// Right-pane for Contacts — profile card for the selected contact.
// Shows identity, balance, device count, linked action buttons:
// Open chat (switch to Messages section), Transfer, View posts (switch
// to Feed author wall), Block (local only for now).

import React, { useEffect, useState } from 'react';
import { useStore } from '@/lib/store';
import { getIdentity, fetchDevices, getBalance } from '@/lib/api';
import { shortAddr } from '@/lib/crypto';
import type { IdentityInfo } from '@/lib/api';

function formatT(ut: number): string {
  return (ut / 1_000_000).toLocaleString(undefined, { maximumFractionDigits: 3 });
}

export function ContactsDetail(): React.ReactElement {
  const sel        = useStore(s => s.selectedContact);
  const contact    = useStore(s => s.contacts.find(c => c.address === sel));
  const setSection = useStore(s => s.setSection);
  const setActive  = useStore(s => s.setActiveChat);
  const setFeedTab = useStore(s => s.setFeedTab);

  const [identity,    setIdentity]    = useState<IdentityInfo | null>(null);
  const [balance,     setBalance]     = useState<number | null>(null);
  const [deviceCount, setDeviceCount] = useState<number | null>(null);

  useEffect(() => {
    if (!sel) return;
    let cancelled = false;
    (async () => {
      const [id, bal, devs] = await Promise.all([
        getIdentity(sel),
        getBalance(sel),
        fetchDevices(sel),
      ]);
      if (cancelled) return;
      setIdentity(id);
      setBalance(bal);
      setDeviceCount(devs.length);
    })();
    return () => { cancelled = true; };
  }, [sel]);

  if (!sel || !contact) {
    return (
      <div style={{
        height: '100%', display: 'flex',
        alignItems: 'center', justifyContent: 'center',
        color: '#6a6a6a', fontSize: 13, padding: 40, textAlign: 'center',
      }}>
        Pick a contact on the left to view their profile.
      </div>
    );
  }

  const displayName = contact.username
    ? `@${contact.username}`
    : (identity?.nickname ? `@${identity.nickname}` : (contact.alias ?? shortAddr(contact.address, 8)));

  const openChat = () => {
    setActive(contact.address);
    setSection('messages');
  };
  const viewPosts = () => {
    setFeedTab({ kind: 'author', pub: contact.address });
    setSection('feed');
  };
  const copy = (s: string) => navigator.clipboard.writeText(s).catch(() => {});

  return (
    <div style={{
      height: '100%', overflowY: 'auto',
      padding: '22px 26px', background: '#000',
    }}>
      {/* Header card */}
      <div style={{ display: 'flex', alignItems: 'center', gap: 14 }}>
        <div style={{
          width: 64, height: 64, borderRadius: 32,
          background: '#1a1a1a', color: '#d0d0d0',
          display: 'flex', alignItems: 'center', justifyContent: 'center',
          fontSize: 28, fontWeight: 700,
        }}>{displayName.replace(/^@/, '').charAt(0).toUpperCase()}</div>
        <div style={{ flex: 1, minWidth: 0 }}>
          <div style={{ color: '#fff', fontSize: 22, fontWeight: 800 }}>
            {displayName}
          </div>
          <div className="selectable" style={{
            color: '#8b8b8b', fontSize: 12, fontFamily: 'monospace',
            marginTop: 4, wordBreak: 'break-all',
          }}>{contact.address}</div>
        </div>
      </div>

      {/* Actions */}
      <div style={{ display: 'flex', gap: 10, marginTop: 16, flexWrap: 'wrap' }}>
        <Btn primary onClick={openChat}>Open chat</Btn>
        <Btn onClick={viewPosts}>View posts</Btn>
        <Btn onClick={() => copy(contact.address)}>Copy address</Btn>
      </div>

      {/* Stats grid */}
      <div style={{
        marginTop: 22, display: 'grid',
        gridTemplateColumns: 'repeat(auto-fit, minmax(180px, 1fr))', gap: 10,
      }}>
        <Stat label="Balance"     value={balance === null ? '…' : `${formatT(balance)} T`} />
        <Stat label="Devices"     value={deviceCount === null ? '…' : String(deviceCount)} />
        <Stat label="Encryption"  value={contact.x25519Pub ? 'E2E (NaCl)' : 'no key'} />
        <Stat label="Added"       value={new Date(contact.addedAt).toLocaleDateString()} />
      </div>

      {/* Identity details */}
      {identity && (
        <div style={{
          marginTop: 22, padding: 14, borderRadius: 12,
          background: '#0a0a0a', border: '1px solid #1f1f1f',
        }}>
          <div style={{
            color: '#8b8b8b', fontSize: 11, fontWeight: 700,
            letterSpacing: 1, textTransform: 'uppercase', marginBottom: 8,
          }}>Identity</div>
          <Row k="DC address" v={identity.address} copyable onCopy={() => copy(identity.address)} />
          {identity.nickname && <Row k="Username" v={`@${identity.nickname}`} />}
          {identity.x25519_pub && (
            <Row
              k="Published X25519"
              v={shortAddr(identity.x25519_pub, 8)}
              copyable
              onCopy={() => copy(identity.x25519_pub)}
            />
          )}
          {typeof identity.device_count === 'number' && (
            <Row k="Device count" v={String(identity.device_count)} />
          )}
        </div>
      )}
    </div>
  );
}

function Btn({ children, onClick, primary }: {
  children: React.ReactNode; onClick: () => void; primary?: boolean;
}) {
  return (
    <button
      onClick={onClick}
      style={{
        padding: '9px 16px', borderRadius: 999,
        background: primary ? '#1d9bf0' : 'transparent',
        border: primary ? 'none' : '1px solid #1f1f1f',
        color: '#fff', fontSize: 13, fontWeight: 700, cursor: 'pointer',
      }}
    >{children}</button>
  );
}

function Stat({ label, value }: { label: string; value: string }) {
  return (
    <div style={{
      padding: 12, borderRadius: 12,
      background: '#0a0a0a', border: '1px solid #1f1f1f',
    }}>
      <div style={{
        color: '#8b8b8b', fontSize: 11, fontWeight: 700,
        letterSpacing: 1, textTransform: 'uppercase',
      }}>{label}</div>
      <div style={{ color: '#fff', fontSize: 15, fontWeight: 700, marginTop: 4 }}>
        {value}
      </div>
    </div>
  );
}

function Row({
  k, v, copyable, onCopy,
}: { k: string; v: string; copyable?: boolean; onCopy?: () => void }) {
  return (
    <div style={{
      display: 'flex', padding: '6px 0',
      borderBottom: '1px solid #141414',
      alignItems: 'center', gap: 10,
    }}>
      <div style={{ color: '#8b8b8b', fontSize: 12, flex: '0 0 140px' }}>{k}</div>
      <div className="selectable" style={{
        color: '#fff', fontSize: 13, fontFamily: 'monospace',
        flex: 1, wordBreak: 'break-all',
      }}>{v}</div>
      {copyable && (
        <button
          onClick={onCopy}
          style={{
            background: 'transparent', border: 'none',
            color: '#1d9bf0', fontSize: 11, fontWeight: 600,
            cursor: 'pointer',
          }}
        >copy</button>
      )}
    </div>
  );
}