import { useNavigate, useParams } from 'react-router-dom';
import { Brain, ChevronRight, Radar } from 'lucide-react';
import { useQuery, useZino } from '../api/provider';
import { FINDING_KIND, QUEUES, RECORD_VIEW, STAGE_TONE } from '../api/config';
import { Badge, Button, Empty, ErrorNote, Spinner } from '../components/core';
import type { Row } from '../api/types';
import { dateTime, headline, money, num, prose, sentences, str, workStatement } from '../format';

/**
 * A queue, as a morning briefing.
 *
 * The first thing on the page is not a list: it is one strip that says what
 * Ava did and what is waiting — "reviewed everything, one thing needs you,
 * worth $1.09M". A manager who reads only that line has the day's status.
 * The cases follow, each led by its one-sentence verdict and the money.
 *
 * POLLS, because cases move on their own — Investigating → Awaiting Review with
 * no user action to hang a refresh off. A stale list looks like a stuck system.
 */
export function QueueScreen() {
  const { q } = useParams();
  const navigate = useNavigate();
  const { client } = useZino();
  const queue = QUEUES.find((x) => x.path === q) ?? QUEUES[0];

  const rows = useQuery(
    () =>
      client.rows(RECORD_VIEW, {
        limit: 100,
        sortBy: 'updated_at',
        sortDir: 'desc',
        filters: queue.stage ? [{ field_key: 'current_state_name', value: queue.stage, data_type: 'text' }] : [],
      }),
    [queue.path],
    true,
    8000,
  );
  // The briefing needs the whole picture, whichever queue is open.
  const all = useQuery(() => client.rows(RECORD_VIEW, { limit: 100, sortBy: 'updated_at', sortDir: 'desc' }), [], true, 15000);

  const list = rows.data ?? [];

  return (
    <div className="mx-auto max-w-5xl space-y-4">
      <Briefing rows={all.data ?? []} onRun={() => navigate('/review')} />

      <header className="flex flex-wrap items-end justify-between gap-3 pt-2">
        <div>
          <h1 className="text-lg font-semibold text-ink">{queue.label}</h1>
          <p className="mt-0.5 text-sm text-muted">{queue.hint}</p>
        </div>
        {!rows.loading && <Badge tone="slate">{list.length} case{list.length === 1 ? '' : 's'}</Badge>}
      </header>

      {rows.error && <ErrorNote>{rows.error}</ErrorNote>}
      {rows.loading && !rows.data && <Spinner label="Loading cases…" />}
      {rows.data && list.length === 0 && (
        <Empty>No cases in this queue.</Empty>
      )}

      <div className="space-y-3">
        {list.map((r) => (
          <CaseCard key={str(r.instance_id)} row={r} onOpen={() => navigate(`/c/${str(r.instance_id)}`)} />
        ))}
      </div>
    </div>
  );
}

/** The one strip a manager reads. */
function Briefing({ rows, onRun }: { rows: Row[]; onRun: () => void }) {
  const byState = (s: string) => rows.filter((r) => str(r.current_state_name) === s);
  const waiting = byState('Awaiting Review');
  const working = [...byState('Investigating'), ...byState('Monitoring')];
  const needsHuman = byState('Needs Human');
  const recoverable = waiting.reduce((t, r) => t + (num(r.recoverable_amount) ?? 0), 0);
  const latest = rows[0];

  return (
    <section className="lift rounded-xl border border-line bg-panel">
      <div className="flex flex-wrap items-center gap-4 px-5 py-4">
        <span className="rounded-full bg-ai-soft p-2.5 text-ai ring-1 ring-ai-edge ring-inset">
          <Brain className="h-5 w-5" />
        </span>
        <div className="min-w-0 flex-1">
          <p className="text-[11px] font-semibold tracking-wide text-faint uppercase">
            Daily review{latest ? ` · last run ${dateTime(latest.updated_at)}` : ''}
          </p>
          <p className="mt-0.5 text-[19px] leading-snug font-semibold text-ink">
            {waiting.length === 0 && working.length === 0 && needsHuman.length === 0
              ? 'No cases awaiting decision.'
              : [
                  waiting.length > 0 &&
                    `${waiting.length} case${waiting.length === 1 ? '' : 's'} awaiting decision${
                      recoverable > 0 ? ` · ${money(recoverable)} recoverable` : ''
                    }`,
                  working.length > 0 && `${working.length} review${working.length === 1 ? '' : 's'} in progress`,
                  needsHuman.length > 0 && `${needsHuman.length} escalated`,
                ]
                  .filter(Boolean)
                  .join(' · ')}
          </p>
          <p className="mt-0.5 text-xs text-muted">
            Automated review of all payers, departments and front desks. A case is opened only when a change clears the materiality threshold.
          </p>
        </div>
        <Button kind="primary" onClick={onRun}>
          <Radar className="h-4 w-4" /> Run review
        </Button>
      </div>
    </section>
  );
}

/** A case, led by its verdict and its money. */
function CaseCard({ row, onOpen }: { row: Row; onOpen: () => void }) {
  const state = str(row.current_state_name);
  const summary = prose(row.summary);
  const scanned = prose(row.scanned_summary);
  const flagged = num(row.flagged_count);
  const kind = str(row.finding_kind);
  const recoverable = num(row.recoverable_amount);
  const aiOwned = state === 'Investigating' || state === 'Monitoring';
  const quiet = flagged === 0 && !summary;
  const waiting = state === 'Awaiting Review';

  return (
    <button
      onClick={onOpen}
      className={`lift block w-full rounded-xl border bg-panel px-5 py-4 text-left transition-colors hover:border-brand/60 focus-visible:outline focus-visible:outline-2 focus-visible:outline-brand ${
        waiting ? 'border-warn-edge' : 'border-line'
      }`}
    >
      <div className="flex flex-wrap items-center gap-2">
        <Badge tone={quiet ? 'slate' : (STAGE_TONE[state] ?? 'slate')} dot={aiOwned}>
          {quiet ? 'No findings' : waiting ? 'Awaiting decision' : state}
        </Badge>
        {kind && FINDING_KIND[kind] && <Badge tone="violet">{FINDING_KIND[kind]}</Badge>}
        <span className="ml-auto text-[11px] text-faint">
          #{str(row.instance_id)} · {dateTime(row.updated_at)}
        </span>
      </div>

      <div className="mt-2.5 flex items-start gap-4">
        <p className="min-w-0 flex-1 text-[16px] leading-snug font-semibold text-ink">
          {summary
            ? headline(summary, 160)
            : quiet
              ? 'No material change detected across payers, departments or front desks.'
              : 'Review in progress…'}
        </p>
        {recoverable != null && recoverable > 0 && (
          <span className="shrink-0 text-right">
            <span className="tnum block text-[22px] leading-none font-bold text-good">{money(recoverable)}</span>
            <span className="block text-[11px] text-faint">recoverable</span>
          </span>
        )}
        <ChevronRight className="mt-1 h-4 w-4 shrink-0 text-faint" />
      </div>
      {quiet && scanned && (
        <p className="mt-1.5 line-clamp-2 text-xs text-muted">
          {(workStatement(scanned)?.find((r) => r.key === 'REVIEWED')?.items ?? sentences(scanned).slice(0, 1)).join(' · ')}
        </p>
      )}
    </button>
  );
}