import { useCallback, useEffect, useMemo, useState } from "react";
import { ArrowUpRight, Plus, Users2, Star } from "lucide-react";
import { api } from "../api.js";
import { Badge, Button, cx, Dialog, Empty, ErrorNote, Field, fmt, fmtDate, Panel, Spinner, Stat, StatCell, StatRow } from "../ui.jsx";

export default function Team() {
  const [data, setData] = useState(null);
  const [error, setError] = useState(null);
  const [person, setPerson] = useState("");
  const [project, setProject] = useState("");
  const [overdueOnly, setOverdueOnly] = useState(false);
  const [q, setQ] = useState("");
  const [creating, setCreating] = useState(false);

  const load = useCallback(() => api("/api/team").then(setData).catch(setError), []);
  useEffect(() => { load(); }, [load]);

  const tasks = useMemo(() => {
    const term = q.trim().toLowerCase();
    return (data?.tasks || []).filter(
      (t) =>
        (!person || t.assignees.some((a) => String(a.id) === person)) &&
        (!project || String(t.project?.id) === project) &&
        (!overdueOnly || t.overdue) &&
        (!term || t.name.toLowerCase().includes(term) || t.project?.name.toLowerCase().includes(term))
    );
  }, [data, person, project, overdueOnly, q]);

  if (error) return <ErrorNote error={error} />;
  if (!data) return <Spinner label="Loading from Odoo…" />;

  if (!data.status.connected) {
    return (
      <div className="space-y-5">
        <h1 className="text-[22px] font-extrabold">Team</h1>
        <Panel>
          <Empty icon={Users2} title={data.status.configured ? "Can't reach Odoo" : "Connect Odoo to see the team"}>
            {data.status.error || "An admin can connect it in Connections → Odoo (address, database, username and API key)."}
          </Empty>
        </Panel>
      </div>
    );
  }

  const all = data.tasks;
  const overdue = all.filter((t) => t.overdue).length;
  const unassigned = all.filter((t) => !t.assignees.length).length;
  const usedProjects = data.projects.filter((p) => all.some((t) => t.project?.id === p.id));
  const busiest = data.workload.reduce((m, w) => Math.max(m, w.open), 0);

  return (
    <div className="space-y-5">
      <header className="flex items-end justify-between gap-4">
        <div>
          <h1 className="text-[22px] font-extrabold">Team</h1>
          <p className="text-muted mt-0.5">Live from {data.status.url?.replace(/^https?:\/\//, "")} · Odoo {data.status.version?.split("-")[0]}</p>
        </div>
        {data.status.allowWrites && <Button variant="primary" icon={Plus} onClick={() => setCreating(true)}>New task</Button>}
      </header>

      <StatRow className="grid-cols-4">
        <StatCell><Stat label="Open tasks" value={fmt(all.length)} note={`${usedProjects.length} projects`} /></StatCell>
        <StatCell><Stat label="Overdue" value={fmt(overdue)} tone={overdue ? "bad" : null} note={overdue ? "past their deadline" : "nothing late"} /></StatCell>
        <StatCell><Stat label="Unassigned" value={fmt(unassigned)} tone={unassigned ? "warn" : null} note="no one owns these" /></StatCell>
        <StatCell><Stat label="Team members" value={fmt(data.workload.length)} note="internal Odoo users" /></StatCell>
      </StatRow>

      <div className="grid grid-cols-[300px_minmax(0,1fr)] gap-5 items-start">
        <Panel title="Workload" subtitle="Open tasks per person">
          <ul className="divide-y divide-line">
            {data.workload.map((w) => (
              <li key={w.id}>
                <button
                  onClick={() => setPerson(person === String(w.id) ? "" : String(w.id))}
                  className={cx("w-full text-left px-4 py-2.5", person === String(w.id) ? "bg-brand-soft" : "hover:bg-[#f8fafc]")}
                >
                  <div className="flex justify-between items-baseline gap-2">
                    <span className="font-medium truncate">{w.name}</span>
                    <span className="num text-[12.5px] text-ink-2 shrink-0">
                      {w.open}{w.overdue > 0 && <span className="text-bad"> · {w.overdue} late</span>}
                    </span>
                  </div>
                  <div className="h-1.5 rounded-full bg-[#eef0f3] mt-1.5 overflow-hidden flex">
                    <div className="bg-bad" style={{ width: `${(w.overdue / Math.max(busiest, 1)) * 100}%` }} />
                    <div className="bg-brand" style={{ width: `${((w.open - w.overdue) / Math.max(busiest, 1)) * 100}%` }} />
                  </div>
                </button>
              </li>
            ))}
          </ul>
        </Panel>

        <Panel
          title="Tasks"
          subtitle={`${tasks.length} shown`}
          action={
            <div className="flex items-center gap-2">
              <input className="input h-8 w-[180px]" placeholder="Search tasks" value={q} onChange={(e) => setQ(e.target.value)} />
              <select className="input h-8 w-[200px]" value={project} onChange={(e) => setProject(e.target.value)}>
                <option value="">All projects</option>
                {usedProjects.map((p) => <option key={p.id} value={p.id}>{p.name}</option>)}
              </select>
              <label className="flex items-center gap-1.5 text-[12.5px] text-ink-2 whitespace-nowrap">
                <input type="checkbox" className="accent-brand" checked={overdueOnly} onChange={(e) => setOverdueOnly(e.target.checked)} /> Overdue
              </label>
            </div>
          }
          bodyClass="overflow-x-auto"
        >
          {tasks.length ? (
            <table className="tbl">
              <thead><tr><th>Task</th><th>Assignee</th><th>Stage</th><th>Deadline</th><th /></tr></thead>
              <tbody>
                {tasks.map((t) => (
                  <tr key={t.id}>
                    <td className="max-w-[360px]">
                      <div className="flex items-center gap-1.5">
                        {t.priority === "1" && <Star className="size-3.5 text-warn fill-current shrink-0" />}
                        <span className="font-medium text-ink truncate">{t.name}</span>
                      </div>
                      <div className="text-[12px] text-muted truncate">{t.project?.name || "No project"}</div>
                    </td>
                    <td className="text-ink-2">{t.assignees.map((a) => a.name).join(", ") || <Badge tone="warn">unassigned</Badge>}</td>
                    <td><Badge>{t.stage?.name || "—"}</Badge></td>
                    <td className={cx("whitespace-nowrap num", t.overdue ? "text-bad font-medium" : "text-ink-2")}>
                      {t.deadline ? fmtDate(t.deadline.replace(" ", "T") + "Z") : "—"}
                      {t.overdue && <span className="block text-[11.5px] font-normal">overdue</span>}
                    </td>
                    <td className="text-right">
                      <a href={t.url} target="_blank" rel="noopener" className="text-muted hover:text-brand inline-flex" aria-label="Open in Odoo"><ArrowUpRight className="size-4" /></a>
                    </td>
                  </tr>
                ))}
              </tbody>
            </table>
          ) : (
            <Empty title="No tasks match">Clear the filters to see every open task.</Empty>
          )}
        </Panel>
      </div>

      <NewTaskDialog open={creating} onClose={() => setCreating(false)} data={data} onCreated={load} />
    </div>
  );
}

function NewTaskDialog({ open, onClose, data, onCreated }) {
  const [form, setForm] = useState({ projectId: "", name: "", description: "", userIds: [], deadline: "" });
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState(null);
  useEffect(() => { if (open) { setForm({ projectId: "", name: "", description: "", userIds: [], deadline: "" }); setError(null); } }, [open]);
  const set = (k) => (e) => setForm((f) => ({ ...f, [k]: e.target.value }));
  const toggleUser = (id) => setForm((f) => ({ ...f, userIds: f.userIds.includes(id) ? f.userIds.filter((x) => x !== id) : [...f.userIds, id] }));

  const submit = async () => {
    setBusy(true);
    setError(null);
    try {
      await api("/api/team/tasks", { method: "POST", body: form });
      onClose();
      onCreated();
    } catch (e) {
      setError(e);
    } finally {
      setBusy(false);
    }
  };

  return (
    <Dialog
      open={open}
      onClose={onClose}
      title="New task in Odoo"
      footer={<><Button onClick={onClose}>Cancel</Button><Button variant="primary" loading={busy} disabled={!form.projectId || !form.name.trim()} onClick={submit}>Create task</Button></>}
    >
      <div className="space-y-3.5">
        <Field label="Project">
          <select className="input" value={form.projectId} onChange={set("projectId")}>
            <option value="">Choose a project</option>
            {data.projects.map((p) => <option key={p.id} value={p.id}>{p.name}</option>)}
          </select>
        </Field>
        <Field label="Task">
          <input className="input" value={form.name} onChange={set("name")} placeholder="e.g. Reel: dry eyes in furnace season (Wallaceton)" />
        </Field>
        <Field label="Brief" hint="Paste the creative brief: hook, format, length, on-screen text, CTA.">
          <textarea className="input" rows={5} value={form.description} onChange={set("description")} />
        </Field>
        <div className="grid grid-cols-[1fr_160px] gap-3">
          <Field label="Assign to">
            <div className="border border-line-strong rounded-md max-h-[132px] overflow-y-auto divide-y divide-line">
              {data.workload.map((w) => (
                <label key={w.id} className="flex items-center justify-between gap-2 px-2.5 py-1.5 text-[13px] cursor-pointer hover:bg-[#f8fafc]">
                  <span className="flex items-center gap-2"><input type="checkbox" className="accent-brand" checked={form.userIds.includes(w.id)} onChange={() => toggleUser(w.id)} />{w.name}</span>
                  <span className="text-[11.5px] text-muted num">{w.open} open</span>
                </label>
              ))}
            </div>
          </Field>
          <Field label="Deadline">
            <input className="input" type="date" value={form.deadline} onChange={set("deadline")} />
          </Field>
        </div>
        <ErrorNote error={error} />
      </div>
    </Dialog>
  );
}