import { useState } from 'react';
import { extractApiError } from '@/api/client';
import { useC2Callbacks, useC2CallbackHistory, useImportC2 } from '@/hooks/useC2';
import { C2CallbackPicker } from './C2CallbackPicker';
import { C2TaskStatusBadge } from './C2TaskStatusBadge';
import { useToast } from '@/hooks/useToast';

const PAGE_SIZE = 25;

interface ImportC2HistoryModalProps {
  simulationId: number;
  engagementId: number;
  onClose: () => void;
}

export function ImportC2HistoryModal({
  simulationId,
  engagementId,
  onClose,
}: ImportC2HistoryModalProps): JSX.Element {
  const { push } = useToast();

  const callbacksQuery = useC2Callbacks(engagementId, { enabled: true });
  const importMutation = useImportC2(simulationId);

  const [selectedCallbackId, setSelectedCallbackId] = useState<number | null>(null);
  const [page, setPage] = useState(1);
  const [checkedIds, setCheckedIds] = useState<Set<number>>(new Set());
  const [submitError, setSubmitError] = useState<string | null>(null);

  const historyQuery = useC2CallbackHistory(engagementId, selectedCallbackId, {
    page,
    pageSize: PAGE_SIZE,
    enabled: selectedCallbackId !== null,
  });

  const historyTasks = historyQuery.data?.tasks ?? [];
  const total = historyQuery.data?.total ?? 0;
  const totalPages = Math.max(1, Math.ceil(total / PAGE_SIZE));

  const callbacks = callbacksQuery.data?.callbacks ?? [];

  function handleCallbackSelect(id: number) {
    setSelectedCallbackId(id);
    setPage(1);
    setCheckedIds(new Set());
  }

  function toggleCheck(displayId: number) {
    setCheckedIds((prev) => {
      const next = new Set(prev);
      if (next.has(displayId)) {
        next.delete(displayId);
      } else {
        next.add(displayId);
      }
      return next;
    });
  }

  const canImport = checkedIds.size > 0 && selectedCallbackId !== null;

  const onImport = async () => {
    if (!canImport) return;
    setSubmitError(null);
    try {
      const result = await importMutation.mutateAsync({
        callback_display_id: selectedCallbackId,
        task_display_ids: Array.from(checkedIds),
      });
      const msg =
        result.skipped > 0
          ? `Imported ${result.imported} task(s), ${result.skipped} already attached`
          : `Imported ${result.imported} task(s)`;
      push(msg, 'success');
      onClose();
    } catch (err) {
      setSubmitError(extractApiError(err, 'Could not import tasks'));
    }
  };

  return (
    <div
      role="dialog"
      aria-modal="true"
      aria-labelledby="c2-import-modal-title"
      data-testid="c2-import-modal"
      className="fixed inset-0 z-50 flex items-center justify-center"
    >
      <div className="modal-backdrop absolute inset-0" onClick={onClose} aria-hidden="true" />

      <div className="relative card-product w-full max-w-4xl mx-md flex flex-col gap-md max-h-[90vh] overflow-y-auto">
        <h2 id="c2-import-modal-title" className="text-[20px] font-medium text-ink">
          Import C2 history
        </h2>

        {/* Step 1: callback picker */}
        <div className="flex flex-col gap-xs">
          <span className="text-[14px] font-medium text-ink">Select callback</span>
          <C2CallbackPicker
            callbacks={callbacks}
            isLoading={callbacksQuery.isLoading}
            isError={callbacksQuery.isError}
            error={callbacksQuery.error}
            selectedId={selectedCallbackId}
            onSelect={handleCallbackSelect}
            rowTestId="c2-import-callback-row"
          />
        </div>

        {/* Step 2: history table (shown once a callback is selected) */}
        {selectedCallbackId !== null && (
          <div className="flex flex-col gap-xs">
            <span className="text-[14px] font-medium text-ink">
              Task history{' '}
              {total > 0 && (
                <span className="text-graphite font-normal">({total} total)</span>
              )}
            </span>

            {historyQuery.isLoading && (
              <p className="text-[14px] text-graphite">Loading history…</p>
            )}

            {historyQuery.isError && (
              <p className="text-[14px] text-bloom-deep">
                {extractApiError(historyQuery.error, 'Could not load history')}
              </p>
            )}

            {!historyQuery.isLoading && historyTasks.length === 0 && !historyQuery.isError && (
              <p className="text-[14px] text-graphite">No task history for this callback.</p>
            )}

            {historyTasks.length > 0 && (
              <>
                <div className="border border-hairline overflow-x-auto">
                  <table className="w-full text-[14px]">
                    <thead>
                      <tr className="bg-cloud border-b border-hairline">
                        <th className="px-md py-sm w-8" aria-label="Select" />
                        <th className="px-md py-sm text-left font-medium text-ink">#</th>
                        <th className="px-md py-sm text-left font-medium text-ink">Command</th>
                        <th className="px-md py-sm text-left font-medium text-ink">Status</th>
                        <th className="px-md py-sm text-left font-medium text-ink">Completed</th>
                        <th className="px-md py-sm text-left font-medium text-ink">Timestamp</th>
                      </tr>
                    </thead>
                    <tbody>
                      {historyTasks.map((task) => (
                        <tr
                          key={task.display_id}
                          data-testid="c2-history-row"
                          onClick={() => toggleCheck(task.display_id)}
                          className="cursor-pointer border-b border-hairline hover:bg-cloud"
                        >
                          <td className="px-md py-sm">
                            <input
                              type="checkbox"
                              data-testid="c2-history-row-checkbox"
                              checked={checkedIds.has(task.display_id)}
                              onChange={() => toggleCheck(task.display_id)}
                              onClick={(e) => e.stopPropagation()}
                              className="h-4 w-4 accent-primary"
                            />
                          </td>
                          <td className="px-md py-sm font-mono">{task.display_id}</td>
                          <td
                            className="px-md py-sm font-mono max-w-[200px] truncate"
                            title={task.command}
                          >
                            {task.command}
                          </td>
                          <td className="px-md py-sm">
                            <C2TaskStatusBadge status={task.status} />
                          </td>
                          <td className="px-md py-sm text-[14px]">
                            {task.completed ? 'Yes' : 'No'}
                          </td>
                          <td className="px-md py-sm font-mono text-graphite">
                            {task.created_at}
                          </td>
                        </tr>
                      ))}
                    </tbody>
                  </table>
                </div>

                {/* Pagination */}
                <div className="flex items-center gap-md text-[14px] text-graphite">
                  <button
                    type="button"
                    data-testid="c2-history-prev"
                    className="btn-outline-ink"
                    onClick={() => setPage((p) => Math.max(1, p - 1))}
                    disabled={page <= 1}
                  >
                    Prev
                  </button>
                  <span>
                    Page {page} of {totalPages}
                  </span>
                  <button
                    type="button"
                    data-testid="c2-history-next"
                    className="btn-outline-ink"
                    onClick={() => setPage((p) => Math.min(totalPages, p + 1))}
                    disabled={page >= totalPages}
                  >
                    Next
                  </button>
                  {checkedIds.size > 0 && (
                    <span className="ml-auto text-ink">
                      {checkedIds.size} selected
                    </span>
                  )}
                </div>
              </>
            )}
          </div>
        )}

        {submitError && (
          <p role="alert" className="text-[14px] text-bloom-deep">
            {submitError}
          </p>
        )}

        {/* Footer */}
        <div className="flex items-center gap-md pt-xs">
          <button
            type="button"
            data-testid="c2-import-submit-btn"
            className="btn-primary"
            onClick={onImport}
            disabled={!canImport || importMutation.isPending}
          >
            {importMutation.isPending ? 'Importing…' : 'Import selected'}
          </button>
          <button
            type="button"
            className="btn-outline-ink"
            onClick={onClose}
            disabled={importMutation.isPending}
          >
            Cancel
          </button>
        </div>
      </div>
    </div>
  );
}