"""
Settings dialog.

Built dynamically from app.config.SETTINGS_SCHEMA, grouped by section
(Database, JIRA, ...). When a new service adds settings to that
schema, they show up here automatically - no UI changes needed.

The number of settings has grown a lot, so the group content lives in
a QScrollArea and the dialog's height is capped to the actual screen's
available space - Save/Cancel stay outside the scroll area, pinned at
the bottom, so they're always reachable no matter how tall the content
gets or how small the screen is.
"""
from __future__ import annotations

from collections import defaultdict

from PyQt6.QtWidgets import (
    QDialog,
    QVBoxLayout,
    QFormLayout,
    QLineEdit,
    QPushButton,
    QHBoxLayout,
    QGroupBox,
    QLabel,
    QMessageBox,
    QScrollArea,
    QWidget,
    QApplication,
)

from app import config


class SettingsDialog(QDialog):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setWindowTitle("Settings")

        self._fields: dict[str, QLineEdit] = {}
        current_values = config.load_settings()

        # Group schema entries by their group label, preserving order
        groups: dict[str, list[tuple[str, str, bool]]] = defaultdict(list)
        for key, (label, group, is_secret) in config.SETTINGS_SCHEMA.items():
            groups[group].append((key, label, is_secret))

        outer_layout = QVBoxLayout(self)
        outer_layout.addWidget(
            QLabel("Changes are saved to your .env file and applied immediately.")
        )

        # All the group boxes live inside a scrollable area, since the
        # full list no longer reliably fits on smaller screens.
        scroll_content = QWidget()
        content_layout = QVBoxLayout(scroll_content)
        for group_name, entries in groups.items():
            box = QGroupBox(group_name)
            form = QFormLayout(box)
            for key, label, is_secret in entries:
                field = QLineEdit(current_values.get(key, ""))
                if is_secret:
                    field.setEchoMode(QLineEdit.EchoMode.Password)
                form.addRow(label, field)
                self._fields[key] = field
            content_layout.addWidget(box)
        content_layout.addStretch()

        scroll_area = QScrollArea()
        scroll_area.setWidget(scroll_content)
        scroll_area.setWidgetResizable(True)
        outer_layout.addWidget(scroll_area, stretch=1)

        button_row = QHBoxLayout()
        save_button = QPushButton("Save")
        cancel_button = QPushButton("Cancel")
        save_button.clicked.connect(self._on_save)
        cancel_button.clicked.connect(self.reject)
        button_row.addStretch()
        button_row.addWidget(cancel_button)
        button_row.addWidget(save_button)
        outer_layout.addLayout(button_row)

        self._size_to_fit_screen()

    def _size_to_fit_screen(self) -> None:
        """Start at a comfortable size, but never taller/wider than the
        actual screen has room for - whatever's left just scrolls."""
        width, height = 560, 720

        screen = self.screen() or QApplication.primaryScreen()
        if screen is not None:
            available = screen.availableGeometry()
            # Leave a little breathing room so window chrome/taskbars don't
            # push Save off-screen either.
            height = min(height, available.height() - 80)
            width = min(width, available.width() - 80)

        self.resize(max(width, 400), max(height, 300))

    def _on_save(self) -> None:
        values = {key: field.text().strip() for key, field in self._fields.items()}
        try:
            config.save_settings(values)
        except OSError as exc:
            QMessageBox.critical(self, "Couldn't save settings", str(exc))
            return
        self.accept()