import Link from 'next/link';
import type { ReactNode } from 'react';
import { fmt1, fmtDate, fmtInt, fmtPct, num } from '@/lib/format';
import { routes } from '@/lib/site';
import { Derived } from './shared';

export type Row = Record<string, unknown>;
export const str = (r: Row, k: string): string | null => (typeof r[k] === 'string' ? (r[k] as string) : r[k] == null ? null : String(r[k]));
export const n = (r: Row, k: string): number => num(r[k] as number | string | null) ?? 0;

export interface Column {
  key: string;
  label: string;
  num?: boolean;
  derived?: boolean;
  render: (r: Row) => ReactNode;
}

export interface MetricDef {
  key: string;
  label: string;
  title: string;
  description: string;
  /** Label for the HBars chart / primary value. */
  primaryLabel: string;
  primary: (r: Row) => number;
  primaryFormat?: (v: number) => string;
  name: (r: Row) => string;
  href: (r: Row) => string | null;
  columns: Column[];
  note?: ReactNode;
  warn?: string;
}

function NameCell({ href, name, sub, mono = false }: { href: string | null; name: string; sub?: ReactNode; mono?: boolean }) {
  return (
    <div className="min-w-0">
      {href ? (
        <Link href={href} className={`link font-medium ${mono ? 'mono' : ''}`}>{name}</Link>
      ) : (
        <span className={`font-medium ${mono ? 'mono' : ''}`}>{name}</span>
      )}
      {sub && <p className="mt-0.5 truncate text-xs text-ink-3">{sub}</p>}
    </div>
  );
}

const shellHref = (shell: number) => routes.satellites(`orbit_class=LEO&min_perigee=${shell}&max_perigee=${shell + 50}&on_orbit=true`);

export const METRICS: MetricDef[] = [
  {
    key: 'constellations',
    label: 'Constellations',
    title: 'Largest constellations by active satellites',
    description: 'Constellations ranked by active satellites, with fleet size, launches in the last 365 days and the derived activity score.',
    primaryLabel: 'Active satellites',
    primary: (r) => n(r, 'active'),
    name: (r) => str(r, 'name') ?? '—',
    href: (r) => (str(r, 'slug') ? routes.constellation(str(r, 'slug') as string) : null),
    columns: [
      { key: 'name', label: 'Constellation', render: (r) => <NameCell href={str(r, 'slug') ? routes.constellation(str(r, 'slug') as string) : null} name={str(r, 'name') ?? '—'} sub={str(r, 'operator_slug') ? <Link href={routes.operator(str(r, 'operator_slug') as string)} className="hover:text-accent">{str(r, 'operator_name')}</Link> : str(r, 'operator_name')} /> },
      { key: 'active', label: 'Active', num: true, render: (r) => fmtInt(n(r, 'active')) },
      { key: 'total', label: 'Total', num: true, render: (r) => fmtInt(n(r, 'total')) },
      { key: 'launched_last_365d', label: 'Launched 365 d', num: true, render: (r) => fmtInt(n(r, 'launched_last_365d')) },
      { key: 'activity_score', label: 'Activity score', num: true, derived: true, render: (r) => <span className="mono">{fmt1(r['activity_score'] as number | string | null)}</span> },
    ],
    note: (
      <>
        Constellation membership and the activity score are <Derived className="mx-1" /> metrics (0–10, weighted recent launch cadence and fleet health).
      </>
    ),
  },
  {
    key: 'operators',
    label: 'Operators',
    title: 'Largest operators by active payloads',
    description: 'Operators ranked by active payloads on orbit, with total fleet, payloads launched in the last 365 days, constellations and launches.',
    primaryLabel: 'Active payloads',
    primary: (r) => n(r, 'active_payloads'),
    name: (r) => str(r, 'name') ?? '—',
    href: (r) => (str(r, 'slug') ? routes.operator(str(r, 'slug') as string) : null),
    columns: [
      { key: 'name', label: 'Operator', render: (r) => <NameCell href={str(r, 'slug') ? routes.operator(str(r, 'slug') as string) : null} name={str(r, 'name') ?? '—'} sub={str(r, 'country_name') ?? str(r, 'country_code') ?? undefined} /> },
      { key: 'active_payloads', label: 'Active', num: true, render: (r) => fmtInt(n(r, 'active_payloads')) },
      { key: 'total_payloads', label: 'Total payloads', num: true, render: (r) => fmtInt(n(r, 'total_payloads')) },
      { key: 'payloads_last_365d', label: 'Launched 365 d', num: true, render: (r) => fmtInt(n(r, 'payloads_last_365d')) },
      { key: 'constellations', label: 'Constellations', num: true, render: (r) => fmtInt(n(r, 'constellations')) },
      { key: 'launches', label: 'Launches', num: true, render: (r) => fmtInt(n(r, 'launches')) },
    ],
  },
  {
    key: 'countries',
    label: 'Countries',
    title: 'Countries by active payloads',
    description: 'Countries ranked by active payloads, with objects on orbit, operators, launches and payloads launched in the last 365 days (SATCAT owner codes mapped to ISO 3166).',
    primaryLabel: 'Active payloads',
    primary: (r) => n(r, 'active_payloads'),
    name: (r) => str(r, 'name') ?? '—',
    href: (r) => (str(r, 'slug') ? routes.country(str(r, 'slug') as string) : null),
    columns: [
      { key: 'name', label: 'Country', render: (r) => <NameCell href={str(r, 'slug') ? routes.country(str(r, 'slug') as string) : null} name={str(r, 'name') ?? '—'} sub={<span className="mono">{str(r, 'code')}</span>} /> },
      { key: 'active_payloads', label: 'Active payloads', num: true, render: (r) => fmtInt(n(r, 'active_payloads')) },
      { key: 'on_orbit_payloads', label: 'Payloads on orbit', num: true, render: (r) => fmtInt(n(r, 'on_orbit_payloads')) },
      { key: 'objects_on_orbit', label: 'Objects on orbit', num: true, render: (r) => fmtInt(n(r, 'objects_on_orbit')) },
      { key: 'operators', label: 'Operators', num: true, render: (r) => fmtInt(n(r, 'operators')) },
      { key: 'launches', label: 'Launches', num: true, render: (r) => fmtInt(n(r, 'launches')) },
      { key: 'payloads_last_365d', label: 'Launched 365 d', num: true, render: (r) => fmtInt(n(r, 'payloads_last_365d')) },
    ],
  },
  {
    key: 'countries-debris',
    label: 'Debris by country',
    title: 'Countries by debris on orbit',
    description: 'Countries ranked by catalogued debris fragments currently on orbit, with rocket bodies, objects on orbit and active payloads. Object counts only.',
    primaryLabel: 'Debris on orbit',
    primary: (r) => n(r, 'debris_on_orbit'),
    name: (r) => str(r, 'name') ?? '—',
    href: (r) => (str(r, 'slug') ? routes.country(str(r, 'slug') as string) : null),
    columns: [
      { key: 'name', label: 'Country', render: (r) => <NameCell href={str(r, 'slug') ? routes.country(str(r, 'slug') as string) : null} name={str(r, 'name') ?? '—'} sub={<span className="mono">{str(r, 'code')}</span>} /> },
      { key: 'debris_on_orbit', label: 'Debris on orbit', num: true, render: (r) => fmtInt(n(r, 'debris_on_orbit')) },
      { key: 'rocket_bodies_on_orbit', label: 'Rocket bodies', num: true, render: (r) => fmtInt(n(r, 'rocket_bodies_on_orbit')) },
      { key: 'objects_on_orbit', label: 'Objects on orbit', num: true, render: (r) => fmtInt(n(r, 'objects_on_orbit')) },
      { key: 'active_payloads', label: 'Active payloads', num: true, render: (r) => fmtInt(n(r, 'active_payloads')) },
    ],
    warn: 'Counts of catalogued objects attributed to the owner country. Not a collision-risk or responsibility metric.',
  },
  {
    key: 'launches',
    label: 'Launch sites',
    title: 'Busiest launch sites',
    description: 'Launch sites ranked by orbital launches with at least one catalogued object, with launches in the last 365 days, payloads and last launch date.',
    primaryLabel: 'Launches',
    primary: (r) => n(r, 'launches'),
    name: (r) => str(r, 'name') ?? '—',
    href: (r) => (str(r, 'slug') ? routes.launchSite(str(r, 'slug') as string) : null),
    columns: [
      { key: 'name', label: 'Launch site', render: (r) => <NameCell href={str(r, 'slug') ? routes.launchSite(str(r, 'slug') as string) : null} name={str(r, 'name') ?? '—'} sub={<><span className="mono">{str(r, 'code')}</span> · {str(r, 'country_name') ?? str(r, 'country_code') ?? '—'}</>} /> },
      { key: 'launches', label: 'Launches', num: true, render: (r) => fmtInt(n(r, 'launches')) },
      { key: 'launches_last_365d', label: 'Last 365 d', num: true, render: (r) => fmtInt(n(r, 'launches_last_365d')) },
      { key: 'payloads', label: 'Payloads', num: true, render: (r) => fmtInt(n(r, 'payloads')) },
      { key: 'last_launch', label: 'Last launch', render: (r) => <span className="mono text-xs">{fmtDate(str(r, 'last_launch'))}</span> },
    ],
  },
  {
    key: 'fastest-growing',
    label: 'Fastest growing',
    title: 'Fastest-growing constellations',
    description: 'Constellations ranked by growth: satellites launched in the last 365 days relative to the fleet size a year ago (minimum 5 launched).',
    primaryLabel: 'Growth (%)',
    primary: (r) => n(r, 'growth_pct'),
    primaryFormat: (v) => fmtPct(v, 0),
    name: (r) => str(r, 'name') ?? '—',
    href: (r) => (str(r, 'slug') ? routes.constellation(str(r, 'slug') as string) : null),
    columns: [
      { key: 'name', label: 'Constellation', render: (r) => <NameCell href={str(r, 'slug') ? routes.constellation(str(r, 'slug') as string) : null} name={str(r, 'name') ?? '—'} sub={str(r, 'operator_name') ?? undefined} /> },
      { key: 'growth_pct', label: 'Growth', num: true, derived: true, render: (r) => <span className="mono text-active">+{fmtPct(n(r, 'growth_pct'), 0)}</span> },
      { key: 'launched_last_365d', label: 'Launched 365 d', num: true, render: (r) => fmtInt(n(r, 'launched_last_365d')) },
      { key: 'active', label: 'Active', num: true, render: (r) => fmtInt(n(r, 'active')) },
      { key: 'total', label: 'Total', num: true, render: (r) => fmtInt(n(r, 'total')) },
      { key: 'first_launch', label: 'First launch', render: (r) => <span className="mono text-xs">{fmtDate(str(r, 'first_launch'))}</span> },
    ],
    note: (
      <>
        Growth = satellites launched in the last 365 d ÷ fleet a year ago (total − launched last 365 d), minimum 5 launched. <Derived className="mx-1" /> New constellations with no fleet a year ago show very large percentages.
      </>
    ),
  },
  {
    key: 'congested-shells',
    label: 'LEO shells',
    title: 'Most populated 50 km LEO shells',
    description: 'LEO altitude shells (50 km, by perigee) ranked by number of tracked objects on orbit, with active payloads, debris and constellations present. Object counts only — not a collision-risk metric.',
    primaryLabel: 'Objects on orbit',
    primary: (r) => n(r, 'objects'),
    name: (r) => `${fmtInt(n(r, 'shell_km'))}–${fmtInt(n(r, 'shell_km') + 50)} km`,
    href: (r) => shellHref(n(r, 'shell_km')),
    columns: [
      { key: 'shell_km', label: 'Shell (perigee)', render: (r) => <NameCell mono href={shellHref(n(r, 'shell_km'))} name={`${fmtInt(n(r, 'shell_km'))}–${fmtInt(n(r, 'shell_km') + 50)} km`} sub="Browse objects in this shell" /> },
      { key: 'objects', label: 'Objects', num: true, render: (r) => fmtInt(n(r, 'objects')) },
      { key: 'active_payloads', label: 'Active payloads', num: true, render: (r) => fmtInt(n(r, 'active_payloads')) },
      { key: 'debris', label: 'Debris', num: true, render: (r) => fmtInt(n(r, 'debris')) },
      { key: 'constellations', label: 'Constellations', num: true, render: (r) => fmtInt(n(r, 'constellations')) },
    ],
    warn: 'SatelliteIndex orbital density (object counts per 50 km perigee shell), NOT a collision-risk metric. No conjunction or collision probability is computed or implied.',
  },
  {
    key: 'launch-years',
    label: 'Launch years',
    title: 'Launch years by orbital launches',
    description: 'Calendar years ranked by orbital launches with catalogued objects, with the number of payloads catalogued for that year.',
    primaryLabel: 'Launches',
    primary: (r) => n(r, 'launches'),
    name: (r) => String(n(r, 'year')),
    href: (r) => routes.launches(`year=${n(r, 'year')}`),
    columns: [
      { key: 'year', label: 'Year', render: (r) => <NameCell mono href={routes.launches(`year=${n(r, 'year')}`)} name={String(n(r, 'year'))} /> },
      { key: 'launches', label: 'Launches', num: true, render: (r) => fmtInt(n(r, 'launches')) },
      { key: 'payloads', label: 'Payloads', num: true, render: (r) => fmtInt(n(r, 'payloads')) },
      { key: 'ratio', label: 'Payloads / launch', num: true, derived: true, render: (r) => <span className="mono">{n(r, 'launches') ? fmt1(n(r, 'payloads') / n(r, 'launches')) : '—'}</span> },
    ],
  },
];

export const DEFAULT_METRIC = 'constellations';
export const findMetric = (key: string | undefined): MetricDef => METRICS.find((m) => m.key === key) ?? (METRICS[0] as MetricDef);