import React, { useState } from 'react';
import { View, Text, ScrollView, StyleSheet } from 'react-native';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import { LinearGradient } from 'expo-linear-gradient';
import { Colors, Fonts, FontSize, BorderRadius, Shadows, Spacing } from '@/constants/theme';
import { formatPrice, formatPercent, formatCurrency } from '@/utils/format';
import SegmentedControl from '@/components/SegmentedControl';
import AnimatedCard from '@/components/AnimatedCard';
import Sparkline from '@/components/Sparkline';
import PillBadge from '@/components/PillBadge';
import { useTradingData } from '@/providers/TradingDataProvider';
import { toPositionCards } from '@/lib/tradingViewModels';

type MobileOrder = {
  id: string;
  symbol: string;
  type: string;
  side: string;
  qty: number;
  price: number;
  status: string;
  action?: 'ENTRY' | 'EXIT';
  source?: 'BOT' | 'MANUAL';
  timestamp: number;
};

function PositionCard({ pos, index }: { pos: ReturnType<typeof toPositionCards>[number]; index: number }) {
  const isPositive = pos.unrealizedPnl >= 0;
  const sideColor = pos.side === 'BUY' ? Colors.accent.green : Colors.accent.red;

  return (
    <AnimatedCard index={index} style={[Shadows.card, { borderRadius: BorderRadius.large }]}>
      <LinearGradient
        colors={['rgba(20,21,26,0.9)', 'rgba(14,15,18,0.95)']}
        start={{ x: 0, y: 0 }}
        end={{ x: 1, y: 1 }}
        style={styles.posCard}
      >
        <View style={[styles.accentLine, { backgroundColor: sideColor }]} />

        <View style={styles.row}>
          <Text style={styles.symbol}>{pos.symbol}</Text>
          <PillBadge
            label={pos.side === 'BUY' ? 'LONG' : 'SHORT'}
            color={sideColor}
            bgColor={pos.side === 'BUY' ? 'rgba(0,255,136,0.15)' : 'rgba(255,51,102,0.15)'}
          />
          <PillBadge
            label={pos.source}
            color={pos.source === 'BOT' ? Colors.accent.purple : Colors.accent.orange}
            bgColor={pos.source === 'BOT' ? 'rgba(168,85,247,0.15)' : 'rgba(230,126,34,0.15)'}
          />
        </View>

        <Text style={styles.profileText}>{pos.profileName}</Text>

        <View style={styles.metricsGrid}>
          <MetricCell label="ENTRY" value={formatPrice(pos.entryPrice)} />
          <MetricCell label="CURRENT" value={formatPrice(pos.currentPrice)} />
          <MetricCell label="SIZE" value={`${pos.size} ${pos.symbol.split('/')[0]}`} />
          <MetricCell label="MKT VALUE" value={formatPrice(pos.marketValue)} />
        </View>

        <View style={styles.slTpRow}>
          <Text style={[styles.slTp, { color: Colors.accent.red }]}>SL {formatPrice(pos.stopLoss)}</Text>
          <Text style={[styles.slTp, { color: Colors.accent.green }]}>TP {formatPrice(pos.takeProfit)}</Text>
        </View>

        <Text style={[styles.pnlHero, { color: isPositive ? Colors.accent.green : Colors.accent.red }]}>
          {formatCurrency(pos.unrealizedPnl)} ({formatPercent(pos.unrealizedPnlPercent)})
        </Text>

        <Sparkline
          data={pos.sparkData}
          width={300}
          height={50}
          color={isPositive ? Colors.accent.green : Colors.accent.red}
        />
      </LinearGradient>
    </AnimatedCard>
  );
}

function OrderCard({ order, index }: { order: MobileOrder; index: number }) {
  const actionColors = {
    ENTRY: { bg: 'rgba(59,130,246,0.1)', color: '#3b82f6', border: 'rgba(59,130,246,0.2)' },
    EXIT: { bg: 'rgba(245,158,11,0.1)', color: '#f59e0b', border: 'rgba(245,158,11,0.2)' },
  };
  const statusColors: Record<string, { bg: string; color: string }> = {
    filled: { bg: 'rgba(0,255,136,0.15)', color: Colors.accent.green },
    pending_new: { bg: 'rgba(250,204,21,0.15)', color: Colors.accent.amber },
    cancelled: { bg: 'rgba(255,255,255,0.05)', color: Colors.text.secondary },
  };
  const actionKey = order.action || 'ENTRY';
  const ac = actionColors[actionKey];
  const sc = statusColors[order.status] || statusColors.cancelled;
  const source = order.source || 'BOT';

  return (
    <AnimatedCard index={index} style={[Shadows.card, { borderRadius: BorderRadius.medium }]}>
      <View style={styles.orderCard}>
        <View style={styles.row}>
          <Text style={styles.symbol}>{order.symbol}</Text>
          <PillBadge label={actionKey} color={ac.color} bgColor={ac.bg} borderColor={ac.border} />
          <PillBadge label={order.status.replace('_', ' ')} color={sc.color} bgColor={sc.bg} />
        </View>
        <View style={styles.orderDetails}>
          <Text style={styles.orderType}>{order.type} {order.side}</Text>
          <Text style={styles.orderQty}>{order.qty} @ {formatPrice(order.price)}</Text>
        </View>
        <View style={styles.orderFooter}>
          <PillBadge
            label={source}
            color={source === 'BOT' ? Colors.accent.purple : Colors.accent.orange}
            bgColor={source === 'BOT' ? 'rgba(168,85,247,0.15)' : 'rgba(230,126,34,0.15)'}
          />
          <Text style={styles.orderTime}>
            {new Date(order.timestamp).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' })}
          </Text>
        </View>
      </View>
    </AnimatedCard>
  );
}

function MetricCell({ label, value }: { label: string; value: string }) {
  return (
    <View style={styles.metricCell}>
      <Text style={styles.metricLabel}>{label}</Text>
      <Text style={styles.metricValue}>{value}</Text>
    </View>
  );
}

export default function PositionsScreen() {
  const insets = useSafeAreaInsets();
  const [activeTab, setActiveTab] = useState(0);
  const { botState } = useTradingData();
  const positions = toPositionCards(botState?.positions || [], botState?.symbols);
  const orders: MobileOrder[] = botState?.orders || [];

  return (
    <View style={[styles.container, { paddingTop: insets.top }]}>
      <View style={styles.headerSection}>
        <Text style={styles.sectionLabel}>PORTFOLIO</Text>
        <Text style={styles.pageTitle}>Positions</Text>
        <SegmentedControl
          segments={['Positions', 'Orders']}
          activeIndex={activeTab}
          onPress={setActiveTab}
        />
      </View>

      <ScrollView
        style={styles.scroll}
        contentContainerStyle={styles.listContent}
        showsVerticalScrollIndicator={false}
      >
        {activeTab === 0 ? (
          positions.length > 0
            ? positions.map((pos, i) => <PositionCard key={pos.id} pos={pos} index={i} />)
            : <View style={styles.emptyState}><Text style={styles.emptyText}>No open positions</Text><Text style={styles.emptyHint}>Active positions will appear here once the bot enters a trade.</Text></View>
        ) : (
          orders.length > 0
            ? orders.map((ord, i) => <OrderCard key={ord.id} order={ord} index={i} />)
            : <View style={styles.emptyState}><Text style={styles.emptyText}>No pending orders</Text><Text style={styles.emptyHint}>Orders placed by the bot or manually will appear here.</Text></View>
        )}
      </ScrollView>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: Colors.background.primary,
  },
  headerSection: {
    padding: Spacing.screenPadding,
    gap: 12,
  },
  sectionLabel: {
    fontFamily: Fonts.inter.black,
    fontSize: FontSize.micro,
    color: Colors.accent.green,
    letterSpacing: 4,
  },
  pageTitle: {
    fontFamily: Fonts.inter.black,
    fontSize: FontSize.hero,
    color: Colors.text.primary,
    letterSpacing: -0.5,
  },
  scroll: {
    flex: 1,
  },
  listContent: {
    padding: Spacing.screenPadding,
    paddingTop: 0,
    gap: 16,
    paddingBottom: 120,
  },
  posCard: {
    borderRadius: BorderRadius.large,
    padding: Spacing.cardPadding,
    borderWidth: 1,
    borderColor: Colors.border.default,
    overflow: 'hidden',
    gap: 10,
  },
  accentLine: {
    position: 'absolute',
    top: 0,
    left: 0,
    right: 0,
    height: 2,
    opacity: 0.6,
  },
  row: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 8,
  },
  symbol: {
    fontFamily: Fonts.inter.black,
    fontSize: FontSize.subheading,
    color: Colors.text.primary,
    letterSpacing: -0.3,
  },
  profileText: {
    fontFamily: Fonts.inter.medium,
    fontSize: FontSize.badge,
    color: Colors.text.secondary,
  },
  metricsGrid: {
    flexDirection: 'row',
    flexWrap: 'wrap',
    gap: 12,
    marginTop: 4,
  },
  metricCell: {
    width: '46%',
  },
  metricLabel: {
    fontFamily: Fonts.inter.black,
    fontSize: FontSize.micro,
    color: Colors.text.secondary,
    letterSpacing: 0.8,
    marginBottom: 3,
  },
  metricValue: {
    fontFamily: Fonts.mono.extraBold,
    fontSize: FontSize.bodyLarge,
    color: Colors.text.primary,
  },
  slTpRow: {
    flexDirection: 'row',
    gap: 16,
    marginTop: 4,
  },
  slTp: {
    fontFamily: Fonts.mono.medium,
    fontSize: FontSize.badge,
  },
  pnlHero: {
    fontFamily: Fonts.mono.extraBold,
    fontSize: FontSize.heading,
    marginTop: 4,
  },
  orderCard: {
    backgroundColor: Colors.background.card,
    borderRadius: BorderRadius.medium,
    padding: Spacing.cardPadding,
    borderWidth: 1,
    borderColor: Colors.border.default,
    gap: 10,
  },
  orderDetails: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
  },
  orderType: {
    fontFamily: Fonts.inter.bold,
    fontSize: FontSize.body,
    color: Colors.text.primary,
  },
  orderQty: {
    fontFamily: Fonts.mono.bold,
    fontSize: FontSize.body,
    color: Colors.text.primary,
  },
  orderFooter: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
  },
  orderTime: {
    fontFamily: Fonts.mono.regular,
    fontSize: FontSize.micro,
    color: Colors.text.secondary,
  },
  emptyState: {
    alignItems: 'center' as const,
    justifyContent: 'center' as const,
    paddingVertical: 60,
    gap: 10,
  },
  emptyText: {
    fontFamily: Fonts.inter.bold,
    fontSize: FontSize.subheading,
    color: Colors.text.secondary,
  },
  emptyHint: {
    fontFamily: Fonts.inter.medium,
    fontSize: FontSize.body,
    color: Colors.text.muted,
    textAlign: 'center' as const,
    maxWidth: 260,
    lineHeight: 20,
  },
});