# ---------------------------------------------------------------------------
# Sky-Plot Widget
# ---------------------------------------------------------------------------
import math

from PyQt5.QtCore import Qt
from PyQt5.QtGui import QPainter, QRadialGradient, QColor, QBrush, QPen, QFont
from PyQt5.QtWidgets import QWidget

from defines import GNSS_NAMES, GNSS_COLORS


class SkyPlotWidget(QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)
        self._satellites = []
        self.setMinimumSize(400, 400)
        self.setStyleSheet("background-color: #1a1a2e;")

    def update_satellites(self, sats: list):
        self._satellites = sats
        self.update()

    def paintEvent(self, event):
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing)
        w, h   = self.width(), self.height()
        cx, cy = w / 2, h / 2
        radius = min(w, h) / 2 - 30
        self._draw_background(painter, cx, cy, radius)
        self._draw_grid(painter, cx, cy, radius)
        self._draw_satellites(painter, cx, cy, radius)
        self._draw_legend(painter)

    def _draw_background(self, painter, cx, cy, radius):
        grad = QRadialGradient(cx, cy, radius)
        grad.setColorAt(0.0, QColor("#0d1b2a"))
        grad.setColorAt(1.0, QColor("#1a1a2e"))
        painter.setBrush(QBrush(grad))
        painter.setPen(Qt.NoPen)
        painter.drawEllipse(
            int(cx - radius), int(cy - radius),
            int(radius * 2),  int(radius * 2),
        )

    def _draw_grid(self, painter, cx, cy, radius):
        pen = QPen(QColor("#2a4a6a"), 1, Qt.DashLine)
        painter.setPen(pen)
        painter.setFont(QFont("Monospace", 8))

        for elev in (0, 30, 60):
            r = radius * (1 - elev / 90)
            painter.drawEllipse(int(cx - r), int(cy - r), int(r * 2), int(r * 2))
            painter.setPen(QColor("#4a7a9b"))
            painter.drawText(int(cx + 4), int(cy - r), f"{elev}°")
            painter.setPen(pen)

        for azim in range(0, 360, 45):
            rad = math.radians(azim)
            painter.drawLine(
                int(cx + math.sin(rad) * radius * 0.05),
                int(cy - math.cos(rad) * radius * 0.05),
                int(cx + math.sin(rad) * radius),
                int(cy - math.cos(rad) * radius),
            )

        painter.setPen(QColor("#7ab7d4"))
        painter.setFont(QFont("Monospace", 10, QFont.Bold))
        for label, azim in (("N", 0), ("O", 90), ("S", 180), ("W", 270)):
            rad = math.radians(azim)
            painter.drawText(
                int(cx + math.sin(rad) * (radius + 15) - 6),
                int(cy - math.cos(rad) * (radius + 15) + 5),
                label,
            )

    @staticmethod
    def _az_el_to_xy(azim, elev, cx, cy, radius):
        r   = radius * (1 - elev / 90)
        rad = math.radians(azim)
        return cx + math.sin(rad) * r, cy - math.cos(rad) * r

    def _draw_satellites(self, painter, cx, cy, radius):
        for sat in self._satellites:
            if sat["elev"] < 0:
                continue
            color = GNSS_COLORS.get(sat["gnssId"], QColor("#ffffff"))
            x, y  = self._az_el_to_xy(sat["azim"], sat["elev"], cx, cy, radius)
            cno   = max(0, min(50, sat["cno"]))
            dot_r = 4 + int(cno / 50 * 8)

            glow = QColor(color)
            glow.setAlpha(60)
            painter.setBrush(QBrush(glow))
            painter.setPen(Qt.NoPen)
            painter.drawEllipse(
                int(x - dot_r * 1.8), int(y - dot_r * 1.8),
                int(dot_r * 3.6),     int(dot_r * 3.6),
            )

            if sat["used"]:
                painter.setBrush(QBrush(color))
                painter.setPen(QPen(QColor("#ffffff"), 1))
            else:
                faded = QColor(color)
                faded.setAlpha(120)
                painter.setBrush(QBrush(faded))
                painter.setPen(QPen(color, 1, Qt.DashLine))

            painter.drawEllipse(
                int(x - dot_r), int(y - dot_r), dot_r * 2, dot_r * 2
            )
            painter.setPen(QColor("#ffffff"))
            painter.setFont(QFont("Monospace", 7))
            painter.drawText(int(x + dot_r + 2), int(y + 4), str(sat["svId"]))

    def _draw_legend(self, painter):
        painter.setFont(QFont("Monospace", 8))
        x, y = 10, 20
        for gnss_id, name in GNSS_NAMES.items():
            color = GNSS_COLORS[gnss_id]
            painter.setBrush(QBrush(color))
            painter.setPen(Qt.NoPen)
            painter.drawEllipse(x, y - 8, 10, 10)
            painter.setPen(QColor("#cccccc"))
            painter.drawText(x + 14, y, name)
            y += 16