import { useMemo, useState } from "react";
import {
  Alert,
  Box,
  Button,
  Chip,
  CircularProgress,
  FormControl,
  InputLabel,
  MenuItem,
  Paper,
  Select,
  Stack,
  TextField,
  Typography,
} from "@mui/material";
import { SettingsNav } from "@/components/common/settings-nav";
import {
  DROPDOWN_OPTION_CATEGORIES,
  type DropdownOption,
  type DropdownOptionCategory,
} from "@/domain/settings/dropdown-options/types/dropdown-option";
import { useCreateDropdownOption } from "@/domain/settings/dropdown-options/use-cases/use-create-dropdown-option";
import { useDeleteDropdownOption } from "@/domain/settings/dropdown-options/use-cases/use-delete-dropdown-option";
import { useDropdownOptionsByCategory } from "@/domain/settings/dropdown-options/use-cases/use-dropdown-options-by-category";
import { useUpdateDropdownOption } from "@/domain/settings/dropdown-options/use-cases/use-update-dropdown-option";

export default function DropdownOptionsPage() {
  const [activeCategory, setActiveCategory] = useState<DropdownOptionCategory>("Trade");
  const [newValue, setNewValue] = useState("");
  const [newParent, setNewParent] = useState("");
  const [editingId, setEditingId] = useState<string | number | null>(null);
  const [editValue, setEditValue] = useState("");

  const categoryConfig = useMemo(
    () => DROPDOWN_OPTION_CATEGORIES.find((category) => category.key === activeCategory),
    [activeCategory],
  );

  const parentCategory =
    categoryConfig && "parent" in categoryConfig ? categoryConfig.parent : undefined;

  const { data: options = [], isLoading, error } = useDropdownOptionsByCategory(activeCategory);
  const { data: parentOptions = [] } = useDropdownOptionsByCategory("Trade", {
    enabled: Boolean(parentCategory),
  });

  const createMutation = useCreateDropdownOption();
  const updateMutation = useUpdateDropdownOption();
  const deleteMutation = useDeleteDropdownOption();

  const resetFormState = () => {
    setNewValue("");
    setNewParent("");
    setEditingId(null);
    setEditValue("");
  };

  const handleCategoryChange = (category: DropdownOptionCategory) => {
    if (category !== activeCategory) {
      resetFormState();
    }
    setActiveCategory(category);
  };

  const handleAdd = () => {
    const value = newValue.trim();
    if (!value) {
      return;
    }

    createMutation.mutate(
      {
        category: activeCategory,
        value,
        parentValue: parentCategory ? newParent || null : null,
        sortOrder: options.length,
        isActive: true,
      },
      {
        onSuccess: () => {
          setNewValue("");
          setNewParent("");
        },
      },
    );
  };

  const handleEditSave = (item: DropdownOption) => {
    const value = editValue.trim();
    if (!value) {
      return;
    }

    updateMutation.mutate(
      {
        id: item.id,
        category: item.category,
        value,
        parentValue: item.parentValue,
        sortOrder: item.sortOrder,
        isActive: item.isActive,
      },
      {
        onSuccess: () => {
          setEditingId(null);
        },
      },
    );
  };

  const handleDelete = (id: string | number) => {
    deleteMutation.mutate(id);
  };

  const addPlaceholder = `Add new ${categoryConfig?.label.slice(0, -1) ?? "option"}...`;
  const isMutating =
    createMutation.isPending || updateMutation.isPending || deleteMutation.isPending;

  return (
    <Box className="flex flex-col gap-4 p-4">
      <SettingsNav />
      <Stack spacing={0.5}>
        <Typography variant="h5" component="h1">
          Dropdown Options
        </Typography>
        <Typography
          variant="body2"
          sx={{
            color: "text.secondary",
          }}
        >
          Manage configurable dropdown values for work orders
        </Typography>
      </Stack>
      <Paper variant="outlined" className="flex min-h-[400px] overflow-hidden">
        <Stack className="w-[180px] shrink-0 border-r border-border bg-muted/30" spacing={0}>
          {DROPDOWN_OPTION_CATEGORIES.map((category) => (
            <Button
              key={category.key}
              onClick={() => handleCategoryChange(category.key)}
              className={`justify-start rounded-none border-b border-border px-4 py-3 text-left normal-case ${
                activeCategory === category.key
                  ? "border-r-2 border-r-primary bg-background font-semibold text-primary"
                  : "font-medium text-muted-foreground hover:bg-muted/50"
              }`}
            >
              {category.label}
            </Button>
          ))}
        </Stack>

        <Box className="flex flex-1 flex-col gap-4 p-4">
          <Stack
            direction={{ xs: "column", sm: "row" }}
            spacing={2}
            sx={{
              alignItems: "stretch",
            }}
          >
            {Boolean(parentCategory) && (
              <FormControl size="small" className="min-w-[160px]">
                <InputLabel id="parent-trade-label">Parent Trade</InputLabel>
                <Select
                  labelId="parent-trade-label"
                  label="Parent Trade"
                  value={newParent}
                  onChange={(event) => setNewParent(event.target.value)}
                >
                  <MenuItem value="">Parent: All</MenuItem>
                  {parentOptions.map((option) => (
                    <MenuItem key={String(option.id)} value={option.value}>
                      {option.value}
                    </MenuItem>
                  ))}
                </Select>
              </FormControl>
            )}

            <TextField
              size="small"
              value={newValue}
              onChange={(event) => setNewValue(event.target.value)}
              onKeyDown={(event) => {
                if (event.key === "Enter") {
                  event.preventDefault();
                  handleAdd();
                }
              }}
              placeholder={addPlaceholder}
              className="flex-1"
            />

            <Button
              variant="contained"
              onClick={handleAdd}
              disabled={!newValue.trim() || isMutating}
              className="shrink-0"
            >
              Add
            </Button>
          </Stack>

          {Boolean(error) && (
            <Alert severity="error">
              {error instanceof Error ? error.message : "Failed to load options"}
            </Alert>
          )}

          {isLoading ? (
            <Stack
              className="py-10"
              sx={{
                alignItems: "center",
              }}
            >
              <CircularProgress size={28} />
            </Stack>
          ) : options.length === 0 ? (
            <Typography
              align="center"
              className="py-10"
              sx={{
                color: "text.secondary",
              }}
            >
              No options configured yet
            </Typography>
          ) : (
            <Stack spacing={1}>
              {options.map((item) => (
                <Paper
                  key={String(item.id)}
                  variant="outlined"
                  className="flex items-center justify-between gap-3 px-3 py-2"
                >
                  {editingId === item.id ? (
                    <TextField
                      size="small"
                      value={editValue}
                      onChange={(event) => setEditValue(event.target.value)}
                      onKeyDown={(event) => {
                        if (event.key === "Enter") {
                          handleEditSave(item);
                        }
                        if (event.key === "Escape") {
                          setEditingId(null);
                        }
                      }}
                      autoFocus
                      className="flex-1"
                    />
                  ) : (
                    <Stack
                      direction="row"
                      spacing={1}
                      className="min-w-0"
                      sx={{
                        alignItems: "center",
                      }}
                    >
                      <Typography variant="body2" className="truncate">
                        {item.value}
                      </Typography>
                      {Boolean(item.parentValue) && (
                        <Chip size="small" label={item.parentValue} variant="outlined" />
                      )}
                    </Stack>
                  )}

                  <Stack direction="row" spacing={1} className="shrink-0">
                    {editingId === item.id ? (
                      <>
                        <Button
                          size="small"
                          variant="contained"
                          color="success"
                          onClick={() => handleEditSave(item)}
                          disabled={isMutating}
                        >
                          Save
                        </Button>
                        <Button
                          size="small"
                          variant="outlined"
                          color="inherit"
                          onClick={() => setEditingId(null)}
                        >
                          Cancel
                        </Button>
                      </>
                    ) : (
                      <>
                        <Button
                          size="small"
                          variant="outlined"
                          onClick={() => {
                            setEditingId(item.id);
                            setEditValue(item.value);
                          }}
                        >
                          Edit
                        </Button>
                        <Button
                          size="small"
                          variant="outlined"
                          color="error"
                          onClick={() => handleDelete(item.id)}
                          disabled={isMutating}
                        >
                          Delete
                        </Button>
                      </>
                    )}
                  </Stack>
                </Paper>
              ))}
            </Stack>
          )}
        </Box>
      </Paper>
    </Box>
  );
}