"use client";

import Link from "next/link";
import { useState } from "react";

/*
 * One record-line entry. `copy` marks the value as worth lifting to the
 * clipboard an instance UUID or a licence ID, the strings people paste into
 * support tickets.
 */
export type RecordField = { key: string; value: string; copy?: boolean };

function CopyButton({ value }: { value: string }) {
    const [done, setDone] = useState(false);
    return (
        <button
            type="button"
            // Never the thing that wraps: it is 5 characters and the value
            // beside it may be 36.
            onClick={async () => {
                try {
                    await navigator.clipboard.writeText(value);
                    setDone(true);
                    setTimeout(() => setDone(false), 1200);
                } catch {
                    // Clipboard is refused without a secure context or a user
                    // gesture the browser trusts. The value is on screen and
                    // selectable either way, so this needs no error state.
                }
            }}
            className="shrink-0 rounded-sm border border-rule px-1.5 py-px font-mono text-[0.62rem] uppercase tracking-[0.1em] text-ink-3 hover:border-accent hover:text-accent"
        >
            {done ? "Copied" : "Copy"}
        </button>
    );
}

/*
 * The page frame every screen starts with, replacing nine hand-rolled header
 * blocks that each picked their own gaps and their own place for actions.
 *
 * The record line is the one new idea: Vantage HQ is a registry, so every screen
 * is a record and records have reference numbers. Giving the reference a fixed
 * slot, in mono, above the fold, means "where is the ID" stops being a per-page
 * question. It costs one hairline rule.
 */
export function PageHeader({
    back,
    title,
    subtitle,
    actions,
    record,
    status,
}: {
    back?: { href: string; label: string };
    title: string;
    subtitle?: React.ReactNode;
    actions?: React.ReactNode;
    record?: RecordField[];
    status?: React.ReactNode;
}) {
    return (
        <header className="grid gap-3">
            {back && (
                <Link href={back.href} className="justify-self-start font-mono text-[0.7rem] uppercase tracking-[0.1em] text-ink-3 hover:text-accent">
                    &larr; {back.label}
                </Link>
            )}

            <div className="flex flex-wrap items-start justify-between gap-4">
                <div className="min-w-0">
                    <h1 className="text-[1.9rem]">{title}</h1>
                    {subtitle && <p className="mt-1 text-[0.92rem] text-ink-2">{subtitle}</p>}
                </div>
                {actions && <div className="flex flex-wrap items-center gap-2">{actions}</div>}
            </div>

            {(record?.length || status) && (
                <div className="flex flex-wrap items-center gap-x-5 gap-y-2.5 border-t border-rule pt-2.5">
                    {record?.map((f) => (
                        // min-w-0 and break-all because the commonest value here
                        // is a 36-character UUID with a Copy button beside it,
                        // which does not fit a 320px screen as one unbreakable
                        // token and pushed the whole page sideways.
                        <span key={f.key} className="flex min-w-0 items-center gap-2">
                            <span className="shrink-0 font-mono text-[0.64rem] uppercase tracking-[0.14em] text-ink-3">{f.key}</span>
                            <span className="min-w-0 break-all font-mono text-[0.78rem] tabular-nums text-ink-2">{f.value}</span>
                            {f.copy && <CopyButton value={f.value} />}
                        </span>
                    ))}
                    {status && <span className="ml-auto">{status}</span>}
                </div>
            )}
        </header>
    );
}