// IvantiCountsChart.js
// Collapsible trend panel for the Vulnerability Triage page.
// Shows open vs closed Ivanti finding counts over time (last sync per day).

import React, { useState, useEffect, useMemo } from 'react';
import {
    LineChart, Line,
    XAxis, YAxis, CartesianGrid,
    Tooltip, Legend, ReferenceLine,
    ResponsiveContainer,
} from 'recharts';
import { TrendingUp, ChevronDown, ChevronUp, Loader } from 'lucide-react';

const API_BASE = process.env.REACT_APP_API_BASE || 'http://localhost:3001/api';

const AMBER  = '#F59E0B';
const SKY    = '#0EA5E9';
const GREEN  = '#10B981';
const RED    = '#EF4444';

const AXIS_STYLE   = { fontFamily: 'monospace', fontSize: '0.6rem', fill: '#475569' };
const GRID_STYLE   = { stroke: 'rgba(255,255,255,0.05)', strokeDasharray: '3 3' };
const LEGEND_STYLE = { fontFamily: 'monospace', fontSize: '0.62rem', color: '#64748B' };

// ---------------------------------------------------------------------------
// Custom dark tooltip
// ---------------------------------------------------------------------------
function DarkTooltip({ active, payload, label }) {
    if (!active || !payload?.length) return null;

    const openVal   = payload.find(p => p.dataKey === 'open_count')?.value;
    const closedVal = payload.find(p => p.dataKey === 'closed_count')?.value;

    return (
        <div style={{
            background: 'rgba(10,17,32,0.97)',
            border: '1px solid rgba(245,158,11,0.3)',
            borderRadius: '0.375rem',
            padding: '0.5rem 0.75rem',
            fontFamily: 'monospace',
            fontSize: '0.7rem',
            minWidth: '160px',
        }}>
            <div style={{ color: AMBER, marginBottom: '0.35rem', fontWeight: '700', fontSize: '0.65rem' }}>
                {label}
            </div>
            {payload.map(p => (
                <div key={p.dataKey} style={{ color: p.color, marginTop: '0.125rem', display: 'flex', justifyContent: 'space-between', gap: '1rem' }}>
                    <span style={{ opacity: 0.8 }}>{p.name}</span>
                    <span style={{ fontWeight: '700' }}>{p.value}</span>
                </div>
            ))}
            {openVal != null && closedVal != null && (
                <div style={{ borderTop: '1px solid rgba(255,255,255,0.06)', marginTop: '0.35rem', paddingTop: '0.3rem', color: '#475569', display: 'flex', justifyContent: 'space-between', gap: '1rem' }}>
                    <span>total</span>
                    <span style={{ color: '#64748B', fontWeight: '600' }}>{openVal + closedVal}</span>
                </div>
            )}
        </div>
    );
}

// ---------------------------------------------------------------------------
// Shorten YYYY-MM-DD to MM/DD/YY
// ---------------------------------------------------------------------------
function fmtDate(d) {
    if (!d) return '';
    const p = d.split('-');
    if (p.length === 3) return `${p[1]}/${p[2]}/${p[0].slice(2)}`;
    return d;
}

// ---------------------------------------------------------------------------
// Main component
// ---------------------------------------------------------------------------
export default function IvantiCountsChart() {
    const [collapsed, setCollapsed] = useState(false);
    const [loading,   setLoading]   = useState(true);
    const [history,   setHistory]   = useState([]);

    useEffect(() => {
        let cancelled = false;
        const load = async () => {
            setLoading(true);
            try {
                const res = await fetch(`${API_BASE}/ivanti/findings/counts/history`, { credentials: 'include' });
                if (res.ok && !cancelled) {
                    const d = await res.json();
                    setHistory(d.history || []);
                }
            } catch { /* silent — chart shows no-data state */ }
            finally { if (!cancelled) setLoading(false); }
        };
        load();
        return () => { cancelled = true; };
    }, []);

    const chartData = useMemo(
        () => history.map(r => ({ ...r, date: fmtDate(r.date) })),
        [history]
    );

    // Compute a simple delta label for the latest vs previous point
    const deltaLabel = useMemo(() => {
        if (chartData.length < 2) return null;
        const latest = chartData[chartData.length - 1];
        const prev   = chartData[chartData.length - 2];
        const delta  = latest.open_count - prev.open_count;
        if (delta === 0) return { text: 'no change in open', color: '#475569' };
        if (delta < 0)   return { text: `▼ ${Math.abs(delta)} open since ${prev.date}`, color: GREEN };
        return             { text: `▲ ${delta} open since ${prev.date}`, color: RED };
    }, [chartData]);

    return (
        <div style={{ marginBottom: '1.25rem' }}>

            {/* ── Header ────────────────────────────────────────────────── */}
            <button
                onClick={() => setCollapsed(c => !c)}
                style={{
                    width: '100%', display: 'flex', alignItems: 'center', justifyContent: 'space-between',
                    background: 'none', border: 'none', cursor: 'pointer',
                    padding: '0 0 0.625rem 0',
                    borderBottom: collapsed ? 'none' : '1px solid rgba(245,158,11,0.1)',
                    marginBottom: collapsed ? 0 : '0.875rem',
                }}
            >
                <div style={{ display: 'flex', alignItems: 'center', gap: '0.5rem' }}>
                    <TrendingUp style={{ width: '14px', height: '14px', color: AMBER }} />
                    <span style={{
                        fontFamily: 'monospace', fontSize: '0.65rem', fontWeight: '700',
                        color: '#334155', textTransform: 'uppercase', letterSpacing: '0.1em',
                    }}>
                        Findings Trend
                    </span>
                    {loading && (
                        <Loader style={{ width: '12px', height: '12px', color: '#334155', animation: 'spin 1s linear infinite' }} />
                    )}
                    {!loading && deltaLabel && (
                        <span style={{ fontFamily: 'monospace', fontSize: '0.62rem', color: deltaLabel.color, marginLeft: '0.25rem' }}>
                            {deltaLabel.text}
                        </span>
                    )}
                </div>
                {collapsed
                    ? <ChevronDown style={{ width: '14px', height: '14px', color: '#334155' }} />
                    : <ChevronUp   style={{ width: '14px', height: '14px', color: '#334155' }} />
                }
            </button>

            {!collapsed && (
                <div style={{
                    background: 'linear-gradient(135deg,rgba(30,41,59,0.95) 0%,rgba(15,23,42,0.98) 100%)',
                    border: '1px solid rgba(245,158,11,0.15)',
                    borderRadius: '0.5rem',
                    padding: '1rem 1.25rem 0.875rem',
                }}>
                    <div style={{ marginBottom: '0.625rem', display: 'flex', justifyContent: 'space-between', alignItems: 'baseline' }}>
                        <div style={{ fontFamily: 'monospace', fontSize: '0.65rem', color: '#334155', textTransform: 'uppercase', letterSpacing: '0.08em' }}>
                            Open vs Closed — end-of-day snapshot per sync day
                        </div>
                        {chartData.length > 0 && (
                            <div style={{ fontFamily: 'monospace', fontSize: '0.62rem', color: '#334155' }}>
                                {chartData.length} day{chartData.length !== 1 ? 's' : ''} of data
                            </div>
                        )}
                    </div>

                    {chartData.length < 2 ? (
                        <div style={{
                            display: 'flex', alignItems: 'center', justifyContent: 'center',
                            height: '160px', color: '#334155',
                            fontFamily: 'monospace', fontSize: '0.72rem',
                            border: '1px dashed rgba(245,158,11,0.1)', borderRadius: '0.375rem',
                        }}>
                            {chartData.length === 0
                                ? 'Trend data begins accumulating after the first sync — check back tomorrow'
                                : 'Need at least 2 days of syncs to display a trend'}
                        </div>
                    ) : (
                        <ResponsiveContainer width="100%" height={220}>
                            <LineChart data={chartData} margin={{ top: 4, right: 12, bottom: 0, left: -12 }}>
                                <CartesianGrid {...GRID_STYLE} />
                                <XAxis dataKey="date" tick={AXIS_STYLE} />
                                <YAxis tick={AXIS_STYLE} allowDecimals={false} />
                                <Tooltip content={<DarkTooltip />} />
                                <Legend wrapperStyle={LEGEND_STYLE} iconSize={8} />
                                <Line
                                    type="monotone" dataKey="open_count" name="Open"
                                    stroke={AMBER} strokeWidth={2}
                                    dot={{ r: 3, fill: AMBER, strokeWidth: 0 }}
                                    activeDot={{ r: 5 }}
                                />
                                <Line
                                    type="monotone" dataKey="closed_count" name="Closed"
                                    stroke={SKY} strokeWidth={2}
                                    dot={{ r: 3, fill: SKY, strokeWidth: 0 }}
                                    activeDot={{ r: 5 }}
                                />
                            </LineChart>
                        </ResponsiveContainer>
                    )}
                </div>
            )}
        </div>
    );
}