import { api } from "../lib/api.js";

function formatCurrency(value) {
  if (value == null) return "$0";
  return new Intl.NumberFormat("es-AR", { style: "currency", currency: "ARS", maximumFractionDigits: 0 }).format(value);
}

function formatNumber(value) {
  if (value == null) return "0";
  return new Intl.NumberFormat("es-AR", { maximumFractionDigits: 1 }).format(value);
}

/** Lee una CSS custom property del :root. Fallback al hex provisto. */
function cssVar(name, fallback = "") {
  const v = getComputedStyle(document.documentElement).getPropertyValue(name).trim();
  return v || fallback;
}

/** rgba con alpha desde un hex (#RRGGBB) o sky/etc — para fills de charts. */
function withAlpha(hex, alpha) {
  const m = /^#?([0-9a-f]{6})$/i.exec(hex || "");
  if (!m) return hex;
  const n = parseInt(m[1], 16);
  return `rgba(${(n >> 16) & 255}, ${(n >> 8) & 255}, ${n & 255}, ${alpha})`;
}

class HomeDashboard extends HTMLElement {
  constructor() {
    super();
    this.attachShadow({ mode: "open" });
    this.stats = null;
    this.loading = false;
    this.charts = {};

    this.shadowRoot.innerHTML = `
      <style>
        :host { display:block; height:100%; min-height:0; overflow-y:auto; font-family: var(--font-sans); }
        * { box-sizing: border-box; }
        .container {
          background: var(--bg);
          color: var(--text);
          padding: var(--space-6);
        }
        .header {
          display: flex; justify-content: space-between; align-items: baseline;
          margin-bottom: var(--space-6);
        }
        .header h1 {
          font-size: var(--fs-xl);
          font-weight: var(--fw-semibold);
          letter-spacing: -0.02em;
          margin: 0;
        }
        .sync-info { font-size: var(--fs-sm); color: var(--text-muted); }
        .grid {
          display: grid;
          grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
          gap: var(--space-6);
        }
        .chart-card {
          background: var(--panel);
          border: 1px solid var(--border);
          border-radius: var(--r-lg);
          padding: var(--space-5);
          box-shadow: var(--shadow-sm);
        }
        .chart-card.full-width { grid-column: 1 / -1; }
        .chart-title {
          font-size: var(--fs-xs);
          font-weight: var(--fw-semibold);
          color: var(--text-muted);
          text-transform: uppercase;
          letter-spacing: 0.06em;
          margin-bottom: var(--space-4);
        }
        .chart-container { position: relative; height: 260px; }
        .chart-container.tall { height: 320px; }
        .chart-container.short { height: 200px; }
        .loading {
          display: flex; align-items: center; justify-content: center;
          height: 200px; color: var(--text-muted);
        }
        .kpi-row {
          display: grid;
          grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
          gap: var(--space-4);
          margin-bottom: var(--space-6);
        }
        .kpi-card {
          background: var(--panel);
          border: 1px solid var(--border);
          border-radius: var(--r-lg);
          padding: var(--space-5);
          box-shadow: var(--shadow-sm);
        }
        .kpi-value {
          font-size: var(--fs-xl);
          font-weight: var(--fw-bold);
          letter-spacing: -0.02em;
          margin-bottom: 4px;
        }
        .kpi-label {
          font-size: var(--fs-xs);
          color: var(--text-muted);
          text-transform: uppercase;
          letter-spacing: 0.06em;
          font-weight: var(--fw-medium);
        }
        .donut-row {
          display: grid;
          grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
          gap: var(--space-4);
        }
        canvas { max-width: 100%; }
      </style>
      <div class="container">
        <div class="header">
          <h1>Dashboard de Ventas</h1>
          <div class="sync-info"></div>
        </div>
        <div class="kpi-row"></div>
        <div class="grid">
          <div class="chart-card full-width">
            <div class="chart-title">Ventas Totales por Mes</div>
            <div class="chart-container tall">
              <canvas id="monthly-chart"></canvas>
            </div>
          </div>
          <div class="chart-card">
            <div class="chart-title">Web vs WhatsApp</div>
            <div class="chart-container">
              <canvas id="source-chart"></canvas>
            </div>
          </div>
          <div class="chart-card">
            <div class="chart-title">Comparativa Año a Año</div>
            <div class="chart-container">
              <canvas id="yoy-chart"></canvas>
            </div>
          </div>
          <div class="donut-row">
            <div class="chart-card">
              <div class="chart-title">Por Canal</div>
              <div class="chart-container short">
                <canvas id="source-donut"></canvas>
              </div>
            </div>
            <div class="chart-card">
              <div class="chart-title">Delivery vs Retiro</div>
              <div class="chart-container short">
                <canvas id="shipping-donut"></canvas>
              </div>
            </div>
          </div>
          <div class="chart-card full-width">
            <div class="chart-title">Top Productos por Facturación</div>
            <div class="chart-container tall">
              <canvas id="products-chart"></canvas>
            </div>
          </div>
          <div class="chart-card">
            <div class="chart-title">Top por Kg Vendidos</div>
            <div class="chart-container">
              <canvas id="kg-chart"></canvas>
            </div>
          </div>
          <div class="chart-card">
            <div class="chart-title">Top por Unidades</div>
            <div class="chart-container">
              <canvas id="units-chart"></canvas>
            </div>
          </div>
        </div>
      </div>
    `;
  }

  connectedCallback() {
    this.loadStats();
  }

  disconnectedCallback() {
    // Destruir charts para liberar memoria
    Object.values(this.charts).forEach(chart => chart?.destroy?.());
    this.charts = {};
  }

  async loadStats() {
    this.loading = true;
    try {
      this.stats = await api.getOrderStats();
      this.render();
    } catch (err) {
      console.error("[home-dashboard] loadStats error:", err);
    } finally {
      this.loading = false;
    }
  }

  render() {
    if (!this.stats) return;

    // Actualizar sync info
    const syncInfo = this.shadowRoot.querySelector(".sync-info");
    syncInfo.textContent = `${this.stats.total_in_cache || 0} pedidos en cache`;
    if (this.stats.synced > 0) {
      syncInfo.textContent += ` (${this.stats.synced} nuevos sincronizados)`;
    }

    // Renderizar KPIs
    this.renderKPIs();

    // Renderizar charts
    this.renderMonthlyChart();
    this.renderSourceChart();
    this.renderYoyChart();
    this.renderDonuts();
    this.renderProductsChart();
    this.renderKgChart();
    this.renderUnitsChart();
  }

  renderKPIs() {
    const totals = this.stats.totals_aggregated || {};
    const kpiRow = this.shadowRoot.querySelector(".kpi-row");
    kpiRow.innerHTML = `
      <div class="kpi-card">
        <div class="kpi-value" style="color: var(--chart-blue)">${formatCurrency(totals.total_revenue)}</div>
        <div class="kpi-label">Total Facturado</div>
      </div>
      <div class="kpi-card">
        <div class="kpi-value">${formatNumber(totals.total_orders)}</div>
        <div class="kpi-label">Pedidos</div>
      </div>
      <div class="kpi-card">
        <div class="kpi-value" style="color: var(--chart-green)">${formatCurrency(totals.by_source?.whatsapp)}</div>
        <div class="kpi-label">WhatsApp</div>
      </div>
      <div class="kpi-card">
        <div class="kpi-value" style="color: var(--chart-blue)">${formatCurrency(totals.by_source?.web)}</div>
        <div class="kpi-label">Web</div>
      </div>
    `;
  }

  renderMonthlyChart() {
    const ctx = this.shadowRoot.getElementById("monthly-chart");
    if (!ctx) return;

    if (this.charts.monthly) this.charts.monthly.destroy();

    const months = this.stats.months || [];
    const totals = this.stats.totals || [];

    this.charts.monthly = new Chart(ctx, {
      type: "bar",
      data: {
        labels: months.map(m => {
          const [y, mo] = m.split("-");
          return `${mo}/${y.slice(2)}`;
        }),
        datasets: [{
          label: "Ventas",
          data: totals,
          backgroundColor: withAlpha(cssVar("--chart-blue"), 0.7),
          borderColor: cssVar("--chart-blue"),
          borderWidth: 1,
        }],
      },
      options: {
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
          legend: { display: false },
        },
        scales: {
          y: {
            beginAtZero: true,
            ticks: { color: cssVar("--text-muted") },
            grid: { color: cssVar("--border") },
          },
          x: {
            ticks: { color: cssVar("--text-muted") },
            grid: { display: false },
          },
        },
      },
    });
  }

  renderSourceChart() {
    const ctx = this.shadowRoot.getElementById("source-chart");
    if (!ctx) return;

    if (this.charts.source) this.charts.source.destroy();

    const months = this.stats.months || [];
    const waData = this.stats.by_source?.whatsapp || [];
    const webData = this.stats.by_source?.web || [];

    this.charts.source = new Chart(ctx, {
      type: "bar",
      data: {
        labels: months.map(m => {
          const [y, mo] = m.split("-");
          return `${mo}/${y.slice(2)}`;
        }),
        datasets: [
          {
            label: "WhatsApp",
            data: waData,
            backgroundColor: cssVar("--chart-green"),
          },
          {
            label: "Web",
            data: webData,
            backgroundColor: cssVar("--chart-blue"),
          },
        ],
      },
      options: {
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
          legend: {
            position: "top",
            labels: { color: cssVar("--text-muted") },
          },
        },
        scales: {
          y: {
            stacked: true,
            beginAtZero: true,
            ticks: { color: cssVar("--text-muted") },
            grid: { color: cssVar("--border") },
          },
          x: {
            stacked: true,
            ticks: { color: cssVar("--text-muted") },
            grid: { display: false },
          },
        },
      },
    });
  }

  renderYoyChart() {
    const ctx = this.shadowRoot.getElementById("yoy-chart");
    if (!ctx) return;

    if (this.charts.yoy) this.charts.yoy.destroy();

    const yoy = this.stats.yoy || {};

    this.charts.yoy = new Chart(ctx, {
      type: "line",
      data: {
        labels: yoy.months || [],
        datasets: [
          {
            label: String(yoy.current_year || "Actual"),
            data: yoy.current_year_data || [],
            borderColor: cssVar("--chart-blue"),
            backgroundColor: withAlpha(cssVar("--chart-blue"), 0.15),
            fill: true,
            tension: 0.3,
          },
          {
            label: String(yoy.last_year || "Anterior"),
            data: yoy.last_year_data || [],
            borderColor: cssVar("--chart-gray"),
            backgroundColor: withAlpha(cssVar("--chart-gray"), 0.15),
            fill: true,
            tension: 0.3,
          },
        ],
      },
      options: {
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
          legend: {
            position: "top",
            labels: { color: cssVar("--text-muted") },
          },
        },
        scales: {
          y: {
            beginAtZero: true,
            ticks: { color: cssVar("--text-muted") },
            grid: { color: cssVar("--border") },
          },
          x: {
            ticks: { color: cssVar("--text-muted") },
            grid: { display: false },
          },
        },
      },
    });
  }

  renderDonuts() {
    const totals = this.stats.totals_aggregated || {};

    // Source donut
    const sourceCtx = this.shadowRoot.getElementById("source-donut");
    if (sourceCtx) {
      if (this.charts.sourceDonut) this.charts.sourceDonut.destroy();
      this.charts.sourceDonut = new Chart(sourceCtx, {
        type: "doughnut",
        data: {
          labels: ["WhatsApp", "Web"],
          datasets: [{
            data: [totals.by_source?.whatsapp || 0, totals.by_source?.web || 0],
            backgroundColor: [cssVar("--chart-green"), cssVar("--chart-blue")],
          }],
        },
        options: this.getDonutOptions(),
      });
    }

    // Shipping donut
    const shippingCtx = this.shadowRoot.getElementById("shipping-donut");
    if (shippingCtx) {
      if (this.charts.shippingDonut) this.charts.shippingDonut.destroy();
      this.charts.shippingDonut = new Chart(shippingCtx, {
        type: "doughnut",
        data: {
          labels: ["Delivery", "Retiro"],
          datasets: [{
            data: [totals.by_shipping?.delivery || 0, totals.by_shipping?.pickup || 0],
            backgroundColor: [cssVar("--chart-purple"), cssVar("--chart-orange")],
          }],
        },
        options: this.getDonutOptions(),
      });
    }

  }

  getDonutOptions() {
    return {
      responsive: true,
      maintainAspectRatio: false,
      plugins: {
        legend: {
          position: "bottom",
          labels: { color: cssVar("--text-muted") },
        },
      },
    };
  }

  renderProductsChart() {
    const ctx = this.shadowRoot.getElementById("products-chart");
    if (!ctx) return;

    if (this.charts.products) this.charts.products.destroy();

    const products = this.stats.top_products_revenue || [];
    const labels = products.map(p => p.name?.slice(0, 30) || "Sin nombre");
    const data = products.map(p => p.revenue || 0);

    this.charts.products = new Chart(ctx, {
      type: "bar",
      data: {
        labels,
        datasets: [{
          label: "Facturación",
          data,
          backgroundColor: withAlpha(cssVar("--chart-blue"), 0.7),
          borderColor: cssVar("--chart-blue"),
          borderWidth: 1,
        }],
      },
      options: {
        indexAxis: "y",
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
          legend: { display: false },
        },
        scales: {
          x: {
            beginAtZero: true,
            ticks: { color: cssVar("--text-muted") },
            grid: { color: cssVar("--border") },
          },
          y: {
            ticks: { color: cssVar("--text-muted") },
            grid: { display: false },
          },
        },
      },
    });
  }

  renderKgChart() {
    const ctx = this.shadowRoot.getElementById("kg-chart");
    if (!ctx) return;

    if (this.charts.kg) this.charts.kg.destroy();

    const products = this.stats.top_products_kg || [];
    const labels = products.map(p => p.name?.slice(0, 25) || "Sin nombre");
    const data = products.map(p => p.kg || 0);

    this.charts.kg = new Chart(ctx, {
      type: "bar",
      data: {
        labels,
        datasets: [{
          label: "Kg",
          data,
          backgroundColor: withAlpha(cssVar("--chart-purple"), 0.7),
          borderColor: cssVar("--chart-purple"),
          borderWidth: 1,
        }],
      },
      options: {
        indexAxis: "y",
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
          legend: { display: false },
        },
        scales: {
          x: {
            beginAtZero: true,
            ticks: { color: cssVar("--text-muted") },
            grid: { color: cssVar("--border") },
          },
          y: {
            ticks: { color: cssVar("--text-muted"), font: { size: 10 } },
            grid: { display: false },
          },
        },
      },
    });
  }

  renderUnitsChart() {
    const ctx = this.shadowRoot.getElementById("units-chart");
    if (!ctx) return;

    if (this.charts.units) this.charts.units.destroy();

    const products = this.stats.top_products_units || [];
    const labels = products.map(p => p.name?.slice(0, 25) || "Sin nombre");
    const data = products.map(p => p.units || 0);

    this.charts.units = new Chart(ctx, {
      type: "bar",
      data: {
        labels,
        datasets: [{
          label: "Unidades",
          data,
          backgroundColor: withAlpha(cssVar("--chart-orange"), 0.7),
          borderColor: cssVar("--chart-orange"),
          borderWidth: 1,
        }],
      },
      options: {
        indexAxis: "y",
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
          legend: { display: false },
        },
        scales: {
          x: {
            beginAtZero: true,
            ticks: { color: cssVar("--text-muted") },
            grid: { color: cssVar("--border") },
          },
          y: {
            ticks: { color: cssVar("--text-muted"), font: { size: 10 } },
            grid: { display: false },
          },
        },
      },
    });
  }
}

customElements.define("home-dashboard", HomeDashboard);