import sys
from PySide6.QtCore import Qt, QTimer, QSize
from PySide6.QtGui import QFont
from PySide6.QtWidgets import (
    QApplication, QMainWindow, QWidget, QLabel, QPushButton,
    QHBoxLayout, QVBoxLayout, QGridLayout, QStackedWidget, QSizePolicy
)


# ---------- Themes (QSS) ----------
THEME_NIGHT = """
/* Global */
QWidget { background: #0B0E11; color: #E6EAF0; font-family: Inter, Roboto, Sans-Serif; }
QLabel { color: #E6EAF0; }
#TopBar, #BottomBar { background: #0F1318; border: 0px; }
#Divider { background: #1B2330; }

QPushButton { border: 0px; }
QPushButton#IconChip {
  background: #161A1F;
  padding: 10px 14px;
  border-radius: 14px;
  color: #E6EAF0;
  font-size: 16px;
}
QPushButton#IconChip:pressed { background: #1B2330; }

QPushButton#NavBtn {
  background: transparent;
  padding: 10px 8px;
  border-radius: 14px;
  color: #8A93A6;
  font-size: 14px;
}
QPushButton#NavBtn[active="true"] {
  color: #E6EAF0;
}
QPushButton#NavBtn[active="true"] #NavUnderline {
  background: #3A86FF;
}

QWidget#Card {
  background: #161A1F;
  border-radius: 20px;
}
QLabel#CardTitle { color: #8A93A6; font-size: 16px; }
QLabel#CardValue { color: #E6EAF0; font-size: 34px; font-weight: 600; }
QLabel#CardSub   { color: #8A93A6; font-size: 14px; }

QPushButton#PrimaryBtn {
  background: #3A86FF;
  color: #0B0E11;
  border-radius: 16px;
  padding: 12px 16px;
  font-size: 16px;
  font-weight: 600;
}
QPushButton#PrimaryBtn:pressed { background: #2F6BE0; }
"""

THEME_DAY = """
/* Global */
QWidget { background: #F4F6F8; color: #111827; font-family: Inter, Roboto, Sans-Serif; }
QLabel { color: #111827; }
#TopBar, #BottomBar { background: #FFFFFF; border: 0px; }
#Divider { background: #E5E7EB; }

QPushButton { border: 0px; }
QPushButton#IconChip {
  background: #F1F5F9;
  padding: 10px 14px;
  border-radius: 14px;
  color: #111827;
  font-size: 16px;
}
QPushButton#IconChip:pressed { background: #E2E8F0; }

QPushButton#NavBtn {
  background: transparent;
  padding: 10px 8px;
  border-radius: 14px;
  color: #6B7280;
  font-size: 14px;
}
QPushButton#NavBtn[active="true"] {
  color: #111827;
}
QPushButton#NavBtn[active="true"] #NavUnderline {
  background: #2563EB;
}

QWidget#Card {
  background: #FFFFFF;
  border-radius: 20px;
}
QLabel#CardTitle { color: #6B7280; font-size: 16px; }
QLabel#CardValue { color: #111827; font-size: 34px; font-weight: 600; }
QLabel#CardSub   { color: #6B7280; font-size: 14px; }

QPushButton#PrimaryBtn {
  background: #2563EB;
  color: #FFFFFF;
  border-radius: 16px;
  padding: 12px 16px;
  font-size: 16px;
  font-weight: 600;
}
QPushButton#PrimaryBtn:pressed { background: #1D4ED8; }
"""


# ---------- Small UI helpers ----------
def divider(height=1):
    w = QWidget()
    w.setObjectName("Divider")
    w.setFixedHeight(height)
    return w


class Card(QWidget):
    """Premium card tile for dashboard."""
    def __init__(self, title: str, value: str, sub: str, icon_text: str = "◻"):
        super().__init__()
        self.setObjectName("Card")
        self.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)

        root = QVBoxLayout(self)
        root.setContentsMargins(18, 16, 18, 16)
        root.setSpacing(10)

        top = QHBoxLayout()
        top.setSpacing(10)

        lbl_title = QLabel(title)
        lbl_title.setObjectName("CardTitle")

        icon = QLabel(icon_text)
        icon.setAlignment(Qt.AlignCenter)
        icon.setFixedSize(44, 44)
        icon.setStyleSheet("background: rgba(58,134,255,0.12); border-radius: 14px;")

        top.addWidget(lbl_title, 1, Qt.AlignLeft | Qt.AlignVCenter)
        top.addWidget(icon, 0, Qt.AlignRight | Qt.AlignVCenter)

        lbl_value = QLabel(value)
        lbl_value.setObjectName("CardValue")

        lbl_sub = QLabel(sub)
        lbl_sub.setObjectName("CardSub")

        root.addLayout(top)
        root.addStretch(1)
        root.addWidget(lbl_value)
        root.addWidget(lbl_sub)

        # clickable feel
        self.setCursor(Qt.PointingHandCursor)

    def mousePressEvent(self, event):
        # заглушка клика по карточке
        print(f"[Card] Click: {self.objectName()}")
        super().mousePressEvent(event)


class NavButton(QPushButton):
    """Bottom navigation button with active underline."""
    def __init__(self, text: str):
        super().__init__()
        self.setObjectName("NavBtn")
        self.setCheckable(False)
        self.setCursor(Qt.PointingHandCursor)

        self._wrap = QWidget()
        wrap_layout = QVBoxLayout(self._wrap)
        wrap_layout.setContentsMargins(0, 0, 0, 0)
        wrap_layout.setSpacing(6)

        self._label = QLabel(text)
        self._label.setAlignment(Qt.AlignCenter)

        self._underline = QWidget()
        self._underline.setObjectName("NavUnderline")
        self._underline.setFixedHeight(3)
        self._underline.setFixedWidth(36)
        self._underline.setStyleSheet("background: transparent; border-radius: 2px;")

        wrap_layout.addStretch(1)
        wrap_layout.addWidget(self._label)
        wrap_layout.addWidget(self._underline, 0, Qt.AlignHCenter)
        wrap_layout.addStretch(1)

        btn_layout = QVBoxLayout(self)
        btn_layout.setContentsMargins(0, 0, 0, 0)
        btn_layout.addWidget(self._wrap)

    def set_active(self, active: bool):
        self.setProperty("active", "true" if active else "false")
        # important to re-polish to apply dynamic property styling:
        self.style().unpolish(self)
        self.style().polish(self)


# ---------- Screens ----------
class HomeScreen(QWidget):
    def __init__(self):
        super().__init__()
        root = QVBoxLayout(self)
        root.setContentsMargins(18, 16, 18, 16)
        root.setSpacing(16)

        hdr = QHBoxLayout()
        title = QLabel("Dashboard")
        title.setFont(QFont("", 22, 600))
        hint = QLabel("Premium UI • 1024×600")
        hint.setStyleSheet("color: rgba(138,147,166,0.9);")

        hdr.addWidget(title, 0, Qt.AlignLeft | Qt.AlignVCenter)
        hdr.addStretch(1)
        hdr.addWidget(hint, 0, Qt.AlignRight | Qt.AlignVCenter)

        grid = QGridLayout()
        grid.setContentsMargins(0, 0, 0, 0)
        grid.setHorizontalSpacing(16)
        grid.setVerticalSpacing(16)

        # 2×2 cards
        grid.addWidget(Card("MEDIA", "No track", "Tap to open", "♫"), 0, 0)
        grid.addWidget(Card("MAP / TRACK", "Idle", "Last trip: —", "⌁"), 0, 1)
        grid.addWidget(Card("CAR STATUS", "OK", "OBD: not connected", "⛭"), 1, 0)
        grid.addWidget(Card("CLOUD / YOUBLE", "Offline", "No sync yet", "☁"), 1, 1)

        root.addLayout(hdr)
        root.addLayout(grid, 1)


class StubScreen(QWidget):
    def __init__(self, title_text: str):
        super().__init__()
        root = QVBoxLayout(self)
        root.setContentsMargins(18, 16, 18, 16)
        root.setSpacing(12)

        title = QLabel(title_text)
        title.setFont(QFont("", 22, 600))

        sub = QLabel("Заглушка экрана. Тут будет функционал.")
        sub.setStyleSheet("color: rgba(138,147,166,0.9);")

        root.addWidget(title)
        root.addWidget(sub)
        root.addStretch(1)


# ---------- Main Window ----------
class MainWindow(QMainWindow):
    def __init__(self, app: QApplication):
        super().__init__()
        self.app = app
        self.is_night = True

        self.setWindowTitle("Car UI (Premium)")
        self.setMinimumSize(QSize(1024, 600))
        self.showFullScreen()

        # Root layout container
        central = QWidget()
        outer = QVBoxLayout(central)
        outer.setContentsMargins(0, 0, 0, 0)
        outer.setSpacing(0)

        # Top bar
        self.topbar = QWidget()
        self.topbar.setObjectName("TopBar")
        top = QHBoxLayout(self.topbar)
        top.setContentsMargins(16, 10, 16, 10)
        top.setSpacing(10)

        self.lbl_time = QLabel("--:--")
        self.lbl_time.setFont(QFont("", 16, 600))

        chip_bt = QPushButton("BT")
        chip_bt.setObjectName("IconChip")
        chip_wifi = QPushButton("Wi-Fi")
        chip_wifi.setObjectName("IconChip")
        chip_lte = QPushButton("LTE")
        chip_lte.setObjectName("IconChip")

        self.lbl_vol = QLabel("VOL 45%")
        self.lbl_vol.setStyleSheet("color: rgba(138,147,166,0.95); font-size: 14px;")

        self.btn_theme = QPushButton("🌙")
        self.btn_theme.setObjectName("IconChip")
        self.btn_theme.clicked.connect(self.toggle_theme)

        top.addWidget(self.lbl_time)
        top.addSpacing(10)
        top.addWidget(chip_bt)
        top.addWidget(chip_wifi)
        top.addWidget(chip_lte)
        top.addStretch(1)
        top.addWidget(self.lbl_vol)
        top.addWidget(self.btn_theme)

        # Content stack
        self.stack = QStackedWidget()
        self.stack.addWidget(HomeScreen())             # 0
        self.stack.addWidget(StubScreen("Media"))      # 1
        self.stack.addWidget(StubScreen("Car"))        # 2
        self.stack.addWidget(StubScreen("Maps"))       # 3
        self.stack.addWidget(StubScreen("Settings"))   # 4

        # Bottom bar (nav)
        self.bottombar = QWidget()
        self.bottombar.setObjectName("BottomBar")
        bottom = QHBoxLayout(self.bottombar)
        bottom.setContentsMargins(16, 8, 16, 8)
        bottom.setSpacing(10)

        self.nav_buttons = [
            NavButton("HOME"),
            NavButton("MEDIA"),
            NavButton("CAR"),
            NavButton("MAPS"),
            NavButton("SETTINGS"),
        ]

        for i, btn in enumerate(self.nav_buttons):
            btn.clicked.connect(lambda checked=False, idx=i: self.go(idx))
            bottom.addWidget(btn, 1)

        outer.addWidget(self.topbar)
        outer.addWidget(divider(1))
        outer.addWidget(self.stack, 1)
        outer.addWidget(divider(1))
        outer.addWidget(self.bottombar)

        self.setCentralWidget(central)

        # timers
        self._clock_timer = QTimer(self)
        self._clock_timer.timeout.connect(self.update_time)
        self._clock_timer.start(500)

        self.apply_theme()
        self.go(0)

    def update_time(self):
        from datetime import datetime
        self.lbl_time.setText(datetime.now().strftime("%H:%M"))

    def apply_theme(self):
        self.app.setStyleSheet(THEME_NIGHT if self.is_night else THEME_DAY)
        self.btn_theme.setText("🌙" if self.is_night else "☀")

    def toggle_theme(self):
        self.is_night = not self.is_night
        self.apply_theme()

    def go(self, idx: int):
        self.stack.setCurrentIndex(idx)
        for i, b in enumerate(self.nav_buttons):
            b.set_active(i == idx)


def main():
    app = QApplication(sys.argv)
    win = MainWindow(app)
    win.show()
    sys.exit(app.exec())


if __name__ == "__main__":
    main()