"""Panneau lateral : arbre des sessions SSH enregistrees + terminaux locaux, et
leur CRUD (creer / modifier / dupliquer / supprimer). N'ouvre aucune connexion
elle-meme : elle emet des signaux que ConnectionController ecoute."""
from __future__ import annotations

import copy
import uuid

from PySide6.QtCore import Qt, Signal, QObject
from PySide6.QtWidgets import (
    QWidget, QVBoxLayout, QHBoxLayout, QToolButton, QTreeWidget, QTreeWidgetItem,
    QMenu, QMessageBox,
)

from app.session_manager import SessionStore, Session
from app.key_manager import KeyManager
from app.local_terminal import SHELL_LABELS
from app.dialogs.session_dialog import SessionDialog
from app.openssh.config import (
    OpenSSHHost, default_config_path, load_openssh_hosts, session_from_openssh_host,
)

SESSION_ROLE = Qt.UserRole + 10
LOCAL_SHELL_ROLE = Qt.UserRole + 11
OPENSSH_HOST_ROLE = Qt.UserRole + 12


class SessionController(QObject):
    open_session_requested = Signal(object)      # Session
    open_sftp_requested = Signal(object)         # Session
    open_local_shell_requested = Signal(str)     # identifiant de shell
    open_openssh_host_requested = Signal(object)  # OpenSSHHost
    quick_sftp_requested = Signal()
    manage_keys_requested = Signal()
    manage_known_hosts_requested = Signal()

    def __init__(
        self,
        session_store: SessionStore,
        key_manager: KeyManager,
        broadcast_button: QToolButton,
        parent_widget: QWidget | None = None,
        openssh_config_path=None,
    ):
        super().__init__(parent_widget)
        self.session_store = session_store
        self.key_manager = key_manager
        self._parent_widget = parent_widget
        self._openssh_config_path = openssh_config_path or default_config_path()

        self.widget = QWidget(parent_widget)
        layout = QVBoxLayout(self.widget)
        layout.setContentsMargins(6, 6, 6, 6)
        layout.setSpacing(6)

        toolbar = QHBoxLayout()
        new_btn = QToolButton()
        new_btn.setObjectName("primary")
        new_btn.setText("+ Session")
        new_btn.clicked.connect(self.new_session)
        toolbar.addWidget(new_btn)

        term_btn = QToolButton()
        term_btn.setText("💻 Terminal")
        term_btn.setPopupMode(QToolButton.InstantPopup)
        term_menu = QMenu(term_btn)
        for shell_id, label in SHELL_LABELS.items():
            term_menu.addAction(label, lambda s=shell_id: self.open_local_shell_requested.emit(s))
        term_btn.setMenu(term_menu)
        toolbar.addWidget(term_btn)

        toolbar.addWidget(broadcast_button)

        sftp_btn = QToolButton()
        sftp_btn.setText("📁 SFTP")
        sftp_btn.setToolTip("Ouvrir un gestionnaire de fichiers SFTP (sans session enregistree)")
        sftp_btn.clicked.connect(self.quick_sftp_requested.emit)
        toolbar.addWidget(sftp_btn)

        toolbar.addStretch()

        manage_btn = QToolButton()
        manage_btn.setText("⚙")
        manage_btn.setToolTip("Cles SSH et hotes connus")
        manage_btn.setPopupMode(QToolButton.InstantPopup)
        manage_menu = QMenu(manage_btn)
        manage_menu.addAction("Gestionnaire de cles SSH...", self.manage_keys_requested.emit)
        manage_menu.addAction("Gestionnaire des hotes connus...", self.manage_known_hosts_requested.emit)
        manage_menu.addSeparator()
        manage_menu.addAction("Rafraichir la configuration OpenSSH (~/.ssh/config)", self.reload)
        manage_btn.setMenu(manage_menu)
        toolbar.addWidget(manage_btn)

        layout.addLayout(toolbar)

        self.tree = QTreeWidget()
        self.tree.setHeaderHidden(True)
        self.tree.itemDoubleClicked.connect(self._on_tree_double_click)
        self.tree.setContextMenuPolicy(Qt.CustomContextMenu)
        self.tree.customContextMenuRequested.connect(self._on_tree_context_menu)
        layout.addWidget(self.tree)

        # Sans minimum explicite, la largeur plancher est imposee par le contenu
        # (les noms de sessions), ce qui empeche de retrecir vraiment le panneau.
        self.widget.setMinimumWidth(120)
        self.tree.setMinimumWidth(0)

        self.reload()

    # ---------- arbre ----------
    def reload(self) -> None:
        self.tree.clear()

        locals_header = QTreeWidgetItem(["💻  Terminaux locaux"])
        locals_header.setFlags(locals_header.flags() & ~Qt.ItemIsSelectable)
        font = locals_header.font(0)
        font.setBold(True)
        locals_header.setFont(0, font)
        self.tree.addTopLevelItem(locals_header)
        for shell, label in SHELL_LABELS.items():
            child = QTreeWidgetItem([f"   {label}"])
            child.setData(0, LOCAL_SHELL_ROLE, shell)
            locals_header.addChild(child)

        sessions_header = QTreeWidgetItem(["🔐  Sessions SSH"])
        sessions_header.setFlags(sessions_header.flags() & ~Qt.ItemIsSelectable)
        sessions_header.setFont(0, font)
        self.tree.addTopLevelItem(sessions_header)

        folder_items: dict[str, QTreeWidgetItem] = {}

        def get_folder(path: str) -> QTreeWidgetItem:
            if not path:
                return sessions_header
            if path in folder_items:
                return folder_items[path]
            parent_path, _, name = path.rpartition("/")
            parent_item = get_folder(parent_path)
            item = QTreeWidgetItem([f"📁 {name}"])
            item.setFlags(item.flags() & ~Qt.ItemIsSelectable)
            parent_item.addChild(item)
            folder_items[path] = item
            return item

        for session in sorted(self.session_store.sessions, key=lambda s: s.name.lower()):
            parent = get_folder(session.group)
            item = QTreeWidgetItem([f"🖥  {session.name}  ({session.host})"])
            item.setData(0, SESSION_ROLE, session.id)
            parent.addChild(item)

        if not self.session_store.sessions:
            hint = QTreeWidgetItem(["   (aucune session — bouton « + Session » ou « 📁 SFTP »)"])
            hint.setFlags(hint.flags() & ~Qt.ItemIsSelectable)
            hint.setForeground(0, Qt.gray)
            sessions_header.addChild(hint)

        openssh_header = QTreeWidgetItem(["⚙  Configuration OpenSSH"])
        openssh_header.setFlags(openssh_header.flags() & ~Qt.ItemIsSelectable)
        openssh_header.setFont(0, font)
        openssh_header.setToolTip(0, str(self._openssh_config_path))
        self.tree.addTopLevelItem(openssh_header)

        hosts = load_openssh_hosts(self._openssh_config_path)
        for host in hosts:
            label = f"🖥  {host.alias}  ({host.display_target})"
            if host.proxy_jump:
                label += f"  · via {host.proxy_jump}"
            item = QTreeWidgetItem([label])
            item.setData(0, OPENSSH_HOST_ROLE, host)
            if host.proxy_jump:
                item.setToolTip(
                    0,
                    f"ProxyJump : {host.proxy_jump} (pas encore applique automatiquement, "
                    "connexion directe pour l'instant)",
                )
            openssh_header.addChild(item)

        if not hosts:
            hint = QTreeWidgetItem([f"   (aucun host trouve dans {self._openssh_config_path})"])
            hint.setFlags(hint.flags() & ~Qt.ItemIsSelectable)
            hint.setForeground(0, Qt.gray)
            openssh_header.addChild(hint)

        self.tree.expandAll()

    def _session_from_item(self, item: QTreeWidgetItem) -> Session | None:
        if not item:
            return None
        session_id = item.data(0, SESSION_ROLE)
        if not session_id:
            return None
        return next((s for s in self.session_store.sessions if s.id == session_id), None)

    def _shell_from_item(self, item: QTreeWidgetItem) -> str | None:
        if not item:
            return None
        return item.data(0, LOCAL_SHELL_ROLE)

    def _openssh_host_from_item(self, item: QTreeWidgetItem) -> OpenSSHHost | None:
        if not item:
            return None
        return item.data(0, OPENSSH_HOST_ROLE)

    def _on_tree_double_click(self, item: QTreeWidgetItem, _col: int) -> None:
        session = self._session_from_item(item)
        if session:
            self.open_session_requested.emit(session)
            return
        shell = self._shell_from_item(item)
        if shell:
            self.open_local_shell_requested.emit(shell)
            return
        host = self._openssh_host_from_item(item)
        if host:
            self.open_openssh_host_requested.emit(host)

    def _on_tree_context_menu(self, pos) -> None:
        item = self.tree.itemAt(pos)
        menu = QMenu(self.widget)
        session = self._session_from_item(item) if item else None
        shell = self._shell_from_item(item) if item else None
        openssh_host = self._openssh_host_from_item(item) if item else None

        if session:
            connect_action = menu.addAction("🖥  Ouvrir un terminal SSH")
            sftp_action = menu.addAction("📁  Ouvrir en SFTP (gestionnaire de fichiers)")
            menu.addSeparator()
            edit_action = menu.addAction("Modifier...")
            duplicate_action = menu.addAction("Dupliquer")
            delete_action = menu.addAction("Supprimer")
            action = menu.exec(self.tree.viewport().mapToGlobal(pos))
            if action == connect_action:
                self.open_session_requested.emit(session)
            elif action == sftp_action:
                self.open_sftp_requested.emit(session)
            elif action == edit_action:
                self.edit_session(session)
            elif action == duplicate_action:
                self.duplicate_session(session)
            elif action == delete_action:
                self.delete_session(session)
        elif shell:
            open_action = menu.addAction("Ouvrir")
            action = menu.exec(self.tree.viewport().mapToGlobal(pos))
            if action == open_action:
                self.open_local_shell_requested.emit(shell)
        elif openssh_host:
            connect_action = menu.addAction("🖥  Se connecter")
            import_action = menu.addAction("Importer comme session PySSH...")
            menu.addSeparator()
            refresh_action = menu.addAction("🔄 Rafraichir la configuration")
            action = menu.exec(self.tree.viewport().mapToGlobal(pos))
            if action == connect_action:
                self.open_openssh_host_requested.emit(openssh_host)
            elif action == import_action:
                self.import_openssh_host(openssh_host)
            elif action == refresh_action:
                self.reload()
        else:
            new_action = menu.addAction("Nouvelle session...")
            action = menu.exec(self.tree.viewport().mapToGlobal(pos))
            if action == new_action:
                self.new_session()

    # ---------- CRUD ----------
    def new_session(self) -> None:
        dialog = SessionDialog(self.key_manager, parent=self._parent_widget)
        if dialog.exec():
            self.session_store.add(dialog.result_session())
            self.reload()

    def edit_session(self, session: Session) -> None:
        dialog = SessionDialog(self.key_manager, session=session, parent=self._parent_widget)
        if dialog.exec():
            self.session_store.update(dialog.result_session())
            self.reload()

    def duplicate_session(self, session: Session) -> None:
        new_session = copy.deepcopy(session)
        new_session.id = str(uuid.uuid4())
        new_session.name = f"{session.name} (copie)"
        self.session_store.add(new_session)
        self.reload()

    def delete_session(self, session: Session) -> None:
        if QMessageBox.question(
            self._parent_widget, "Supprimer", f"Supprimer la session '{session.name}' ?"
        ) == QMessageBox.Yes:
            self.session_store.delete(session.id)
            self.reload()

    # ---------- OpenSSH config ----------
    def import_openssh_host(self, host: OpenSSHHost) -> None:
        """Ouvre l'editeur de session pre-rempli depuis ce Host, pour permettre
        d'ajuster avant d'enregistrer (comme une connexion rapide)."""
        dialog = SessionDialog(
            self.key_manager, session=session_from_openssh_host(host), parent=self._parent_widget,
            title=f"Importer « {host.alias} » comme session",
        )
        if dialog.exec():
            self.session_store.add(dialog.result_session())
            self.reload()