import Link from 'next/link';
import { ExternalLink } from 'lucide-react';
import { Badge } from '@/components/ui/badge';
import { Breadcrumbs } from '@/components/layout/breadcrumbs';
import { Tabs } from '@/components/ui/tabs';
import { GraphLink } from '@/components/graph/graph-link';
import { CODE_SYSTEM_LABEL, codeUrl } from '@/lib/site';
import { humanize, fmtInt } from '@/lib/format';
import { TABS, type CancerBundle, type TabKey } from './load';

const PRIMARY_SYSTEMS = ['ncit', 'oncotree', 'icd10', 'icd10cm', 'doid', 'umls', 'mesh', 'mondo'];

export function CancerHeader({ b, tab }: { b: CancerBundle; tab: TabKey }) {
  const { cancer: c, counters, codes, aliases, path } = b;
  const abbreviations = aliases.filter((a) => a.alias_type === 'abbreviation').map((a) => a.alias);
  const shown = codes.filter((k) => PRIMARY_SYSTEMS.includes(k.system)).sort((a, b2) => PRIMARY_SYSTEMS.indexOf(a.system) - PRIMARY_SYSTEMS.indexOf(b2.system));
  const otherCodes = codes.length - shown.length;

  const badges: Array<{ label: string; tone?: 'neutral' | 'accent' | 'warn' | 'outline'; title: string }> = [];
  if (c.rare_cancer === true) badges.push({ label: 'Rare', tone: 'accent', title: 'Flagged rare from incidence data (rule: age-standardized incidence < 6 per 100,000)' });
  if (c.pediatric_relevant) badges.push({ label: 'Pediatric', title: 'Pediatric-relevant entity (NCIt childhood neoplasm branch)' });
  if (c.hematologic) badges.push({ label: 'Hematologic', title: 'Hematologic malignancy' });
  if (!c.malignant) badges.push({ label: c.entity_type === 'precursor_condition' ? 'Precursor' : 'Non-malignant', tone: 'outline', title: 'Not a malignant neoplasm; kept for taxonomy completeness' });
  if (c.top_level) badges.push({ label: 'Top-level', tone: 'outline', title: 'Member of the mutually exclusive global ranking set' });
  if (counters) {
    if (counters.active_trial_count > 0) badges.push({ label: `${fmtInt(counters.active_trial_count)} active trials`, tone: 'outline', title: 'From ClinicalTrials.gov, over descendants' });
    if (counters.approved_drug_count > 0) badges.push({ label: `${fmtInt(counters.approved_drug_count)} approved drugs`, tone: 'outline', title: 'Drugs with at least one approval in any jurisdiction' });
    if (counters.evidence_count > 0) badges.push({ label: `${fmtInt(counters.evidence_count)} evidence items`, tone: 'outline', title: 'Accepted CIViC evidence items' });
  }

  const crumbs = [{ label: 'Cancers', href: '/cancers' }, ...path.slice(0, -1).map((p) => ({ label: p.canonical_name, href: `/cancer/${p.slug}` })), { label: c.canonical_name }];

  return (
    <header className="pt-5">
      <Breadcrumbs items={crumbs} />
      {b.redirectedFrom ? (
        <p className="mt-2 border-l-2 border-warn pl-3 text-[12.5px] text-warn">
          <span className="ci-mono">{b.redirectedFrom.id}</span> ({b.redirectedFrom.canonical_name}) was merged into this entity.
        </p>
      ) : null}
      {c.status === 'deprecated' ? <p className="mt-2 border-l-2 border-danger pl-3 text-[12.5px] text-danger">Deprecated entity{c.deprecated_reason ? `: ${c.deprecated_reason}` : ''}. Kept for identifier stability.</p> : null}
      <div className="mt-3 flex flex-wrap items-start justify-between gap-4">
        <div className="min-w-0">
          <p className="ci-kicker mb-1">{humanize(c.entity_type)}</p>
          <h1 className="text-3xl leading-tight sm:text-[40px]">{c.canonical_name}</h1>
          <p className="mt-1.5 flex flex-wrap items-center gap-x-3 gap-y-1 text-[13px] text-ink-3">
            <span className="ci-mono text-ink-2">{c.id}</span>
            {c.short_name && c.short_name !== c.canonical_name ? <span>{c.short_name}</span> : null}
            {abbreviations.length ? <span>{abbreviations.slice(0, 6).join(' · ')}</span> : null}
            <GraphLink type="cancer" entityRef={c.slug} />
          </p>
          {badges.length ? (
            <div className="mt-2 flex flex-wrap gap-1.5">
              {badges.map((bd) => (
                <Badge key={bd.label} tone={bd.tone ?? 'neutral'} title={bd.title}>
                  {bd.label}
                </Badge>
              ))}
            </div>
          ) : null}
        </div>
        <dl className="grid shrink-0 grid-cols-[auto_1fr] gap-x-3 gap-y-1 text-[12.5px]">
          {shown.map((k) => {
            const url = codeUrl(k.system, k.code);
            return (
              <div key={`${k.system}-${k.code}`} className="contents">
                <dt className="text-ink-3">{CODE_SYSTEM_LABEL[k.system] ?? k.system}</dt>
                <dd>
                  {url ? (
                    <a href={url} target="_blank" rel="noopener noreferrer" className="ci-mono inline-flex items-center gap-1 border border-rule px-1.5 py-[1px] text-ink no-underline hover:border-accent hover:text-accent" title={`Open ${k.code} in the ${CODE_SYSTEM_LABEL[k.system] ?? k.system} browser`}>
                      {k.code} <ExternalLink className="h-3 w-3" aria-hidden />
                    </a>
                  ) : (
                    <span className="ci-mono border border-rule px-1.5 py-[1px]">{k.code}</span>
                  )}
                </dd>
              </div>
            );
          })}
          {otherCodes > 0 ? (
            <div className="contents">
              <dt className="text-ink-3">Other</dt>
              <dd>
                <Link href={`/cancer/${c.slug}/sources`} className="ci-link">
                  {otherCodes} more {otherCodes === 1 ? 'code' : 'codes'}
                </Link>
              </dd>
            </div>
          ) : null}
          {shown.length === 0 && otherCodes === 0 ? <dd className="col-span-2 text-ink-4">No cross-reference codes yet</dd> : null}
        </dl>
      </div>
      <div className="mt-4">
        <Tabs
          ariaLabel="Entity sections"
          current={tab}
          tabs={TABS.map((t) => ({
            key: t.key,
            label: t.label,
            href: t.key === 'overview' ? `/cancer/${c.slug}` : `/cancer/${c.slug}/${t.key}`,
            count:
              t.key === 'trials'
                ? counters?.trial_count
                : t.key === 'evidence'
                  ? counters?.evidence_count
                  : t.key === 'drugs'
                    ? counters?.drug_count
                    : t.key === 'statistics'
                      ? counters?.epidemiology_obs_count
                      : t.key === 'survival'
                        ? counters?.survival_obs_count
                        : t.key === 'genomics'
                          ? counters?.cohort_count
                          : null,
          }))}
        />
      </div>
    </header>
  );
}