import Select from "@mui/material/Select";
import type { SelectProps } from "@mui/material/Select";
import React, { forwardRef } from "react";
import { useTheme } from "@mui/material/styles";
import Stack from "@mui/material/Stack";
import { FieldLabel } from "./FieldLabel";
import { ChevronDown } from "lucide-react";
import Typography from "@mui/material/Typography";

interface SelectInputProps<T> extends Omit<SelectProps<T>, "label"> {
	fieldLabel?: string;
	required?: boolean;
	placeholder?: string;
	helperText?: string;
}

const SelectInputInner = <T,>(
	{ fieldLabel, required, placeholder, helperText, ...props }: SelectInputProps<T>,
	ref: React.ForwardedRef<HTMLDivElement>
) => {
	const theme = useTheme();
	const emptyPlaceholderColor = theme.palette.text.secondary;

	const renderValue = (selected: unknown) => {
		const isMultiple = Boolean((props as { multiple?: boolean }).multiple);
		const isEmpty = isMultiple
			? !Array.isArray(selected) || selected.length === 0
			: selected === undefined || selected === null || selected === "";

		if (isEmpty && placeholder) {
			return <Typography color={emptyPlaceholderColor}>{placeholder}</Typography>;
		}

		if (isMultiple) {
			const items: string[] = Array.isArray(selected) ? selected : [];
			const capitalized = items.map(
				(item) => item.charAt(0).toUpperCase() + item.slice(1)
			);
			return <Typography>{capitalized.join(" | ")}</Typography>;
		}

		const nodes = React.Children.toArray(props.children as React.ReactNode);
		for (const node of nodes) {
			if (!React.isValidElement(node)) continue;
			const el = node as React.ReactElement<{
				value?: unknown;
				children?: React.ReactNode;
			}>;
			if (el.props?.value === selected) {
				return (el.props.children ?? selected) as React.ReactNode;
			}
		}
		return selected as React.ReactNode;
	};

	const select = (
		<Select<T>
			{...props}
			ref={ref}
			displayEmpty
			renderValue={renderValue}
			inputProps={{
				...(props.inputProps || {}),
				"aria-placeholder": placeholder,
			}}
			IconComponent={() => (
				<ChevronDown
					size={18}
					strokeWidth={1.5}
					style={{ marginRight: theme.spacing(3) }}
				/>
			)}
			sx={{
				height: "34px",
				"& .MuiSelect-select": {
					display: "flex",
					alignItems: "center",
					height: "100%",
					boxSizing: "border-box",
				},
				"& .MuiSelect-icon": {
					right: theme.spacing(3),
				},
				"& .MuiOutlinedInput-notchedOutline": {
					borderRadius: theme.shape.borderRadius,
					borderColor: theme.palette.divider,
				},
				"&:hover .MuiOutlinedInput-notchedOutline": {
					borderColor: theme.palette.divider,
				},
				...props.sx,
			}}
		/>
	);

	const helper = helperText ? (
		<Typography
			variant="caption"
			color={props.error ? theme.palette.error.main : theme.palette.text.secondary}
		>
			{helperText}
		</Typography>
	) : null;

	if (fieldLabel || helper) {
		return (
			<Stack spacing={theme.spacing(2)}>
				{fieldLabel && <FieldLabel required={required}>{fieldLabel}</FieldLabel>}
				{select}
				{helper}
			</Stack>
		);
	}

	return select;
};

export const SelectInput = forwardRef(SelectInputInner) as <T>(
	props: SelectInputProps<T> & { ref?: React.ForwardedRef<HTMLDivElement> }
) => React.ReactElement;