import { useEffect, useRef, useState, type ReactNode } from 'react';
import {
    opportunityErrorGroup,
    opportunityMissingGroups,
    type FillGroup,
} from '@/lib/opportunity-fill-flow';

export default function OpportunityFillFlow({
    groups,
    errors,
    renderField,
    onOpenResources,
    missingPaths = [],
}: {
    groups: FillGroup[];
    errors: Record<string, string>;
    renderField: (field: string) => ReactNode;
    onOpenResources?: (group: string) => void;
    missingPaths?: string[];
}) {
    const [active, setActive] = useState(groups[0]?.id ?? '');
    const groupIds = groups.map((group) => group.id).join(',');
    useEffect(() => {
        const saved = window.location.hash.replace('#fill-', '');
        if (groupIds.split(',').includes(saved)) setActive(saved);
    }, [groupIds]);
    const heading = useRef<HTMLHeadingElement | null>(null);
    const errorGroup = opportunityErrorGroup(groups, errors);
    const missing = opportunityMissingGroups(groups, missingPaths);
    const errorKey = JSON.stringify(errors);
    useEffect(() => {
        if (errorGroup) setActive(errorGroup);
    }, [errorGroup, errorKey]);
    const index = Math.max(
        0,
        groups.findIndex((group) => group.id === active),
    );
    const current = groups[index];
    if (!current) return null;
    const go = (id: string) => {
        setActive(id);
        window.history.replaceState(window.history.state, '', `#fill-${id}`);
        requestAnimationFrame(() => heading.current?.focus());
    };
    return (
        <div className="space-y-4">
            <p>
                Pode escolher qualquer grupo, guardar incompleto e retomar. As
                informações já preenchidas mantêm-se ao avançar e regressar.
            </p>
            <nav
                aria-label="Preencher a oportunidade"
                className="flex flex-wrap gap-2"
            >
                {groups.map((group) => (
                    <a
                        key={group.id}
                        href={`#fill-${group.id}`}
                        aria-current={
                            current.id === group.id ? 'step' : undefined
                        }
                        className={`rounded border px-3 py-2 text-left ${current.id === group.id ? 'bg-primary text-primary-foreground' : 'bg-background'}`}
                        onClick={(event) => {
                            event.preventDefault();
                            go(group.id);
                        }}
                    >
                        {group.title}
                        {opportunityErrorGroup([group], errors)
                            ? ' — verificar'
                            : missing.some((item) => item.id === group.id)
                              ? ' — dados em falta'
                              : ''}
                    </a>
                ))}
            </nav>
            {missing.length > 0 && (
                <p>
                    Pendências da última gravação:{' '}
                    {missing.map((group) => group.title).join(' · ')}. Guarde
                    para actualizar esta indicação.
                </p>
            )}
            <h2 ref={heading} tabIndex={-1} className="text-xl font-semibold">
                {current.title}
            </h2>
            <p>{current.hint}</p>
            {groups.map((group) => (
                <section
                    key={group.id}
                    id={`fill-${group.id}`}
                    hidden={current.id !== group.id}
                    aria-label={group.title}
                    className="space-y-4"
                >
                    {group.fields.map((field) => (
                        <div key={field}>{renderField(field)}</div>
                    ))}
                    {onOpenResources &&
                        group.fields.some((field) =>
                            ['locations', 'documents', 'images'].includes(
                                field,
                            ),
                        ) && (
                            <button
                                type="button"
                                className="rounded border px-4 py-2 font-medium"
                                onClick={() => onOpenResources(group.id)}
                            >
                                Guardar e abrir documentos, imagens e
                                localizações
                            </button>
                        )}
                </section>
            ))}
            <div className="flex flex-wrap items-center justify-between gap-3 border-t pt-3">
                <span className="text-sm">
                    Grupo {index + 1} de {groups.length} · navegação livre
                </span>
                <div className="flex gap-3">
                    {index > 0 && (
                        <a
                            href={`#fill-${groups[index - 1].id}`}
                            className="rounded border px-4 py-2"
                            onClick={(event) => {
                                event.preventDefault();
                                go(groups[index - 1].id);
                            }}
                        >
                            Anterior
                        </a>
                    )}
                    {index < groups.length - 1 && (
                        <a
                            href={`#fill-${groups[index + 1].id}`}
                            className="rounded border px-4 py-2"
                            onClick={(event) => {
                                event.preventDefault();
                                go(groups[index + 1].id);
                            }}
                        >
                            Continuar: {groups[index + 1].title}
                        </a>
                    )}
                </div>
            </div>
        </div>
    );
}