"use client";

import { Box, Tab, Tabs, Snackbar, Alert, CircularProgress, Typography, TextField, Button, Stack } from "@mui/material";
import { useState, useCallback, useEffect, useRef } from "react";
import { useSession } from "next-auth/react";
import { useTranslation } from "react-i18next";
import { AUTH } from "@/authorities";
import { SessionWithTokens } from "@/config/authConfig";
import { AllPickedStockTakeListReponse, getLatestApproverStockTakeHeader } from "@/app/api/stockTake/actions";
import PickerCardList from "./PickerCardList";
import type { PickerCardListFilters } from "./PickerCardList";
import PickerStockTake from "./PickerStockTake";
import PickerReStockTake from "./PickerReStockTake";
import ApproverStockTakeAll from "./ApproverStockTakeAll";
import { useStockTakeQtyGapWarnPercent } from "./useStockTakeQtyGapWarnPercent";
import {
  parseQtyGapWarnPercent,
  saveStockTakeQtyGapWarnPercent,
} from "./qtyGapWarnSettingClient";
import { STOCK_TAKE_QTY_GAP_WARN_PERCENT } from "./stockTakeQtyGapWarning";

type ViewScope = "picker" | "approver-all";
const DEFAULT_PICKER_CARD_LIST_FILTERS: PickerCardListFilters = {
  sectionDescription: "All",
  stockTakeSession: "",
  status: "All",
  area: "",
  storeId: "All",
};

const StockTakeTab: React.FC = () => {
  const { t } = useTranslation(["stockTake", "common"]);
  const { data: session } = useSession() as { data: SessionWithTokens | null };
  const isAdmin = (session?.abilities ?? session?.user?.abilities ?? []).some(
    (ability) => String(ability).trim() === AUTH.ADMIN,
  );
  const qtyGapWarnPercent = useStockTakeQtyGapWarnPercent();
  const [qtyGapDraft, setQtyGapDraft] = useState(String(STOCK_TAKE_QTY_GAP_WARN_PERCENT));
  const [qtyGapSaving, setQtyGapSaving] = useState(false);
  const qtyGapSaveLock = useRef(false);
  const [tabValue, setTabValue] = useState(0);
  const [selectedSession, setSelectedSession] = useState<AllPickedStockTakeListReponse | null>(null);
  const [viewMode, setViewMode] = useState<"details" | "reStockTake">("details");
  const [viewScope, setViewScope] = useState<ViewScope>("picker");
  const [approverSession, setApproverSession] = useState<AllPickedStockTakeListReponse | null>(null);
  const [approverLoading, setApproverLoading] = useState(false);
  /** 從卡片列表進入明細後返回時保留分頁 */
  const [pickerListPage, setPickerListPage] = useState(0);
  const [pickerListPageSize] = useState(6);
  const [pickerSearchFilters, setPickerSearchFilters] = useState<PickerCardListFilters>(DEFAULT_PICKER_CARD_LIST_FILTERS);
  const [pickerAppliedFilters, setPickerAppliedFilters] = useState<PickerCardListFilters>(DEFAULT_PICKER_CARD_LIST_FILTERS);
  const [snackbar, setSnackbar] = useState<{ 
    open: boolean; 
    message: string; 
    severity: "success" | "error" | "warning" 
  }>({
    open: false,
    message: "",
    severity: "success",
  });

  const handleCardClick = useCallback((session: AllPickedStockTakeListReponse) => {
    setSelectedSession(session);
    setViewMode("details");
  }, []);

  const handleReStockTakeClick = useCallback((session: AllPickedStockTakeListReponse) => {
    setSelectedSession(session);
    setViewMode("reStockTake");
    setViewScope("picker");
  }, []);

  const handleBackToList = useCallback(() => {
    setSelectedSession(null);
    setViewMode("details");
  }, []);

  const handleSnackbar = useCallback((message: string, severity: "success" | "error" | "warning") => {
    setSnackbar({
      open: true,
      message,
      severity,
    });
  }, []);

  useEffect(() => {
    setQtyGapDraft(String(qtyGapWarnPercent));
  }, [qtyGapWarnPercent]);

  const saveQtyGapWarnPercent = useCallback(async () => {
    if (!isAdmin || qtyGapSaveLock.current) return;
    const parsed = Number(qtyGapDraft.trim());
    if (!Number.isInteger(parsed) || parsed < 0 || parsed > 1000) {
      handleSnackbar(t("qtyGapWarnPercentInvalid"), "warning");
      return;
    }
    qtyGapSaveLock.current = true;
    setQtyGapSaving(true);
    try {
      await saveStockTakeQtyGapWarnPercent(parsed);
      setQtyGapDraft(String(parseQtyGapWarnPercent(String(parsed))));
      handleSnackbar(t("qtyGapWarnPercentSaved"), "success");
    } catch (e) {
      handleSnackbar(e instanceof Error ? e.message : t("qtyGapWarnPercentInvalid"), "error");
    } finally {
      qtyGapSaveLock.current = false;
      setQtyGapSaving(false);
    }
  }, [handleSnackbar, isAdmin, qtyGapDraft, t]);

  useEffect(() => {
    if (tabValue !== 1 && tabValue !== 2) return;
    setApproverLoading(true);
    getLatestApproverStockTakeHeader()
      .then((header) => {
        setApproverSession(header ?? null);
      })
      .catch((e) => {
        console.error(e);
        setApproverSession(null);
      })
      .finally(() => setApproverLoading(false));
  }, [tabValue]);

  if (selectedSession && viewScope === "picker") {
    return (
      <Box>
        {viewScope === "picker" && (
          tabValue === 0 ? (
            viewMode === "reStockTake" ? (
              <PickerReStockTake
                selectedSession={selectedSession}
                onBack={handleBackToList}
                onSnackbar={handleSnackbar}
              />
            ) : (
              <PickerStockTake
                selectedSession={selectedSession}
                onBack={handleBackToList}
                onSnackbar={handleSnackbar}
              />
            )
          ) : null
        )}
        <Snackbar
          open={snackbar.open}
          autoHideDuration={6000}
          onClose={() => setSnackbar({ ...snackbar, open: false })}
        >
          <Alert onClose={() => setSnackbar({ ...snackbar, open: false })} severity={snackbar.severity}>
            {snackbar.message}
          </Alert>
        </Snackbar>
      </Box>
    );
  }

  return (
    <Box>
      {isAdmin && (
        <Stack direction="row" spacing={1} alignItems="center" sx={{ mb: 1 }}>
          <Typography
            component="label"
            htmlFor="stock-take-qty-gap-warn"
            sx={{ m: 0, height: 40, fontSize: 18, fontWeight: 500, lineHeight: "40px" }}
          >
            {t("qtyGapWarnPercent")}
          </Typography>
          <TextField
            id="stock-take-qty-gap-warn"
            size="small"
            type="number"
            value={qtyGapDraft}
            onChange={(e) => setQtyGapDraft(e.target.value.replace(/[^\d]/g, ""))}
            inputProps={{ min: 0, max: 1000, inputMode: "numeric" }}
            sx={{
              width: 88,
              m: 0,
              "& .MuiFilledInput-root": { height: 40 },
              "& .MuiFilledInput-input.MuiInputBase-inputSizeSmall": {
                height: 40,
                boxSizing: "border-box",
                paddingTop: 0,
                paddingBottom: 0,
                lineHeight: "40px",
              },
            }}
          />
          <Button
            size="small"
            variant="outlined"
            disabled={qtyGapSaving}
            onClick={saveQtyGapWarnPercent}
            sx={{ height: 40 }}
          >
            {t("Save")}
          </Button>
        </Stack>
      )}
      <Tabs
        value={tabValue}
        onChange={(e, newValue) => {
          setTabValue(newValue);
          if (newValue === 0) {
            setViewScope("picker");
          } else {
            setViewScope("approver-all");
          }
        }}
        sx={{ mb: 2 }}
      >
        <Tab label={t("Picker")} />
        <Tab label={t("Approver Pending")} />
        <Tab label={t("Approver Approved")} />
      </Tabs>

      {tabValue === 0 && (
        <PickerCardList
          page={pickerListPage}
          pageSize={pickerListPageSize}
          onListPageChange={setPickerListPage}
          searchFilters={pickerSearchFilters}
          appliedFilters={pickerAppliedFilters}
          onSearchFiltersChange={setPickerSearchFilters}
          onAppliedFiltersChange={setPickerAppliedFilters}
          onCardClick={(session) => {
            setViewScope("picker");
            handleCardClick(session);
          }}
          onReStockTakeClick={handleReStockTakeClick}
        />
      )}
      {tabValue === 1 && (
        <Box>
          {approverLoading ? (
            <Box sx={{ display: "flex", justifyContent: "center", p: 3 }}>
              <CircularProgress />
            </Box>
          ) : approverSession ? (
            <ApproverStockTakeAll
              selectedSession={approverSession}
              mode="pending"
              onSnackbar={handleSnackbar}
            />
          ) : (
            <Typography variant="body2" color="text.secondary">
              {t("No data")}
            </Typography>
          )}
        </Box>
      )}
      {tabValue === 2 && (
        <Box>
          {approverSession ? (
            <ApproverStockTakeAll
              selectedSession={approverSession}
              mode="approved"
              onSnackbar={handleSnackbar}
            />
          ) : (
            <Typography variant="body2" color="text.secondary">
              {t("No data")}
            </Typography>
          )}
        </Box>
      )}

      <Snackbar
        open={snackbar.open}
        autoHideDuration={6000}
        onClose={() => setSnackbar({ ...snackbar, open: false })}
      >
        <Alert onClose={() => setSnackbar({ ...snackbar, open: false })} severity={snackbar.severity}>
          {snackbar.message}
        </Alert>
      </Snackbar>
    </Box>
  );
};

export default StockTakeTab;