"""APIClient - Agent — Multi-tab request manager."""
from PyQt6.QtWidgets import QWidget, QVBoxLayout, QTabWidget, QPushButton, QTabBar
from PyQt6.QtCore import pyqtSignal, Qt

from app.ui.request_panel import RequestPanel
from app.models import HttpRequest


class RequestTab(QWidget):
    send_requested = pyqtSignal(object)

    def __init__(self, parent=None):
        super().__init__(parent)
        layout = QVBoxLayout(self)
        layout.setContentsMargins(0, 0, 0, 0)
        layout.setSpacing(0)
        self.request_panel = RequestPanel()
        self.request_panel.send_requested.connect(self.send_requested)
        layout.addWidget(self.request_panel)

    def load_request(self, req: HttpRequest):
        self.request_panel.load_request(req)

    def get_request(self) -> HttpRequest:
        return self.request_panel.get_request()


class TabsManager(QWidget):
    send_requested      = pyqtSignal(object)
    current_tab_changed = pyqtSignal()

    def __init__(self, parent=None):
        super().__init__(parent)
        layout = QVBoxLayout(self)
        layout.setContentsMargins(0, 0, 0, 0)
        layout.setSpacing(0)

        self.tab_widget = QTabWidget()
        self.tab_widget.setTabsClosable(False)   # we manage close buttons ourselves
        self.tab_widget.setMovable(True)
        self.tab_widget.currentChanged.connect(lambda _: self.current_tab_changed.emit())

        # "+" new tab button in the corner
        new_btn = QPushButton("+")
        new_btn.setObjectName("ghost")
        new_btn.setFixedSize(28, 28)
        new_btn.setToolTip("New Tab  (Ctrl+T)")
        new_btn.clicked.connect(lambda: self.new_tab())
        self.tab_widget.setCornerWidget(new_btn, Qt.Corner.TopRightCorner)

        layout.addWidget(self.tab_widget)
        self._tab_counter = 0
        self.new_tab()

    # ── Public API ────────────────────────────────────────────────────────────

    def new_tab(self, req: HttpRequest = None) -> RequestTab:
        tab = RequestTab()
        tab.send_requested.connect(self.send_requested)
        if req:
            tab.load_request(req)
        self._tab_counter += 1
        label = req.name if (req and req.name) else f"Request {self._tab_counter}"
        idx = self.tab_widget.addTab(tab, label)
        self.tab_widget.setCurrentIndex(idx)
        self._add_close_button(idx, tab)
        return tab

    def _add_close_button(self, idx: int, tab: RequestTab):
        btn = QPushButton("×")
        btn.setObjectName("tabCloseBtn")
        btn.setFixedSize(18, 18)
        btn.setToolTip("Close Tab")
        btn.clicked.connect(lambda: self._close_tab(self.tab_widget.indexOf(tab)))
        self.tab_widget.tabBar().setTabButton(idx, QTabBar.ButtonPosition.RightSide, btn)

    def close_current_tab(self):
        self._close_tab(self.tab_widget.currentIndex())

    def _close_tab(self, index: int):
        if self.tab_widget.count() > 1:
            self.tab_widget.removeTab(index)

    def current_tab(self) -> RequestTab | None:
        w = self.tab_widget.currentWidget()
        return w if isinstance(w, RequestTab) else None

    def load_request_in_new_tab(self, req: HttpRequest):
        self.new_tab(req)

    def load_request_in_current_tab(self, req: HttpRequest):
        tab = self.current_tab()
        if tab:
            tab.load_request(req)

    def rename_current_tab(self, name: str):
        self.tab_widget.setTabText(self.tab_widget.currentIndex(), name)