import type { ICredentialDataDecryptedObject, ICredentialTypes } from 'n8n-workflow';
import { deepCopy, LoggerProxy as Logger, jsonParse } from 'n8n-workflow';
import type { ICredentialsOverwrite } from '@/Interfaces';
import * as GenericHelpers from '@/GenericHelpers';

class CredentialsOverwritesClass {
	private overwriteData: ICredentialsOverwrite = {};

	private resolvedTypes: string[] = [];

	constructor(private credentialTypes: ICredentialTypes) {}

	async init() {
		const data = (await GenericHelpers.getConfigValue('credentials.overwrite.data')) as string;

		const overwriteData = jsonParse<ICredentialsOverwrite>(data, {
			errorMessage: 'The credentials-overwrite is not valid JSON.',
		});

		this.setData(overwriteData);
	}

	setData(overwriteData: ICredentialsOverwrite) {
		// If data gets reinitialized reset the resolved types cache
		this.resolvedTypes.length = 0;

		this.overwriteData = overwriteData;

		for (const type in overwriteData) {
			const overwrites = this.getOverwrites(type);

			if (overwrites && Object.keys(overwrites).length) {
				this.overwriteData[type] = overwrites;
			}
		}
	}

	applyOverwrite(type: string, data: ICredentialDataDecryptedObject) {
		const overwrites = this.get(type);

		if (overwrites === undefined) {
			return data;
		}

		const returnData = deepCopy(data);
		// Overwrite only if there is currently no data set
		for (const key of Object.keys(overwrites)) {
			// @ts-ignore
			if ([null, undefined, ''].includes(returnData[key])) {
				returnData[key] = overwrites[key];
			}
		}

		return returnData;
	}

	private getOverwrites(type: string): ICredentialDataDecryptedObject | undefined {
		if (this.resolvedTypes.includes(type)) {
			// Type got already resolved and can so returned directly
			return this.overwriteData[type];
		}

		if (!this.credentialTypes.recognizes(type)) {
			Logger.warn(`Unknown credential type ${type} in Credential overwrites`);
			return;
		}

		const credentialTypeData = this.credentialTypes.getByName(type);

		if (credentialTypeData.extends === undefined) {
			this.resolvedTypes.push(type);
			return this.overwriteData[type];
		}

		const overwrites: ICredentialDataDecryptedObject = {};
		for (const credentialsTypeName of credentialTypeData.extends) {
			Object.assign(overwrites, this.getOverwrites(credentialsTypeName));
		}

		if (this.overwriteData[type] !== undefined) {
			Object.assign(overwrites, this.overwriteData[type]);
		}

		this.resolvedTypes.push(type);

		return overwrites;
	}

	private get(type: string): ICredentialDataDecryptedObject | undefined {
		return this.overwriteData[type];
	}

	getAll(): ICredentialsOverwrite {
		return this.overwriteData;
	}
}

let credentialsOverwritesInstance: CredentialsOverwritesClass | undefined;

// eslint-disable-next-line @typescript-eslint/naming-convention
export function CredentialsOverwrites(
	credentialTypes?: ICredentialTypes,
): CredentialsOverwritesClass {
	if (!credentialsOverwritesInstance) {
		if (credentialTypes) {
			credentialsOverwritesInstance = new CredentialsOverwritesClass(credentialTypes);
		} else {
			throw new Error('CredentialsOverwrites not initialized yet');
		}
	}

	return credentialsOverwritesInstance;
}