// Dashboard — KPIs, time-series charts, breakdown, recent requests, health.
import { h, mount, money, moneyEl, num, ms, pct, timeAgo, toast, confirmDialog } from "../ui.js";
import { t, trTier } from "../i18n.js";
import { api } from "../api.js";
import { lineChart, barList } from "../charts.js";
import { SITE_URL } from "../app.js";

const RANGES = ["1h", "24h", "7d"];
const GROUPS = ["model", "tier", "label", "account"];

function kpi(big, lbl) {
  return h("div", { class: "kpi" }, h("div", { class: "big" }, big), h("div", { class: "lbl" }, lbl));
}

function seg(options, current, onPick, labelFn) {
  return h(
    "div",
    { class: "seg" },
    ...options.map((o) =>
      h("button", { class: o === current ? "active" : "", onClick: () => onPick(o) }, labelFn ? labelFn(o) : o)
    )
  );
}

export async function renderDashboard() {
  let range = "24h";
  let groupby = "model";
  const root = h("div");

  // ── host metrics: CPU sparkline + RAM / disk bars, refreshed every 2 s ──
  const sysHost = h("div", {});
  const cpuHistory = []; // last ~60 samples (2 min)
  function fmtG(n) {
    return (n / 1e9).toFixed(1) + " GB";
  }
  function bar(frac, cls) {
    return h("div", { class: "sysbar" }, h("i", { class: cls || "", style: `width:${Math.min(100, frac * 100)}%` }));
  }
  function sparkline(values, w, hgt) {
    const c = document.createElement("canvas");
    c.width = w;
    c.height = hgt;
    const ctx = c.getContext("2d");
    const accent = getComputedStyle(document.documentElement).getPropertyValue("--accent").trim() || "#5b8def";
    ctx.strokeStyle = accent;
    ctx.lineWidth = 1.5;
    ctx.beginPath();
    const n = Math.max(values.length, 2);
    values.forEach((v, i) => {
      const x = (i / (n - 1)) * (w - 2) + 1;
      const y = hgt - 2 - (Math.min(v, 100) / 100) * (hgt - 4);
      if (i === 0) ctx.moveTo(x, y);
      else ctx.lineTo(x, y);
    });
    ctx.stroke();
    return c;
  }
  async function refreshSystem() {
    let sys;
    try {
      sys = await api.system();
    } catch {
      return;
    }
    if (!sys.ts) return;
    cpuHistory.push(sys.cpu_percent || 0);
    if (cpuHistory.length > 60) cpuHistory.shift();
    const ramFrac = sys.ram_total ? sys.ram_used / sys.ram_total : 0;
    const diskFrac = sys.disk_total ? (sys.disk_total - sys.disk_free) / sys.disk_total : 0;
    mount(
      sysHost,
      h(
        "div",
        { class: "card" },
        h("div", { class: "card-title" }, t("dash.sys.title")),
        h(
          "div",
          { class: "sysgrid" },
          h("div", { class: "sysitem" },
            h("div", { class: "flex" },
              h("span", { class: "k grow" }, `CPU · ${sys.cores} ${t("dash.sys.cores")}`),
              h("span", { class: "v mono" }, (sys.cpu_percent || 0).toFixed(0) + "%")),
            sparkline(cpuHistory, 220, 36),
            h("div", { class: "muted small" }, `load ${Number(sys.load1 || 0).toFixed(1)}`)),
          h("div", { class: "sysitem" },
            h("div", { class: "flex" },
              h("span", { class: "k grow" }, "RAM"),
              h("span", { class: "v mono" }, `${fmtG(sys.ram_used)} / ${fmtG(sys.ram_total)}`)),
            bar(ramFrac, ramFrac > 0.9 ? "bad" : ""),
            h("div", { class: "muted small" }, t("dash.sys.gateway") + " " + (sys.process_rss / 1e6).toFixed(0) + " MB")),
          h("div", { class: "sysitem" },
            h("div", { class: "flex" },
              h("span", { class: "k grow" }, t("dash.sys.disk")),
              h("span", { class: "v mono" }, t("dash.sys.free") + " " + fmtG(sys.disk_free)),
            ),
            bar(diskFrac, diskFrac > 0.92 ? "bad" : ""),
            h("div", { class: "muted small" }, `${fmtG(sys.disk_total - sys.disk_free)} / ${fmtG(sys.disk_total)}`))
        )
      )
    );
  }
  const sysTimer = setInterval(() => {
    if (!root.isConnected) {
      clearInterval(sysTimer);
      return;
    }
    refreshSystem();
  }, 2000);
  refreshSystem();

  async function load() {
    const rangeSecs = range;
    let stats, recent, health;
    try {
      [stats, recent, health] = await Promise.all([
        api.stats(rangeSecs, groupby),
        api.requests(40, 0),
        api.health().catch(() => null),
      ]);
    } catch (e) {
      mount(root, h("div", { class: "callout" }, String(e.message || e)));
      return;
    }
    const tot = stats.totals || {};
    const series = stats.series || [];
    const breakdown = (stats.breakdown || []).map((b) => ({ key: b.key || t("common.none"), value: b.requests }));

    mount(
      root,
      h(
        "div",
        { class: "page-head" },
        h(
          "div",
          { class: "flex" },
          h("div", { class: "grow" }, h("h2", {}, t("dash.title")), h("p", {}, t("dash.subtitle"))),
          h("div", { class: "flex", style: "gap:8px;align-items:center" },
            seg(RANGES, range, (r) => {
              range = r;
              load();
            }, (r) => t("dash.range." + r)),
            h("button", {
              class: "btn sm danger",
              onClick: async () => {
                if (!(await confirmDialog(t("dash.clearConfirm")))) return;
                try {
                  await api.clearStats();
                  toast(t("dash.cleared"), "good");
                  await load();
                } catch (e) {
                  toast(String(e.message || e), "bad");
                }
              },
            }, t("dash.clear")))
        )
      ),

      // KPIs
      h(
        "div",
        { class: "kpis" },
        kpi(num(tot.requests), t("dash.kpi.requests")),
        kpi(num(tot.total_tokens), t("dash.kpi.tokens")),
        kpi(moneyEl(tot.cost_usd), t("dash.kpi.cost")),
        kpi(ms(tot.avg_latency_ms), t("dash.kpi.latency")),
        kpi(pct(tot.success_rate), t("dash.kpi.success")),
        kpi(num(tot.failovers), t("dash.kpi.failovers"))
      ),

      sysHost,

      h(
        "div",
        { class: "grid cols-2" },
        h(
          "div",
          { class: "card" },
          h("div", { class: "card-head" }, h("h3", {}, t("dash.series.title"))),
          series.length < 2 ? h("div", { class: "empty" }, t("dash.series.empty")) : lineChart(series, "requests")
        ),
        h(
          "div",
          { class: "card" },
          h("div", { class: "card-head" }, h("h3", {}, t("dash.series.cost"))),
          series.length < 2 ? h("div", { class: "empty" }, t("dash.series.empty")) : lineChart(series, "cost_usd")
        )
      ),

      // breakdown
      h(
        "div",
        { class: "card" },
        h(
          "div",
          { class: "card-head" },
          h("h3", {}, t("dash.breakdown.title")),
          h(
            "div",
            { class: "right" },
            seg(GROUPS, groupby, (g) => {
              groupby = g;
              load();
            }, (g) => t("dash.groupby." + g))
          )
        ),
        barList(breakdown, num)
      ),

      // semantic cache
      stats.cache && stats.cache.enabled
        ? h(
            "div",
            { class: "card" },
            h("div", { class: "card-head" }, h("h3", {}, t("dash.cache"))),
            h(
              "div",
              { class: "kpis" },
              kpi(pct(stats.cache.hit_rate), t("dash.cache.hitRate")),
              kpi(num(stats.cache.hits), t("dash.cache.hits")),
              kpi(money(stats.cache.saved_usd), t("dash.cache.saved"))
            )
          )
        : null,

      // recent
      h(
        "div",
        { class: "card" },
        h("div", { class: "card-head" }, h("h3", {}, t("dash.recent.title"))),
        recentTable(recent.requests || [])
      ),

      health ? healthCard(health) : null
    );
  }

  await load();
  return root;
}

function recentTable(rows) {
  if (!rows.length) return h("div", { class: "empty" }, t("dash.recent.empty"));
  return h(
    "div",
    { class: "table-wrap" },
    h(
      "table",
      {},
      h(
        "thead",
        {},
        h(
          "tr",
          {},
          h("th", {}, t("dash.col.time")),
          h("th", {}, t("dash.col.model")),
          h("th", {}, t("dash.col.tier")),
          h("th", {}, t("dash.col.task")),
          h("th", {}, t("dash.col.tokens")),
          h("th", {}, t("dash.col.cost")),
          h("th", {}, t("dash.col.latency")),
          h("th", {}, t("dash.col.outcome"))
        )
      ),
      h(
        "tbody",
        {},
        ...rows.map((r) =>
          h(
            "tr",
            {},
            h("td", { class: "mono" }, timeAgo(r.ts)),
            h("td", {}, r.model_id || "—", r.failover ? h("span", { class: "badge warn", style: "margin-left:6px" }, "fo") : null),
            h("td", {},
              r.tier ? h("span", { class: "badge tier-" + r.tier }, trTier(r.tier)) : "—",
              r.score > 0 ? h("span", { class: "muted small mono", style: "margin-left:6px" }, r.score.toFixed(2)) : null),
            h("td", {}, r.task_label || "—"),
            h("td", { class: "mono" }, `${r.prompt_tokens}/${r.completion_tokens}`),
            h("td", { class: "mono" }, money(r.cost_usd)),
            h("td", { class: "mono" }, ms(r.latency_ms)),
            h("td", {}, h("span", { class: "badge " + (r.outcome === "ok" ? "ok" : "error") }, r.outcome))
          )
        )
      )
    )
  );
}

function keySourceLabel(src) {
  if (src === "store") return t("models.form.secretStored");
  if (src === "env") return t("models.form.secretEnv");
  return t("models.form.secretMissing");
}

function healthCard(hh) {
  const r = hh.router || {};
  const keySrc = r.key_source || "none";
  const err = r.last_error;
  // problems fixed on the site (get / pay for a key) get the top-up link
  const needsSite =
    !r.reachable || keySrc === "missing" || (err && ["auth", "payment", "quota"].includes(err.kind));
  return h(
    "div",
    { class: "card" },
    h("div", { class: "card-head" }, h("h3", {}, t("dash.health.title"))),
    h(
      "div",
      { class: "flex wrap", style: "margin-bottom:12px" },
      h(
        "span",
        { class: "badge " + (r.reachable ? "ok" : "bad"), title: r.url || "" },
        t("status.router") + ": " + (r.reachable ? t("dash.health.reachable") : t("dash.health.unreachable"))
      ),
      keySrc !== "none"
        ? h(
            "span",
            { class: "badge " + keyBadge(keySrc), title: r.key_env || "" },
            t("models.col.key") + ": " + keySourceLabel(keySrc)
          )
        : null,
      err ? h("span", { class: "badge bad" }, t("router.probe." + (err.kind || "error"))) : null,
      needsSite
        ? h("a", { href: SITE_URL, target: "_blank", rel: "noopener" }, t("dash.health.getKey") + " ↗")
        : null
    ),
    h(
      "div",
      { class: "table-wrap" },
      h(
        "table",
        {},
        h("thead", {}, h("tr", {}, h("th", {}, t("models.col.id")), h("th", {}, t("models.col.provider")), h("th", {}, t("models.col.model")), h("th", {}, t("models.col.key")))),
        h(
          "tbody",
          {},
          ...(hh.models || []).map((m) =>
            h(
              "tr",
              {},
              h("td", { class: "mono" }, m.id),
              h("td", {}, m.provider),
              h("td", { class: "mono" }, m.model),
              h("td", {}, h("span", { class: "badge " + keyBadge(m.key_source) }, m.key_source))
            )
          )
        )
      )
    )
  );
}

function keyBadge(src) {
  if (src === "store") return "store";
  if (src === "env") return "env";
  if (src === "missing") return "bad";
  return "";
}