"use client";

import React, { useCallback, useRef, useState, useEffect } from "react";
import type {
  BuilderProps,
  Config,
  ImmutableTree,
  JsonLogicResult,
  JsonTree,
} from "react-awesome-query-builder";
import { Builder, Query, Utils as QbUtils } from "react-awesome-query-builder";

import { classNames } from "@calcom/lib";
import { downloadAsCsv, sanitizeValue } from "@calcom/lib/csvUtils";
import { useInViewObserver } from "@calcom/lib/hooks/useInViewObserver";
import { useLocale } from "@calcom/lib/hooks/useLocale";
import { trpc } from "@calcom/trpc/react";
import type { inferSSRProps } from "@calcom/types/inferSSRProps";
import { Button, showToast } from "@calcom/ui";

import SingleForm, {
  getServerSidePropsForSingleFormView as getServerSideProps,
} from "../../components/SingleForm";
import {
  withRaqbSettingsAndWidgets,
  ConfigFor,
} from "../../components/react-awesome-query-builder/config/uiConfig";
import type { JsonLogicQuery } from "../../jsonLogicToPrisma";
import {
  getQueryBuilderConfigForFormFields,
  type FormFieldsQueryBuilderConfigWithRaqbFields,
} from "../../lib/getQueryBuilderConfig";

export { getServerSideProps };

const Result = ({
  formName,
  formId,
  jsonLogicQuery,
}: {
  formName: string;
  formId: string;
  jsonLogicQuery: JsonLogicQuery | null;
}) => {
  const { t } = useLocale();
  const [isDownloading, setIsDownloading] = useState(false);

  const { isPending, status, data, isFetching, error, isFetchingNextPage, hasNextPage, fetchNextPage } =
    trpc.viewer.appRoutingForms.report.useInfiniteQuery(
      {
        formId: formId,
        // Send jsonLogicQuery only if it's a valid logic, otherwise send a logic with no query.
        jsonLogicQuery: jsonLogicQuery?.logic
          ? jsonLogicQuery
          : {
              logic: {},
            },
      },
      {
        getNextPageParam: (lastPage) => lastPage.nextCursor,
      }
    );
  const exportQuery = trpc.viewer.appRoutingForms.report.useInfiniteQuery(
    {
      limit: 100, // 100 is max
      formId: formId,
      // Send jsonLogicQuery only if it's a valid logic, otherwise send a logic with no query.
      jsonLogicQuery: jsonLogicQuery?.logic
        ? jsonLogicQuery
        : {
            logic: {},
          },
    },
    {
      getNextPageParam: (lastPage) => lastPage.nextCursor,
      enabled: false,
    }
  );
  const buttonInView = useInViewObserver(() => {
    if (!isFetching && hasNextPage && status === "success") {
      fetchNextPage();
    }
  });

  const headers = useRef<string[] | null>(null);

  if (!isPending && !data) {
    return <div>Error loading report {error?.message} </div>;
  }
  headers.current = (data?.pages && data?.pages[0]?.headers) || headers.current;

  const numberOfRows = data?.pages.reduce((total, page) => total + (page.responses?.length || 0), 0);
  const downloadButtonDisabled = !numberOfRows || !data || !headers.current || isDownloading;

  const handleDownload = async () => {
    try {
      setIsDownloading(true);

      if (downloadButtonDisabled) {
        return;
      }

      const result = await exportQuery.refetch();
      if (!result.data) {
        throw new Error("There are no routing forms found.");
      }
      const allRows = result.data.pages.flatMap((page) =>
        page.responses.map((response) => `${response.map((value) => sanitizeValue(value)).join(",")}\n`)
      );
      let lastPage = result.data.pages[result.data.pages.length - 1];
      while (lastPage.nextCursor) {
        const nextPage = await exportQuery.fetchNextPage();
        if (!nextPage.data) {
          break;
        }
        const latestPageItems = nextPage.data.pages[nextPage.data.pages.length - 1].responses ?? [];
        allRows.push(
          ...latestPageItems.map((response) => `${response.map((value) => sanitizeValue(value)).join(",")}\n`)
        );
        lastPage = nextPage.data.pages[nextPage.data.pages.length - 1];
      }

      const header = `${(headers.current ?? []).map((value) => sanitizeValue(value)).join(",")}\n`;
      const csvRaw = header + allRows.join("");
      const filename = `${formName}_${new Date().toISOString().split("T")[0]}.csv`; // e.g., ${FormName}_2024-10-30.csv
      downloadAsCsv(csvRaw, filename);
    } catch (error) {
      showToast(`Error: ${error}`, "error");
    } finally {
      setIsDownloading(false);
    }
  };

  return (
    <div className="w-full max-w-[2000px] overflow-x-scroll">
      {!isPending && (
        <div className="mb-4 inline-block flex min-w-full items-center px-3">
          <Button
            disabled={downloadButtonDisabled}
            StartIcon="file-down"
            color="secondary"
            className="mr-3"
            onClick={() => handleDownload()}>
            {t("download")}
          </Button>
          <div className="text-default text-md">
            {`${numberOfRows} ${numberOfRows === 1 ? t("row") : t("rows")}`}
          </div>
        </div>
      )}
      <table
        data-testid="reporting-table"
        className="border-default bg-subtle mx-3 mb-4 min-w-full table-fixed border-separate border-spacing-0 overflow-hidden rounded-md border">
        <tr
          data-testid="reporting-header"
          className="border-default text-default bg-emphasis rounded-md border-b">
          {headers.current?.map((header, index) => (
            <th
              className={classNames(
                "border-default border-b px-2 py-3 text-left text-base font-medium",
                index !== (headers.current?.length || 0) - 1 ? "border-r" : ""
              )}
              key={index}>
              {header}
            </th>
          ))}
        </tr>
        {!isPending &&
          data?.pages.map((page) => {
            return page.responses?.map((responses, rowIndex) => {
              const isLastRow = page.responses.length - 1 === rowIndex;
              return (
                <tr
                  key={rowIndex}
                  data-testid="reporting-row"
                  className={classNames(
                    "text-center text-sm",
                    rowIndex % 2 ? "" : "bg-default",
                    isLastRow ? "" : "border-b"
                  )}>
                  {responses.map((r, columnIndex) => {
                    const isLastColumn = columnIndex === responses.length - 1;
                    return (
                      <td
                        className={classNames(
                          "border-default overflow-x-hidden whitespace-pre-line px-2 py-3 text-left",
                          isLastRow ? "" : "border-b",
                          isLastColumn ? "" : "border-r"
                        )}
                        key={columnIndex}>
                        {r}
                      </td>
                    );
                  })}
                </tr>
              );
            });
          })}
      </table>
      {isPending ? <div className="text-default p-2">{t("loading")}</div> : ""}
      {hasNextPage && (
        <Button
          type="button"
          color="minimal"
          ref={buttonInView.ref}
          loading={isFetchingNextPage}
          disabled={!hasNextPage}
          onClick={() => fetchNextPage()}>
          {hasNextPage ? t("load_more_results") : t("no_more_results")}
        </Button>
      )}
    </div>
  );
};

const getInitialQuery = (config: ReturnType<typeof getQueryBuilderConfigForFormFields>) => {
  const uuid = QbUtils.uuid();
  const queryValue: JsonTree = { id: uuid, type: "group" } as JsonTree;
  const tree = QbUtils.checkTree(QbUtils.loadTree(queryValue), config as unknown as Config);
  return {
    state: { tree, config },
    queryValue,
  };
};

const Reporter = ({ form }: { form: inferSSRProps<typeof getServerSideProps>["form"] }) => {
  const config = getQueryBuilderConfigForFormFields(form, true);
  const [query, setQuery] = useState(getInitialQuery(config));
  const [jsonLogicQuery, setJsonLogicQuery] = useState<JsonLogicResult | null>(null);
  const onChange = (immutableTree: ImmutableTree, config: FormFieldsQueryBuilderConfigWithRaqbFields) => {
    const jsonTree = QbUtils.getTree(immutableTree);
    setQuery(() => {
      const newValue = {
        state: { tree: immutableTree, config: config },
        queryValue: jsonTree,
      };
      setJsonLogicQuery(QbUtils.jsonLogicFormat(newValue.state.tree, config as unknown as Config));
      return newValue;
    });
  };

  const renderBuilder = useCallback(
    (props: BuilderProps) => (
      <div className="query-builder-container">
        <div className="query-builder qb-lite">
          <Builder {...props} />
        </div>
      </div>
    ),
    []
  );
  return (
    <div className="cal-query-builder">
      <Query
        {...withRaqbSettingsAndWidgets({
          config,
          configFor: ConfigFor.FormFields,
        })}
        value={query.state.tree}
        onChange={(immutableTree, config) => {
          onChange(immutableTree, config as unknown as FormFieldsQueryBuilderConfigWithRaqbFields);
        }}
        renderBuilder={renderBuilder}
      />
      <Result formName={form.name} formId={form.id} jsonLogicQuery={jsonLogicQuery as JsonLogicQuery} />
    </div>
  );
};

export default function ReporterWrapper({
  ...props
}: inferSSRProps<typeof getServerSideProps> & { appUrl: string }) {
  const [isClient, setIsClient] = useState(false);

  useEffect(() => {
    // It isn't possible to render Reporter without hydration errors if it is rendered on the server.
    // This is because the RAQB generates some dynamic ids on elements which change b/w client and server.
    // This is a workaround to render the Reporter on the client only.
    setIsClient(true);
  }, []);

  return (
    <SingleForm
      {...props}
      Page={({ form }) => (
        <div className="route-config bg-default fixed inset-0 w-full overflow-scroll pt-12 ltr:mr-2 rtl:ml-2 sm:pt-0">
          {isClient && <Reporter form={form} />}
        </div>
      )}
    />
  );
}