import { useEffect, useRef, useState, type KeyboardEvent, type ClipboardEvent } from "react";
import { X } from "lucide-react";
import type { EmailAddress } from "@/jmap/types";
import { isValidEmail, parseAddressList, displayName } from "@/lib/address";
import { useContacts, type Suggestion } from "@/store/contacts";
import { Avatar } from "@/ui/misc";
import { t as translate } from "@/lib/i18n";

interface Props {
  value: EmailAddress[];
  onChange: (v: EmailAddress[]) => void;
  placeholder?: string;
  autoFocus?: boolean;
  id?: string;
}

export function RecipientInput({ value, onChange, placeholder, autoFocus, id }: Props) {
  const [text, setText] = useState("");
  const [sugg, setSugg] = useState<Suggestion[]>([]);
  const [active, setActive] = useState(0);
  const [open, setOpen] = useState(false);
  const inputRef = useRef<HTMLInputElement>(null);
  const suggest = useContacts((s) => s.suggest);
  const reqId = useRef(0);

  useEffect(() => {
    const q = text.trim();
    if (!q) {
      setSugg([]);
      setOpen(false);
      return;
    }
    const id = ++reqId.current;
    const t = window.setTimeout(() => {
      void suggest(q).then((list) => {
        if (id !== reqId.current) return;
        const existing = new Set(value.map((v) => v.email.toLowerCase()));
        const filtered = list.filter((s) => !existing.has(s.email.toLowerCase()));
        setSugg(filtered);
        setActive(0);
        setOpen(filtered.length > 0);
      });
    }, 120);
    return () => window.clearTimeout(t);
  }, [text, suggest, value]);

  const commit = (raw?: string) => {
    const s = (raw ?? text).trim().replace(/[,;]+$/, "");
    if (!s) return;
    const parsed = parseAddressList(s);
    if (!parsed.length) return;
    onChange([...value, ...parsed.filter((p) => !value.some((v) => v.email.toLowerCase() === p.email.toLowerCase()))]);
    setText("");
    setOpen(false);
  };

  const pick = (s: Suggestion) => {
    onChange([...value, { name: s.name, email: s.email }]);
    setText("");
    setOpen(false);
    inputRef.current?.focus();
  };

  const onKey = (e: KeyboardEvent<HTMLInputElement>) => {
    if (open && sugg.length) {
      if (e.key === "ArrowDown") {
        e.preventDefault();
        setActive((a) => (a + 1) % sugg.length);
        return;
      }
      if (e.key === "ArrowUp") {
        e.preventDefault();
        setActive((a) => (a - 1 + sugg.length) % sugg.length);
        return;
      }
      if (e.key === "Enter" || e.key === "Tab") {
        if (sugg[active]) {
          e.preventDefault();
          pick(sugg[active]!);
          return;
        }
      }
      if (e.key === "Escape") {
        setOpen(false);
        e.stopPropagation();
        return;
      }
    }
    if (e.key === "Enter" || e.key === "," || e.key === ";") {
      if (text.trim()) {
        e.preventDefault();
        commit();
      } else if (e.key === "Enter") e.preventDefault();
    } else if (e.key === "Tab" && text.trim()) {
      commit();
    } else if (e.key === "Backspace" && !text && value.length) {
      const last = value[value.length - 1]!;
      onChange(value.slice(0, -1));
      setText(last.name ? `${last.name} <${last.email}>` : last.email);
    }
  };

  const onPaste = (e: ClipboardEvent<HTMLInputElement>) => {
    const t = e.clipboardData.getData("text");
    if (t && /[,;\n]|<.+@.+>/.test(t)) {
      e.preventDefault();
      commit(text + t);
    }
  };

  return (
    <div className="recipients" onClick={() => inputRef.current?.focus()}>
      {value.map((a, i) => (
        <span key={`${a.email}-${i}`} className={`chip ${isValidEmail(a.email) ? "" : "invalid"}`} title={a.email}>
          <span className="truncate" style={{ maxWidth: 220 }}>{a.name ? displayName(a) : a.email}</span>
          <button type="button" className="chip-x" aria-label={translate("Remove {address}", { address: a.email })} onClick={(e) => { e.stopPropagation(); onChange(value.filter((_, j) => j !== i)); }}>
            <X size={12} />
          </button>
        </span>
      ))}
      <input
        id={id}
        ref={inputRef}
        value={text}
        placeholder={value.length ? "" : placeholder}
        autoFocus={autoFocus}
        onChange={(e) => setText(e.target.value)}
        onKeyDown={onKey}
        onPaste={onPaste}
        onBlur={() => { window.setTimeout(() => { setOpen(false); if (text.trim()) commit(); }, 150); }}
        onFocus={() => sugg.length && setOpen(true)}
        autoComplete="off"
        autoCapitalize="off"
        spellCheck={false}
        aria-autocomplete="list"
        aria-expanded={open}
      />
      {open && (
        <div className="suggest-list" role="listbox">
          {sugg.map((s, i) => (
            <div key={s.email} className={`suggest-item ${i === active ? "active" : ""}`} role="option" aria-selected={i === active} onMouseDown={(e) => { e.preventDefault(); pick(s); }} onMouseEnter={() => setActive(i)}>
              <Avatar who={s} size="sm" />
              <div className="col" style={{ minWidth: 0 }}>
                <span className="s-name truncate">{s.name ?? s.email}</span>
                {s.name && <span className="s-email truncate">{s.email}</span>}
              </div>
              <span className="s-src">{s.source === "gal" ? "Directory" : s.source === "recent" ? "Recent" : ""}</span>
            </div>
          ))}
        </div>
      )}
    </div>
  );
}