import { useState } from "react";
import { useApp } from "../context/AppContext.jsx";
import { fmt, pct, fmtDatum } from "../utils/format.js";
import { GREEN, RED, GOLD } from "../constants/index.js";


import { VCard, VBadge } from "../components/ui/index.jsx";

export default function DashboardTab() {
  const { ev, totEV, evRows, cats, T, darkMode, currentUser } = useApp();

  const hour = new Date().getHours();
  const dagdeel = hour < 12 ? "Goedemorgen" : hour < 18 ? "Goedemiddag" : "Goedenavond";
  const rawNaam = currentUser?.naam?.trim().split(/\s+/)[0] || "";
  const voornaam = rawNaam ? rawNaam.charAt(0).toUpperCase() + rawNaam.slice(1) : "";

  const catSum = (row) =>
    cats.reduce((a, c) => a + (row[c.id] || 0), 0);

  const startEV    = evRows.length > 0 ? (evRows[evRows.length - 1]?.nettoWaarde || 0) : 0;
  const extraFiat  = evRows.length > 1
    ? evRows.slice(0, -1).reduce((acc, row) => acc + catSum(row), 0) : 0;
  const totaalFiat = startEV + extraFiat;
  const winst      = totEV - totaalFiat;
  const roi        = totaalFiat > 0 ? winst / totaalFiat : 0;
  const doel       = ev.doel || 1;
  const progressPct = Math.min(totEV / doel, 1);
  const milestones  = [0, 0.25, 0.5, 0.75, 1].map((f) => f * doel);
  const kpis = [
    { label: "Start eigen vermogen",       val: fmt(startEV),    accent: T.accentTekst},
    { label: "Extra geïnvesteerde fiat",   val: fmt(extraFiat),  accent: T.accentTekst},
    { label: "Totaal geïnvesteerde fiat",  val: fmt(totaalFiat), accent: T.accentTekst},
    { label: "Totaal eigen vermogen",      val: fmt(totEV),      accent: GREEN  },
    { label: "Winst op investering",       val: fmt(winst),      accent: winst >= 0 ? GREEN : RED },
    { label: "ROI %",                      val: totaalFiat > 0 ? pct(roi, 2) : "—", accent: roi >= 0 ? GREEN : RED },
  ];

  // Minigrafiek data
  const vData = [...evRows].sort((a, b) => a.datum.localeCompare(b.datum));

  // Cumulatief geïnvesteerde fiat, op dezelfde datums als vData. Dezelfde
  // opbouw als de KPI's hierboven: het oudste punt is de start-EV (daar is de
  // inleg per definitie gelijk aan de waarde), elk volgend punt telt de
  // stortingen van die rij erbij op. Het laatste punt is daarmee gelijk aan
  // "Totaal geïnvesteerde fiat".
  const fiatData = vData.reduce((acc, row, i) => {
    acc.push(i === 0 ? (row.nettoWaarde || 0) : acc[i - 1] + catSum(row));
    return acc;
  }, []);

  return (
    <div>
      <div style={{ marginBottom: 24 }}>
        <div style={{ fontSize: 14, color: T.muted, marginBottom: 6 }}>
          Hi{voornaam ? ` ${voornaam},` : ","}
        </div>
        <h1 style={{ fontSize: 32, fontWeight: 800, margin: "0 0 32px", color: T.text, letterSpacing: "-0.5px", lineHeight: 1.15 }}>
          {dagdeel} 👋
        </h1>
        <div style={{ fontSize: 32, fontWeight: 800, color: T.text, letterSpacing: "-0.5px", lineHeight: 1.15 }}>
          The Road naar {fmt(doel)}
        </div>
      </div>

      {/* KPI grid */}
      <div style={{
        display: "grid",
        gridTemplateColumns: "repeat(3, 1fr)",
        gap: 12, marginBottom: 20,
      }}>
        {kpis.map(({ label, val, accent }) => (
          <VCard key={label} style={{
            background: `linear-gradient(to right, ${accent}cc 0%, ${accent}44 50%, transparent 80%) bottom / 100% 3px no-repeat, ${T.card}`,
            border: `1px solid ${T.border}`,
          }}>
            <div style={{
              fontSize: 11, color: T.muted, marginBottom: 6,
              textTransform: "uppercase", letterSpacing: "0.05em",
            }}>{label}</div>
            <div style={{ fontSize: 20, fontWeight: 700, color: accent }}>{val}</div>
          </VCard>
        ))}
      </div>

      {/* Doel progressie */}
      <VCard style={{ background: T.card, border: `1px solid ${T.border}`, marginBottom: 16 }}>
        <div style={{
          display: "flex", alignItems: "center",
          justifyContent: "space-between", marginBottom: 12,
        }}>
          <div style={{ display: "flex", alignItems: "center", gap: 10 }}>
            <span style={{ fontSize: 16 }}>🎯</span>
            <span style={{ fontWeight: 600 }}>Doel &amp; Bijbehorende Progressie</span>
            <VBadge label={fmt(doel)} color={T.accentTekst} />
          </div>
          <span style={{ color: T.muted, fontSize: 13 }}>{pct(progressPct)} behaald</span>
        </div>
        <div style={{
          height: 14, background: T.inputBg,
          borderRadius: 99, overflow: "hidden",
          position: "relative", marginBottom: 8,
        }}>
          <div style={{
            position: "absolute", inset: 0,
            width: `${progressPct * 100}%`,
            background: `linear-gradient(90deg, ${T.accent}, ${T.accentLicht})`,
            borderRadius: 99, transition: "width 0.7s ease",
          }} />
          {[0.25, 0.5, 0.75].map((f) => (
            <div key={f} style={{
              position: "absolute", left: `${f * 100}%`,
              top: 0, bottom: 0, width: 1,
              background: "rgba(0,0,0,0.3)",
            }} />
          ))}
        </div>
        <div style={{ display: "flex", justifyContent: "space-between" }}>
          {milestones.map((m) => (
            <span key={m} style={{ fontSize: 11, color: T.muted }}>{fmt(m)}</span>
          ))}
        </div>
      </VCard>

      {/* EV Grafiek */}
      <VCard style={{ background: T.card, border: `1px solid ${T.border}`, marginBottom: 20 }}>
        <div style={{
          display: "flex", alignItems: "center", justifyContent: "space-between",
          gap: 12, flexWrap: "wrap", marginBottom: 16,
        }}>
          <div style={{ fontWeight: 600 }}>Ontwikkeling van Eigen Vermogen</div>
          {vData.length >= 2 && (
            <div style={{ display: "flex", alignItems: "center", gap: 14, fontSize: 11, color: T.muted }}>
              <Legenda kleur={`linear-gradient(90deg, ${T.chartVan}, ${T.chartTot})`} label="Eigen vermogen" />
              <Legenda
                kleur={`repeating-linear-gradient(90deg, ${GOLD} 0 5px, transparent 5px 9px)`}
                label="Geïnvesteerde fiat"
              />
            </div>
          )}
        </div>
        {vData.length < 2 ? (
          <div style={{ textAlign: "center", padding: "32px 0", color: T.muted }}>
            <div style={{ fontSize: 28, marginBottom: 8 }}>📈</div>
            <div style={{ fontSize: 13 }}>
              Leg minimaal 2 voortgangsmomenten vast in het Eigen Vermogen tabblad om de grafiek te tonen.
            </div>
          </div>
        ) : (
          <MiniLineChart vData={vData} fiatData={fiatData} darkMode={darkMode} T={T} />
        )}
      </VCard>

    </div>
  );
}

// ── Legenda-item bij de grafiek ─────────────────────────────────────────────
function Legenda({ kleur, label }) {
  return (
    <span style={{ display: "inline-flex", alignItems: "center", gap: 6 }}>
      <span style={{ width: 16, height: 3, borderRadius: 2, background: kleur }} />
      {label}
    </span>
  );
}

// ── Smooth Catmull-Rom bezier path ──────────────────────────────────────────
function crPath(xs, ys, t = 0.4) {
  if (xs.length < 2) return "";
  let d = `M ${xs[0]},${ys[0]}`;
  for (let i = 0; i < xs.length - 1; i++) {
    const p0 = i > 0 ? [xs[i-1], ys[i-1]] : [xs[i], ys[i]];
    const p1 = [xs[i], ys[i]];
    const p2 = [xs[i+1], ys[i+1]];
    const p3 = i < xs.length - 2 ? [xs[i+2], ys[i+2]] : [xs[i+1], ys[i+1]];
    const cp1x = (p1[0] + (p2[0] - p0[0]) * t).toFixed(2);
    const cp1y = (p1[1] + (p2[1] - p0[1]) * t).toFixed(2);
    const cp2x = (p2[0] - (p3[0] - p1[0]) * t).toFixed(2);
    const cp2y = (p2[1] - (p3[1] - p1[1]) * t).toFixed(2);
    d += ` C ${cp1x},${cp1y} ${cp2x},${cp2y} ${p2[0]},${p2[1]}`;
  }
  return d;
}

// ── Mini inline SVG grafiek ────────────────────────────────────────────────────
function MiniLineChart({ vData, fiatData, darkMode, T }) {
  const [hovered, setHovered] = useState(null);
  const W = 700, H = 230, pl = 62, pr = 16, pt = 16, pb = 52;
  const vals  = vData.map((d) => d.nettoWaarde || 0);
  const fVals = fiatData;
  // Beide reeksen staan in euro's op dezelfde as, dus het bereik moet ze allebei
  // omvatten — anders loopt de inleglijn buiten beeld zodra die boven de EV uitkomt.
  const mn   = Math.min(...vals, ...fVals) * 0.95;
  const mx   = Math.max(...vals, ...fVals) * 1.05;
  const rng  = mx - mn || 1;
  const iW   = W - pl - pr, iH = H - pt - pb;
  const xs   = vData.map((_, i) => pl + (i / Math.max(vData.length - 1, 1)) * iW);
  const ys   = vals.map((v) => pt + (1 - (v - mn) / rng) * iH);
  const fYs  = fVals.map((v) => pt + (1 - (v - mn) / rng) * iH);
  const linePath = crPath(xs, ys);
  const areaPath = `${linePath} L ${xs[xs.length-1]},${pt+iH} L ${xs[0]},${pt+iH} Z`;
  // Rechte segmenten, geen crPath: de inleg loopt nooit terug, en de bezier-
  // afronding zou tussen twee stortingen een dip tekenen die er niet is.
  const fiatPath = xs.map((x, i) => `${i ? "L" : "M"} ${x},${fYs[i]}`).join(" ");
  const gc   = darkMode ? "rgba(255,255,255,0.07)" : "rgba(0,0,0,0.06)";
  const lc   = T.muted;

  const handleMouseMove = (e) => {
    const rect = e.currentTarget.getBoundingClientRect();
    const svgX = ((e.clientX - rect.left) / rect.width) * W;
    const dists = xs.map((x) => Math.abs(x - svgX));
    setHovered(dists.indexOf(Math.min(...dists)));
  };

  const h = hovered;
  const tipW = 150, tipH = 76;
  // Náást de hoverlijn, niet erboven of eronder. Zodra de twee punten ver uit
  // elkaar liggen is er verticaal geen ruimte voor een kaart van 76px: dan
  // klapte hij naar onderen tot buiten de tekening, over de datumlabels heen en
  // half afgekapt. Zijwaarts past hij altijd; de klemmen houden hem binnen het
  // tekenvlak.
  const naarRechts = h !== null && xs[h] < pl + iW / 2;
  const tipX = h === null ? 0 : naarRechts
    ? Math.min(xs[h] + 16, W - pr - tipW)
    : Math.max(xs[h] - tipW - 16, pl);
  const tipY = h === null ? 0
    : Math.max(pt, Math.min((ys[h] + fYs[h]) / 2 - tipH / 2, pt + iH - tipH));
  const resultaat = h !== null ? vals[h] - fVals[h] : 0;

  return (
    <svg
      viewBox={`0 0 ${W} ${H}`}
      style={{ width: "100%", height: "auto", display: "block", cursor: "crosshair" }}
      onMouseMove={handleMouseMove}
      onMouseLeave={() => setHovered(null)}
    >
      <defs>
        <linearGradient id="chartLineGrad" x1="0%" y1="0%" x2="100%" y2="0%">
          <stop offset="0%"   stopColor={T.chartVan} />
          <stop offset="100%" stopColor={T.chartTot} />
        </linearGradient>
        <linearGradient id="chartFadeMask" x1="0" y1="0" x2="0" y2="1">
          <stop offset="0%"   stopColor="white" stopOpacity="1" />
          <stop offset="100%" stopColor="white" stopOpacity="0" />
        </linearGradient>
        <mask id="chartAreaMask">
          <rect x={pl} y={pt} width={iW} height={iH} fill="url(#chartFadeMask)" />
        </mask>
      </defs>

      {/* Gestippelde gridlijnen */}
      {[0, 0.25, 0.5, 0.75, 1].map((f) => {
        const gy = pt + (1 - f) * iH;
        return (
          <g key={f}>
            <line x1={pl} y1={gy} x2={W - pr} y2={gy}
              stroke={gc} strokeWidth="1" strokeDasharray="4,4" />
            <text x={pl - 6} y={gy + 4} fill={lc} fontSize="9" textAnchor="end">
              {fmt(mn + f * rng)}
            </text>
          </g>
        );
      })}

      {/* Vlakkleur met gradient + fade */}
      <path d={areaPath} fill="url(#chartLineGrad)" mask="url(#chartAreaMask)" opacity="0.4" />

      {/* Geïnvesteerde fiat — gestippeld, zodat het als referentielijn leest
          en de EV-lijn de hoofdrol houdt */}
      <path d={fiatPath} fill="none" stroke={GOLD} strokeWidth="1.8"
        strokeDasharray="5,4" strokeLinecap="round" strokeLinejoin="round" opacity="0.85" />

      {/* Lijn */}
      <path d={linePath} fill="none" stroke="url(#chartLineGrad)"
        strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round" />

      {/* Verticale hover-lijn */}
      {h !== null && (
        <line x1={xs[h]} y1={pt} x2={xs[h]} y2={pt + iH}
          stroke={T.muted} strokeOpacity="0.6" strokeWidth="1" strokeDasharray="4,3" />
      )}

      {/* Hover punten */}
      {h !== null && (
        <>
          <circle cx={xs[h]} cy={fYs[h]} r="4.5"
            fill={GOLD} stroke={T.card} strokeWidth="2.5" />
          <circle cx={xs[h]} cy={ys[h]} r="5.5"
            fill={T.chartVan} stroke={T.card} strokeWidth="2.5" />
        </>
      )}

      {/* Tooltip */}
      {h !== null && (
        <g>
          <rect x={tipX} y={tipY} width={tipW} height={tipH} rx="7"
            fill={T.card}
            stroke={T.border} strokeWidth="1" />
          <text x={tipX + tipW / 2} y={tipY + 16} fill={lc} fontSize="9" textAnchor="middle">
            {fmtDatum(vData[h].datum)}
          </text>
          <text x={tipX + 10} y={tipY + 33} fill={lc} fontSize="9">Vermogen</text>
          <text x={tipX + tipW - 10} y={tipY + 33} fill={T.chartVan} fontSize="10"
            fontWeight="700" textAnchor="end">
            {fmt(vals[h])}
          </text>
          <text x={tipX + 10} y={tipY + 48} fill={lc} fontSize="9">Ingelegd</text>
          <text x={tipX + tipW - 10} y={tipY + 48} fill={GOLD} fontSize="10"
            fontWeight="700" textAnchor="end">
            {fmt(fVals[h])}
          </text>
          <line x1={tipX + 10} y1={tipY + 55} x2={tipX + tipW - 10} y2={tipY + 55}
            stroke={gc} strokeWidth="1" />
          <text x={tipX + 10} y={tipY + 68} fill={lc} fontSize="9">Resultaat</text>
          <text x={tipX + tipW - 10} y={tipY + 68}
            fill={resultaat >= 0 ? GREEN : RED} fontSize="10"
            fontWeight="700" textAnchor="end">
            {`${resultaat >= 0 ? "+" : ""}${fmt(resultaat)}`}
          </text>
        </g>
      )}

      {/* X-as labels */}
      {xs.map((x, i) => (
        <text key={i} x={x} y={H - pb + 16} fill={lc} fontSize="8"
          textAnchor="end" transform={`rotate(-45, ${x}, ${H - pb + 16})`}>
          {fmtDatum(vData[i].datum)}
        </text>
      ))}
    </svg>
  );
}