import { useEffect, useState } from 'react';

import { Button } from '@/components/ui/Button';
import { Card } from '@/components/ui/Card';
import { FlowNode } from '@/components/ui/FlowNode';
import { SectionHeader } from '@/components/ui/SectionHeader';
import { Tag } from '@/components/ui/Tag';
import { apiGet } from '@/lib/api';

interface HealthResponse {
  status: string;
  version: string;
}

interface DbDiagResponse {
  reachable: boolean;
  alembic_revision?: string | null;
  table_count?: number;
  error?: string;
}

type HealthState =
  | { kind: 'loading' }
  | { kind: 'ok'; data: HealthResponse }
  | { kind: 'error'; error: string };

type DbState =
  | { kind: 'loading' }
  | { kind: 'ok'; data: DbDiagResponse }
  | { kind: 'error'; error: string };

export function HomePage() {
  const [health, setHealth] = useState<HealthState>({ kind: 'loading' });
  const [db, setDb] = useState<DbState>({ kind: 'loading' });

  useEffect(() => {
    let cancelled = false;
    apiGet<HealthResponse>('/health', { anonymous: true })
      .then((data) => !cancelled && setHealth({ kind: 'ok', data }))
      .catch((err: unknown) =>
        !cancelled &&
        setHealth({ kind: 'error', error: err instanceof Error ? err.message : String(err) }),
      );
    apiGet<DbDiagResponse>('/diag/db', { anonymous: true })
      .then((data) => !cancelled && setDb({ kind: 'ok', data }))
      .catch((err: unknown) =>
        !cancelled &&
        setDb({ kind: 'error', error: err instanceof Error ? err.message : String(err) }),
      );
    return () => {
      cancelled = true;
    };
  }, []);

  return (
    <>
      <header className="text-center mb-12">
        <h1 className="font-mono text-[28px] font-bold tracking-tight text-text-bright">
          <span className="text-red">Meta</span>
          <span>morph</span>{' '}
          <span className="text-purple">Purple Team Platform</span>
        </h1>
        <p className="font-mono text-sm font-light text-text-dim mt-2">
          Collaborative red &amp; blue test orchestration — M4 milestone (MITRE ATT&amp;CK)
        </p>
      </header>
      <SectionHeader
        prefix="System"
        highlight="Health"
        accent="cyan"
        description="Live status pulled from /api/v1/health and /api/v1/diag/db."
      />
      <div className="grid gap-4 [grid-template-columns:repeat(auto-fill,minmax(420px,1fr))]">
        <Card
          accent={health.kind === 'ok' ? 'green' : health.kind === 'error' ? 'red' : 'cyan'}
          title="API"
          sub={
            health.kind === 'loading'
              ? 'probing…'
              : health.kind === 'error'
                ? 'unreachable'
                : `version ${health.data.version}`
          }
        >
          {health.kind === 'loading' && <p>Waiting for the backend…</p>}
          {health.kind === 'ok' && (
            <p>
              Status:{' '}
              <code className="accent-fill-green px-2 py-[2px] rounded-sm font-mono text-4xs">
                {health.data.status}
              </code>
            </p>
          )}
          {health.kind === 'error' && (
            <p>
              Error:{' '}
              <code className="accent-fill-red px-2 py-[2px] rounded-sm font-mono text-4xs">
                {health.error}
              </code>
            </p>
          )}
        </Card>

        <Card
          accent={db.kind === 'ok' && db.data.reachable ? 'blue' : db.kind === 'error' ? 'red' : 'cyan'}
          title="Database"
          sub={
            db.kind === 'loading'
              ? 'probing…'
              : db.kind === 'error'
                ? 'unreachable'
                : db.data.reachable
                  ? `revision ${db.data.alembic_revision?.slice(0, 8) ?? 'unknown'}`
                  : 'unreachable'
          }
        >
          {db.kind === 'ok' && db.data.reachable && (
            <p>
              Tables:{' '}
              <code
                className="accent-fill-blue px-2 py-[2px] rounded-sm font-mono text-4xs"
                data-testid="db-table-count"
              >
                {db.data.table_count}
              </code>{' '}
              · Alembic head reached.
            </p>
          )}
          {(db.kind === 'loading' || (db.kind === 'ok' && !db.data.reachable)) && (
            <p>Querying schema metadata…</p>
          )}
          {db.kind === 'error' && (
            <p>
              Error:{' '}
              <code className="accent-fill-red px-2 py-[2px] rounded-sm font-mono text-4xs">
                {db.error}
              </code>
            </p>
          )}
        </Card>

        <Card accent="purple" title="Roadmap" sub="14 milestones">
          <p>
            M0 + M1 + M2 + M3 + M4 done. Next:{' '}
            <code className="accent-fill-cyan px-2 py-[2px] rounded-sm font-mono text-4xs">
              M5 — Test &amp; scenario templates
            </code>
            .
          </p>
        </Card>
      </div>

      <SectionHeader
        prefix="Design"
        highlight="Tokens"
        accent="orange"
        description="Sanity check of the RTOps design system primitives (cf. tasks/design.md)."
      />
      <div className="mb-6">
        <Tag accent="red">EVASION</Tag>
        <Tag accent="purple">C2</Tag>
        <Tag accent="cyan">LATERAL</Tag>
        <Tag accent="orange">CRED</Tag>
        <Tag accent="green">PHISH</Tag>
        <Tag accent="teal">PERSIST</Tag>
      </div>
      <div className="flex items-center gap-1 flex-wrap py-3 mb-6">
        <FlowNode accent="orange">recon</FlowNode>
        <span className="text-text-dim font-mono text-2xs">→</span>
        <FlowNode accent="green">phish</FlowNode>
        <span className="text-text-dim font-mono text-2xs">→</span>
        <FlowNode accent="purple">c2</FlowNode>
        <span className="text-text-dim font-mono text-2xs">→</span>
        <FlowNode accent="cyan">lateral</FlowNode>
        <span className="text-text-dim font-mono text-2xs">→</span>
        <FlowNode accent="red">impact</FlowNode>
      </div>
      <div className="flex gap-2">
        <Button accent="cyan">Primary</Button>
        <Button accent="red">Danger</Button>
        <Button variant="ghost">Cancel</Button>
      </div>
    </>
  );
}