"""Deterministic code templates for ICS-SimLab logic generation (tank model)."""

from dataclasses import dataclass
from typing import Iterable, Optional


@dataclass(frozen=True)
class TankParams:
    dt: float = 0.1
    area: float = 1.0
    max_level: float = 1.0
    inflow_rate: float = 0.25
    outflow_rate: float = 0.25
    leak_rate: float = 0.0


def _header(comment: str) -> str:
    return (
        '"""\n'
        f"{comment}\n\n"
        "Autogenerated by ics-simlab-config-gen (deterministic templates).\n"
        '"""\n\n'
    )


def render_plc_threshold(
    plc_name: str,
    level_id: str,
    inlet_valve_id: str,
    outlet_valve_id: str,
    low: float = 0.2,
    high: float = 0.8,
) -> str:
    return (
        _header(f"PLC logic for {plc_name}: threshold control for tank level.")
        + "from typing import Any, Callable, Dict\n\n\n"
        + "def _get_float(regs: Dict[str, Any], key: str, default: float = 0.0) -> float:\n"
        + "    try:\n"
        + "        return float(regs[key]['value'])\n"
        + "    except Exception:\n"
        + "        return default\n\n\n"
        + "def _write(\n"
        + "    out_regs: Dict[str, Any],\n"
        + "    cbs: Dict[str, Callable[[], None]],\n"
        + "    key: str,\n"
        + "    value: int,\n"
        + ") -> None:\n"
        + "    if key not in out_regs:\n"
        + "        return\n"
        + "    cur = out_regs[key].get('value', None)\n"
        + "    if cur == value:\n"
        + "        return\n"
        + "    out_regs[key]['value'] = value\n"
        + "    if key in cbs:\n"
        + "        cbs[key]()\n\n\n"
        + "def logic(input_registers, output_registers, state_update_callbacks):\n"
        + f"    level = _get_float(input_registers, '{level_id}', default=0.0)\n"
        + f"    low = {float(low)}\n"
        + f"    high = {float(high)}\n\n"
        + "    if level <= low:\n"
        + f"        _write(output_registers, state_update_callbacks, '{inlet_valve_id}', 1)\n"
        + f"        _write(output_registers, state_update_callbacks, '{outlet_valve_id}', 0)\n"
        + "        return\n"
        + "    if level >= high:\n"
        + f"        _write(output_registers, state_update_callbacks, '{inlet_valve_id}', 0)\n"
        + f"        _write(output_registers, state_update_callbacks, '{outlet_valve_id}', 1)\n"
        + "        return\n"
        + "    return\n"
    )


def render_plc_stub(plc_name: str) -> str:
    return (
        _header(f"PLC logic for {plc_name}: stub (does nothing).")
        + "def logic(input_registers, output_registers, state_update_callbacks):\n"
        + "    return\n"
    )


def render_hil_tank(
    hil_name: str,
    level_out_id: str,
    inlet_cmd_in_id: str,
    outlet_cmd_in_id: str,
    required_output_ids: Iterable[str],
    params: Optional[TankParams] = None,
    initial_level: Optional[float] = None,
) -> str:
    p = params or TankParams()
    init_level = float(initial_level) if initial_level is not None else (0.5 * p.max_level)

    required_outputs_list = list(required_output_ids)

    lines = []
    lines.append(_header(f"HIL logic for {hil_name}: tank physical model (discrete-time)."))
    lines.append("def _as_float(x, default=0.0):\n")
    lines.append("    try:\n")
    lines.append("        return float(x)\n")
    lines.append("    except Exception:\n")
    lines.append("        return float(default)\n\n\n")
    lines.append("def _as_cmd01(x) -> float:\n")
    lines.append("    v = _as_float(x, default=0.0)\n")
    lines.append("    return 1.0 if v > 0.5 else 0.0\n\n\n")
    lines.append("def logic(physical_values):\n")

    lines.append("    # Initialize required output physical values (robust defaults)\n")
    for oid in required_outputs_list:
        if oid == level_out_id:
            lines.append(f"    physical_values.setdefault('{oid}', {init_level})\n")
        else:
            lines.append(f"    physical_values.setdefault('{oid}', 0.0)\n")

    lines.append("\n")
    lines.append(f"    inlet_cmd = _as_cmd01(physical_values.get('{inlet_cmd_in_id}', 0.0))\n")
    lines.append(f"    outlet_cmd = _as_cmd01(physical_values.get('{outlet_cmd_in_id}', 0.0))\n")
    lines.append("\n")
    lines.append(f"    dt = {float(p.dt)}\n")
    lines.append(f"    area = {float(p.area)}\n")
    lines.append(f"    max_level = {float(p.max_level)}\n")
    lines.append(f"    inflow_rate = {float(p.inflow_rate)}\n")
    lines.append(f"    outflow_rate = {float(p.outflow_rate)}\n")
    lines.append(f"    leak_rate = {float(p.leak_rate)}\n")
    lines.append("\n")
    lines.append(f"    level = _as_float(physical_values.get('{level_out_id}', 0.0), default=0.0)\n")
    lines.append("    inflow = inlet_cmd * inflow_rate\n")
    lines.append("    outflow = outlet_cmd * outflow_rate\n")
    lines.append("    dlevel = dt * (inflow - outflow - leak_rate) / area\n")
    lines.append("    level = level + dlevel\n")
    lines.append("    if level < 0.0:\n")
    lines.append("        level = 0.0\n")
    lines.append("    if level > max_level:\n")
    lines.append("        level = max_level\n")
    lines.append(f"    physical_values['{level_out_id}'] = level\n")
    lines.append("    return\n")

    return "".join(lines)


def render_hil_stub(hil_name: str, required_output_ids: Iterable[str]) -> str:
    lines = []
    lines.append(_header(f"HIL logic for {hil_name}: stub (only init outputs)."))
    lines.append("def logic(physical_values):\n")
    for oid in required_output_ids:
        lines.append(f"    physical_values.setdefault('{oid}', 0.0)\n")
    lines.append("    return\n")
    return "".join(lines)