import { useEffect, useMemo, useState } from "react";

import { coverBackground } from "./constants.jsx";

/**
 * Asks which notebook something should go into.
 *
 * "All Notes", "Starred" and the dashboard are views, not places — a note
 * created while one of them is open has no notebook to belong to. The app used
 * to answer that silently with `notebooks[0]`, so a note or an imported PDF
 * landed in whichever notebook happened to sort first. Nothing was lost, but
 * finding it again meant knowing that rule.
 *
 * The last choice is remembered, so the common case — always the same notebook —
 * is one Enter away, while the answer stays visible instead of being guessed.
 */
const LAST_KEY = "inknote_last_notebook";

export const rememberNotebook = (id) => {
  try {
    localStorage.setItem(LAST_KEY, id);
  } catch {
    /* private mode: the default simply is not remembered */
  }
};

const recalledNotebook = () => {
  try {
    return localStorage.getItem(LAST_KEY);
  } catch {
    return null;
  }
};

export function NotebookPicker({ notebooks, title, confirmLabel = "Continue", onPick, onClose, dark }) {
  const remembered = recalledNotebook();
  const [selected, setSelected] = useState(
    () => notebooks.find((nb) => nb.id === remembered)?.id || notebooks[0]?.id || null
  );

  const T = useMemo(
    () => ({
      bg: dark ? "#161b22" : "#fff",
      border: dark ? "#30363d" : "#d0d7de",
      text: dark ? "#e6edf3" : "#1f2328",
      muted: dark ? "#8b949e" : "#656d76",
      accent: dark ? "#388bfd" : "#0969da",
      row: dark ? "#0d1117" : "#f6f8fa",
    }),
    [dark]
  );

  useEffect(() => {
    const onKey = (e) => {
      if (e.key === "Escape") onClose();
      if (e.key === "Enter" && selected) confirm();
    };
    window.addEventListener("keydown", onKey);
    return () => window.removeEventListener("keydown", onKey);
  });

  const confirm = () => {
    if (!selected) return;
    rememberNotebook(selected);
    onPick(selected);
  };

  return (
    <div
      style={{
        position: "fixed",
        inset: 0,
        background: "rgba(0,0,0,0.5)",
        display: "flex",
        alignItems: "center",
        justifyContent: "center",
        zIndex: 2000,
        backdropFilter: "blur(4px)",
      }}
      onClick={onClose}
    >
      <div
        onClick={(e) => e.stopPropagation()}
        style={{
          background: T.bg,
          borderRadius: 16,
          padding: 24,
          width: 400,
          maxWidth: "92vw",
          border: `1px solid ${T.border}`,
          boxShadow: "0 20px 40px rgba(0,0,0,0.3)",
          fontFamily: "'DM Sans',sans-serif",
        }}
      >
        <div
          style={{
            fontSize: 17,
            fontWeight: 600,
            color: T.text,
            marginBottom: 4,
            fontFamily: "'Newsreader',Georgia,serif",
          }}
        >
          {title}
        </div>
        <div style={{ fontSize: 12, color: T.muted, marginBottom: 14 }}>Which notebook should it go in?</div>

        <div
          role="listbox"
          aria-label="Notebook"
          style={{ maxHeight: 280, overflowY: "auto", display: "flex", flexDirection: "column", gap: 4 }}
        >
          {notebooks.map((nb) => {
            const active = nb.id === selected;
            return (
              <button
                key={nb.id}
                role="option"
                aria-selected={active}
                data-notebook-option={nb.id}
                onClick={() => setSelected(nb.id)}
                onDoubleClick={confirm}
                style={{
                  display: "flex",
                  alignItems: "center",
                  gap: 10,
                  width: "100%",
                  padding: "9px 12px",
                  borderRadius: 10,
                  border: `1px solid ${active ? T.accent + "66" : "transparent"}`,
                  background: active ? T.accent + "1a" : T.row,
                  color: T.text,
                  cursor: "pointer",
                  fontSize: 13,
                  textAlign: "left",
                }}
              >
                <span
                  style={{
                    width: 10,
                    height: 10,
                    borderRadius: 3,
                    flexShrink: 0,
                    background: coverBackground(nb.cover, nb.coverPattern),
                  }}
                />
                <span style={{ flex: 1, overflow: "hidden", textOverflow: "ellipsis", whiteSpace: "nowrap" }}>
                  {nb.name}
                </span>
                {nb.id === remembered && <span style={{ fontSize: 10, color: T.muted }}>last used</span>}
              </button>
            );
          })}
        </div>

        <div style={{ display: "flex", gap: 10, justifyContent: "flex-end", marginTop: 18 }}>
          <button
            onClick={onClose}
            style={{
              padding: "8px 18px",
              borderRadius: 10,
              border: `1px solid ${T.border}`,
              background: "transparent",
              color: T.text,
              cursor: "pointer",
              fontSize: 13,
            }}
          >
            Cancel
          </button>
          <button
            onClick={confirm}
            disabled={!selected}
            style={{
              padding: "8px 18px",
              borderRadius: 10,
              border: "none",
              background: selected ? T.accent : T.border,
              color: "#fff",
              cursor: selected ? "pointer" : "default",
              fontSize: 13,
              fontWeight: 600,
            }}
          >
            {confirmLabel}
          </button>
        </div>
      </div>
    </div>
  );
}