import { useReducer, useState } from "react";
import { useMutation, useQueryClient } from "@tanstack/react-query";
import * as stylex from "@stylexjs/stylex";
import { clientPrefixesPutMutation } from "@/lib/queries";
import type { ClientPrefix, Group } from "@/lib/types";
import { defaultGroupId } from "@/lib/defaultGroup";
import { firstProblem, initPrefixEditor, isDirty, prefixEditorReducer, toInputs } from "./prefixEditor";
import InlineError from "@/lib/InlineError";
import Select from "@/ui/Select";
import { styles as shared } from "@/ui/styles";
import { colors } from "@/ui/tokens.stylex";
import { READ_ONLY_HINT, useReadOnlyConfig } from "@/features/settings/authority";

interface Props {
	prefixes: ClientPrefix[];
	groups: Group[];
}

const styles = stylex.create({
	section: {
		marginTop: "2.5rem",
	},
	heading: {
		fontSize: "1.25rem",
		lineHeight: "1.75rem",
		fontWeight: 600,
	},
	intro: {
		marginTop: "0.25rem",
		fontSize: "0.875rem",
		lineHeight: "1.25rem",
		color: colors.textMuted,
	},
	empty: {
		marginTop: "1rem",
		fontSize: "0.875rem",
		lineHeight: "1.25rem",
		color: colors.textMuted,
	},
	rows: {
		display: "flex",
		flexDirection: "column",
		gap: "0.5rem",
		marginTop: "1rem",
		listStyleType: "none",
		padding: 0,
	},
	row: {
		display: "flex",
		flexWrap: "wrap",
		alignItems: "center",
		gap: "0.5rem",
	},
	prefixInput: {
		width: "13rem",
	},
	priorityInput: {
		width: "5rem",
	},
	removeButton: {
		borderRadius: "0.25rem",
		borderWidth: 1,
		borderStyle: "solid",
		borderColor: colors.borderStrong,
		backgroundColor: "transparent",
		paddingInline: "0.5rem",
		paddingBlock: "0.375rem",
		fontSize: "0.875rem",
		lineHeight: "1.25rem",
		color: colors.danger,
	},
	validation: {
		marginTop: "0.5rem",
		fontSize: "0.875rem",
		lineHeight: "1.25rem",
		color: colors.danger,
	},
	actions: {
		display: "flex",
		gap: "0.5rem",
		marginTop: "1rem",
	},
});

export default function PrefixesEditor({ prefixes, groups }: Props) {
	const queryClient = useQueryClient();
	const mutation = useMutation(clientPrefixesPutMutation(queryClient));
	const [state, dispatch] = useReducer(prefixEditorReducer, prefixes, initPrefixEditor);
	const [validation, setValidation] = useState<string | null>(null);
	const dirty = isDirty(state);
	const fallbackGroupId = defaultGroupId(groups);
	const readOnly = useReadOnlyConfig();
	const groupOptions = groups.map((group) => ({ value: String(group.id), label: group.name }));

	const save = () => {
		const problem = firstProblem(state.rows);
		setValidation(problem);
		if (problem !== null) return;
		mutation.mutate(toInputs(state.rows), {
			onSuccess: (stored) => dispatch({ type: "reset", prefixes: stored }),
		});
	};

	return (
		<section {...stylex.props(styles.section)}>
			<h2 {...stylex.props(styles.heading)}>Client prefixes</h2>
			<p {...stylex.props(styles.intro)}>
				Prefixes assign a group to whole address ranges. The list is saved as a whole; the highest priority
				match wins.
			</p>
			{state.rows.length === 0 ? (
				<p {...stylex.props(styles.empty)}>No prefixes configured.</p>
			) : (
				<ul {...stylex.props(styles.rows)}>
					{state.rows.map((row, index) => (
						<li key={index} {...stylex.props(styles.row)}>
							<input
								type="text"
								aria-label={`Prefix ${index + 1}`}
								placeholder="192.168.1.0/24"
								value={row.prefix}
								onChange={(event) =>
									dispatch({ type: "edit", index, patch: { prefix: event.target.value } })
								}
								{...stylex.props(shared.smallInput, styles.prefixInput, shared.focusRing)}
							/>
							<Select
								aria-label={`Group for prefix ${index + 1}`}
								variant="inline"
								value={String(row.group_id)}
								onChange={(value) =>
									dispatch({ type: "edit", index, patch: { group_id: Number(value) } })
								}
								options={groupOptions}
							/>
							<input
								type="text"
								inputMode="numeric"
								aria-label={`Priority for prefix ${index + 1}`}
								placeholder="100"
								value={row.priority}
								onChange={(event) =>
									dispatch({ type: "edit", index, patch: { priority: event.target.value } })
								}
								{...stylex.props(shared.smallInput, styles.priorityInput, shared.focusRing)}
							/>
							<button
								type="button"
								onClick={() => dispatch({ type: "remove", index })}
								{...stylex.props(styles.removeButton, shared.focusRing)}
							>
								Remove
							</button>
						</li>
					))}
				</ul>
			)}
			{validation !== null && (
				<p role="alert" {...stylex.props(styles.validation)}>
					{validation}
				</p>
			)}
			<InlineError error={mutation.error} />
			<div {...stylex.props(styles.actions)}>
				<button
					type="button"
					onClick={() => dispatch({ type: "add", groupId: fallbackGroupId })}
					{...stylex.props(shared.button, shared.focusRing)}
				>
					Add prefix
				</button>
				<button
					type="button"
					onClick={save}
					disabled={!dirty || mutation.isPending || readOnly}
					title={readOnly ? READ_ONLY_HINT : undefined}
					{...stylex.props(shared.primaryButton, shared.focusRing)}
				>
					Save prefixes
				</button>
				{dirty && (
					<button
						type="button"
						onClick={() => {
							setValidation(null);
							dispatch({ type: "reset", prefixes });
						}}
						{...stylex.props(shared.button, shared.focusRing)}
					>
						Discard changes
					</button>
				)}
			</div>
		</section>
	);
}