"""
Metrics card widget for displaying statistics.
"""

from typing import List, Optional
from dataclasses import dataclass

try:
    from PyQt6.QtWidgets import (
        QWidget, QVBoxLayout, QHBoxLayout, QLabel, QGridLayout
    )
    from PyQt6.QtCore import Qt
    from PyQt6.QtGui import QFont
    HAS_QT = True
except ImportError:
    HAS_QT = False
    QWidget = object


@dataclass
class StatItem:
    """Single statistic item."""
    label: str
    value: str
    change: Optional[str] = None
    positive: bool = True


class MetricsCard(QWidget if HAS_QT else object):
    """Card displaying multiple metrics."""
    
    def __init__(self, title: str = "Metrics", parent=None):
        if not HAS_QT:
            return
        super().__init__(parent)
        self._stats: List[StatItem] = []
        self._setup_ui(title)
    
    def _setup_ui(self, title: str):
        self.setStyleSheet("""
            MetricsCard {
                background-color: #2d2d2d;
                border-radius: 8px;
                padding: 15px;
            }
            QLabel {
                color: #ffffff;
            }
            .metric-label {
                color: #888888;
                font-size: 12px;
            }
            .metric-value {
                font-size: 18px;
                font-weight: bold;
            }
            .metric-positive {
                color: #4caf50;
            }
            .metric-negative {
                color: #f44336;
            }
        """)
        
        layout = QVBoxLayout(self)
        layout.setContentsMargins(15, 15, 15, 15)
        layout.setSpacing(15)
        
        # Title
        self.title_label = QLabel(title)
        font = QFont()
        font.setBold(True)
        font.setPointSize(14)
        self.title_label.setFont(font)
        layout.addWidget(self.title_label)
        
        # Stats grid
        self.stats_layout = QGridLayout()
        self.stats_layout.setSpacing(10)
        layout.addLayout(self.stats_layout)
        
        layout.addStretch()
    
    def set_stats(self, stats: List[StatItem]):
        """Update displayed statistics."""
        if not HAS_QT:
            return
        
        self._stats = stats
        
        # Clear existing
        while self.stats_layout.count():
            item = self.stats_layout.takeAt(0)
            if item.widget():
                item.widget().deleteLater()
        
        # Add stats
        for i, stat in enumerate(stats):
            row = i // 2
            col = (i % 2) * 2
            
            # Label
            label = QLabel(stat.label)
            label.setStyleSheet("color: #888888; font-size: 11px;")
            self.stats_layout.addWidget(label, row * 2, col)
            
            # Value with optional change
            value_text = stat.value
            if stat.change:
                value_text += f" <span style='color: {'#4caf50' if stat.positive else '#f44336'}'>{stat.change}</span>"
            
            value_label = QLabel(value_text)
            value_label.setStyleSheet("font-size: 16px; font-weight: bold; color: #ffffff;")
            self.stats_layout.addWidget(value_label, row * 2 + 1, col)
    
    def update_stat(self, index: int, value: str, change: Optional[str] = None):
        """Update a single statistic."""
        if 0 <= index < len(self._stats):
            self._stats[index].value = value
            self._stats[index].change = change
            self.set_stats(self._stats)