"""
Filename: welcome.py
Description: Welcome dialog for FLARES
Note: Compliant with pylance strict type checking

Author: Tyler de Zeeuw
License: GPL-3.0
"""

from PySide6.QtWidgets import QTextBrowser, QVBoxLayout, QLabel, QDialog, QHBoxLayout, QPushButton
from PySide6.QtGui import QDesktopServices, QIcon
from PySide6.QtCore import QUrl
from PySide6.QtNetwork import QNetworkAccessManager, QNetworkRequest, QNetworkReply

from src.shared.shareddata import APP_NAME, CURRENT_VERSION, CHANGELOG_URL, resource_path


class WelcomeDialog(QDialog):
    def __init__(self, parent: QDialog | None = None, direct: bool = True, first: bool = False):
        super().__init__(parent)
        self.setWindowTitle(f"What's New - {APP_NAME.upper()}")
        self.setMinimumSize(550, 450)
        self.resize(800, 500)
        
        layout = QVBoxLayout(self)
        
        header_layout = QHBoxLayout()
        logo_label = QLabel(self)

        # NOTE: might not work on mac and need the icns file
        logo_label.setPixmap(QIcon(resource_path("icons/main.ico")).pixmap(48, 48))
        if first:
            title_label = QLabel(f"<h2>Welcome to {APP_NAME.upper()}!</h2>", self)
        elif direct:
            title_label = QLabel(f"<h2>{APP_NAME.upper()} has been sucessfully updated to version {CURRENT_VERSION}!</h2>", self)
        else:
            title_label = QLabel(f"<h2>{APP_NAME.upper()} is currently running version {CURRENT_VERSION}.</h2>", self)

        header_layout.addWidget(logo_label)
        header_layout.addWidget(title_label)
        header_layout.addStretch()
        layout.addLayout(header_layout)
        
        self.text_browser = QTextBrowser(self)
        self.text_browser.setHtml("<p style='color: gray;'>Loading latest updates from server...</p>")

        # Ensure links open in the default web browser and not in this window
        self.text_browser.setOpenLinks(False)
        self.text_browser.anchorClicked.connect(QDesktopServices.openUrl)
        layout.addWidget(self.text_browser)
        
        footer_layout = QHBoxLayout()
        
        ok_button = QPushButton("OK", self)
        ok_button.setDefault(True)
        ok_button.clicked.connect(self.accept)
        
        footer_layout.addStretch()
        footer_layout.addWidget(ok_button)
        layout.addLayout(footer_layout)
        
        # Fetch markdown from the web asynchronously
        self.network_manager = QNetworkAccessManager(self)
        self.network_manager.finished.connect(self._on_download_complete)
        self.network_manager.get(QNetworkRequest(QUrl(CHANGELOG_URL)))


    def _on_download_complete(self, reply: QNetworkReply) -> None:
        """Processes the downloaded markdown and drops it into the view frame."""
        if reply.error() == reply.NetworkError.NoError:
            raw_bytes = reply.readAll().data()

            # Convert raw bytes to standard text string
            markdown_text = str(raw_bytes, encoding='utf-8')
            self.text_browser.setMarkdown(markdown_text)
        else:
            self.text_browser.setHtml(
                f"<p style='color: red;'><b>Failed to load content.</b><br>Error: {reply.errorString()}</p>"
            )
        reply.deleteLater()