"""Application Preferences dialog."""
from PyQt6.QtWidgets import (
    QDialog, QVBoxLayout, QFormLayout, QGroupBox,
    QComboBox, QSpinBox, QCheckBox, QDialogButtonBox, QLabel,
)
from PyQt6.QtCore import pyqtSignal

from app.config.settings import get_settings

_FONT_FAMILIES = ["Consolas", "JetBrains Mono", "Fira Code", "Cascadia Code", "Courier New"]
_PAGE_SIZES    = [50, 100, 500, 1000, 0]   # 0 → All
_PAGE_LABELS   = ["50", "100", "500", "1 000", "All"]


class PreferencesDialog(QDialog):
    settings_applied = pyqtSignal()

    def __init__(self, parent=None):
        super().__init__(parent)
        self.setWindowTitle("Preferences")
        self.setMinimumWidth(400)
        self.resize(420, 380)
        self._build_ui()
        self._load()

    def _build_ui(self):
        root = QVBoxLayout(self)
        root.setSpacing(12)
        root.setContentsMargins(16, 16, 16, 16)

        # ── SQL Editor ────────────────────────────────────────────────────────
        editor_box = QGroupBox("SQL Editor")
        ef = QFormLayout(editor_box)
        ef.setSpacing(8)

        self._font_family = QComboBox()
        self._font_family.addItems(_FONT_FAMILIES)
        ef.addRow("Font family:", self._font_family)

        self._font_size = QSpinBox()
        self._font_size.setRange(8, 28)
        self._font_size.setSuffix(" pt")
        ef.addRow("Font size:", self._font_size)

        self._word_wrap = QCheckBox("Word wrap")
        ef.addRow("", self._word_wrap)

        root.addWidget(editor_box)

        # ── Results ───────────────────────────────────────────────────────────
        results_box = QGroupBox("Results")
        rf = QFormLayout(results_box)
        rf.setSpacing(8)

        self._page_size = QComboBox()
        for lbl in _PAGE_LABELS:
            self._page_size.addItem(lbl)
        rf.addRow("Default page size:", self._page_size)

        self._timeout = QSpinBox()
        self._timeout.setRange(5, 600)
        self._timeout.setSuffix(" s")
        rf.addRow("Query timeout:", self._timeout)

        root.addWidget(results_box)

        # ── General ───────────────────────────────────────────────────────────
        general_box = QGroupBox("General")
        gf = QFormLayout(general_box)
        gf.setSpacing(8)

        self._max_history = QSpinBox()
        self._max_history.setRange(50, 10_000)
        self._max_history.setSingleStep(100)
        gf.addRow("Max history entries:", self._max_history)

        self._auto_commit = QCheckBox("Auto-commit queries")
        gf.addRow("", self._auto_commit)

        root.addWidget(general_box)

        root.addStretch()

        # ── Buttons ───────────────────────────────────────────────────────────
        note = QLabel("Font changes take effect immediately in open editors.")
        note.setObjectName("statusLabel")
        root.addWidget(note)

        bb = QDialogButtonBox(
            QDialogButtonBox.StandardButton.Cancel |
            QDialogButtonBox.StandardButton.Apply  |
            QDialogButtonBox.StandardButton.Ok
        )
        bb.rejected.connect(self.reject)
        bb.button(QDialogButtonBox.StandardButton.Apply).clicked.connect(self._apply)
        bb.accepted.connect(self._ok)
        root.addWidget(bb)

    # ── Load / save ───────────────────────────────────────────────────────────

    def _load(self):
        s = get_settings()

        family = s.get("font_family", "Consolas")
        idx = self._font_family.findText(family)
        self._font_family.setCurrentIndex(max(idx, 0))

        self._font_size.setValue(s.get("font_size", 13))
        self._word_wrap.setChecked(s.get("word_wrap", False))

        page = s.get("result_page_size", 100)
        pi = _PAGE_SIZES.index(page) if page in _PAGE_SIZES else 1
        self._page_size.setCurrentIndex(pi)

        self._timeout.setValue(s.get("query_timeout", 60))
        self._max_history.setValue(s.get("max_history", 500))
        self._auto_commit.setChecked(s.get("auto_commit", True))

    def _apply(self):
        s = get_settings()
        s.set("font_family",      self._font_family.currentText())
        s.set("font_size",        self._font_size.value())
        s.set("word_wrap",        self._word_wrap.isChecked())
        s.set("result_page_size", _PAGE_SIZES[self._page_size.currentIndex()])
        s.set("query_timeout",    self._timeout.value())
        s.set("max_history",      self._max_history.value())
        s.set("auto_commit",      self._auto_commit.isChecked())
        s.save()
        self.settings_applied.emit()

    def _ok(self):
        self._apply()
        self.accept()