import { useState } from "react";
import { Button, Paper, Stack, Text } from "@mantine/core";
import { Upload } from "lucide-react";

import { PhasedMultiFileDropzone } from "@/components/contracts/PhasedFileDropzone";
import { PhasedUploadedFileRow } from "@/components/contracts/PhasedUploadedFileRow";

export type TransitPermitUploadedRow = {
  code: string;
  label: string;
  file: { id: string; name: string };
};

export interface TransitPermitMultiUploadProps {
  title?: string;
  uploaded?: TransitPermitUploadedRow[];
  replaceMode?: boolean;
  submitLabel?: string;
  fileFieldPrefix: string;
  disabled?: boolean;
  onSubmit: (files: Record<string, File>) => Promise<void>;
  onViewFile?: (file: { name: string; url: string }) => void;
  onDownloadFile?: (file: { id: string; name: string }) => void;
}

/** Multi-file transit permit upload — import pre-booking and export post-booking. */
export function TransitPermitMultiUpload({
  title = "Transit Permit",
  uploaded = [],
  replaceMode = false,
  submitLabel,
  fileFieldPrefix,
  disabled = false,
  onSubmit,
  onViewFile,
  onDownloadFile,
}: TransitPermitMultiUploadProps) {
  const [files, setFiles] = useState<File[]>([]);
  const [loading, setLoading] = useState(false);

  const label = submitLabel ?? (replaceMode ? "Replace transit permit" : "Upload transit permit");

  return (
    <Stack gap="md">
      <Text size="sm" fw={700}>
        {title}
      </Text>

      {uploaded.length > 0 ? (
        <Stack gap={8}>
          <Text size="xs" fw={700} c="dimmed" tt="uppercase">
            Current file{uploaded.length > 1 ? "s" : ""}
          </Text>
          {uploaded.map((row) => (
            <PhasedUploadedFileRow
              key={row.code}
              label={row.label}
              file={row.file}
              onView={onViewFile}
              onDownload={onDownloadFile}
            />
          ))}
        </Stack>
      ) : null}

      <Paper withBorder radius="md" p="md" bg="var(--mantine-color-gray-0)">
        <PhasedMultiFileDropzone
          label="Transit permit documents"
          description={
            replaceMode
              ? "Replace transit permit files — upload one or more documents (PDF or image)."
              : "Upload one or more transit permit documents (PDF or image)."
          }
          value={files}
          onChange={setFiles}
          replaceMode={replaceMode}
          disabled={disabled || loading}
        />
      </Paper>

      <Button
        color="edr-green"
        loading={loading}
        disabled={disabled || files.length === 0}
        leftSection={<Upload size={16} />}
        fullWidth
        onClick={async () => {
          setLoading(true);
          try {
            const payload = Object.fromEntries(
              files.map((file, index) => [`${fileFieldPrefix}_${index}`, file]),
            ) as Record<string, File>;
            await onSubmit(payload);
            setFiles([]);
          } catch {
            // Caller shows toast for upload errors.
          } finally {
            setLoading(false);
          }
        }}
      >
        {label}
      </Button>
    </Stack>
  );
}