import { useMemo, useState } from "react";
import {
  Alert,
  Box,
  Button,
  Chip,
  CircularProgress,
  Stack,
  Tab,
  Tabs,
  Typography,
} from "@mui/material";
import type { GridRowParams, GridRowSelectionModel } from "@mui/x-data-grid";
import { isReadyToPay } from "@seahaven-ap/shared";
import { CreatePayRunButton } from "@/dashboard/CreatePayRunButton";
import { InvoiceDataGrid } from "@/dashboard/InvoiceDataGrid";
import { pendingApprovalColumns, readyToPayColumns } from "@/dashboard/columns";
import { countSelectedRows } from "@/dashboard/selection";
import { useInvoices, useUpdateInvoicePayDate } from "@/domain/invoices/use-invoices";
import type { MockInvoice } from "@/mocks";
import { useNavigate } from "@/router";

type PaymentTab = "outside" | "select" | "pending" | "scheduled" | "errors" | "outbox";

const emptySelection: GridRowSelectionModel = {
  type: "include",
  ids: new Set(),
};

const rowClickSx = {
  border: 1,
  borderColor: "divider",
  backgroundColor: "background.paper",
  cursor: "pointer",
  borderRadius: 1,
} as const;

export function PaymentProcessingGrids() {
  const navigate = useNavigate();
  const [tab, setTab] = useState<PaymentTab>("select");
  const [selection, setSelection] = useState<GridRowSelectionModel>(emptySelection);
  const { data: invoices = [], isLoading, isError, error } = useInvoices();
  const updatePayDate = useUpdateInvoicePayDate();

  const openInvoice = (params: GridRowParams<MockInvoice>) => {
    navigate("/invoices/:id", { params: { id: params.row.id } });
  };

  const selectRows = useMemo(
    () => invoices.filter((invoice) => isReadyToPay(invoice.status)),
    [invoices],
  );
  const pendingRows = useMemo(
    () => invoices.filter((invoice) => invoice.status === "pending_approval"),
    [invoices],
  );
  const scheduledRows = useMemo(
    () => invoices.filter((invoice) => invoice.status === "scheduled"),
    [invoices],
  );

  const selectedCount = countSelectedRows(
    selection,
    selectRows.map((invoice) => invoice.id),
  );

  const totalDue = selectRows.reduce((sum, row) => sum + row.amountDue, 0);

  const processRowUpdate = async (newRow: MockInvoice, oldRow: MockInvoice) => {
    if (newRow.payDate === oldRow.payDate) {
      return oldRow;
    }
    const nextPayDate = newRow.payDate?.trim() ? newRow.payDate.trim() : null;
    return updatePayDate.mutateAsync({ id: newRow.id, payDate: nextPayDate });
  };

  if (isLoading) {
    return (
      <Box sx={{ display: "flex", justifyContent: "center", py: 6 }}>
        <CircularProgress aria-label="Loading payments" />
      </Box>
    );
  }

  if (isError) {
    return (
      <Alert severity="error">
        {error instanceof Error ? error.message : "Failed to load payments"}
      </Alert>
    );
  }

  return (
    <Stack spacing={0} data-testid="payment-processing">
      <Box sx={{ bgcolor: "#E8EEF7", px: 1, pt: 1 }}>
        <Tabs
          value={tab}
          onChange={(_event, value: PaymentTab) => {
            setTab(value);
            setSelection(emptySelection);
          }}
          variant="scrollable"
          aria-label="Payment Processing tabs"
          sx={{
            minHeight: 44,
            "& .MuiTab-root": {
              bgcolor: "rgba(47,128,237,0.18)",
              mr: 0.5,
              borderTopLeftRadius: 6,
              borderTopRightRadius: 6,
              color: "text.primary",
            },
            "& .Mui-selected": {
              bgcolor: "#fff !important",
              color: "text.primary !important",
            },
            "& .MuiTabs-indicator": { display: "none" },
          }}
        >
          <Tab label="Paying Outside Stampli (0)" value="outside" data-testid="tab-pay-outside" />
          <Tab
            label={`Select to Pay (${selectRows.length})`}
            value="select"
            data-testid="tab-select-to-pay"
          />
          <Tab
            label={`Pending Approval (${pendingRows.length})`}
            value="pending"
            data-testid="tab-pay-pending"
          />
          <Tab
            label={`Scheduled (${scheduledRows.length})`}
            value="scheduled"
            data-testid="tab-scheduled"
          />
          <Tab label="Payment Export Errors (0)" value="errors" data-testid="tab-export-errors" />
          <Tab label="Outbox (0)" value="outbox" data-testid="tab-outbox" />
        </Tabs>
      </Box>

      <Box sx={{ bgcolor: "background.paper", p: 2 }}>
        <Alert severity="warning" sx={{ mb: 2 }} data-testid="expedite-banner">
          Expedited payments are currently unavailable for you due to various factors. (parity stub)
        </Alert>

        <Stack direction="row" spacing={1} alignItems="center" sx={{ mb: 2 }} flexWrap="wrap">
          <Chip label="Vendor Name" variant="outlined" size="small" />
          <Chip label="Payment Method" variant="outlined" size="small" />
          <Chip label="Bank Account" variant="outlined" size="small" />
          <Chip label="Status" variant="outlined" size="small" />
          <Box sx={{ flexGrow: 1 }} />
          <Button variant="outlined" size="small" data-testid="bulk-edit">
            Bulk Edit
          </Button>
          <CreatePayRunButton selectedCount={selectedCount} />
        </Stack>

        {tab === "select" && (
          <InvoiceDataGrid
            data-testid="grid-select-to-pay"
            rows={selectRows}
            columns={readyToPayColumns}
            checkboxSelection
            rowSelectionModel={selection}
            onRowSelectionModelChange={(model) => setSelection(model)}
            processRowUpdate={processRowUpdate}
            onProcessRowUpdateError={(processError) => {
              console.error(processError);
            }}
            onRowClick={openInvoice}
            sx={rowClickSx}
          />
        )}

        {tab === "pending" && (
          <InvoiceDataGrid
            data-testid="grid-pay-pending"
            rows={pendingRows}
            columns={pendingApprovalColumns}
            onRowClick={openInvoice}
            sx={rowClickSx}
          />
        )}

        {tab === "scheduled" && (
          <InvoiceDataGrid
            data-testid="grid-scheduled"
            rows={scheduledRows}
            columns={readyToPayColumns}
            onRowClick={openInvoice}
            sx={rowClickSx}
          />
        )}

        {(tab === "outside" || tab === "errors" || tab === "outbox") && (
          <Box
            sx={{
              py: 8,
              textAlign: "center",
              border: 1,
              borderColor: "divider",
              borderRadius: 1,
            }}
            data-testid="payment-empty-stub"
          >
            <Typography color="text.secondary">No Result Found</Typography>
            <Typography variant="caption" color="text.secondary">
              parity stub
            </Typography>
          </Box>
        )}

        <Stack direction="row" spacing={4} sx={{ mt: 2 }} data-testid="payment-footer-totals">
          <Typography variant="body2">
            <Box component="span" color="text.secondary">
              Total Due:{" "}
            </Box>
            <strong>
              {totalDue.toLocaleString("en-US", { style: "currency", currency: "USD" })}
            </strong>
          </Typography>
          <Typography variant="body2">
            <Box component="span" color="text.secondary">
              Total To Pay:{" "}
            </Box>
            <strong>$0.00</strong>
          </Typography>
          <Typography variant="body2">
            <Box component="span" color="text.secondary">
              Estimated USD:{" "}
            </Box>
            <strong>$0.00</strong>
          </Typography>
        </Stack>
      </Box>
    </Stack>
  );
}