import { useEffect, useRef, useState } from 'react';
import { useNavigate } from 'react-router-dom';
import { useTranslation } from 'react-i18next';
import { Settings, ExternalLink, Pencil, Trash2, Plus, Globe, Download } from 'lucide-react';
import { parse as yamlParse } from 'yaml';
import { stringify as yamlStringify } from 'yaml';
import { environments } from '../../api';
import type { Environment } from '../../api';
import {
  Breadcrumbs,
  Button,
  Card,
  ContextMenu,
  DescriptionList,
  Modal,
  Timestamp,
  UuidBadge,
} from '../../ui';
import styles from '../Page.module.css';

function EnvironmentCard({ env, onDelete }: { env: Environment; onDelete: (id: string) => void }) {
  const { t } = useTranslation();
  const navigate = useNavigate();
  const dataEntries = Object.entries(env.data ?? {}).filter(([, v]) => v);

  const handleExport = async () => {
    const data = await environments.exportEnvironment(env.id);
    const blob = new Blob([yamlStringify(data)], { type: 'application/yaml' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = `environment-${env.name}.yaml`;
    a.click();
    URL.revokeObjectURL(url);
  };

  const header = (
    <div className={styles.envCardHeader}>
      <span className={styles.envCardName}>{env.name}</span>
      <div onClick={(e) => e.stopPropagation()}>
        <ContextMenu
          align="right"
          trigger={
            <Button variant="ghost" size="sm" aria-label={t('environments.menu_label')}>
              <Settings size={14} />
            </Button>
          }
          items={[
            {
              label: t('environments.action_view'),
              icon: <ExternalLink size={14} />,
              onClick: () => navigate(`/environments/${env.id}`),
            },
            {
              label: t('environments.action_edit'),
              icon: <Pencil size={14} />,
              onClick: () => navigate(`/environments/${env.id}/edit`),
            },
            {
              label: t('environments.action_export'),
              icon: <Download size={14} />,
              onClick: () => void handleExport(),
            },
            {
              label: t('environments.action_delete'),
              icon: <Trash2 size={14} />,
              variant: 'danger',
              onClick: () => onDelete(env.id),
            },
          ]}
        />
      </div>
    </div>
  );

  const footer = (
    <div className={styles.envCardFooter}>
      <UuidBadge id={env.id} />
      <Timestamp value={env.updatedAt} />
    </div>
  );

  return (
    <Card
      className={styles.envCard}
      header={header}
      headerVariant="primary"
      footer={footer}
      onClick={() => navigate(`/environments/${env.id}`)}
    >
      {dataEntries.length > 0 && (
        <DescriptionList
          layout="compact"
          truncate
          items={dataEntries.map(([key, value]) => ({ term: key, detail: value }))}
        />
      )}
      {dataEntries.length === 0 && (
        <p className={styles.envCardEmpty}>{t('environments.no_data')}</p>
      )}
    </Card>
  );
}

function AddEnvironmentCard() {
  const { t } = useTranslation();
  const navigate = useNavigate();
  return (
    <div className={styles.envCardAdd}>
      <Button variant="ghost" onClick={() => navigate('/environments/new')}>
        <Plus size={16} />
        {t('environments.action_add')}
      </Button>
    </div>
  );
}

export function EnvironmentsPage() {
  const { t } = useTranslation();
  const navigate = useNavigate();
  const [items, setItems] = useState<Environment[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [deleteId, setDeleteId] = useState<string | null>(null);
  const [deleting, setDeleting] = useState(false);
  const fileInputRef = useRef<HTMLInputElement>(null);

  const load = () => {
    environments
      .list()
      .then((res) => setItems(res.data))
      .catch((err: Error) => setError(err.message))
      .finally(() => setLoading(false));
  };

  useEffect(() => {
    load();
  }, []);

  const requestDelete = (id: string) => {
    setDeleteId(id);
  };

  const handleDelete = async () => {
    if (!deleteId) return;
    setDeleting(true);
    try {
      await environments.remove(deleteId);
      setItems((prev) => prev.filter((e) => e.id !== deleteId));
      setDeleteId(null);
    } finally {
      setDeleting(false);
    }
  };

  const handleImport = async (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (!file) return;
    e.target.value = '';
    try {
      const text = await file.text();
      const payload = yamlParse(text) as unknown;
      const imported = await environments.importEnvironment(payload);
      navigate(`/environments/${imported.id}`);
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    }
  };

  return (
    <div>
      <div className={styles.pageToolbar}>
        <Breadcrumbs items={[{ label: t('environments.title'), icon: <Globe size={14} /> }]} />
        <div className={styles.toolbarActions}>
          <input
            ref={fileInputRef}
            type="file"
            accept=".yaml,.yml,.json"
            style={{ display: 'none' }}
            onChange={handleImport}
          />
          <Button variant="secondary" size="sm" onClick={() => fileInputRef.current?.click()}>
            <Download size={14} />
            {t('environments.action_import')}
          </Button>
        </div>
      </div>
      {loading ? (
        <p className={styles.muted}>{t('environments.loading')}</p>
      ) : (
        <div className={styles.envGrid}>
          {items.map((env) => (
            <EnvironmentCard key={env.id} env={env} onDelete={requestDelete} />
          ))}
          <AddEnvironmentCard />
        </div>
      )}

      <Modal
        open={deleteId != null}
        title={t('environments.action_delete')}
        onClose={() => !deleting && setDeleteId(null)}
        footer={(
          <>
            <Button variant="secondary" onClick={() => setDeleteId(null)} disabled={deleting}>
              Cancel
            </Button>
            <Button variant="danger" onClick={handleDelete} disabled={deleting}>
              {t('environments.action_delete')}
            </Button>
          </>
        )}
      >
        Are you sure you want to delete this environment?
      </Modal>
    </div>
  );
}