import { useEffect, useState } from 'react';
import { Badge } from './ui/badge';
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from './ui/card';
import StatBar from './StatBar';
import { nationColor } from '@shared/protocol';
import { RELATION_COLORS } from '@/lib/colors';
import { keyToName } from '@/lib/regions';
import type { Nation, RelationStatus } from '@shared/types';

/** Human labels for a diplomatic status (the raw value is kept in data-attrs). */
const RELATION_LABEL: Record<RelationStatus, string> = {
  ally: 'Ally',
  neutral: 'Neutral',
  rival: 'Rival',
  hostile: 'Hostile',
  war: 'At war',
};

interface Props {
  nation: Nation;
  nations: Record<string, Nation>;
  /** True when this is the nation the player is leading. */
  isPlayer: boolean;
  /**
   * Render without the outer card chrome (the surrounding floating window
   * provides the border, backdrop, and title bar). Same content, same testids.
   */
  inWindow?: boolean;
}

/**
 * A single nation's dossier: identity + color chip, the four 0–100 stat bars
 * (colored by value: low = red → high = green, animated on change), territory as
 * color-coded region chips, and diplomacy as a list with a colored indicator per
 * relation (ally = green, rival = amber, war = red, neutral = slate). Used for
 * the player (highlighted) or any inspected nation.
 */
export default function NationPanel({ nation, nations, isPlayer, inWindow = false }: Props) {
  const color = nationColor(nation.id);
  const relations = Object.entries(nation.relations).sort(([a], [b]) => a.localeCompare(b));
  const regions = nation.territory;

  // Human region names for the territory chips (region key -> name), loaded once
  // (cached in @/lib/regions). A key with no known name falls back to the raw key.
  const [keyNames, setKeyNames] = useState<Record<string, string>>({});
  useEffect(() => {
    let cancelled = false;
    keyToName()
      .then((m) => {
        if (!cancelled) setKeyNames(m);
      })
      .catch(() => {
        /* names are cosmetic — a failed fetch just leaves the raw keys */
      });
    return () => {
      cancelled = true;
    };
  }, []);

  const identity = (
    <div className="flex items-center gap-3">
      <span
        className="inline-block size-4 shrink-0 rounded-md ring-2 ring-white/10"
        style={{ background: color }}
        data-testid="nation-color-chip"
      />
      <div className="min-w-0 flex-1 space-y-0.5">
        <CardTitle className="truncate text-lg">{nation.name}</CardTitle>
        <CardDescription>
          {nation.type} · {regions.length} region{regions.length === 1 ? '' : 's'}
        </CardDescription>
      </div>
      {isPlayer && (
        <Badge variant="default" className="shrink-0">
          Your nation
        </Badge>
      )}
    </div>
  );

  const sections = (
    <div className="space-y-5">
      <section>
        <h3 className="mb-2 text-xs font-medium uppercase tracking-wide text-muted-foreground">
          Status
        </h3>
        <div className="space-y-2">
          <StatBar
            label="Military"
            value={nation.stats.military}
            testId={isPlayer ? 'stat-military' : undefined}
          />
          <StatBar
            label="Economy"
            value={nation.stats.economy}
            testId={isPlayer ? 'stat-economy' : undefined}
          />
          <StatBar
            label="Stability"
            value={nation.stats.stability}
            testId={isPlayer ? 'stat-stability' : undefined}
          />
          <StatBar
            label="Population"
            value={nation.stats.population}
            testId={isPlayer ? 'stat-population' : undefined}
          />
        </div>
      </section>

      <section>
        <h3 className="mb-2 text-xs font-medium uppercase tracking-wide text-muted-foreground">
          Territory
        </h3>
        {regions.length > 0 ? (
          <div className="flex flex-wrap gap-1.5">
            {regions.map((key) => {
              const label = keyNames[key] ?? key;
              return (
                <span
                  key={key}
                  className="rounded border px-1.5 py-0.5 text-xs"
                  style={{ borderColor: `${color}66`, color, background: `${color}12` }}
                  title={key}
                  data-region-key={key}
                >
                  {label}
                </span>
              );
            })}
          </div>
        ) : (
          <p className="text-sm text-muted-foreground">No territory.</p>
        )}
      </section>

      <section>
        <h3 className="mb-2 text-xs font-medium uppercase tracking-wide text-muted-foreground">
          Diplomacy
        </h3>
        {relations.length > 0 ? (
          <ul className="space-y-1.5" data-testid="relations-list">
            {relations.map(([id, status]) => {
              const other = nations[id];
              const c = RELATION_COLORS[status] ?? '#94a3b8';
              return (
                <li
                  key={id}
                  className="flex items-center gap-2 text-sm"
                  data-testid="relation-row"
                  data-status={status}
                >
                  <span className="inline-block size-2.5 shrink-0 rounded-full" style={{ background: c }} />
                  <span className="min-w-0 flex-1 truncate text-foreground/85">
                    {other?.name ?? id}
                  </span>
                  <span className="shrink-0 text-xs font-medium" style={{ color: c }}>
                    {RELATION_LABEL[status] ?? status}
                  </span>
                </li>
              );
            })}
          </ul>
        ) : (
          <p className="text-sm text-muted-foreground">No diplomatic relations yet.</p>
        )}
      </section>
    </div>
  );

  if (inWindow) {
    return (
      <div data-testid="nation-panel" className="space-y-4 p-4">
        {identity}
        {sections}
      </div>
    );
  }

  return (
    <Card data-testid="nation-panel" className={isPlayer ? 'border-primary/40' : undefined}>
      <CardHeader className="space-y-0">{identity}</CardHeader>
      <CardContent>{sections}</CardContent>
    </Card>
  );
}