join(dangling)} to a named net, or mark NC."
        out.append(Finding(
            designator=ref,
            mpn=comp.mpn or "",
            aspect="hierarchy",
            finding=f"{ref} pin(s) {', '.join(dangling)} have no net.",
            facts=f"{ref} pins {dangling} net=''.",
            requirement="Every IC pin lands on a named net (or is explicitly NC).",
            inference="Empty pin map is a graph FACT, not a layout millimetre claim.",
            why="Component → pin → net hierarchy.",
            status="INFO",
            recommendation=rec,
            action=rec,
            source="hierarchy_check",
            rule_id="PE-HIER-001",
            finding_class="INFO",
            provenance="TYPICAL",
            evidence_status="SUFFICIENT",
            pins=[f"{ref}.{p}" for p in dangling],
        ))
    _ = plan
    return out