import React, { useCallback, useEffect, useState } from 'react';
import { Mail, RefreshCw, Loader2 } from 'lucide-react';
import { Button } from '@/components/ui/button';
import { apiFetch } from '@/lib/api';
import { cn } from '@/lib/utils';

export default function ConnectMailboxSettings() {
    const [loading, setLoading] = useState(true);
    const [busy, setBusy] = useState(false);
    const [accounts, setAccounts] = useState([]);
    const [defaultRefId, setDefaultRefId] = useState(null);

    const load = useCallback(async () => {
        setLoading(true);
        try {
            const r = await apiFetch('/api/unipile/mailbox/campaign-defaults');
            const d = r.ok ? await r.json() : {};
            setAccounts(d.accounts || []);
            setDefaultRefId(d.default_mailbox_unipile_account_ref_id ?? null);
        } catch {
            setAccounts([]);
        } finally {
            setLoading(false);
        }
    }, []);

    useEffect(() => {
        load();
    }, [load]);

    const connectAccount = async () => {
        setBusy(true);
        try {
            const res = await apiFetch('/api/unipile/mailbox/hosted-link', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    label: 'Mailbox',
                }),
            });
            const data = await res.json().catch(() => ({}));
            if (!res.ok) throw new Error(data.detail || 'Could not start mailbox connect');
            if (data.url) window.location.href = data.url;
        } catch (e) {
            alert(e.message || 'Connect failed');
        } finally {
            setBusy(false);
        }
    };

    return (
        <section className="rounded-2xl border border-slate-200 bg-white p-6 shadow-sm">
            <div className="flex flex-wrap items-start justify-between gap-3">
                <div className="flex items-center gap-2 font-semibold text-slate-800">
                    <Mail className="h-5 w-5 text-violet-600" />
                    Connect Mailbox
                </div>
                <Button type="button" variant="outline" size="sm" disabled={loading || busy} onClick={load}>
                    <RefreshCw className={cn('mr-2 h-4 w-4', loading && 'animate-spin')} />
                    Refresh
                </Button>
            </div>

            <div className="mt-4 flex flex-col gap-3 md:flex-row md:items-end">
                <Button type="button" disabled={busy} onClick={connectAccount} className="bg-slate-900 text-white">
                    Connect mailbox
                </Button>
            </div>

            {loading ? (
                <div className="mt-6 flex justify-center py-8 text-slate-400">
                    <Loader2 className="h-8 w-8 animate-spin" />
                </div>
            ) : accounts.length === 0 ? (
                <p className="mt-6 text-sm text-slate-500">Connected mailboxes: 0</p>
            ) : (
                <div className="mt-6 space-y-3">
                    <p className="text-sm font-medium text-slate-700">
                        Connected mailboxes ({accounts.length}) — default for email sequence steps
                    </p>
                    <ul className="space-y-2">
                        {accounts.map((a) => {
                            const name = a.display_name || a.label || 'Mailbox';
                            const checked = defaultRefId != null && Number(defaultRefId) === Number(a.id);
                            return (
                                <li
                                    key={a.id}
                                    className={cn(
                                        'flex cursor-pointer items-center gap-3 rounded-xl border px-3 py-2 transition',
                                        checked ? 'border-violet-300 bg-violet-50/60' : 'border-slate-200 hover:bg-slate-50'
                                    )}
                                    onClick={() => setDefaultRefId(a.id)}
                                >
                                    <input
                                        type="radio"
                                        className="h-4 w-4 accent-violet-600"
                                        checked={checked}
                                        onChange={() => setDefaultRefId(a.id)}
                                    />
                                    <div className="min-w-0 flex-1">
                                        <p className="truncate font-medium text-slate-900">{name}</p>
                                        <p className="truncate text-xs text-slate-500">{a.label}</p>
                                    </div>
                                    <span className="text-[10px] font-semibold uppercase text-slate-400">
                                        {a.status || '—'}
                                    </span>
                                </li>
                            );
                        })}
                    </ul>
                </div>
            )}
        </section>
    );
}