from __future__ import annotations

import sys
import tempfile
from collections.abc import Callable
from pathlib import Path

from PySide6.QtCore import QObject, QProcess, Qt
from PySide6.QtWidgets import QApplication, QMessageBox

from bedit_core.models import Component
from bedit_gui.documents import Document
from bedit_gui.services import simulation_files
from bedit_gui.services.application_logging import get_logger
from bedit_gui.services.simulation_loader import component_choices
from bedit_gui.services.simulation_handoff import send_simulation_handoff
from bedit_gui.simulation_models import CompiledModel, SimulationRoot
from bedit_gui.views.main_window import MainWindow
from bedit_simulation import ModelBuildResult, compile_component_sync

logger = get_logger(__name__)

Compiler = Callable[[Component, str | Path], ModelBuildResult]
Launcher = Callable[[Path, CompiledModel], bool]


def _launch_simulator(path: Path, compiled_model: CompiledModel) -> bool:
    if send_simulation_handoff(path, compiled_model):
        return True
    arguments = ["-m", "bedit_gui.simulation_application", "--handoff", "--model-name", compiled_model.model_name, "--executable", compiled_model.executable, "--working-directory", compiled_model.working_directory, str(path)]
    launched = QProcess.startDetached(sys.executable, arguments)
    return launched[0] if isinstance(launched, tuple) else bool(launched)


class SimulationController(QObject):
    """Compile the active BEdit simulation and launch the simulator process."""

    def __init__(self, document: Document, window: MainWindow, compiler: Compiler = compile_component_sync, launcher: Launcher = _launch_simulator) -> None:
        super().__init__(window)
        self.document = document
        self.window = window
        self.compiler = compiler
        self.launcher = launcher
        self.compiled_root: SimulationRoot | None = None
        self.compiled_model: CompiledModel | None = None
        window.ui.actionCompile_Model.triggered.connect(self.compile_model)
        window.ui.actionOpen_Simulation_Window.triggered.connect(self.open_simulation)

    def compile_model(self) -> SimulationRoot | None:
        database = self.document.simulation_database()
        settings = database.simulations.get(database.active_simulation) if database.active_simulation is not None else None
        if settings is None:
            QMessageBox.warning(self.window, "No active simulation", "Select and accept a simulation settings block first.")
            return None
        match = next((choice for choice in component_choices(self.document.model) if choice[0] == settings.component), None)
        if match is None:
            QMessageBox.critical(self.window, "Could not compile", "The active simulation references a missing component.")
            return None
        component_id, component, component_path = match
        build_directory = Path(tempfile.mkdtemp(prefix="bedit-compiled-"))
        QApplication.setOverrideCursor(Qt.CursorShape.WaitCursor)
        self.window.statusBar().showMessage(f"Compiling {component_path}…")
        logger.info("Compiling model: %s", component_path)
        try:
            self.document.infer_causality(component)
            build = self.compiler(component, build_directory)
        except (OSError, RuntimeError, ValueError) as exc:
            logger.error("Could not compile model %s:\n%s", component_path, exc)
            QMessageBox.critical(self.window, "Could not compile", str(exc))
            self.window.statusBar().showMessage("Compilation failed")
            return None
        finally:
            QApplication.restoreOverrideCursor()
        self.compiled_model = CompiledModel(build.model_name, str(build.executable.resolve()), str(build.executable.parent.resolve()), build.output, build.errors)
        self.compiled_root = SimulationRoot(
            format_version=1,
            source_document=str(self.document.path.resolve()) if self.document.path is not None else None,
            source_document_id=str(self.document.model.id),
            component=component_id,
            component_path=component_path,
            settings_name=settings.name,
            settings=settings,
        )
        self.window.statusBar().showMessage(f"Compiled {component_path}")
        logger.info("Compiled model %s: %s", build.model_name, self.compiled_model.executable)
        if build.output.strip():
            logger.info("Compiler output:\n%s", build.output.strip())
        if build.errors.strip():
            logger.warning("Compiler errors:\n%s", build.errors.strip())
        return self.compiled_root

    def open_simulation(self) -> None:
        root = self.compile_model()
        if root is None or self.compiled_model is None:
            return
        transfer_directory = Path(tempfile.mkdtemp(prefix="bedit-simulator-launch-"))
        transfer_path = transfer_directory / "simulation.bes"
        try:
            simulation_files.save(root, transfer_path)
            if not self.launcher(transfer_path, self.compiled_model):
                raise RuntimeError("the simulator process could not be started")
        except (OSError, RuntimeError, ValueError) as exc:
            QMessageBox.critical(self.window, "Could not open simulator", str(exc))