"use client";

import { useState } from "react";
import type { ChannelResponse } from "@/lib/types";

export function useChannelOrder(channels: ChannelResponse[] | undefined) {
  const [channelOrder, setChannelOrder] = useState<string[]>(() => {
    try {
      const stored = localStorage.getItem("k-tv-channel-order");
      return stored ? JSON.parse(stored) : [];
    } catch {
      return [];
    }
  });

  const saveOrder = (order: string[]) => {
    setChannelOrder(order);
    try {
      localStorage.setItem("k-tv-channel-order", JSON.stringify(order));
    } catch {}
  };

  const sortedChannels = channels
    ? [...channels].sort((a, b) => {
        const ai = channelOrder.indexOf(a.id);
        const bi = channelOrder.indexOf(b.id);
        if (ai === -1 && bi === -1) return 0;
        if (ai === -1) return 1;
        if (bi === -1) return -1;
        return ai - bi;
      })
    : [];

  const handleMoveUp = (channelId: string) => {
    const ids = sortedChannels.map((c) => c.id);
    const idx = ids.indexOf(channelId);
    if (idx <= 0) return;
    const next = [...ids];
    [next[idx - 1], next[idx]] = [next[idx], next[idx - 1]];
    saveOrder(next);
  };

  const handleMoveDown = (channelId: string) => {
    const ids = sortedChannels.map((c) => c.id);
    const idx = ids.indexOf(channelId);
    if (idx === -1 || idx >= ids.length - 1) return;
    const next = [...ids];
    [next[idx], next[idx + 1]] = [next[idx + 1], next[idx]];
    saveOrder(next);
  };

  return { channelOrder, sortedChannels, handleMoveUp, handleMoveDown };
}