"""Modal editor for non-secret settings and the stored API key."""

from __future__ import annotations

import os
from pathlib import Path

from PySide6.QtCore import Signal
from PySide6.QtWidgets import (
    QDialog,
    QDialogButtonBox,
    QCheckBox,
    QFileDialog,
    QFormLayout,
    QHBoxLayout,
    QLineEdit,
    QMessageBox,
    QPushButton,
    QSpinBox,
    QToolButton,
    QVBoxLayout,
    QWidget,
)

from voice_transcriptor.models import AppSettings
from voice_transcriptor.services.credentials import CredentialError, CredentialService
from voice_transcriptor.services.settings import SettingsError, SettingsRepository


class SettingsDialog(QDialog):
    """Edit application settings while keeping the API key out of normal storage."""

    settings_saved = Signal(AppSettings)

    def __init__(
        self,
        settings: AppSettings,
        repository: SettingsRepository,
        credentials: CredentialService,
        parent=None,
    ) -> None:
        super().__init__(parent)
        self._repository = repository
        self._credentials = credentials
        self.setWindowTitle("Settings")

        self.model_input = QLineEdit(settings.model, self)
        self.model_input.setObjectName("modelInput")
        self.language_input = QLineEdit(settings.language, self)
        self.language_input.setObjectName("languageInput")
        self.api_key_input = QLineEdit(self)
        self.api_key_input.setObjectName("apiKeyInput")
        self.api_key_input.setEchoMode(QLineEdit.EchoMode.Password)
        self.output_directory_input = QLineEdit(str(settings.output_directory), self)
        self.output_directory_input.setObjectName("outputDirectoryInput")
        self.choose_directory_button = QPushButton("Browse…", self)
        self.choose_directory_button.setObjectName("chooseDirectoryButton")
        self.choose_directory_button.clicked.connect(self.choose_output_directory)

        output_directory_layout = QHBoxLayout()
        output_directory_layout.addWidget(self.output_directory_input)
        output_directory_layout.addWidget(self.choose_directory_button)

        form = QFormLayout()
        form.addRow("OpenAI API key", self.api_key_input)
        form.addRow("Model", self.model_input)
        form.addRow("Language", self.language_input)
        form.addRow("Output directory", output_directory_layout)

        self.advanced_toggle = QToolButton(self)
        self.advanced_toggle.setText("Advanced")
        self.advanced_toggle.setCheckable(True)
        self.advanced_toggle.setObjectName("advancedToggle")
        self.advanced_panel = QWidget(self)
        self.advanced_panel.setObjectName("advancedPanel")
        advanced_form = QFormLayout(self.advanced_panel)
        self.chunk_duration_input = QSpinBox(self.advanced_panel)
        self.chunk_duration_input.setObjectName("chunkDurationInput")
        self.chunk_duration_input.setRange(1, 86400)
        self.chunk_duration_input.setSuffix(" seconds")
        self.chunk_duration_input.setValue(settings.chunk_duration_seconds)
        self.chunk_overlap_input = QSpinBox(self.advanced_panel)
        self.chunk_overlap_input.setObjectName("chunkOverlapInput")
        self.chunk_overlap_input.setRange(0, 3600)
        self.chunk_overlap_input.setSuffix(" seconds")
        self.chunk_overlap_input.setValue(settings.chunk_overlap_seconds)
        self.retain_temporary_files_input = QCheckBox("Retain temporary files for debugging", self.advanced_panel)
        self.retain_temporary_files_input.setObjectName("retainTemporaryFilesInput")
        self.retain_temporary_files_input.setChecked(settings.retain_temporary_files)
        advanced_form.addRow("Chunk duration", self.chunk_duration_input)
        advanced_form.addRow("Overlap", self.chunk_overlap_input)
        advanced_form.addRow(self.retain_temporary_files_input)
        self.advanced_panel.hide()
        self.advanced_toggle.toggled.connect(self.advanced_panel.setVisible)

        self.button_box = QDialogButtonBox(
            QDialogButtonBox.StandardButton.Save | QDialogButtonBox.StandardButton.Cancel,
            parent=self,
        )
        self.save_button = self.button_box.button(QDialogButtonBox.StandardButton.Save)
        self.save_button.setObjectName("saveButton")
        self.cancel_button = self.button_box.button(QDialogButtonBox.StandardButton.Cancel)
        self.cancel_button.setObjectName("cancelButton")
        self.button_box.accepted.connect(self.save)
        self.button_box.rejected.connect(self.reject)

        layout = QVBoxLayout(self)
        layout.addLayout(form)
        layout.addWidget(self.advanced_toggle)
        layout.addWidget(self.advanced_panel)
        layout.addWidget(self.button_box)

    def choose_output_directory(self) -> None:
        directory = QFileDialog.getExistingDirectory(
            self,
            "Choose output directory",
            self.output_directory_input.text(),
        )
        if directory:
            self.output_directory_input.setText(directory)

    def save(self) -> None:
        """Persist valid settings and, only when supplied, replace the API key."""
        api_key = self.api_key_input.text().strip()
        self.api_key_input.clear()

        output_directory = self._output_directory()
        if output_directory is None:
            QMessageBox.warning(
                self,
                "Invalid output directory",
                "Choose an accessible output directory.",
            )
            return

        model = self.model_input.text().strip()
        language = self.language_input.text().strip()
        if not model or not language:
            QMessageBox.warning(self, "Invalid settings", "Model and language are required.")
            return

        chunk_duration = self.chunk_duration_input.value()
        overlap = self.chunk_overlap_input.value()
        if overlap >= chunk_duration:
            QMessageBox.warning(self, "Invalid settings", "Overlap must be smaller than chunk duration.")
            return
        updated_settings = AppSettings(
            model, language, output_directory, chunk_duration, overlap,
            self.retain_temporary_files_input.isChecked(),
        )
        try:
            self._repository.save(updated_settings)
        except SettingsError:
            QMessageBox.warning(self, "Could not save settings", "Settings could not be saved.")
            return

        if api_key:
            try:
                self._credentials.set_api_key(api_key)
            except CredentialError:
                QMessageBox.warning(
                    self,
                    "Could not save settings",
                    "The API key could not be saved.",
                )
                return

        self.settings_saved.emit(updated_settings)
        self.accept()

    def _output_directory(self) -> Path | None:
        value = self.output_directory_input.text().strip()
        if not value:
            return None

        directory = Path(value)
        try:
            if not directory.is_dir():
                return None
            if not os.access(directory, os.R_OK | os.W_OK):
                return None
        except OSError:
            return None
        return directory