import { useEffect, useState } from 'react';
import type { ChannelItem } from '../../../stores';
import DialogSurface from './DialogSurface';

type AddChannelDialogProps = {
  open: boolean;
  loading: boolean;
  availableChannels: ChannelItem[];
  initialSelected: ChannelItem[];
  onClose: () => void;
  onConfirm: (items: ChannelItem[]) => Promise<void>;
};

export default function AddChannelDialog({
  open,
  loading,
  availableChannels,
  initialSelected,
  onClose,
  onConfirm,
}: AddChannelDialogProps) {
  const [searchQuery, setSearchQuery] = useState('');
  const [localSelected, setLocalSelected] = useState<ChannelItem[]>([]);
  const [error, setError] = useState<string | null>(null);
  const [submitting, setSubmitting] = useState(false);

  useEffect(() => {
    if (!open) return;

    setSearchQuery('');
    setError(null);
    setSubmitting(false);
    setLocalSelected(initialSelected.map((item) => ({ ...item })));
  }, [open, initialSelected]);

  const query = searchQuery.trim().toLowerCase();
  const existingChannelUrls = new Set(localSelected.map((item) => item.channelUrl));
  const candidateChannels = availableChannels.filter((item) => !existingChannelUrls.has(item.channelUrl));
  const filteredChannels = (query
    ? candidateChannels.filter((item) => (
      item.channelName.toLowerCase().includes(query)
      || item.channelUrl.toLowerCase().includes(query)
    ))
    : candidateChannels)
    .slice(0, 8);

  function addChannel(item: ChannelItem): void {
    setLocalSelected((current) => {
      if (current.some((channel) => channel.channelUrl === item.channelUrl)) return current;
      return [...current, { ...item }];
    });
    setSearchQuery('');
  }

  function removeChannel(id: string): void {
    setLocalSelected((current) => current.filter((item) => item.id !== id));
  }

  async function handleConfirm(): Promise<void> {
    setSubmitting(true);
    setError(null);

    try {
      await onConfirm(localSelected.map((item) => ({ ...item })));
    } catch (confirmError) {
      setError(confirmError instanceof Error ? confirmError.message : String(confirmError));
      setSubmitting(false);
      return;
    }

    setSubmitting(false);
  }

  return (
    <DialogSurface open={open} title="关联渠道" onClose={onClose}>
      <div className="space-y-5">
        <div className="space-y-2">
          <div className="text-[14px] font-bold text-[#171717]/80 dark:text-[#f3f4f6]/80">搜索添加渠道</div>
          <input
            value={searchQuery}
            onChange={(event) => setSearchQuery(event.target.value)}
            placeholder="输入渠道名称或链接"
            className="h-[48px] w-full rounded-[12px] border border-transparent bg-[#EDECE4] px-4 text-[14px] text-[#171717] outline-none transition-colors placeholder:text-[#99A0AE] focus:border-[#3B6DE8] dark:bg-[#222225] dark:text-[#f3f4f6]"
          />

          <div className="min-h-[52px] rounded-[12px] border border-black/5 bg-[#E8E6DE]/30 p-2 dark:border-[#2a2a2d] dark:bg-[#222225]/50">
            {loading ? (
              <div className="px-2 py-3 text-[13px] text-[#99A0AE] dark:text-gray-500">正在加载可用渠道...</div>
            ) : filteredChannels.length > 0 ? (
              <div className="space-y-1">
                {filteredChannels.map((item) => (
                  <button
                    key={item.channelUrl}
                    type="button"
                    className="flex w-full flex-col rounded-[10px] px-3 py-2 text-left transition-colors hover:bg-[#E8E6DE] dark:hover:bg-[#2a2a2d]"
                    onClick={() => addChannel(item)}
                  >
                    <span className="text-[13px] font-medium text-[#171717] dark:text-[#f3f4f6]">{item.channelName}</span>
                    <span className="truncate text-[12px] text-[#99A0AE] dark:text-gray-500">{item.channelUrl}</span>
                  </button>
                ))}
              </div>
            ) : (
              <div className="px-2 py-3 text-[13px] text-[#99A0AE] dark:text-gray-500">
                {availableChannels.length === 0 ? '暂无可用渠道，请先检查脚本配置。' : '没有匹配到可添加的渠道。'}
              </div>
            )}
          </div>
        </div>

        <div className="space-y-2">
          <div className="text-[14px] font-bold text-[#171717]/80 dark:text-[#f3f4f6]/80">已选渠道</div>
          <div className="max-h-[240px] space-y-2 overflow-y-auto pr-1">
            {localSelected.length > 0 ? (
              localSelected.map((item) => (
                <div
                  key={item.id}
                  className="flex items-center justify-between gap-3 rounded-[12px] border border-black/5 bg-[#E8E6DE]/50 p-3 dark:border-[#2a2a2d] dark:bg-[#222225]"
                >
                  <div className="min-w-0 flex-1">
                    <div className="truncate text-[13px] font-medium text-[#171717] dark:text-[#f3f4f6]">{item.channelName}</div>
                    <div className="truncate text-[12px] text-[#99A0AE] dark:text-gray-500">{item.channelUrl}</div>
                  </div>

                  <button
                    type="button"
                    className="shrink-0 rounded-full p-1 text-[#99A0AE] transition-colors hover:text-[#ef4444]"
                    onClick={() => removeChannel(item.id)}
                    aria-label={`移除渠道 ${item.channelName}`}
                  >
                    <svg viewBox="0 0 24 24" className="h-[18px] w-[18px] fill-none stroke-current" strokeWidth="1.8">
                      <path d="M3 6H21M8 6V4H16V6M7 6L8 19H16L17 6" strokeLinecap="round" strokeLinejoin="round" />
                    </svg>
                  </button>
                </div>
              ))
            ) : (
              <div className="rounded-[12px] border border-dashed border-black/5 bg-[#E8E6DE]/30 px-4 py-6 text-center text-[13px] text-[#99A0AE] dark:border-[#2a2a2d] dark:bg-[#222225]/50 dark:text-gray-500">
                未选择任何渠道
              </div>
            )}
          </div>
        </div>

        {error ? (
          <div className="rounded-[12px] border border-[#f2c7cd] bg-[#fff5f6] px-4 py-3 text-[13px] text-[#c24150] dark:border-[#4b2229] dark:bg-[#2b1c1f] dark:text-[#ffb4bf]">
            {error}
          </div>
        ) : null}

        <div className="flex justify-end gap-3 pt-2">
          <button
            type="button"
            className="h-[40px] rounded-full bg-[#EDECE4] px-6 text-[13px] font-semibold text-[#4B4B4B] transition-colors hover:bg-[#E5E4DC] dark:bg-[#222225] dark:text-gray-200"
            onClick={onClose}
            disabled={submitting}
          >
            取消
          </button>
          <button
            type="button"
            className="h-[40px] rounded-full bg-[#2B7FFF] px-6 text-[13px] font-semibold text-white transition-opacity hover:opacity-90 disabled:cursor-not-allowed disabled:opacity-60"
            onClick={() => {
              void handleConfirm();
            }}
            disabled={submitting}
          >
            {submitting ? '保存中...' : '确认'}
          </button>
        </div>
      </div>
    </DialogSurface>
  );
}