import type {
	ICredentialTestFunctions,
	ICredentialsDecrypted,
	IDataObject,
	IExecuteFunctions,
	INodeCredentialTestResult,
} from 'n8n-workflow';
import { NodeOperationError } from 'n8n-workflow';
import { createClient } from 'redis';

import type { RedisCredential, RedisClient } from './types';

export function setupRedisClient(credentials: RedisCredential, isTest = false): RedisClient {
	const socketConfig: any = {
		host: credentials.host,
		port: credentials.port,
		tls: credentials.ssl === true,
		connectTimeout: 10000,
		reconnectStrategy: isTest
			? false
			: (retries: number) => {
					// Retry for ~15min
					if (retries >= 10) {
						return false;
					}

					const jitter = Math.floor(Math.random() * 1000);
					const delay = Math.pow(2, retries) * 1000;

					return delay + jitter;
				},
	};

	// If SSL is enabled and TLS verification should be disabled
	if (credentials.ssl === true && credentials.disableTlsVerification === true) {
		socketConfig.rejectUnauthorized = false;
	}

	const client = createClient({
		socket: socketConfig,
		database: credentials.database,
		username: credentials.user ?? undefined,
		password: credentials.password ?? undefined,
		...(isTest && {
			disableOfflineQueue: true,
			enableOfflineQueue: false,
		}),
	});

	client.on('error', () => {
		// intentionally ignored,required for reconnectStrategy to function, error will be caught by try catch
		// https://github.com/redis/node-redis/blob/a64134c55f550f2f102a0f512218bc11717a5e16/README.md?plain=1#L298
	});

	return client;
}

export async function redisConnectionTest(
	this: ICredentialTestFunctions,
	credential: ICredentialsDecrypted,
): Promise<INodeCredentialTestResult> {
	const credentials = credential.data as RedisCredential;
	let client: RedisClient | undefined;

	try {
		client = setupRedisClient(credentials, true);

		// Add error event handler to catch connection errors
		const errorPromise = new Promise<never>((_, reject) => {
			client!.on('error', (err) => {
				reject(err);
			});
		});

		// Create a timeout promise
		const timeoutPromise = new Promise<never>((_, reject) => {
			setTimeout(() => {
				reject(new Error('Connection timeout: Unable to connect to Redis server'));
			}, 10000); // 10 seconds timeout
		});

		// Race between connecting and error/timeout
		await Promise.race([client.connect(), errorPromise, timeoutPromise]);

		await client.ping();
		return {
			status: 'OK',
			message: 'Connection successful!',
		};
	} catch (error) {
		// Handle specific error types for better user feedback
		let errorMessage = error.message;
		if (error.code === 'ECONNRESET') {
			errorMessage =
				'Connection reset: The Redis server rejected the connection. This often happens when trying to connect without SSL to an SSL-only server.';
		} else if (error.code === 'ECONNREFUSED') {
			errorMessage =
				'Connection refused: Unable to connect to the Redis server. Please check the host and port.';
		}

		return {
			status: 'Error',
			message: errorMessage,
		};
	} finally {
		// Ensure the Redis client is always closed to prevent leaked connections
		if (client) {
			try {
				await client.quit();
			} catch {
				// If quit fails, forcefully disconnect
				try {
					await client.disconnect();
				} catch {
					// Ignore disconnect errors in cleanup
				}
			}
		}
	}
}

/** Parses the given value in a number if it is one else returns a string */
function getParsedValue(value: string): string | number {
	if (value.match(/^[\d.]+$/) === null) {
		// Is a string
		return value;
	} else {
		// Is a number
		return parseFloat(value);
	}
}

/** Converts the Redis Info String into an object */
export function convertInfoToObject(stringData: string): IDataObject {
	const returnData: IDataObject = {};

	let key: string, value: string;
	for (const line of stringData.split('\n')) {
		if (['#', ''].includes(line.charAt(0))) {
			continue;
		}
		[key, value] = line.split(':');
		if (key === undefined || value === undefined) {
			continue;
		}
		value = value.trim();

		if (value.includes('=')) {
			returnData[key] = {};
			let key2: string, value2: string;
			for (const keyValuePair of value.split(',')) {
				[key2, value2] = keyValuePair.split('=');
				(returnData[key] as IDataObject)[key2] = getParsedValue(value2);
			}
		} else {
			returnData[key] = getParsedValue(value);
		}
	}

	return returnData;
}

export async function getValue(client: RedisClient, keyName: string, type?: string) {
	if (type === undefined || type === 'automatic') {
		// Request the type first
		type = await client.type(keyName);
	}

	if (type === 'string') {
		return await client.get(keyName);
	} else if (type === 'hash') {
		return await client.hGetAll(keyName);
	} else if (type === 'list') {
		return await client.lRange(keyName, 0, -1);
	} else if (type === 'sets') {
		return await client.sMembers(keyName);
	}
}

export async function setValue(
	this: IExecuteFunctions,
	client: RedisClient,
	keyName: string,
	value: string | number | object | string[] | number[],
	expire: boolean,
	ttl: number,
	type?: string,
	valueIsJSON?: boolean,
) {
	if (type === undefined || type === 'automatic') {
		// Request the type first
		if (typeof value === 'string') {
			type = 'string';
		} else if (Array.isArray(value)) {
			type = 'list';
		} else if (typeof value === 'object') {
			type = 'hash';
		} else {
			throw new NodeOperationError(
				this.getNode(),
				'Could not identify the type to set. Please set it manually!',
			);
		}
	}

	if (type === 'string') {
		await client.set(keyName, value.toString());
	} else if (type === 'hash') {
		if (valueIsJSON) {
			let values: unknown;
			if (typeof value === 'string') {
				try {
					values = JSON.parse(value);
				} catch {
					// This is how we originally worked and prevents a breaking change
					values = value;
				}
			} else {
				values = value;
			}
			for (const key of Object.keys(values as object)) {
				await client.hSet(keyName, key, (values as IDataObject)[key]!.toString());
			}
		} else {
			const values = value.toString().split(' ');
			await client.hSet(keyName, values);
		}
	} else if (type === 'list') {
		for (let index = 0; index < (value as string[]).length; index++) {
			await client.lSet(keyName, index, (value as IDataObject)[index]!.toString());
		}
	} else if (type === 'sets') {
		//@ts-ignore
		await client.sAdd(keyName, value);
	}

	if (expire) {
		await client.expire(keyName, ttl);
	}
	return;
}