"""Tests for the SDT (structured data type) parser and type enrichment."""

from __future__ import annotations

from pathlib import Path

import pytest

from mitsubishi_label_converter.excel_reader import read_workbook
from mitsubishi_label_converter.excel import write_workbook
from mitsubishi_label_converter.models import (
    GlobalVarSection,
    ProjectMetadata,
    StructMember,
    Variable,
)
from mitsubishi_label_converter.parser import parse_global_vars
from mitsubishi_label_converter.sdt_parser import (
    apply_struct_types,
    parse_struct_definitions,
)

NS = "http://www.plcopen.org/xml/tc6_0201"

SDT_XML = f"""<?xml version="1.0" encoding="utf-16"?>
<project xmlns="{NS}">
  <types>
    <dataTypes>
      <dataType name="ST_Din_STA">
        <baseType>
          <struct>
            <variable name="Value"><type><BOOL/></type></variable>
            <variable name="Status"><type><WORD/></type></variable>
            <variable name="Name">
              <type><string length="16"/></type>
            </variable>
            <variable name="Levels">
              <type><array><dimension lower="1" upper="4"/>
                <baseType><INT/></baseType></array></type>
            </variable>
            <variable name="Sub"><type><derived name="ST_Sub"/></type></variable>
          </struct>
        </baseType>
      </dataType>
      <dataType name="ST_Sub">
        <baseType>
          <struct>
            <variable name="Flag"><type><BOOL/></type></variable>
          </struct>
        </baseType>
      </dataType>
    </dataTypes>
  </types>
</project>
"""

GLOBAL_XML = f"""<?xml version="1.0" encoding="utf-16"?>
<project xmlns="{NS}">
  <instances>
    <configurations>
      <configuration name="">
        <globalVars name="Global">
          <variable name="DI4">
            <type><derived name="ST_Din_STA"/></type>
            <addData>
              <data name="http://www.mitsubishielectric.com/xml/variableStructDeviceAssignment"
                    handleUnknown="implementation">
                <variableStructDeviceAssignment>
                  <member name="Value" address="D0.0"/>
                  <member name="Status" address="D1"/>
                  <member name="Name" address="D10"/>
                  <member name="Levels" address="D20"/>
                  <member name="Sub" address="D30"/>
                  <member name="Unknown" address="D40"/>
                </variableStructDeviceAssignment>
              </data>
            </addData>
          </variable>
          <variable name="FB_Instance">
            <type><derived name="FB_Din"/></type>
            <addData>
              <data name="http://www.mitsubishielectric.com/xml/variableStructDeviceAssignment"
                    handleUnknown="implementation">
                <variableStructDeviceAssignment>
                  <member name="Value" address="R0.0"/>
                </variableStructDeviceAssignment>
              </data>
            </addData>
          </variable>
        </globalVars>
      </configuration>
    </configurations>
  </instances>
</project>
"""


@pytest.fixture()
def sdt_file(tmp_path: Path) -> Path:
    path = tmp_path / "SDT.xml"
    path.write_bytes(SDT_XML.encode("utf-16"))
    return path


@pytest.fixture()
def global_file(tmp_path: Path) -> Path:
    path = tmp_path / "Global.xml"
    path.write_bytes(GLOBAL_XML.encode("utf-16"))
    return path


def test_parse_struct_definitions(sdt_file: Path) -> None:
    definitions = parse_struct_definitions(sdt_file)
    assert definitions["ST_Din_STA"] == {
        "Value": "BOOL",
        "Status": "WORD",
        "Name": "STRING[16]",
        "Levels": "ARRAY[1..4] OF INT",
        "Sub": "ST_Sub",
    }
    assert definitions["ST_Sub"] == {"Flag": "BOOL"}


def test_apply_struct_types(global_file: Path, sdt_file: Path) -> None:
    sections = parse_global_vars(global_file)
    definitions = parse_struct_definitions(sdt_file)
    apply_struct_types(sections, definitions)

    di4 = sections[0].variables[0]
    assert [(m.name, m.type_name) for m in di4.members] == [
        ("Value", "BOOL"),
        ("Status", "WORD"),
        ("Name", "STRING[16]"),
        ("Levels", "ARRAY[1..4] OF INT"),
        ("Sub", "ST_Sub"),
        ("Unknown", ""),  # not part of the struct definition
    ]
    # FB_Din is not defined in the SDT file: members stay untyped
    fb = sections[0].variables[1]
    assert [(m.name, m.type_name) for m in fb.members] == [("Value", "")]


def test_excel_round_trip_with_member_types(
    global_file: Path, sdt_file: Path, tmp_path: Path
) -> None:
    """Members with types survive the Excel write/read round-trip."""
    sections = parse_global_vars(global_file)
    definitions = parse_struct_definitions(sdt_file)
    apply_struct_types(sections, definitions)

    out = tmp_path / "out.xlsx"
    write_workbook(sections, out, metadata=ProjectMetadata())
    read_sections, _ = read_workbook(out)
    assert read_sections == sections


def test_real_files_sdt_enrichment() -> None:
    """Enrich the real Global.xml with the real SDT.xml and verify."""
    assets = Path(__file__).parents[1] / "assets"
    global_xml = assets / "Global.xml"
    sdt_xml = assets / "SDT.xml"
    if not global_xml.is_file() or not sdt_xml.is_file():
        pytest.skip("assets not present")

    sections = parse_global_vars(global_xml)
    definitions = parse_struct_definitions(sdt_xml)

    # All 31 struct types carrying device assignments are ST_* and defined
    # in SDT.xml (FB_* instances have no device-assigned members).
    used = {v.type_name for s in sections for v in s.variables if v.members}
    assert len(used) == 31
    assert all(name.startswith("ST_") for name in used)
    assert used <= set(definitions)

    apply_struct_types(sections, definitions)
    typed = sum(
        1
        for s in sections
        for v in s.variables
        for m in v.members
        if m.type_name
    )
    total = sum(len(v.members) for s in sections for v in s.variables)
    # Every device-assigned member belongs to an ST_* type defined in the
    # SDT file, so every member gets a type.
    assert typed == total


def test_real_sdt_definition_sample() -> None:
    assets = Path(__file__).parents[1] / "assets"
    sdt_xml = assets / "SDT.xml"
    if not sdt_xml.is_file():
        pytest.skip("assets/SDT.xml not present")
    definitions = parse_struct_definitions(sdt_xml)
    assert len(definitions) == 164
    assert definitions["ST_Din_STA"]["Value"] == "BOOL"
    assert definitions["ST_Din_STA"]["Status"] == "WORD"