import { useState, useEffect } from "react";
import {
  Modal,
  Text,
  Button,
  Group,
  Stack,
  Checkbox,
  ScrollArea,
  Box,
  Badge,
  SimpleGrid,
} from "@mantine/core";
import { useTranslation } from "react-i18next";
import DocumentThumbnail from "@app/components/shared/filePreview/DocumentThumbnail";
import { FileId } from "@app/types/file";
import { useFileActionTerminology } from "@app/hooks/useFileActionTerminology";

interface FilePickerModalProps {
  opened: boolean;
  onClose: () => void;
  storedFiles: any[]; // Files from storage (various formats supported)
  onSelectFiles: (selectedFiles: File[]) => void;
}

const FilePickerModal = ({
  opened,
  onClose,
  storedFiles,
  onSelectFiles,
}: FilePickerModalProps) => {
  const { t } = useTranslation();
  const terminology = useFileActionTerminology();
  const [selectedFileIds, setSelectedFileIds] = useState<FileId[]>([]);

  // Reset selection when modal opens
  useEffect(() => {
    if (opened) {
      setSelectedFileIds([]);
    }
  }, [opened]);

  const toggleFileSelection = (fileId: FileId) => {
    setSelectedFileIds((prev) => {
      return prev.includes(fileId)
        ? prev.filter((id) => id !== fileId)
        : [...prev, fileId];
    });
  };

  const selectAll = () => {
    setSelectedFileIds(storedFiles.map((f) => f.id).filter(Boolean));
  };

  const selectNone = () => {
    setSelectedFileIds([]);
  };

  const handleConfirm = async () => {
    const selectedFiles = storedFiles.filter((f) =>
      selectedFileIds.includes(f.id),
    );

    // Convert stored files to File objects
    const convertedFiles = await Promise.all(
      selectedFiles.map(async (fileItem) => {
        try {
          // If it's already a File object, return as is
          if (fileItem instanceof File) {
            return fileItem;
          }

          // If it has a file property, use that
          if (fileItem.file && fileItem.file instanceof File) {
            return fileItem.file;
          }

          // If it's from IndexedDB storage, reconstruct the File
          if (
            fileItem.arrayBuffer &&
            typeof fileItem.arrayBuffer === "function"
          ) {
            const arrayBuffer = await fileItem.arrayBuffer();
            const blob = new Blob([arrayBuffer], {
              type: fileItem.type || "application/pdf",
            });
            return new File([blob], fileItem.name, {
              type: fileItem.type || "application/pdf",
              lastModified: fileItem.lastModified || Date.now(),
            });
          }

          // If it has data property, reconstruct the File
          if (fileItem.data) {
            const blob = new Blob([fileItem.data], {
              type: fileItem.type || "application/pdf",
            });
            return new File([blob], fileItem.name, {
              type: fileItem.type || "application/pdf",
              lastModified: fileItem.lastModified || Date.now(),
            });
          }

          console.warn("Could not convert file item:", fileItem);
          return null;
        } catch (error) {
          console.error("Error converting file:", error, fileItem);
          return null;
        }
      }),
    );

    // Filter out any null values and return valid Files
    const validFiles = convertedFiles.filter((f): f is File => f !== null);

    onSelectFiles(validFiles);
    onClose();
  };

  const formatFileSize = (bytes: number) => {
    if (bytes === 0) return "0 B";
    const k = 1024;
    const sizes = ["B", "KB", "MB", "GB"];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(1)) + " " + sizes[i];
  };

  return (
    <Modal
      opened={opened}
      onClose={onClose}
      title={t("fileUpload.selectFromStorage", "Select Files from Storage")}
      size="lg"
      scrollAreaComponent={ScrollArea.Autosize}
      zIndex={1100}
    >
      <Stack gap="md">
        {storedFiles.length === 0 ? (
          <Text c="dimmed" ta="center" py="xl">
            {terminology.noFilesInStorage}
          </Text>
        ) : (
          <>
            {/* Selection controls */}
            <Group justify="space-between">
              <Text size="sm" c="dimmed">
                {storedFiles.length}{" "}
                {t("fileUpload.filesAvailable", "files available")}
                {selectedFileIds.length > 0 && (
                  <> • {selectedFileIds.length} selected</>
                )}
              </Text>
              <Group gap="xs">
                <Button size="xs" variant="light" onClick={selectAll}>
                  {t("pageEdit.selectAll", "Select All")}
                </Button>
                <Button size="xs" variant="light" onClick={selectNone}>
                  {t("pageEdit.deselectAll", "Select None")}
                </Button>
              </Group>
            </Group>

            {/* File grid */}
            <ScrollArea.Autosize mah={400}>
              <SimpleGrid cols={2} spacing="md">
                {storedFiles.map((file) => {
                  const fileId = file.id;
                  const isSelected = selectedFileIds.includes(fileId);

                  return (
                    <Box
                      key={fileId}
                      p="sm"
                      style={{
                        border: isSelected
                          ? "2px solid var(--mantine-color-blue-6)"
                          : "1px solid var(--mantine-color-gray-3)",
                        borderRadius: 8,
                        backgroundColor: isSelected
                          ? "var(--mantine-color-blue-0)"
                          : "transparent",
                        cursor: "pointer",
                        transition: "all 0.2s ease",
                      }}
                      onClick={() => toggleFileSelection(fileId)}
                    >
                      <Group gap="sm" align="flex-start">
                        <Checkbox
                          checked={isSelected}
                          onChange={() => toggleFileSelection(fileId)}
                          onClick={(e) => e.stopPropagation()}
                        />

                        {/* Thumbnail */}
                        <Box
                          style={{
                            width: 60,
                            height: 80,
                            border: "1px solid var(--mantine-color-gray-3)",
                            borderRadius: 4,
                            backgroundColor: "white",
                            flexShrink: 0,
                            overflow: "hidden",
                          }}
                        >
                          <DocumentThumbnail
                            file={file}
                            thumbnail={
                              file.processedFile?.isEncrypted
                                ? undefined
                                : file.thumbnail
                            }
                            isEncrypted={Boolean(
                              file.processedFile?.isEncrypted,
                            )}
                            iconSize="2rem"
                          />
                        </Box>

                        {/* File info */}
                        <Stack gap="xs" style={{ flex: 1, minWidth: 0 }}>
                          <Text size="sm" fw={500} lineClamp={2}>
                            {file.name}
                          </Text>
                          <Group gap="xs">
                            <Badge size="xs" variant="light" color="gray">
                              {formatFileSize(
                                file.size || file.file?.size || 0,
                              )}
                            </Badge>
                          </Group>
                        </Stack>
                      </Group>
                    </Box>
                  );
                })}
              </SimpleGrid>
            </ScrollArea.Autosize>

            {/* Selection summary */}
            {selectedFileIds.length > 0 && (
              <Text size="sm" c="blue" ta="center">
                {selectedFileIds.length}{" "}
                {t("fileManager.filesSelected", "files selected")}
              </Text>
            )}
          </>
        )}

        {/* Action buttons */}
        <Group justify="flex-end" mt="md">
          <Button variant="light" onClick={onClose}>
            {t("close", "Cancel")}
          </Button>
          <Button
            onClick={handleConfirm}
            disabled={selectedFileIds.length === 0}
          >
            {selectedFileIds.length > 0
              ? `${t("fileUpload.loadFromStorage", "Load")} ${selectedFileIds.length} ${terminology.uploadFiles}`
              : t("fileUpload.loadFromStorage", "Load Files")}
          </Button>
        </Group>
      </Stack>
    </Modal>
  );
};

export default FilePickerModal;