"""
Eigenschaften-Panel (rechte Seitenleiste):
  - Globale Strichdicke
  - Globaler Buchstabenabstand
  - Pro-Glyph-Einstellungen (Offset, Strichdicke-Faktor)
  - Tracing-Schwellenwert
"""
from __future__ import annotations

from PySide6.QtWidgets import (
    QWidget, QVBoxLayout, QHBoxLayout, QLabel, QDoubleSpinBox,
    QSpinBox, QGroupBox, QScrollArea, QSlider, QPushButton,
    QFormLayout, QFrame,
)
from PySide6.QtCore import Signal, Qt


class PropertiesPanel(QWidget):
    # Signale für Änderungen
    letter_spacing_changed = Signal(float)
    stroke_width_changed = Signal(float)
    threshold_changed = Signal(int)
    retrace_requested = Signal()
    export_requested = Signal()

    def __init__(self, parent=None):
        super().__init__(parent)
        self.setFixedWidth(320)
        self._build_ui()

    def _build_ui(self):
        layout = QVBoxLayout(self)
        layout.setContentsMargins(8, 8, 8, 8)
        layout.setSpacing(12)

        # --- Titel ---
        title = QLabel("Eigenschaften")
        title.setStyleSheet("font-size: 16px; font-weight: bold; color: #e0e0e0;")
        layout.addWidget(title)

        layout.addWidget(self._separator())

        # --- Globale Einstellungen ---
        global_group = QGroupBox("Globale Parameter")
        global_group.setStyleSheet(self._group_style())
        gl = QFormLayout(global_group)
        gl.setSpacing(8)

        self.spin_letter_spacing = QDoubleSpinBox()
        self.spin_letter_spacing.setRange(-50.0, 200.0)
        self.spin_letter_spacing.setSingleStep(0.5)
        self.spin_letter_spacing.setValue(0.0)
        self.spin_letter_spacing.setSuffix(" px")
        self.spin_letter_spacing.setDecimals(1)
        self.spin_letter_spacing.valueChanged.connect(self.letter_spacing_changed.emit)
        gl.addRow("Buchstabenabstand:", self.spin_letter_spacing)

        self.spin_stroke_width = QDoubleSpinBox()
        self.spin_stroke_width.setRange(0.0, 50.0)
        self.spin_stroke_width.setSingleStep(0.1)
        self.spin_stroke_width.setValue(1.0)
        self.spin_stroke_width.setSuffix(" px")
        self.spin_stroke_width.setDecimals(1)
        self.spin_stroke_width.valueChanged.connect(self.stroke_width_changed.emit)
        gl.addRow("Strichdicke:", self.spin_stroke_width)

        layout.addWidget(global_group)

        # --- Tracing-Einstellungen ---
        trace_group = QGroupBox("Vektorisierung")
        trace_group.setStyleSheet(self._group_style())
        tl = QFormLayout(trace_group)
        tl.setSpacing(8)

        self.slider_threshold = QSlider(Qt.Orientation.Horizontal)
        self.slider_threshold.setRange(1, 254)
        self.slider_threshold.setValue(128)
        self.slider_threshold.setTickInterval(16)
        self.slider_threshold.setTickPosition(QSlider.TickPosition.TicksBelow)
        self.lbl_threshold = QLabel("128")
        self.slider_threshold.valueChanged.connect(
            lambda v: self.lbl_threshold.setText(str(v))
        )
        self.slider_threshold.valueChanged.connect(self.threshold_changed.emit)

        th_row = QHBoxLayout()
        th_row.addWidget(self.slider_threshold, stretch=1)
        th_row.addWidget(self.lbl_threshold)
        tl.addRow("Schwellenwert:", th_row)

        self.btn_retrace = QPushButton("Neu vektorisieren")
        self.btn_retrace.setStyleSheet(self._button_style())
        self.btn_retrace.clicked.connect(self.retrace_requested.emit)
        tl.addRow(self.btn_retrace)

        layout.addWidget(trace_group)

        # --- Glyph-Liste (scrollbar) ---
        glyph_group = QGroupBox("Pfadgruppen")
        glyph_group.setStyleSheet(self._group_style())
        glyph_layout = QVBoxLayout(glyph_group)

        self.glyph_scroll = QScrollArea()
        self.glyph_scroll.setWidgetResizable(True)
        self.glyph_container = QWidget()
        self.glyph_list_layout = QVBoxLayout(self.glyph_container)
        self.glyph_list_layout.setAlignment(Qt.AlignmentFlag.AlignTop)
        self.glyph_scroll.setWidget(self.glyph_container)
        glyph_layout.addWidget(self.glyph_scroll)

        layout.addWidget(glyph_group, stretch=1)

        layout.addWidget(self._separator())

        # --- Export ---
        self.btn_export = QPushButton("Als PNG exportieren")
        self.btn_export.setStyleSheet(self._button_style(primary=True))
        self.btn_export.clicked.connect(self.export_requested.emit)
        layout.addWidget(self.btn_export)

    def populate_glyphs(self, glyph_names: list[str]):
        """Füllt die Glyph-Liste mit Einträgen."""
        while self.glyph_list_layout.count():
            item = self.glyph_list_layout.takeAt(0)
            if item.widget():
                item.widget().deleteLater()

        for name in glyph_names:
            lbl = QLabel(f"  {name}")
            lbl.setStyleSheet("color: #c0c0c0; padding: 4px 0;")
            self.glyph_list_layout.addWidget(lbl)

    @staticmethod
    def _separator() -> QFrame:
        line = QFrame()
        line.setFrameShape(QFrame.Shape.HLine)
        line.setStyleSheet("color: #555;")
        return line

    @staticmethod
    def _group_style() -> str:
        return """
            QGroupBox {
                font-weight: bold;
                color: #aaa;
                border: 1px solid #444;
                border-radius: 4px;
                margin-top: 8px;
                padding-top: 16px;
            }
            QGroupBox::title {
                subcontrol-origin: margin;
                left: 10px;
                padding: 0 4px;
            }
        """

    @staticmethod
    def _button_style(primary: bool = False) -> str:
        bg = "#0078d4" if primary else "#3c3c3c"
        hover = "#1a8ae8" if primary else "#505050"
        return f"""
            QPushButton {{
                background-color: {bg};
                color: white;
                border: 1px solid #555;
                border-radius: 4px;
                padding: 8px 16px;
                font-size: 13px;
            }}
            QPushButton:hover {{
                background-color: {hover};
            }}
        """