"""M2 L0 structural certifier: presence/connection; AXI N/A; RECOMMENDED not FAIL."""

from __future__ import annotations

import json

from backend.periscopex.models import (
    Component,
    ComponentType,
    DesignGraph,
    Net,
    NetType,
    PinConnection,
)
from backend.periscopex.protocol_l0 import (
    _pack,
    certify_l0,
    protocol_exam,
)
from backend.periscopex.protocol_recognize import recognize_physical_buses


def _ic(ref: str, pins: dict[str, str], *, mpn: str = "", value: str = "") -> Component:
    return Component(
        reference=ref, value=value or mpn, footprint="",
        component_type=ComponentType.IC, mpn=mpn or None, pins=pins,
    )


def _net(name: str, *pairs: tuple[str, str]) -> Net:
    return Net(
        name=name, net_type=NetType.SIGNAL,
        pins=[PinConnection(component_ref=r, pin_number=p) for r, p in pairs],
    )


def _usb_connected() -> DesignGraph:
    return DesignGraph(
        components={
            "U1": _ic("U1", {"1": "USB_D+", "2": "USB_D-"}, mpn="CH340E"),
            "J2": Component(
                reference="J2", value="USB2_TypeA",
                footprint="USB_A",
                component_type=ComponentType.CONNECTOR,
                pins={"2": "USB_D+", "3": "USB_D-"},
            ),
        },
        nets={
            "USB_D+": _net("USB_D+", ("U1", "1"), ("J2", "2")),
            "USB_D-": _net("USB_D-", ("U1", "2"), ("J2", "3")),
        },
    )


def _usb_dangling_minus() -> DesignGraph:
    return DesignGraph(
        components={
            "U1": _ic("U1", {"1": "USB_D+"}, mpn="CH340E"),
            "J2": Component(
                reference="J2", value="USB2_TypeA",
                footprint="USB_A",
                component_type=ComponentType.CONNECTOR,
                pins={"2": "USB_D+", "3": "USB_D-"},
            ),
        },
        nets={
            "USB_D+": _net("USB_D+", ("U1", "1"), ("J2", "2")),
            "USB_D-": _net("USB_D-", ("J2", "3")),
        },
    )


def _axi_graph() -> DesignGraph:
    return DesignGraph(
        components={
            "U3": _ic("U3", {"1": "AXI_AWVALID"}, mpn="XC7A100T", value="AXI4 interconnect"),
        },
        nets={"AXI_AWVALID": _net("AXI_AWVALID", ("U3", "1"))},
    )


def _ddr_one_ended() -> DesignGraph:
    pins = {str(i): f"DDR4_DQ{i}" for i in range(8)}
    pins.update({"8": "DDR4_DQS0_P", "9": "DDR4_DQS0_N"})
    return DesignGraph(
        components={"U5": _ic("U5", pins, mpn="MT41K256M16TW", value="DDR4")},
        nets={n: _net(n, ("U5", p)) for p, n in pins.items()},
    )


def _l0_for(graph: DesignGraph, logical_sub: str) -> list:
    insts = recognize_physical_buses(graph)
    by, _ = certify_l0(graph, insts)
    rows = []
    for inst in insts:
        if logical_sub in inst.logical_protocol_id:
            rows.extend(by.get(inst.instance_id, []))
    return rows


def test_usb_connected_pair_l0_topology_pass():
    rows = _l0_for(_usb_connected(), "usb2")
    topo = [r for r in rows if r.check == "topology"]
    assert topo
    assert topo[0].result == "PASS"
    assert topo[0].level == "L0"
    blob = json.dumps(topo[0].model_dump())
    assert "ohm" not in blob.lower()
    assert "90" not in blob


def test_usb_unconnected_dminus_l0_fail_mandatory():
    g = _usb_dangling_minus()
    insts = recognize_physical_buses(g)
    usb = [i for i in insts if "usb" in i.logical_protocol_id]
    assert usb
    by, findings = certify_l0(g, insts)
    rows = [r for i in usb for r in by[i.instance_id]]
    topo = [r for r in rows if r.check == "topology"]
    assert topo
    assert topo[0].result == "FAIL"
    assert topo[0].mandatory == "MANDATORY"
    assert any(f.status == "ERROR" and f.rule_id == "PE-PRT-L0-001" for f in findings)


def test_axi_internal_l0_not_applicable_not_fail():
    rows = _l0_for(_axi_graph(), "axi4")
    assert rows
    assert all(r.result == "NOT_APPLICABLE" for r in rows)
    assert all(r.result != "FAIL" for r in rows)
    sec, findings = protocol_exam(_axi_graph())
    assert sec.max_level_reached == "L2"
    from backend.periscopex.protocol_report import PACK_MACROPHASE as L5_MACRO
    assert sec.macrophase == L5_MACRO
    assert all(f.status != "ERROR" for f in findings)
    assert all("AXI_AWVALID" not in (f.net or "") for f in findings if f.rule_id == "PE-PRT-L0-001")


def test_ddr_unconnected_memory_fails_l0_connection():
    rows = _l0_for(_ddr_one_ended(), "ddr4")
    mapping = [r for r in rows if r.check == "byte_lane_mapping"]
    assert mapping
    assert mapping[0].result == "FAIL"
    assert "unconnected" in mapping[0].notes


def test_recommended_never_parses_as_fail():
    rec = _pack("return_path", "FAIL", "RECOMMENDED", notes="missing")
    assert rec.result != "FAIL"
    assert rec.status != "ERROR"


def test_l0_does_not_run_impedance():
    rows = _l0_for(_usb_connected(), "usb2")
    assert not any(r.check in {"differential_impedance", "intra_pair_skew", "length"} for r in rows)