{% extends "base.html" %}
{% block title %}Pair Trading{% endblock %}

{% block content %}
<div x-data="pairTradingApp()" x-init="init()" class="space-y-6">

    <!-- Header -->
    <div class="flex flex-col sm:flex-row sm:items-center justify-between gap-4">
        <div>
            <h1 class="text-2xl font-bold text-white flex items-center gap-3">
                <div class="p-2 bg-koin-600/20 rounded-xl">
                    <svg class="w-6 h-6 text-koin-400" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" d="M7.5 21L3 16.5m0 0L7.5 12M3 16.5h13.5m0-13.5L21 7.5m0 0L16.5 12M21 7.5H7.5"/></svg>
                </div>
                Pair Trading
            </h1>
            <p class="text-gray-400 text-sm mt-1">Statistical arbitrage from correlated pair divergence analysis</p>
        </div>
        <div class="flex items-center gap-3">
            <span class="text-xs text-gray-500" x-text="lastRefresh ? 'Updated: ' + lastRefresh : ''"></span>
            <button @click="fetchData()" :disabled="loading"
                    class="px-4 py-2 bg-koin-600 hover:bg-koin-500 text-white text-sm font-medium rounded-lg transition disabled:opacity-50 flex items-center gap-2">
                <svg x-show="loading" class="w-4 h-4 animate-spin" fill="none" viewBox="0 0 24 24"><circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"/><path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z"/></svg>
                <span x-text="loading ? 'Analyzing...' : 'Refresh'"></span>
            </button>
        </div>
    </div>

    <!-- Loading -->
    <div x-show="loading && items.length === 0" x-cloak class="flex items-center justify-center py-16">
        <div class="text-center">
            <svg class="w-8 h-8 animate-spin text-koin-400 mx-auto mb-3" fill="none" viewBox="0 0 24 24">
                <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"/>
                <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"/>
            </svg>
            <p class="text-sm text-gray-500">Analyzing pair correlations...</p>
        </div>
    </div>

    <!-- Error -->
    <div x-show="error" x-cloak class="bg-red-900/20 border border-red-800 rounded-xl p-4">
        <p class="text-sm text-red-400" x-text="error"></p>
    </div>

    <!-- Content -->
    <div x-show="!loading || items.length > 0" x-cloak>

        <!-- Summary Cards -->
        <div class="grid grid-cols-2 md:grid-cols-4 gap-4 mb-6">
            <div class="bg-gray-800 border border-gray-700 rounded-xl p-4">
                <div class="text-xs text-gray-400 uppercase tracking-wider">Total Pairs</div>
                <div class="text-2xl font-bold text-white mt-1" x-text="items.length"></div>
            </div>
            <div class="bg-gray-800 border border-emerald-700/30 rounded-xl p-4">
                <div class="text-xs text-gray-400 uppercase tracking-wider">High Score Pairs</div>
                <div class="text-2xl font-bold text-emerald-400 mt-1" x-text="highScoreCount"></div>
            </div>
            <div class="bg-gray-800 border border-amber-700/30 rounded-xl p-4">
                <div class="text-xs text-gray-400 uppercase tracking-wider">Active Signals</div>
                <div class="text-2xl font-bold text-amber-400 mt-1" x-text="activeSignalCount"></div>
            </div>
            <div class="bg-gray-800 border border-koin-700/30 rounded-xl p-4">
                <div class="text-xs text-gray-400 uppercase tracking-wider">Avg Correlation</div>
                <div class="text-2xl font-bold text-koin-400 mt-1" x-text="fmt(avgCorrelation, 2)"></div>
            </div>
        </div>

        <!-- Info Box -->
        <div class="bg-koin-900/15 border border-koin-700/25 rounded-xl p-4 mb-6">
            <div class="flex items-start gap-3">
                <svg class="w-5 h-5 text-koin-400 mt-0.5 flex-shrink-0" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M13 16h-1v-4h-1m1-4h.01M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>
                <div>
                    <h4 class="text-sm font-medium text-koin-300">Pair Trading / Statistical Arbitrage</h4>
                    <p class="text-xs text-gray-400 mt-1"><strong class="text-gray-300">Pair trading</strong> exploits temporary divergences between correlated assets. When the price spread deviates beyond normal (high Z-score), we expect <strong class="text-gray-300">mean reversion</strong>. <strong class="text-gray-300">Cointegrated</strong> pairs have a long-run equilibrium, making them ideal candidates. Half-life measures expected reversion speed.</p>
                    <div class="flex flex-wrap gap-3 mt-2">
                        <span class="text-[10px] text-gray-500 flex items-center gap-1"><span class="w-2 h-2 rounded-full bg-emerald-500"></span> Buy Spread = oversold pair</span>
                        <span class="text-[10px] text-gray-500 flex items-center gap-1"><span class="w-2 h-2 rounded-full bg-red-500"></span> Sell Spread = overbought pair</span>
                    </div>
                </div>
            </div>
        </div>

        <!-- Filters -->
        <div class="flex flex-col sm:flex-row gap-3 mb-6">
            <div class="flex gap-1 bg-gray-900 p-1 rounded-xl border border-gray-700">
                <template x-for="f in [{v:'all',l:'All'},{v:'buy_spread',l:'Buy Spread'},{v:'sell_spread',l:'Sell Spread'},{v:'neutral',l:'Neutral'}]" :key="f.v">
                    <button @click="filterSignal = f.v"
                            class="px-3 py-1.5 text-xs font-medium rounded-lg transition"
                            :class="filterSignal === f.v ? 'bg-koin-600 text-white' : 'text-gray-400 hover:text-gray-300 hover:bg-gray-800'"
                            x-text="f.l"></button>
                </template>
            </div>
            <div class="flex items-center gap-2 bg-gray-900 px-3 py-1 rounded-xl border border-gray-700">
                <span class="text-xs text-gray-400">Min Score:</span>
                <input type="range" x-model.number="minScore" min="0" max="100" step="5"
                       class="w-20 h-1 accent-koin-500">
                <span class="text-xs text-koin-400 font-medium w-6" x-text="minScore"></span>
            </div>
            <div class="relative flex-1">
                <svg class="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-gray-500" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z"/></svg>
                <input type="text" x-model="search" placeholder="Search pair..."
                       class="w-full pl-10 pr-4 py-2 bg-gray-800 border border-gray-700 rounded-lg text-sm text-gray-200 focus:outline-none focus:ring-1 focus:ring-koin-500">
            </div>
        </div>

        <!-- Cards Grid -->
        <div class="grid grid-cols-1 lg:grid-cols-2 gap-4">
            <template x-for="(item, idx) in filteredItems" :key="(item.symbol_a || '') + (item.symbol_b || '') + idx">
                <div class="bg-gray-800 border border-gray-700 rounded-xl p-5 hover:border-gray-600 transition">
                    <!-- Pair Header -->
                    <div class="flex items-center justify-between mb-4">
                        <div class="flex items-center gap-2">
                            <span class="text-white font-bold text-lg" x-text="item.symbol_a"></span>
                            <span class="text-gray-500">/</span>
                            <span class="text-white font-bold text-lg" x-text="item.symbol_b"></span>
                        </div>
                        <div class="flex items-center gap-2">
                            <span class="px-2 py-0.5 text-xs font-medium rounded-full"
                                  :class="signalBadge(item.signal)"
                                  x-text="signalLabel(item.signal)"></span>
                            <span class="text-sm font-bold"
                                  :class="(item.pair_score || 0) >= 70 ? 'text-koin-400' : (item.pair_score || 0) >= 40 ? 'text-amber-400' : 'text-gray-400'"
                                  x-text="fmt(item.pair_score, 0)"></span>
                        </div>
                    </div>

                    <!-- Pair Score Bar -->
                    <div class="mb-4">
                        <div class="flex items-center justify-between text-xs text-gray-500 mb-1">
                            <span>Pair Score</span>
                            <span x-text="fmt(item.pair_score, 0) + '/100'"></span>
                        </div>
                        <div class="w-full bg-gray-700 rounded-full h-2">
                            <div class="h-2 rounded-full transition-all"
                                 :class="(item.pair_score || 0) >= 70 ? 'bg-koin-500' : (item.pair_score || 0) >= 40 ? 'bg-amber-500' : 'bg-gray-500'"
                                 :style="'width:' + (item.pair_score || 0) + '%'"></div>
                        </div>
                    </div>

                    <!-- Correlation -->
                    <div class="grid grid-cols-3 gap-2 mb-4">
                        <div class="bg-gray-900/40 rounded-lg p-2 text-center">
                            <div class="text-[10px] text-gray-500">Correlation</div>
                            <div class="text-sm font-bold mt-0.5"
                                 :class="(item.correlation || 0) >= 0.8 ? 'text-emerald-400' : (item.correlation || 0) >= 0.5 ? 'text-amber-400' : 'text-red-400'"
                                 x-text="fmt(item.correlation, 3)"></div>
                        </div>
                        <div class="bg-gray-900/40 rounded-lg p-2 text-center">
                            <div class="text-[10px] text-gray-500">Half-Life</div>
                            <div class="text-sm font-medium text-gray-300 mt-0.5" x-text="(item.half_life || '-') + 'd'"></div>
                        </div>
                        <div class="bg-gray-900/40 rounded-lg p-2 text-center">
                            <div class="text-[10px] text-gray-500">Cointegrated</div>
                            <div class="text-sm font-medium mt-0.5"
                                 :class="item.cointegrated ? 'text-emerald-400' : 'text-gray-500'"
                                 x-text="item.cointegrated ? 'YES' : 'NO'"></div>
                        </div>
                    </div>

                    <!-- Z-Score Bar -->
                    <div class="bg-gray-900/60 border border-gray-700/50 rounded-lg p-3 mb-4">
                        <div class="flex items-center justify-between text-xs mb-2">
                            <span class="text-gray-500">Z-Score</span>
                            <span class="font-medium" :class="Math.abs(item.z_score || 0) >= 2 ? 'text-koin-400' : 'text-gray-300'"
                                  x-text="fmt(item.z_score, 2)"></span>
                        </div>
                        <div class="relative w-full bg-gray-700 rounded-full h-3">
                            <div class="absolute left-1/2 top-0 w-0.5 h-3 bg-gray-500"></div>
                            <div class="absolute top-0 h-3 rounded-full transition-all"
                                 :class="(item.z_score || 0) < 0 ? 'bg-emerald-500' : 'bg-red-500'"
                                 :style="zScoreStyle(item.z_score)"></div>
                        </div>
                        <div class="flex justify-between text-[10px] text-gray-600 mt-1">
                            <span>Oversold (-3)</span>
                            <span>0</span>
                            <span>Overbought (+3)</span>
                        </div>
                    </div>

                    <!-- Profit Potential -->
                    <div class="flex items-center justify-between bg-gray-900/40 rounded-lg px-3 py-2 mb-3" x-show="item.profit_potential != null">
                        <span class="text-xs text-gray-400">Est. Profit Potential</span>
                        <span class="text-sm font-bold"
                              :class="(item.profit_potential || 0) > 0 ? 'text-emerald-400' : 'text-gray-400'"
                              x-text="fmtPct(item.profit_potential)"></span>
                    </div>

                    <!-- Key Insight -->
                    <div x-show="item.key_insight" class="border-t border-gray-700 pt-3">
                        <p class="text-xs text-gray-400 leading-relaxed" x-text="item.key_insight"></p>
                    </div>
                </div>
            </template>
        </div>

        <!-- Empty States -->
        <div x-show="filteredItems.length === 0 && items.length > 0" x-cloak class="text-center py-16">
            <svg class="w-12 h-12 text-gray-600 mx-auto mb-3" fill="none" stroke="currentColor" stroke-width="1.5" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" d="M21 21l-5.197-5.197m0 0A7.5 7.5 0 105.196 5.196a7.5 7.5 0 0010.607 10.607z"/></svg>
            <p class="text-gray-500">No pairs matching your filters</p>
        </div>
        <div x-show="items.length === 0 && !loading && !error" x-cloak class="text-center py-16">
            <svg class="w-12 h-12 text-gray-600 mx-auto mb-3" fill="none" stroke="currentColor" stroke-width="1.5" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" d="M7.5 21L3 16.5m0 0L7.5 12M3 16.5h13.5m0-13.5L21 7.5m0 0L16.5 12M21 7.5H7.5"/></svg>
            <p class="text-gray-500">No data available. Click Refresh to scan.</p>
        </div>
    </div>
</div>

<script>
function pairTradingApp() {
    return {
        loading: false, error: null, lastRefresh: null,
        items: [], search: '',
        filterSignal: 'all', minScore: 0,

        get highScoreCount() {
            return this.items.filter(i => (i.pair_score || 0) >= 70).length;
        },
        get activeSignalCount() {
            return this.items.filter(i => i.signal && i.signal !== 'neutral').length;
        },
        get avgCorrelation() {
            if (!this.items.length) return 0;
            return this.items.reduce((s, i) => s + (i.correlation || 0), 0) / this.items.length;
        },

        get filteredItems() {
            let list = [...this.items];
            if (this.search) {
                const q = this.search.toUpperCase();
                list = list.filter(i => (i.symbol_a || '').toUpperCase().includes(q) || (i.symbol_b || '').toUpperCase().includes(q));
            }
            if (this.filterSignal !== 'all') {
                list = list.filter(i => i.signal === this.filterSignal);
            }
            if (this.minScore > 0) {
                list = list.filter(i => (i.pair_score || 0) >= this.minScore);
            }
            list.sort((a, b) => (b.pair_score || 0) - (a.pair_score || 0));
            return list;
        },

        signalBadge(sig) {
            const s = (sig || '').toLowerCase();
            if (s === 'buy_spread') return 'bg-emerald-900/50 text-emerald-300';
            if (s === 'sell_spread') return 'bg-red-900/50 text-red-300';
            return 'bg-gray-700 text-gray-300';
        },
        signalLabel(sig) {
            const s = (sig || 'neutral').toLowerCase();
            return s.replace(/_/g, ' ').replace(/\b\w/g, l => l.toUpperCase());
        },

        zScoreStyle(z) {
            const val = Math.max(-3, Math.min(3, z || 0));
            const pct = ((val + 3) / 6) * 100;
            const center = 50;
            if (pct < center) {
                return `left:${pct}%;width:${center - pct}%`;
            } else {
                return `left:${center}%;width:${pct - center}%`;
            }
        },

        init() { this.fetchData(); },
        async fetchData() {
            this.loading = true; this.error = null;
            try {
                const params = new URLSearchParams({ asset_type: '{{ asset_mode }}' });
                const res = await fetch(`/api/v1/market/pair-trading?${params}`);
                if (res.redirected) { window.location.href = res.url; return; }
                const json = await res.json();
                if (json.error) { this.error = json.error; }
                else { this.items = json.items || json.results || []; }
            } catch (e) { this.error = 'Failed to load: ' + e.message; }
            finally { this.loading = false; this.lastRefresh = new Date().toLocaleTimeString('id-ID'); }
        },
        fmt(n, d=2) { return n != null ? Number(n).toFixed(d) : '-'; },
        fmtPct(n) { return n != null ? (n >= 0 ? '+' : '') + Number(n).toFixed(2) + '%' : '-'; },
        fmtPrice(n) { return n != null ? 'Rp ' + Number(n).toLocaleString('id-ID') : '-'; },
    };
}
</script>
{% endblock %}