"use client";

import { Check, Copy, Repeat2, Square, SquareCheckBig, X } from "lucide-react";
import { useEffect, useRef, useState } from "react";
import { formatAmount, formatUsd } from "@/app/lib/units";
import type { Aisle, GroceryLine, GrocerySummary, ItemId } from "@/app/types";
import { BudgetMeter } from "./BudgetMeter";

interface PanelProps {
  summary: GrocerySummary;
  budget: number;
  priceSourceLabel: string;
  onToggleOnHand: (itemId: ItemId, onHand: boolean) => void;
}

export function GrocerySummaryPanel({ summary, budget, priceSourceLabel, onToggleOnHand }: PanelProps) {
  const [copied, setCopied] = useState(false);
  const byAisle = groupByAisle(summary.lines);
  const remaining = budget - summary.checkoutTotal;

  async function copyList() {
    const text = summary.lines
      .filter((l) => !l.onHand)
      .map((l) => `☐ ${l.packages} × ${l.item.name} (${l.item.packageLabel})`)
      .join("\n");
    try {
      await navigator.clipboard.writeText(text);
      setCopied(true);
      setTimeout(() => setCopied(false), 2000);
    } catch {
      // Clipboard can be blocked; list remains visible on screen.
    }
  }

  return (
    <div>
      {/* --- Tactile Market Receipt Header -------------------------------- */}
      <div className="paper-grain rounded-xl border border-line bg-canvas p-4">
        <BudgetMeter spent={summary.checkoutTotal} budget={budget} />

        <dl className="receipt-rule mt-4 grid grid-cols-2 gap-3 pt-3.5 text-xs">
          <Stat label="At checkout" value={formatUsd(summary.checkoutTotal)} />
          <Stat
            label={remaining >= 0 ? "Left in budget" : "Over budget"}
            value={formatUsd(Math.abs(remaining))}
            tone={remaining >= 0 ? "text-status-ok" : "text-status-danger"}
          />
          <Stat label="Eaten this week" value={formatUsd(summary.usedTotal)} />
          <Stat label="Pantry carryover" value={formatUsd(summary.carryoverValue)} hint="Leftover package value kept" />
        </dl>

        {summary.sharedItemCount > 0 && (
          <p className="mt-3 flex items-center gap-1.5 border-t border-line pt-2.5 text-xs font-medium text-status-ok">
            <Repeat2 className="size-3.5 shrink-0" strokeWidth={2} aria-hidden />
            {summary.sharedItemCount} store item{summary.sharedItemCount > 1 ? "s" : ""} shared across meals
          </p>
        )}
      </div>

      {/* --- Shopping List Header ----------------------------------------- */}
      <div className="mt-5 flex items-center justify-between">
        <div>
          <h3 className="font-serif text-base font-semibold">Shopping list</h3>
          <p className="text-xs text-ink-faint">Tap items you already have on hand</p>
        </div>
        {summary.lines.length > 0 && (
          <button
            type="button"
            onClick={copyList}
            className="trim-cap inline-flex min-h-9 items-center gap-1.5 rounded-lg border border-line-strong bg-surface px-3 py-1.5 text-xs font-semibold text-ink transition-colors hover:bg-raised"
          >
            {copied ? <Check className="size-3.5 text-status-ok" aria-hidden /> : <Copy className="size-3.5 text-ink-muted" aria-hidden />}
            {copied ? "Copied" : "Copy list"}
          </button>
        )}
      </div>

      {summary.lines.length === 0 ? (
        <p className="mt-6 rounded-lg border border-dashed border-line-strong p-6 text-center text-sm text-ink-muted">
          Add meals to build your aisle-sorted grocery receipt.
        </p>
      ) : (
        <div className="mt-3 space-y-5">
          {byAisle.map(([aisle, lines]) => (
            <section key={aisle}>
              <h4 className="border-b border-line pb-1 font-mono text-[11px] font-semibold tracking-wider text-ink-muted uppercase">
                {aisle}
              </h4>
              <ul className="divide-y divide-line">
                {lines.map((line) => (
                  <GroceryRow key={line.item.id} line={line} onToggleOnHand={onToggleOnHand} />
                ))}
              </ul>
            </section>
          ))}
        </div>
      )}

      <p className="mt-6 text-xs text-ink-faint">{priceSourceLabel}. Actual store prices vary by location.</p>
    </div>
  );
}

function GroceryRow({ line, onToggleOnHand }: { line: GroceryLine; onToggleOnHand: PanelProps["onToggleOnHand"] }) {
  const { item } = line;
  return (
    <li>
      <button
        type="button"
        onClick={() => onToggleOnHand(item.id, !line.onHand)}
        aria-pressed={line.onHand}
        aria-label={line.onHand ? `Mark ${item.name} as needed at the store` : `Mark ${item.name} as already on hand`}
        className={`flex min-h-12 w-full items-start justify-between gap-3 py-2.5 text-left text-sm transition-colors hover:bg-raised/50 ${
          line.onHand ? "text-ink-faint" : "text-ink"
        }`}
      >
        <span className="flex min-w-0 items-start gap-2.5">
          <span className="mt-0.5 shrink-0 text-ink-muted">
            {line.onHand ? (
              <SquareCheckBig className="size-4 text-status-ok" strokeWidth={2} aria-hidden />
            ) : (
              <Square className="size-4 text-line-strong" strokeWidth={1.75} aria-hidden />
            )}
          </span>
          <span className="min-w-0">
            <span className={`block leading-snug ${line.onHand ? "line-through" : "font-medium"}`}>
              {line.packages > 1 && <span className="font-mono tabular-nums">{line.packages} × </span>}
              {item.name}
            </span>
            <span className="mt-0.5 block text-xs text-ink-muted">
              {item.packageLabel} · need {formatAmount(line.neededAmount, item.baseUnit)}
              {line.onHand && " · on hand"}
            </span>
            {line.usedBy.length > 1 && (
              <span className="mt-0.5 inline-flex items-center gap-1 text-xs text-ink-faint" title={line.usedBy.join(", ")}>
                <Repeat2 className="size-3 shrink-0" aria-hidden />
                Used in {line.usedBy.length} meals
              </span>
            )}
          </span>
        </span>

        <span className="shrink-0 text-right font-mono text-sm font-medium tabular-nums">
          {line.onHand ? "$0.00" : formatUsd(line.checkoutCost)}
        </span>
      </button>
    </li>
  );
}

function Stat({ label, value, hint, tone = "text-ink" }: { label: string; value: string; hint?: string; tone?: string }) {
  return (
    <div>
      <dt className="text-xs text-ink-faint" title={hint}>
        {label}
      </dt>
      <dd className={`mt-0.5 font-mono text-sm font-semibold tabular-nums ${tone}`}>{value}</dd>
    </div>
  );
}

function groupByAisle(lines: GroceryLine[]): [Aisle, GroceryLine[]][] {
  const groups = new Map<Aisle, GroceryLine[]>();
  for (const line of lines) {
    const group = groups.get(line.item.aisle) ?? [];
    group.push(line);
    groups.set(line.item.aisle, group);
  }
  return [...groups];
}

// ---------------------------------------------------------------------------
// GroceryListDrawer: Native <dialog> mobile bottom sheet with focus trapping,
// scroll locking, and @starting-style spring transition.
// ---------------------------------------------------------------------------

interface DrawerProps extends PanelProps {
  open: boolean;
  onClose: () => void;
}

export function GroceryListDrawer({ open, onClose, ...panelProps }: DrawerProps) {
  const dialogRef = useRef<HTMLDialogElement>(null);

  useEffect(() => {
    const dialog = dialogRef.current;
    if (!dialog) return;
    if (open && !dialog.open) dialog.showModal();
    if (!open && dialog.open) dialog.close();
    return () => {
      if (dialog.open) dialog.close();
    };
  }, [open]);

  return (
    <dialog
      ref={dialogRef}
      onClose={onClose}
      onClick={(e) => e.target === dialogRef.current && onClose()}
      aria-labelledby="grocery-drawer-title"
      className="sheet-dialog m-0 mt-auto max-h-[88dvh] w-full max-w-none overflow-y-auto rounded-t-2xl border-t border-line bg-surface p-0 shadow-2xl lg:hidden"
    >
      <div className="p-4 pb-8 sm:px-6">
        <div className="mb-4 flex items-center justify-between border-b border-line pb-3">
          <h2 id="grocery-drawer-title" className="font-serif text-xl font-semibold">
            Market receipt &amp; list
          </h2>
          <button
            type="button"
            onClick={onClose}
            aria-label="Close grocery list"
            className="grid size-10 place-items-center rounded-lg text-ink-muted transition-colors hover:bg-raised hover:text-ink"
          >
            <X className="size-5" aria-hidden />
          </button>
        </div>
        <GrocerySummaryPanel {...panelProps} />
      </div>
    </dialog>
  );
}